| 1. |
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| 2. |
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| 3. |
- Johansson, Veronica, et al.
(författare)
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Beyond Blind Optimism and Unfounded Fears : Deep Brain Stimulation for Treatment Resistant Depression
- 2013
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Ingår i: Neuroethics. - : Springer Science and Business Media LLC. - 1874-5504 .- 1874-5490. ; 6:3, s. 457-471
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of new medical treatments based on invasive technologies has often been surrounded by both hopes and fears. Hope, since a new intervention can create new opportunities either in terms of providing a cure for the disease or impairment at hand; or as alleviation of symptoms. Fear, since an invasive treatment involving implanting a medical device can result in unknown complications such as hardware failure and undesirable medical consequences. However, hopes and fears may also arise due to the cultural embeddedness of technology, where a therapy due to ethical, social, political and religious concerns could be perceived as either a blessing or a threat. While Deep Brain Stimulation (DBS) for treatment resistant depression (TRD) is still in its cradle, it is important to be proactive and try to scrutinize both surfacing hopes and fears. Patients will not benefit if a promising treatment is banned or avoided due to unfounded fears, nor will they benefit if DBS is used without scrutinizing the arguments which call for caution. Hence blind optimism is equally troublesome. We suggest that specificity, both in terms of a detailed account of relevant scientific concerns as well as ethical considerations, could be a way to analyse expressed concerns regarding DBS for TRD. This approach is particularly fruitful when applied to hopes and fears evoked by DBS for TRD, since it can reveal if our comprehension of DBS for TRD suffer from various biases which may remain unnoticed at first glance. We suggest that such biases exist, albeit a further analysis is needed to explore this issue in full.
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| 4. |
- Johansson, Veronica, et al.
(författare)
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Thinking Ahead on Deep Brain Stimulation: An Analysis of the Ethical Implications of a Developing Technology.
- 2014
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Ingår i: AJOB Neuroscience. - : Informa UK Limited. - 2150-7740 .- 2150-7759. ; 5:1, s. 24-33
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Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation (DBS) is a developing technology. New generations of DBS technology are already in the pipeline, yet this particular fact has been largely ignored among ethicists interested in DBS. Focusing only on ethical concerns raised by the current DBS technology is, albeit necessary, not sufficient. Since current bioethical concerns raised by a specific technology could be quite different from the concerns it will raise a couple of years ahead, an ethical analysis should be sensitive to such alterations, or it could end up with results that soon become dated. The goal of this analysis is to address these changing bioethical concerns, to think ahead on upcoming and future DBS concerns both in terms of a changing technology and changing moral attitudes. By employing the distinction between inherent and noninherent bioethical concerns we identify and make explicit the particular limits and potentials for change within each category, respectively, including how present and upcoming bioethical concerns regarding DBS emerge and become obsolete. Many of the currently identified ethical problems with DBS, such as stimulation-induced mania, are a result of suboptimal technology. These challenges could be addressed by technical advances, while for instance perceptions of an altered body image caused by the mere awareness of having an implant may not. Other concerns will not emerge until the technology has become sophisticated enough for new uses to be realized, such as concerns on DBS for enhancement purposes. As a part of the present analysis, concerns regarding authenticity are used as an example.
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| 5. |
- Andersson, G, et al.
(författare)
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Evidence for a GABA-mediated cerebellar inhibition of the inferior olive in the cat
- 1988
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Ingår i: Experimental Brain Research. - 0014-4819. ; 72:3, s. 450-456
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Tidskriftsartikel (refereegranskat)abstract
- 1. Climbing fibres were activated by peripheral nerve stimulation at 'high' frequencies (greater than 3 Hz) for 15-25 s and then at 0.9 Hz for about 1 min. The high frequency activation induced a post-conditioning inhibition, lasting up to about 1 min, of climbing fibre responses recorded from the cerebellar surface. 2. Electrolytic lesions were made in the superior cerebellar peduncle (brachium conjunctivum). After the lesion, the post-conditioning inhibition was completely eliminated. 3. Injections of the GABA-receptor blocker bicuculline methiodide into the inferior olive reversibly blocked the post-conditioning inhibition. 4. The results support the hypothesis proposed by Andersson and Hesslow (1987a), that post-conditioning inhibition is mediated by a GABA-ergic interposito-olivary pathway.
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| 6. |
- Apps, R, et al.
(författare)
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Anatomical and physiological foundations of cerebellar information processing
- 2005
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Ingår i: Nature Reviews Neuroscience. - : Springer Science and Business Media LLC. - 1471-003X .- 1471-0048. ; 6:4, s. 297-311
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Forskningsöversikt (refereegranskat)abstract
- A coordinated movement is easy to recognize, but we know little about how it is achieved. In search of the neural basis of coordination, we present a model of spinocerebellar interactions in which the structure-functional organizing principle is a division of the cerebellum into discrete microcomplexes. Each microcomplex is the recipient of a specific motor error signal-that is, a signal that conveys information about an inappropriate movement. These signals are encoded by spinal reflex circuits and conveyed to the cerebellar cortex through climbing fibre afferents. This organization reveals salient features of cerebellar information processing, but also highlights the importance of systems level analysis for a fuller understanding of the neural mechanisms that underlie behaviour.
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| 7. |
- Apps, Richard, et al.
(författare)
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Gating of cutaneous input to cerebellar climbing fibres during a reaching task in the cat
- 1997
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Ingår i: Journal of Physiology. - 1469-7793. ; 502:Pt 1, s. 203-214
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Tidskriftsartikel (refereegranskat)abstract
- 1. Task-dependent modulation of cutaneous input to climbing fibres projecting to the C1, C2 and C3 zones in the cerebellar paravermal lobule V was investigated in awake cats during performance of a reaching task. 2. Climbing fibre responses resulting from low intensity (non-noxious) electrical stimulation of the ipsilateral superficial radial nerve were recorded as extracellular field potentials in the cerebellar cortex using chronically implanted microwires. 3. Response size, measured as the time-voltage integral of the evoked field potential, was assessed during three phases of the reaching movement, reaction, reach and grasp, and compared with the response size at rest. 4. At C1 and C3 zone recording sites response size was usually reduced during the task (7/10 sites). The reduction was most pronounced in the grasp phase, occasionally accompanied by a smaller reduction in the reach and reaction phases. In one case an enhancement was found in the reach phase. 5. Response size was also modulated during the task at four of six C2 zone recording sites. However, the results were mixed. In three cases the modulation resembled the pattern at C1/C3 sites with the responses being reduced in the grasp phase accompanied on occasion by a lesser reduction in the reach phase. In the remaining case there was an enhancement during grasp. In this case and one other there was also an enhancement during the reaction phase. 6. The findings indicate significant gating of cutaneous input to climbing fibres projecting to the C1, C2 and C3 zones during reaching movements, while the variability between recording sites suggests functional differences, both between and within zones.
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| 8. |
- Apps, R, et al.
