| 1. |
- Domellöf, Erik, 1970-, et al.
(författare)
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Brain activations during execution and observation of visually guided sequential manual movements in autism and in typical development: A study protocol
- 2024
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:6
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Tidskriftsartikel (refereegranskat)abstract
- Motor issues are frequently observed accompanying core deficits in autism spectrum disorder (ASD). Impaired motor behavior has also been linked to cognitive and social abnormalities, and problems with predictive ability have been suggested to play an important, possibly shared, part across all these domains. Brain imaging of sensory-motor behavior is a promising method for characterizing the neurobiological foundation for this proposed key trait. The present functional magnetic resonance imaging (fMRI) developmental study, involving children/youth with ASD, typically developing (TD) children/youth, and neurotypical adults, will investigate brain activations during execution and observation of a visually guided, goal-directed sequential (two-step) manual task. Neural processing related to both execution and observation of the task, as well as activation patterns during the preparation stage before execution/observation will be investigated. Main regions of interest include frontoparietal and occipitotemporal cortical areas, the human mirror neuron system (MNS), and the cerebellum.
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| 2. |
- Larsson, Ing-Marie, et al.
(författare)
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Post-cardiac arrest serum levels of glial fibrillary acidic protein for predicting neurological outcome
- 2014
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 85:12, s. 1654-1661
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Tidskriftsartikel (refereegranskat)abstract
- Aim of the study: To investigate serum levels of glial fibrillary acidic protein (GFAP) for evaluation of neurological outcome in cardiac arrest (CA) patients and compare GFAP sensitivity and specificity to that of more studied biomarkers neuron-specific enolas (NSE) and S100B. Method: A prospective observational study was performed in three hospitals in Sweden during 2008-2012. The participants were 125 CA patients treated with therapeutic hypothermia (TH) to 32-34. °C for 24. hours. Samples were collected from peripheral blood (n. =. 125) and the jugular bulb (n. =. 47) up to 108. hours post-CA. GFAP serum levels were quantified using a novel, fully automated immunochemical method. Other biomarkers investigated were NSE and S100B. Neurological outcome was assessed using the Cerebral Performance Categories scale (CPC) and dichotomized into good and poor outcome. Results: GFAP predicted poor neurological outcome with 100% specificity and 14-23% sensitivity at 24, 48 and 72. hours post-CA. The corresponding values for NSE were 27-50% sensitivity and for S100B 21-30% sensitivity when specificity was set to 100%. A logistic regression with stepwise combination of the investigated biomarkers, GFAP, did not increase the ability to predict neurological outcome. No differences were found in GFAP, NSE and S100B levels when peripheral and jugular bulb blood samples were compared. Conclusion: Serum GFAP increase in patients with poor outcome but did not show sufficient sensitivity to predict neurological outcome after CA. Both NSE and S100B were shown to be better predictors. The ability to predict neurological outcome did not increased when combining the three biomarkers.
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| 3. |
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| 4. |
- Wiesinger, Birgitta, et al.
(författare)
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Jaw-opening accuracy is not affected by masseter muscle vibration in healthy men
- 2014
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 232:11, s. 3501-3508
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Tidskriftsartikel (refereegranskat)abstract
- There is a functional integration between the jaw and neck regions with head extension–flexion movements during jaw-opening/closing tasks. We recently reported that trigeminal nociceptive input by injection of hypertonic saline into the masseter muscle altered this integrated jaw–neck function during jaw-opening/closing tasks. Thus, in jaw-opening to a predefined position, the head–neck component increased during pain. Previous studies have indicated that muscle spindle stimulation by vibration of the masseter muscle may influence jaw movement amplitudes, but the possible effect on the integrated jaw–neck function is unknown. The aim of this study was to investigate the effect of masseter muscle vibration on jaw–head movements during a continuous jaw-opening/closing task to a target position. Sixteen healthy men performed two trials without vibration (Control) and two trials with bilateral masseter muscle vibration (Vibration). Movements of the mandible and the head were registered with a wireless three-dimensional optoelectronic recording system. Differences in jaw-opening and head movement amplitudes between Control and Vibration, as well as achievement of the predefined jaw-opening target position, were analysed with Wilcoxon’s matched pairs test. No significant group effects from vibration were found for jaw or head movement amplitudes, or in the achievement of the target jaw-opening position. A covariation between the jaw and head movement amplitudes was observed. The results imply a high stability for the jaw motor system in a target jaw-opening task and that this task was achieved with the head–neck and jaw working as an integrated system.
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| 5. |
- Claeson, Anna-Sara, 1974-, et al.
(författare)
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Symptoms from masked acrolein exposure suggest altered trigeminal reactivity in chemical intolerance
- 2017
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Ingår i: Neurotoxicology. - : Elsevier. - 0161-813X .- 1872-9711. ; 60, s. 92-98
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chemical intolerance (CI) is a widespread occupational and public health problem characterized by symptoms that reportedly result from low-levels of chemical exposure. The mechanisms behind CI are unknown, however modifications of the chemical senses (rather than toxic processes) have been suggested as key components. The aim of this study was to investigate whether individuals with self-reported CI report more sensory irritation during masked acrolein exposure compared to controls without CI. Methods: Individuals with CI (n = 18) and controls without CI (n = 19) were exposed in an exposure chamber. Each participant took part in two exposure conditions – one with heptane (the masking compound), and one with heptane and acrolein at a dose below previously reported sensory irritation thresholds. The exposures lasted for 60 min. Symptoms and confidence ratings were measured continuously throughout the exposure as were measurements of electrodermal activity and self-reported tear-film break-up time. Participants were blind to exposure condition. Results: Individuals with CI, compared with controls reported greater sensory irritation in the eyes, nose and throat when exposed to acrolein masked with heptane. There was no difference during exposure to heptane. Conclusions: Masked exposure to acrolein at a concentration below the previously reported detection threshold is perceived as more irritating by individuals with CI compared with controls. The results indicate that there is altered trigeminal reactivity in those with CI compared to controls.