(författare)
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Precise matching of olivo-cortical divergence and cortico-nuclear convergence between somatotopically corresponding areas in the medial C1 and medial C3 zones of the paravermal cerebellum
- 2000
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 12:1, s. 205-214
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Tidskriftsartikel (refereegranskat)abstract
- The paravermal cerebellar cortex contains three spatially separate zones (the C1, C3 and Y zones) which form a functionally coupled system involved in the control of voluntary limb movements. A series of 'modules' has been postulated, each defined by a set of olivary neurons with similar receptive fields, the cortical microzones innervated by these neurons and the group of deep cerebellar nuclear neurons upon which the microzones converge. A key feature of this modular organization is a correspondence between cortical input and output, irrespective of the zonal identity of the microzone. This was tested directly using a combined electrophysiological and bi-directional tracer technique in barbiturate-anaesthetized cats. During an initial operation, small injections of a mix of retrograde and anterograde tracer material (red beads combined with Fluoro-Ruby or green beads combined with biotinylated dextran amine or Fluoro-Emerald) were made into areas of the medial C1 and medial C3 zones in cerebellar lobule V characterized by olivo-cerebellar input from the ventral forelimb. The inferior olive and the deep cerebellar nuclei were then scrutinized for retrogradely labelled cells and anterogradely labelled axon terminals, respectively. For individual experiments, the degree of C1-C3 zone terminal field overlap in the nucleus interpositus anterior was plotted as a function of either the regional overlap of single-labelled cells or the proportion of double-labelled cells in the dorsal accessory olive. The results were highly positively correlated, indicating that cortico-nuclear convergence between parts of the two zones is in close proportion to the corresponding olivo-cerebellar divergence, entirely consistent with the modular hypothesis.
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| 9. |
- Axelsson, Inge, 1947-, et al.
(författare)
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Satsa på cochrane i sverige
- 2018
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Ingår i: Läkartidningen. - 0023-7205 .- 1652-7518. ; 115:39
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Cerminara, Nadia L., et al.
(författare)
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Neuronal activity patterns in microcircuits of the cerebellar cortical C3 zone during reaching
- 2022
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Ingår i: Journal of Physiology. - 0022-3751. ; 600:23, s. 5077-5099
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: The cerebellum is the largest sensorimotor structure in the brain. A fundamental organizational feature of its cortex is its division into a series of rostrocaudally elongated zones. These are defined by their inputs from specific parts of the inferior olive and Purkinje cell output to specific cerebellar and vestibular nuclei. However, little is known about how patterns of neuronal activity in zones, and their microcircuit subdivisions, microzones, are related to behaviour in awake animals. In the present study, we investigated the organization of microzones within the C3 zone and their activity during a skilled forelimb reaching task in cats. Neurons in different microzones of the C3 zone, functionally determined by receptive field characteristics, differed in their patterns of activity during movement. Groups of Purkinje cells belonging to different receptive field classes, and therefore belonging to different microzones, were found to collectively encode different aspects of the reach controlled by the C3 zone. Our results support the hypothesis that the cerebellar C3 zone is organized and operates within a microzonal frame of reference, with a specific relationship between the sensory input to each microzone and its motor output. (Figure presented.). Key points: A defining feature of cerebellar organization is its division into a series of zones and smaller subunits termed microzones. Much of how zones and microzones are organized has been determined in anaesthetized preparations, and little is known about their function in awake animals. We recorded from neurons in the forelimb part of the C3 zone ‘in action’ by recording from single cerebellar cortical neurons located in different microzones defined by their peripheral receptive field properties during a forelimb reach–retrieval task in cats. Neurons from individual microzones had characteristic patterns of activity during movement, indicating that function is organized in relation to microcomplexes.
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| 14. |
- Christensson, Maria, et al.
(författare)
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Ontogenesis of within-session locomotor habituation in the open field.
- 2005
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Ingår i: NeuroReport. - 1473-558X. ; 16:12, s. 1319-1323
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Tidskriftsartikel (refereegranskat)abstract
- Habituation signifies a decreased response to a constant or repeated stimulus or environment. Although habituation is a fundamental form of nonassociative learning, little is known about its ontogenesis. Here, locomotor activity of postnatal ferrets within individual open field sessions was quantitatively analysed. The patterns of activity revealed a gradual shift across developmental time between relative increment and decrement of activity within sessions. The increment-to-decrement turning point was around postnatal day 48. These novel findings indicate that systematic changes in the interplay between mechanisms that drive exploratory behaviour and those that inhibit it shape the ontogenesis of open field habituation. The remarkable robustness of the data underscores the suitability of the ferret as an experimental animal for investigating ontogenesis of habituation.
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| 15. |
- Christensson, Maria, et al.
(författare)
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Time course of cerebellar morphological development in postnatal ferrets: Ontogenetic and comparative perspectives.
- 2007
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 1096-9861 .- 0021-9967. ; 501:6, s. 916-930
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Tidskriftsartikel (refereegranskat)abstract
- We provide the first systematic description of the morphological ontogenesis of the ferret cerebellum and compare its relative time-course to that of the rat cerebellum. Overall cerebellar size, foliation, and thickness of cortical layers were quantified and Purkinje cell morphology was characterized at 24 timepoints in ferrets from postnatal day (P)1 to P63. The ferret cerebellum was substantially larger than that of the rat and had a much longer developmental period. In ferrets, Purkinje cells were dispersed into a monolayer by P9, the formation of folia declined abruptly around P20, and the external granular layer peaked in thickness around P22 and disappeared by P56. Timepoints of corresponding relative developmental maturity of the quantified architectural features of rat and ferret cerebella were determined and their relationship was analyzed by linear regression. The time-conversion equation derived, describing the relationship between cerebellar morphogenesis in the two species, had a determination coefficient (r2) of 0.95. Conspicuously, the equation predicted with high accuracy the timing of structural changes in individual Purkinje cells in the ferret cerebellum. The conversion equation should be useful for precise quantitative translation of data between studies of ferret and rat cerebellum and for comparisons between development of motor and sensory structures and functions in ferrets. The degree of similarity in the time-courses of cerebellar development in two distantly related mammals makes explicit in quantitative terms how remarkably conserved the cerebellum is in phylogenesis. Therefore, the methodology should be applicable to precise quantitative conversions of cerebellar developmental time-courses also between other species.
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| 16. |
- Christensson, Maria, et al.
(författare)
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Time course of postnatal motor development in ferrets: ontogenetic and comparative perspectives.
- 2005
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328. ; 158:2, s. 231-242
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Tidskriftsartikel (refereegranskat)abstract
- We assess relative time courses of motor development in ferrets and rats and evaluate ferrets as experimental animals for studies of motor development. Motor behaviour of ferret pups was characterized in daily sessions from postnatal day (P) 2 to P63. Observations concerning rotational locomotion ('pivoting'), crawling, walking, upright standing ('rearing') and walking on a narrow path; righting on a surface, in mid-air and on an inclined plane ('geotaxis') were quantified in detail and compared with published data on rat motor development. Besides providing a comprehensive characterization of ferret motor development, our results demonstrate that relative time courses of emergence of motor skills in ferrets and rats are highly similar despite substantially different duration of postnatal periods. The relationship between species was determined by linear regression analysis of an x-y-plot of postnatal ages (y: ferret days; x: rat days) corresponding to given levels of performance of specific skills. The model equation y = 2.46x-4.18 represents the conversion between time courses of rat and ferret motor development. Remarkably, the model explained 81% of data variance (r2 = 0.81) and should hence be useful for translation of motor developmental data between ferret and rat and for comparisons between motor and other functions in ferrets. The highly conserved relative time course also has more general implications for the understanding of comparative aspects of development. In addition, the high reproducibility of data within the present study underscores the suitability of the ferret as an experimental animal for studies of motor development.
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| 17. |
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| 18. |
- Ekerot, Carl-Fredrik, et al.
(författare)
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Chapter 24 The control of forelimb movements by intermediate cerebellum
- 1997
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Ingår i: Progress in brain research. - 0079-6123. - 0444801049 ; 114, s. 423-429
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In a series of studies, the functional organization of cerebellar regions contributing to the control of forelimb movements via the rubro- and corticospinal tracts has been characterized in the cat. The system consists of the cerebellar cortical C1, C3 and Y zones and their efferent intracerebellar nucleus, the interpositus anterior. Based on analyses of cutaneous and muscle afferent climbing fibre input, of corticonuclear connections and of limb movements controlled, a modular organization of this cerebellar control system is proposed. Each module consists of a number of cortical microzones, defined by their homogeneous climbing fibre input, and a group of neurones in nucleus interpositus anterior on which these microzones converge. The input to climbing fibres is multi-modal and originates from cutaneous A beta (tactile), A delta and C (nociceptive) fibres and from muscle afferents. The cutaneous receptive fields have spatial characteristics suggestive of a relation to elemental movements. For most climbing fibres, the spatial relationship between cutaneous and muscle afferent input is such that the muscle afferent input originates from muscles that, if activated, would tend to move the cutaneous receptive field of the climbing fibre towards a stimulus applied to the skin. By contrast, the limb movement controlled by the module often has the opposite direction, and would thus tend to move the cutaneous receptive field away from a stimulus applied to the skin. Functional implications of this organization for the involvement of these regions in acute and adaptive motor control of limb movements are discussed.
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| 19. |
- Ekerot, Carl-Fredrik, et al.
(författare)
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Functional relation between corticonuclear input and movements evoked on microstimulation in cerebellar nucleus interpositus anterior in the cat
- 1995
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Ingår i: Experimental Brain Research. - 0014-4819. ; 106:3, s. 365-376
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Tidskriftsartikel (refereegranskat)abstract
- The functional relation between receptive fields of climbing fibres projecting to the C1, C3 and Y zones and forelimb movements controlled by nucleus interpositus anterior via the rubrospinal tract were studied in cats decerebrated at the pre-collicular level. Microelectrode tracks were made through the caudal half of nucleus interpositus anterior. This part of the nucleus receives its cerebellar cortical projection from the forelimb areas of these three sagittal zones. The C3 zone has been demonstrated to consist of smaller functional units called microzones. Natural stimulation of the forelimb skin evoked positive field potentials in the nucleus. These potentials have previously been shown to be generated by climbing fibre-activated Purkinje cells and were mapped at each nuclear site, to establish the climbing fibre receptive fields of the afferent microzones. The forelimb movement evoked by microstimulation at the same site was then studied. The movement usually involved more than one limb segment. Shoulder retraction and elbow flexion were frequently evoked, whereas elbow extension was rare and shoulder protraction never observed. In total, movements at the shoulder and/or elbow occurred for 96% of the interpositus sites. At the wrist, flexion and extension movements caused by muscles with radial, central or ulnar insertions on the paw were all relatively common. Pure supination and pronation movements were also observed. Movements of the digits consisted mainly of dorsal flexion of central or ulnar digits. A comparison of climbing fibre receptive fields and associated movements for a total of 110 nuclear sites indicated a general specificity of the input-output relationship of this cerebellar control system. Several findings suggested that the movement evoked from a particular site would act to withdraw the area of the skin corresponding to the climbing fibre receptive field of the afferent microzones. For example, sites with receptive fields on the dorsum of the paw were frequently associated with palmar flexion at the wrist, whereas sites with receptive fields on the ventral side of the paw and forearm were associated with dorsiflexion at the wrist. Correspondingly, receptive fields on the lateral side of the forearm and paw were often associated with flexion at the elbow, whereas sites with receptive fields on the radial side of the forearm were associated with elbow extension. The proximal movements that were frequently observed also for distal receptive fields may serve to produce a general shortening of the limb to enhance efficiency of the withdrawal. It has previously been suggested that the cerebellar control of forelimb movements via the rubrospinal tract has a modular organisation. Each module would consist of a cell group in the nucleus interpositus anterior and its afferent microzones in the C1, C3 and Y zones, characterised by a homogenous set of climbing fibre receptive fields. The results of the present study support this organisational principle, and suggest that the efferent action of a module is to withdraw the receptive field from an external stimulus. Possible functional interpretations of the action of this system during explorative and reaching movements are discussed.
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| 20. |
- Ekerot, C F, et al.
(författare)
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The postsynaptic dorsal column pathway mediates cutaneous nociceptive information to cerebellar climbing fibres in the cat
- 1991
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Ingår i: Journal of Physiology. - 1469-7793. ; 441, s. 275-284
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Tidskriftsartikel (refereegranskat)abstract
- 1. The location in the spinal cord of the pathway mediating cutaneous nociceptive C fibre input to climbing fibres projecting to the forelimb area of the C3 zone in the cerebellar anterior lobe was investigated in pentobarbitone-anaesthetized cats. Lesions of the spinal cord at the segmental level of C3 sparing the dorsal funiculi (DF preparation) or lesions of the ipsilateral and part of the contralateral dorsal funiculi were made. 2. In the DF preparation, the cutaneous input to climbing fibres projecting to the C3 zone was the same as in cats with an intact spinal cord. Also, the topography of tactile and nociceptive receptive fields and the distribution of A- and C fibre-evoked climbing fibre field potentials was similar to that in cats with an intact spinal cord. 3. In cats with an initially intact spinal cord the cutaneous nociceptive C fibre input and the topographically well organized tactile input to the C3 climbing fibres disappeared following a lesion of the ipsilateral and part of the contralateral dorsal funiculi. Following this lesion the receptive fields of the climbing fibres became indistinct and only irregular responses were evoked on skin stimulation. 4. It is concluded that the cutaneous nociceptive C fibre input from the forelimb to climbing fibres projecting to the C3 zone is mediated by the ipsilateral dorsal funiculus. Since cutaneous C fibres terminate exclusively in the spinal cord close to their entrance zone the postsynaptic dorsal column pathway must be part of this spino-olivocerebellar pathway.
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| 21. |
- Ekerot, Carl-Fredrik, et al.
(författare)
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Topography and nociceptive receptive fields of climbing fibres projecting to the cerebellar anterior lobe in the cat
- 1991
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Ingår i: Journal of Physiology. - 1469-7793. ; 441:1, s. 257-274
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Tidskriftsartikel (refereegranskat)abstract
- 1. The cutaneous receptive fields of 225 climbing fibres projecting to the forelimb area of the C3 zone in the cerebellar anterior lobe were mapped in the pentobarbitoneanaesthetized cat. Responses in climbing fibres were recorded as complex spikes in Purkinje cells. 2. A detailed topographical organization of the nociceptive climbing fibre input to the C3 zone was found. In the medial C3 zone climbing fibres with receptive fields covering proximal and/or lateral parts of the forelimb projected most medially. Climbing fibres with receptive fields located more medially on the forelimb projected successively more laterally. The sequence of receptive fields found in the lateral C3 zone was roughly the reverse of that in the medial C3 zone. Climbing fibres with receptive fields restricted to the digits projected preferentially to the caudal part of the forelimb area, whereas those with receptive fields covering both proximal and ventral areas of the forearm projected to more rostral parts. 3. The representation of the forelimb was uneven. Receptive fields with a focus on the digits or along the lateral side of the forearm dominated. 4. The proximal borders of the receptive fields were located close to joints. The area from which maximal responses were evoked was usually located eccentrically within the receptive field. Based on spatial characteristics the receptive fields could be divided into eight classes, which in turn were tentatively divided into subclasses. Similar subclasses of receptive fields were found in different cats. This classification was further supported by the results of a quantitative analysis of eighty-nine climbing fibres. The receptive fields of these climbing fibres were mapped with standardized noxious stimulation. 5. Climbing fibres terminating within sagittal strips (width, 100-300 ,tm; length, > 1 mm) had receptive fields which belonged to the same subclass. There were commonly abrupt changes in receptive fields between such microzones. Most classes of receptive fields were found in both the medial and the lateral parts of the C3 zone. However, receptive fields with a focus on the ventral side of either the metacarpals, the wrist or the forearm were found only in the medial part of the C3 zone. Furthermore, the class of receptive fields restricted to the lateral side of the upper arm and shoulder was only found in the lateral part of the C3 zone. 6. In the discussion, it is proposed that climbing fibres projecting to each microzone carry information from spinal multireceptive reflex arcs acting on a single muscle or a group of synergistic muscles. It is further suggested that each microzone controls the activity of the corresponding motoneurone pool(s) via pathways through the anterior interposed nucleus and the red nucleus.
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| 22. |
- Eriksson Linsmeier, Cecilia, et al.
(författare)
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Can histology solve the riddle of non-functioning electrodes; factors influencing the biocompatibillity of brain machine interfaces.
- 2011
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Ingår i: Progress in Brain Research. - 0079-6123. ; 194, s. 181-189
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Bokkapitel (refereegranskat)abstract
- Neural interfaces hold great promise to become invaluable clinical and diagnostic tools in the near future. However, the biocompatibility and the long-term stability of the implanted interfaces are far from optimized. There are several factors that need to be addressed and standardized when improving the long-term success of an implanted electrode. We have chosen to focus on three key factors when evaluating the evoked tissue responses after electrode implantation into the brain: implant size, fixation mode, and evaluation period. Further, we show results from an ultrathin multichannel wire electrode that has been implanted in the rat cerebral cortex for 1 year. To improve biocompatibility of implanted electrodes, we would like to suggest that free-floating, very small, flexible, and, in time, wireless electrodes would elicit a diminished cell encapsulation. We would also like to suggest standardized methods for the electrode design, the electrode implantation method, and the analyses of cell reactions after implantation into the CNS in order to improve the long-term success of implanted neural interfaces.
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| 23. |
- Garwicz, Martin, et al.
(författare)
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A unifying model for timing of walking onset in humans and other mammals
- 2009
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:51, s. 21889-21893
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Tidskriftsartikel (refereegranskat)abstract
- The onset of walking is a fundamental milestone in motor development of humans and other mammals, yet little is known about what factors determine its timing. Hoofed animals start walking within hours after birth, rodents and small carnivores require days or weeks, and nonhuman primates take months and humans approximately a year to achieve this locomotor skill. Here we show that a key to the explanation for these differences is that time to the onset of walking counts from conception and not from birth, indicating that mechanisms underlying motor development constitute a functional continuum from pre- to postnatal life. In a multiple-regression model encompassing 24 species representative of 11 extant orders of placental mammals that habitually walk on the ground, including humans, adult brain mass accounted for 94% of variance in time to walking onset postconception. A dichotomous variable reflecting species differences in functional limb anatomy accounted for another 3.8% of variance. The model predicted the timing of walking onset in humans with high accuracy, showing that this milestone in human motor development occurs no later than expected given the mass of the adult human brain, which in turn reflects the duration of its ontogenetic development. The timing of motor development appears to be highly conserved in mammalian evolution as the ancestors of some of the species in the sample presented here diverged in phylogenesis as long as 100 million years ago. Fundamental patterns of early human life history may therefore have evolved before the evolution of primates.
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| 24. |
- Garwicz, Martin, et al.
(författare)
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A unifying model for timing of walking onset in humans and other mammals.
- 2009
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 106, s. 21889-21893
-
Tidskriftsartikel (refereegranskat)abstract
- The onset of walking is a fundamental milestone in motor development of humans and other mammals, yet little is known about what factors determine its timing. Hoofed animals start walking within hours after birth, rodents and small carnivores require days or weeks, and nonhuman primates take months and humans approximately a year to achieve this locomotor skill. Here we show that a key to the explanation for these differences is that time to the onset of walking counts from conception and not from birth, indicating that mechanisms underlying motor development constitute a functional continuum from pre- to postnatal life. In a multiple-regression model encompassing 24 species representative of 11 extant orders of placental mammals that habitually walk on the ground, including humans, adult brain mass accounted for 94% of variance in time to walking onset postconception. A dichotomous variable reflecting species differences in functional limb anatomy accounted for another 3.8% of variance. The model predicted the timing of walking onset in humans with high accuracy, showing that this milestone in human motor development occurs no later than expected given the mass of the adult human brain, which in turn reflects the duration of its ontogenetic development. The timing of motor development appears to be highly conserved in mammalian evolution as the ancestors of some of the species in the sample presented here diverged in phylogenesis as long as 100 million years ago. Fundamental patterns of early human life history may therefore have evolved before the evolution of primates.
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| 25. |
- Garwicz, Martin, et al.
(författare)
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Common principles of sensory encoding in spinal reflex modules and cerebellar climbing fibres.
- 2002
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Ingår i: Journal of Physiology. - : Wiley. - 1469-7793 .- 0022-3751. ; 540:Pt 3, s. 1061-1069
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Tidskriftsartikel (refereegranskat)abstract
- An important step towards understanding the function of olivo-cerebellar climbing fibres must be to clarify what they signal. We suggest that climbing fibres projecting to paravermal cerebellum mediate highly integrated sensorimotor information derived from activity in spinal withdrawal reflex modules acting on single forelimb muscles. To test this hypothesis, cutaneous nociceptive receptive fields of spinal reflex modules were mapped and compared to those of climbing fibres. Quantitative methods were used both for mapping and for comparing receptive fields. The organization of muscle afferent input converging on individual climbing fibres was analysed in the light of results from receptive field comparisons. Individual cutaneous receptive fields in the two systems were readily matched. Matched pairs were highly similar with regard to detailed distributions of sensitivity: correlation coefficient r = 0.85; overlap of receptive field foci 72 % (average values). The olivary targets of muscle afferents from a given muscle were mainly climbing fibres with cutaneous receptive fields similar to that of the muscle itself, but to a lesser extent also other climbing fibres. In conclusion, paravermal climbing fibres apparently convey information integrating (i) cutaneous input to an individual spinal withdrawal reflex module, (ii) muscle afferent input from the output muscle of that module and (iii) muscle afferent input from muscles that constitute the output of functionally related modules. This suggests that an individual climbing fibre signals cutaneous sensory events reflecting activity of a single muscle conditional upon the functional state of the muscle itself and that of functionally related muscles.
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| 26. |
- Garwicz, Martin, et al.
(författare)
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Cutaneous receptive fields and topography of mossy fibres and climbing fibres projecting to cat cerebellar C3 zone
- 1998
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Ingår i: Journal of Physiology. - 1469-7793. ; 512:1, s. 277-293
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Tidskriftsartikel (refereegranskat)abstract
- 1. The topographical organization of mossy fibre input to the forelimb area of the paravermal C3 zone in cerebellar lobules IV and V was investigated in barbiturate-anaesthetized cats and compared with the previously described microzonal organization of climbing fibre input to the same part of the cortex. Recordings were made in the Purkinje cell and granule cell layers from single climbing fibre and mossy fibre units, respectively, and the organization of cutaneous receptive fields was assessed for both types of afferents. 2. Based on spatial characteristics, receptive fields of single mossy fibres could be systematized into ten classes and a total of thirty-two subclasses, mainly in accordance with a scheme previously used for classification of climbing fibres. Different mossy fibres displayed a substantial range of sensitivity to natural peripheral stimulation, responded preferentially to phasic or tonic stimuli and were activated by brushing of hairs or light tapping of the skin. 3. Overall, mossy fibres to any given microzone had receptive fields resembling the climbing fibre receptive field defining that microzone. However, compared with the climbing fibre input, the mossy fibre input had a more intricate topographical organization. Mossy fibres with very similar receptive fields projected to circumscribed cortical regions, with a specific termination not only in the mediolateral, but also in some cases in the rostrocaudal and dorsoventral, dimensions of the zone. On the other hand, mossy fibre units with non-identical, albeit usually similar, receptive fields were frequently found in the same microelectrode track.
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| 27. |
- Garwicz, Martin, et al.
(författare)
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Distribution of Cutaneous Nociceptive and Tactile Climbing Fibre Input to Sagittal Zones in Cat Cerebellar Anterior Lobe
- 1992
-
Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 4:4, s. 289-295
-
Tidskriftsartikel (refereegranskat)abstract
- Climbing fibres projecting to the cerebellar C3 zone (and the related C1 and Y zones) receive spatially well organized tactile and nociceptive inputs from the skin. In the present study, cutaneous tactile and nociceptive input to climbing fibres projecting to the X, B, C2 and D1 zones in lobule V were investigated in pentobarbitone-anaesthetized cats. From the present results and previous studies, it is concluded that the X, C1, CX, C3 and Y zones receive cutaneous nociceptive climbing fibre input. By contrast, climbing fibres to the B, C2 and D1 zones lack cutaneous nociceptive input. Tactile input was found in all zones. The spatial organization of receptive fields of climbing fibres projecting to the X and D1 zones was similar to that in the C3 zone. They were located on the ipsilateral forelimb, mainly its lateral and distal parts, and their proximal borders were located close to joints. In the B zone, more than half of the receptive fields of climbing fibres were confined to the ipsilateral hind- or forelimb. However, frequently more than one limb and parts of the trunk were included. In the C2 zone, the majority of climbing fibres had distal ipsi- or bilateral receptive fields on the forelimbs, often also including the head/face. Some of the bilateral forelimb receptive fields additionally included the hindlimbs ipsi- or bilaterally. The results indicate that each zone has a characteristic set of climbing fibre receptive fields, which is probably related to its efferent control functions.
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| 28. |
- Garwicz, Martin, et al.
(författare)
-
Functional organization of the intermediate cerebellum.
- 1995
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Ingår i: Alpha and Gamma Motor Systems. - Boston, MA : Springer US. - 9780306451867 - 9781461519355 ; , s. 399-402
-
Konferensbidrag (refereegranskat)abstract
- The uniform organisation of the neuronal circuitry throughout the cerebellar cortex suggests a uniform mode of operation and thus emphasises the importance of local afferent and efferent connections in determining the function of a particular part of the cortex. Based on the organisation of these connections the cerebellar cortex of the cat is divided into about ten sagittally oriented zones (see Ito, 1984 for references). A zone is anatomically defined by its projection to a restricted part of the intracerebellar or vestibular nuclei and its climbing fibre input from a circumscribed part of the inferior olive. Some of the zones are functionally coupled in that they receive branching collaterals from common olivary neurones and in turn project to the same subdivision of the intracerebellar nuclei. Since each part of the inferior olive receives input from a specific set of spino-olivary pathways, the zones can be electrophysiologically identified by the latencies and receptive fields of climbing fibre responses evoked on peripheral stimulation. The organisation of olivary afferent and nuclear efferent connections suggests that each zone, or in some cases an ensemble of zones, controls specific motor systems.
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| 29. |
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| 30. |
- Garwicz, Martin, et al.
(författare)
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Micro-organization of olivocerebellar and corticonuclear connections of the paravermal cerebellum in the cat
- 1996
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Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 8:12, s. 2726-2738
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Tidskriftsartikel (refereegranskat)abstract
- The olivocerebellar and corticonuclear connections of the forelimb area of the paravermal medial C3 zone were studied in the cat using a combined electrophysiological and fluorescent tracer technique. During an initial operation under barbiturate anaesthesia, lobules IV/V of the cerebellar anterior lobe were exposed and small injections of dextran amines tagged with rhodamine or fluorescein were made into areas selected from four different electrophysiologically defined parts of the zone. The inferior olive and the deep cerebellar nuclei were then scrutinized for retrogradely labelled cells and anterogradely labelled axon terminals respectively. The findings demonstrate a detailed topographical organization within the olivocerebellar projection to the medial C3 zone and provide some evidence for a topographical organization of its projection to nucleus interpositus anterior. Both projections are described at a level of resolution not previously attained in neuroanatomical studies and the results strongly support the notion of a micro-compartmentalization of cerebellar olivo-corticonuclear circuits.
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| 31. |
- Garwicz, Martin, et al.
(författare)
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Organizational Principles of Cerebellar Neuronal Circuitry
- 1998
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Ingår i: News in Physiological Sciences. - 1522-161X. ; 13:1, s. 26-32
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Tidskriftsartikel (refereegranskat)abstract
- We review our recent studies of cerebellar neuronal organization, emphasizing that consideration of organizational features of cerebellar circuitry represents a necessary step toward the understanding of how the cerebellum does what it does, in terms of both its internal information processing and its interaction with other motor structures.
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| 32. |
- Garwicz, Martin
(författare)
-
Sagittal zonal organization of climbing fibre input to the cerebellar anterior lobe of the ferret
- 1997
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 117:3, s. 389-398
-
Tidskriftsartikel (refereegranskat)abstract
- The organization of climbing fibre input to the cerebellar anterior lobe of the ferret was investigated in barbiturate-anaesthetized animals. Climbing fibre field potentials evoked on electrical stimulation of forelimb and hindlimb nerves were recorded at the cerebellar surface. Based on characteristic latencies of climbing fibre responses and their relative localization along the longitudinal axis of the folia, nine sagittally oriented zones could be distinguished and were tentatively named, from medial to lateral, A, X, B, C1, Cx, C2, C3, D1 and D2. Within the C1, C2 and C3 zones, climbing fibre input from the ipsilateral forelimb was found caudally and from the hindlimb rostrally, while the corresponding topographical representation in the B and D2 zones was medial to lateral. The X, Cx and D1 zones did not receive input from the hindlimb, while input from the forelimb to the A zone was weak. Overall, the sagittal zonal organization of climbing fibre input appears to conform with the compartmentalization of the ferret cerebellum based on the myeloarchitecture of corticonuclear fibres, although the X and Cx zones have not been previously identified. In terms of both general electrophysiological characteristics of input to different zones and intrazonal topographical representation, the organization of climbing fibre input to the ferret cerebellum seems to strongly resemble that in the cat. The findings thus provide evidence of cross-species generality of cerebellar sagittal organization.
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| 33. |
- Garwicz, Martin
(författare)
-
Spinal reflexes provide motor error signals to cerebellar modules - relevance for motor coordination
- 2002
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Ingår i: Brain Research Reviews. - 1872-6321. ; 40:1-3, s. 152-165
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Tidskriftsartikel (refereegranskat)abstract
- The cerebellar olivo-cortico-nuclear network influencing rubro- and corticospinal tracts via the nucleus interpositus anterior (NIA) is one of the most thoroughly characterized mammalian motor systems involved in limb movement control. Recent findings indicate that climbing fibres innervating the NIA system mediate highly integrated sensorimotor information derived from spinal withdrawal reflex modules. In the present paper, the implications of this relationship between spinal and cerebellar neuronal networks for cerebellar sensorimotor processing are put in perspective of the modular organization of the NIA system. Data that should prove useful for computational models of cerebellar sensorimotor processing and motor learning, including functional spino-olivo-cortico-nucleo-spinal connectivity, are reviewed. It is argued that spinal 'pre-processing' of climbing fibre input constitutes a signal conversion from 'sensory' to 'motor' coordinates, providing the cerebellar modules with motor error signals relevant to the action of single limb muscles. Drawing upon their patterns of interconnectivity with spinal reflex modules it is hypothesized how cerebellar modules may adaptively coordinate transitions between agonist and antagonist muscle activity. This mechanism would contribute to the generation of the triphasic EMG patterns that are necessary for smooth acceleration and deceleration of single-joint movements. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 34. |
- Garwicz, Martin, et al.
(författare)
-
Spread of synaptic activity along parallel fibres in cat cerebellar anterior lobe
- 1992
-
Ingår i: Experimental Brain Research. - 0014-4819. ; 88:3, s. 615-622
-
Tidskriftsartikel (refereegranskat)abstract
- 1. Mossy fibre evoked activity in the cerebellar cortex elicited by peripheral electrical stimulation was studied in chloralose anesthetized cats. The distribution of intracortical field potentials in the C3 and D zones was mapped in order to determine if there is a spread of synaptic activity outside the mossy fibre termination area. This area was identified by the presence of short latency synaptic field potentials in the granular layer. 2. Molecular layer field potentials were recorded up to 1.5 mm outside the mossy fibre termination area. The latencies of these potentials increased with increasing distance from the mossy fibre termination area, corresponding to a conduction velocity of about 0.4 m/s. 3. Recordings from Purkinje cells, within and outside the mossy fibre termination area, revealed an increase of simple spike activity at latencies corresponding to those of the field potentials in the same location. 4. From the spatial and temporal characteristics of the evoked activity, it is concluded that a mossy fibre input results in spread of synaptic activity along the parallel fibres. 5. The findings are discussed in relation to the recently discovered microzonal organization of the C3 zone. It is proposed that the organization of this zone offers a possibility for the control of muscle synergies, each synergy being represented by a mossy fibre input and the specific set of microzones activated by this input via the parallel fibres.
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| 35. |
- Garwicz, Martin, et al.
(författare)
-
Topographical organization of the cerebellar cortical projection to nucleus interpositus anterior in the cat
- 1994
-
Ingår i: Journal of Physiology. - 1469-7793. ; 474:2, s. 245-260
-
Tidskriftsartikel (refereegranskat)abstract
- 1. A new methodological approach for detailed study of the organization of the cerebellar corticonuclear projection was evaluated in barbiturate-anaesthetized cats. Extracellular field potentials were simultaneously recorded in nucleus interpositus anterior and in the forelimb area of the C3 zone, at the cerebellar surface. On electrical and natural stimulation of the forelimb skin, the evoked positive field potentials in the nucleus and the climbing fibre field potentials in the cerebellar cortex had similar characteristics, indicating that the nuclear potentials were related to climbing fibre activity. 2. Application of a local anaesthetic to the cerebellar surface reversibly diminished the positive field potentials in the nucleus, demonstrating that the potentials were dependent on cerebellar cortical activity. It was thus concluded that the positive field potentials were mainly generated by climbing fibre-activated Purkinje cells and reflected synaptic inhibitory potentials in nuclear neurones. Accordingly, the positive field potentials in the nucleus could be used to reveal the termination area of Purkinje cells activated by a specific climbing fibre input evoked on peripheral stimulation. 3. The topographical organization of the cerebellar cortical projection to the forelimb part of nucleus interpositus anterior was then investigated by systematically mapping the cutaneous tactile and nociceptive 'receptive fields' of the positive field potentials at different sites in the nucleus. Five groups of receptive fields were distinguished and tentatively divided into a total of nineteen subgroups. 4. Each group of receptive fields corresponded to one or two of the previously described receptive field classes of climbing fibres to the C1, C3 and Y zones and was represented in a single area of the nucleus. Within each area there was an orderly representation of different receptive fields. The results suggest that microzones in the C1, C3 and Y zones with similar climbing fibre input project to a common set of neurones in nucleus interpositus anterior. 5. We propose a modular organization for the cerebellar control of forelimb movements through the rubrospinal tract. Each module would consist of a set of neurones in nucleus interpositus anterior and their afferent microzones in the C1, C3 and Y zones. A module would control a specific group of muscles and receive a homogeneous climbing fibre input related to the movement controlled.
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| 36. |
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| 37. |
- Jankovic, Momcilo, et al.
(författare)
-
Long-term survivors of childhood cancer : cure and care—the Erice Statement (2006) revised after 10 years (2016)
- 2018
-
Ingår i: Journal of Cancer Survivorship. - : Springer Science and Business Media LLC. - 1932-2259 .- 1932-2267. ; 12:5, s. 647-650
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: The number of persons who have successfully completed treatment for a cancer diagnosed during childhood and who have entered adulthood is increasing over time, and former patients will become aging citizens. Methods: Ten years ago, an expert panel met in Erice, Italy, to produce a set of principles concerning the cure and care of survivors of childhood and adolescent cancer. The result was the Erice Statement (Haupt et al. Eur J Cancer 43(12):1778–80, 2007) that was translated into nine languages. Ten years on, it was timely to review, and possibly revise, the Erice Statement in view of the changes in paediatric oncology and the number and results of international follow-up studies conducted during the intervening years. Results: The long-term goal of the cure and care of a child with cancer is that he/she becomes a resilient and autonomous adult with optimal health-related quality of life, accepted in society at the same level as his/her age peers. “Cure” refers to cure from the original cancer, regardless of any potential for, or presence of, remaining disabilities or side effects of treatment. The care of a child with cancer should include complete and honest information for parents and the child. Conclusions and implication for cancer survivors: Some members of the previous expert panel, as well as new invited experts, met again in Erice to review the Erice Statement, producing a revised version including update and integration of each of the ten points. In addition, a declaration has been prepared, by the Childhood Cancer International Survivors Network in Dublin on October 2016 (see Annex 1).
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| 38. |
- Jörntell, Henrik, et al.
(författare)
-
Functional organization of climbing fibre projection to the cerebellar anterior lobe of the rat
- 2000
-
Ingår i: Journal of Physiology. - 1469-7793. ; 522:2, s. 297-309
-
Tidskriftsartikel (refereegranskat)abstract
- 1. The input characteristics and distribution of climbing fibre field potentials evoked by electrical stimulation of various parts of the skin were investigated in the cerebellum of barbiturate anaesthetized rats. 2. Climbing fibre responses were recorded in sagittally oriented microelectrode tracks across the mediolateral width of the anterior lobe. Climbing fibres with similar response latencies and convergence patterns terminated in sagittal bands with widths of 0.5-1.5 mm. The principal organization of the anterior lobe with respect to input characteristics and locations of sagittal zones was similar to that in the cat and ferret. Hence, the sagittal bands in the rat were tentatively named the a, b, c1, c2 and d1 zones. 3. In contrast to the cat and ferret, the a zone of the rat was characterized by short latency ipsilateral climbing fibre input. Furthermore, it was divisible into a medial 'a1' zone with convergent, proximal input and a lateral 'ax' zone with somatotopically organized input. A forelimb area with similar location and input characteristics as the X zone of the cat was found, but it formed an integral part of the ax zone. A somatotopic organization of ipsilateral, short latency climbing fibre input was also found in the c1 zone. 4. Rostrally in the anterior lobe, climbing fibres activated at short latencies from the ipsilateral side of the body terminated in a somatotopically organized transverse band which extended from the midline to the lateral end of the anterior lobe. 5. The absence of the C3 and Y zones may be interpreted as a reflection of differences in the organization of the motor systems in the rat as compared with the cat. Skilled movements, which in the cat are controlled by the C1, C3 and Y zones via the anterior interposed nucleus, may in the rat be partly controlled by the ax zone via the rostrolateral part of the fastigial nucleus.
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| 39. |
- Jörntell, Henrik, et al.
(författare)
-
Relation between cutaneous receptive fields and muscle afferent input to climbing fibres projecting to the cerebellar C3 zone in the cat
- 1996
-
Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 8:8, s. 1769-1779
-
Tidskriftsartikel (refereegranskat)abstract
- Inferior olivary cells projecting as climbing fibres to the forelimb area of the cerebellar C3 zone were investigated with respect to their cutaneous and muscle afferent input in barbiturate-anaesthetized cats. Climbing fibre responses were recorded from single cerebellar cortical Purkinje cells on natural stimulation of the skin and on electrical stimulation of nerves to m. biceps brachii, m. triceps brachii and to nine muscles acting as dorsal or palmar flexors of the paw (and, in some cases, the digits). The analysis was focused on the functional organization of convergence between cutaneous and muscle afferents onto single olivary neurons. Cutaneous receptive fields on the dorsal side of the paw and on the digits were generally associated with moderate to strong input from dorsal flexors, but little or no input from palmar flexors or proximal muscles. Receptive fields on the ventral side of the paw and forearm were associated with relatively strong input from biceps and palmar flexors. Climbing fibres with cutaneous receptive fields extending on the ulnar side of the paw and forearm usually received strong input from the triceps and moderate to strong input from dorsal flexors, whereas input from the palmar flexors was weak or lacking. In conclusion, the results indicate that the cutaneous receptive fields in many cases are associated with input from muscles the action of which would tend to move the receptive field towards a stimulus applied to the skin.
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| 40. |
- Köhler, Per, et al.
(författare)
-
Flexible multi electrode brain-machine interface for recording in the cerebellum.
- 2009
-
Ingår i: IEEE Engineering in Medicine and Biology Society. Conference Proceedings. - 1557-170X. ; 1, s. 536-538
-
Tidskriftsartikel (refereegranskat)abstract
- A new type of chip based microelectrode for acute electrophysiological recordings in the CNS has been developed. It's designed to be adaptable to a multitude of specific neuronal environments, in this study the cerebellar cortex of rat and cat. Photolithographically patternened SU-8 is used to yield flexible and biocompatible penetrating shanks with gold leads. Electrodes with an impedance of about 300 kOmega at 1kHz have excellent signal to noise ratio in acute recordings in cat cerebellum.
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| 41. |
- Levinsson, Anders, et al.
(författare)
-
Sensorimotor transformation in cat nociceptive withdrawal reflex system
- 1999
-
Ingår i: European Journal of Neuroscience. - 1460-9568. ; 11:12, s. 4327-4332
-
Tidskriftsartikel (refereegranskat)abstract
- The withdrawal reflex system of higher vertebrates has been extensively used as a model for spinal sensorimotor integration, nociceptive processing and plasticity. In the rat, the nociceptive withdrawal reflex system appears to have a modular organization. Each reflex module controls a single muscle or a few synergistic muscles, and its cutaneous receptive field corresponds to the skin area withdrawn upon contraction of the effector muscle(s) when the limb is in the standing position. This organization principle is at odds with the 'flexion reflex' concept postulated from cat studies. To assess the generality of the modular organization principle we have therefore re-examined the cutaneous input to the withdrawal reflex system of the cat. The cutaneous receptive fields of hindlimb and forelimb muscles were mapped using calibrated noxious pinch stimulation and electromyographic recording technique in barbiturate anaesthetized animals. The investigated muscles had specific cutaneous receptive fields that appeared to correspond to the area of the skin withdrawn upon contraction of the muscle when the limb is in the standing position. The spatial organization of receptive fields in the cat was similar to that in the rat. However, differences in gain properties of reflexes to some anatomically equivalent muscles in the two species were observed, possibly reflecting adaptations to the biomechanics characteristic of the digitigrade and plantigrade stance in cats and rats, respectively. Implications of the findings for the generality of the modular organization of the withdrawal reflex system and for its adaptive properties are discussed.
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| 42. |
- Ljungquist, Bengt, et al.
(författare)
-
A Bit-Encoding Based New Data Structure for Time and Memory Efficient Handling of Spike Times in an Electrophysiological Setup
- 2018
-
Ingår i: Neuroinformatics. - : Springer. - 1539-2791 .- 1559-0089. ; 16:2, s. 217-229
-
Tidskriftsartikel (refereegranskat)abstract
- Recent neuroscientific and technical developments of brain machine interfaces have put increasing demands on neuroinformatic databases and data handling software, especially when managing data in real time from large numbers of neurons. Extrapolating these developments we here set out to construct a scalable software architecture that would enable near-future massive parallel recording, organization and analysis of neurophysiological data on a standard computer. To this end we combined, for the first time in the present context, bit-encoding of spike data with a specific communication format for real time transfer and storage of neuronal data, synchronized by a common time base across all unit sources. We demonstrate that our architecture can simultaneously handle data from more than one million neurons and provide, in real time (< 25 ms), feedback based on analysis of previously recorded data. In addition to managing recordings from very large numbers of neurons in real time, it also has the capacity to handle the extensive periods of recording time necessary in certain scientific and clinical applications. Furthermore, the bit-encoding proposed has the additional advantage of allowing an extremely fast analysis of spatiotemporal spike patterns in a large number of neurons. Thus, we conclude that this architecture is well suited to support current and near-future Brain Machine Interface requirements.
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| 43. |
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| 44. |
- Ljungquist, Bengt, et al.
(författare)
-
A Novel Framework for Storage, Analysis and Integration through Mediation of Large-scale Electrophysiological Data
- 2011
-
Ingår i: 2011 5TH INTERNATIONAL IEEE/EMBS CONFERENCE ON NEURAL ENGINEERING (NER). - 1948-3546. ; , s. 203-207
-
Konferensbidrag (refereegranskat)abstract
- We present a framework based on object orientation with novel principles for how to store, analyze and integrate electrophysiological data. These principles are: (I) Using a Decorator pattern for storing analysis data in an object model, (II) using a Core Classes data structure for integration through mediation in a service bus architecture, and (III) choosing the single unit as the finest structure of the object model. With these principles, we address the problems of (1) how to relate the analysis data to the original electrophysiological data by utilizing design patterns, (2) how to integrate data from different data sources, both at application and organization levels and (3) avoiding performance problems by choosing the correct level of object granularity for the data.
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| 45. |
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| 46. |
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| 47. |
- Psouni, Elia, et al.
(författare)
-
Impact of carnivory on human development and evolution revealed by a new unifying model of weaning in mammals
- 2012
-
Ingår i: PLoS ONE. - : Public Library of Science. - 1932-6203. ; 7:4
-
Tidskriftsartikel (refereegranskat)abstract
- Our large brain, long life span and high fertility are key elements of human evolutionary success and are often thought to have evolved in interplay with tool use, carnivory and hunting. However, the specific impact of carnivory on human evolution, life history and development remains controversial. Here we show in quantitative terms that dietary profile is a key factor influencing time to weaning across a wide taxonomic range of mammals, including humans. In a model encompassing a total of 67 species and genera from 12 mammalian orders, adult brain mass and two dichotomous variables reflecting species differences regarding limb biomechanics and dietary profile, accounted for 75.5%, 10.3% and 3.4% of variance in time to weaning, respectively, together capturing 89.2% of total variance. Crucially, carnivory predicted the time point of early weaning in humans with remarkable precision, yielding a prediction error of less than 5% with a sample of forty-six human natural fertility societies as reference. Hence, carnivory appears to provide both a necessary and sufficient explanation as to why humans wean so much earlier than the great apes. While early weaning is regarded as essentially differentiating the genus Homo from the great apes, its timing seems to be determined by the same limited set of factors in humans as in mammals in general, despite some 90 million years of evolution. Our analysis emphasizes the high degree of similarity of relative time scales in mammalian development and life history across 67 genera from 12 mammalian orders and shows that the impact of carnivory on time to weaning in humans is quantifiable, and critical. Since early weaning yields shorter interbirth intervals and higher rates of reproduction, with profound effects on population dynamics, our findings highlight the emergence of carnivory as a process fundamentally determining human evolution.
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| 48. |
- Schouenborg, Jens, et al.
(författare)
-
Preface
- 2011
-
Ingår i: Brain Machine Interfaces : Implications for Science, Clinical Practice and Society - Implications for Science, Clinical Practice and Society. - 0079-6123. - 9780444538154 ; 194
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 49. |
- Sveinsdóttir, Kristbjörg, et al.
(författare)
-
Impaired Cerebellar Maturation, Growth Restriction, and Circulating Insulin-Like Growth Factor 1 in Preterm Rabbit Pups
- 2017
-
Ingår i: Developmental Neuroscience. - : S. Karger AG. - 0378-5866 .- 1421-9859. ; 39:6, s. 487-497
-
Tidskriftsartikel (refereegranskat)abstract
- Cerebellar growth is impeded following very preterm birth in human infants and the observed reduction in cerebellar volume is associated with neurodevelopmental impairment. Decreased levels of circulating insulin-like growth factor 1 (IGF-1) are associated with decreased cerebellar volume. The relationship between preterm birth, circulating IGF-1, and key cell populations supporting cerebellar proliferation is unknown. The aim of this study was to evaluate the effect of preterm birth on postnatal growth, circulating IGF-1, and cerebellar maturation in a preterm rabbit pup model. Preterm rabbit pups (PT) were delivered by cesarean section at day 29 of gestation, cared for in closed incubators with humidified air, and gavage fed with formula. Control term pups (T) delivered by spontaneous vaginal delivery at day 32 of gestation were housed and fed by their lactating doe. In vivo perfusion-fixation for immunohistochemical evaluation of cerebellar prolif-eration, cell maturation, and apoptosis was performed at repeated time points in PT and T pups. Results show that the mean weight of the pups and circulating IGF-1 protein levels were lower in the PT group at all time points (p < 0.05) than in the T group. Postnatal weight development correlated with circulating IGF-1 (r(2) = 0.89) independently of gestational age at birth and postnatal age. The proliferative (Ki-67-positive) portion of the external granular layer (EGL) was decreased in the PT group at postnatal day 2 (P2) compared to in the T group (p = 0.01). Purkinje cells exhibited decreased calbindin staining at P0 (p = 0.003), P2 (p = 0.004), and P5 (p = 0.04) in the PT group compared to in the T group. Staining for sonic hedgehog was positive in neuronal EGL progenitors and Purkinje cells at early time points but was restricted to a welldefined Purkinje cell monolayer at later time points. Preterm birth in rabbit pups is associated with lower circulating levels of IGF-1, decreased postnatal growth, and decreased cerebellar EGL proliferation and Purkinje cell maturation. The preterm rabbit pup model exhibits important characteristics of human preterm birth, and may thus be suitable for the evaluation of interventions aiming to modify growth and cerebellar development in the preterm population. (C) 2017 S. Karger AG, Basel
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| 50. |
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