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| 6. |
- Mansouri, Shiva, et al.
(författare)
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GalR3 activation promotes adult neural stem cell survival in response to a diabetic milieu
- 2013
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 127:2, s. 209-220
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes impairs adult neurogenesis which could play a role in the CNS complications of this serious disease. The goal of this study was to determine the potential role of galanin in protecting adult neural stem cells (NSCs) from glucolipotoxicity and to analyze whether apoptosis and the unfolded protein response were involved in the galanin-mediated effect. We also studied the regulation of galanin and its receptor subtypes under diabetes in NSCs in vitro and in the subventricular zone (SVZ) in vivo. The viability of mouse SVZ-derived NSCs and the involvement of apoptosis (Bcl-2, cleaved caspase-3) and unfolded protein response [C/EBP homologous protein (CHOP) Glucose-regulated protein 78/immunoglobulin heavy-chain binding protein (GRP78/BiP), spliced X-box binding protein 1 (XBP1), c-Jun N-terminal kinases (JNK) phosphorylation] were assessed in the presence of glucolipotoxic conditions after 24h. The effect of diabetes on the regulation of galanin and its receptor subtypes was assessed on NSCs in vitro and in SVZ tissues isolated from normal and type 2 diabetes ob/ob mice. We show increased NSC viability following galanin receptor (GalR)3 activation. This protective effect correlated with decreased apoptosis and CHOP levels. We also report how galanin and its receptors are regulated by diabetes in vitro and in vivo. This study shows GalR3-mediated neuroprotection, supporting a potential future therapeutic development, based on GalR3 activation, for the treatment of brain disorders.
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| 7. |
- Olsson, Annakarin, 1969-, et al.
(författare)
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Effects of tracking technology on daily life of persons with dementia : three experimental single-case studies
- 2015
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Ingår i: American Journal of Alzheimer’s Disease and Other Dementia. - : SAGE Publications. - 1533-3175 .- 1938-2731. ; 30:1, s. 29-40
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the effects of using tracking technology on independent outdoor activities and psychological well-being in 3 persons with dementia (PwDs) and their spouses.Methods: Three experimental single-case studies with an A1B1A2B2 design. The intervention entailed access to a passive positioning alarm and technical support. Continual daily measures of independent outdoor activities among PwDs' and spouses' worries about these activities were made during all phases.Results: Access to a tracking technology consistently increased the independent outdoor activities of 2 PwDs. One of the spouses consistently reported decreased worry during B phases, another's worry decreased only in B2, and the third showed little variability in worrying across all phases.Conclusion: Tracking technology may support PwDs to engage in independent outdoor activities and decrease spouses' worries; however, randomized controlled group studies are needed to investigate whether these results can be replicated on a group level.
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| 8. |
- Albert, Frederic, et al.
(författare)
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The Ia afferent feedback of a given movement evokes the illusion of the same movement when returned to the subject via muscle tendon vibration
- 2006
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Ingår i: Experimental Brain Research. - : Springer Science and Business Media LLC. - 0014-4819 .- 1432-1106. ; 172:2, s. 163-174
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to further investigate the contribution of primary muscle spindle feedback to proprioception and higher brain functions, such as movement trajectory recognition. For this purpose, complex illusory movements were evoked in subjects by applying patterns of muscle tendon vibration mimicking the natural Ia afferent pattern. Ia afferent messages were previously recorded using microneurographic method from the six main muscle groups acting on the ankle joint during imposed "writing like" movements. The mean Ia afferent pattern was calculated for each muscle group and used as a template to pilot each vibrator. Eleven different vibratory patterns were applied to ten volunteers. Subjects were asked both to copy the perceived illusory movements by hand on a digitizing tablet and to recognize and name the corresponding graphic symbol. The results show that the Ia afferent feedback of a given movement evokes the illusion of the same movement when it is applied to the subject via the appropriate pattern of muscle tendon vibration. The geometry and the kinematic parameters of the imposed and illusory movements are very similar and the so-called "two-thirds power law" is present in the reproduction of the vibration-induced illusory movements. Vibrations within the "natural" frequency range of Ia fibres firing (around 30 Hz) produce clear illusions of movements in all the tested subjects. In addition, increasing the mean frequency of the vibration patterns resulted in a linear increase in the size of the illusory movements. Lastly, the subjects were able to recognize and name the symbols evoked by the vibration-induced primary muscle spindle afferent patterns in 83% of the trials. These findings suggest that the "proprioceptive signature" of a given movement is associated with the corresponding "perceptual signature". The neural mechanisms possibly underlying the sensory to perceptual transformation are discussed in the general framework of "the neuronal population vector model".
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| 9. |
- Andersson, Linus, 1979-, et al.
(författare)
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Effects of Task Demands on Olfactory, Auditory, and Visual Event-Related Potentials Suggest Similar Top-Down Modulation Across Senses
- 2018
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Ingår i: Chemical Senses. - : Oxford University Press (OUP). - 0379-864X .- 1464-3553. ; 43:2, s. 129-134
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Tidskriftsartikel (refereegranskat)abstract
- A widely held view is that top-down modulation of sensory information relies on an amodal control network that acts through the thalamus to regulate incoming signals. Olfaction lacks a direct thalamic projection, which suggests that it may differ from other modalities in this regard. We investigated the late positive complex (LPC) amplitudes of event-related potentials (ERP) from 28 participants, elicited by intensity-matched olfactory, auditory and visual stimuli, during a condition of focused attention, a neutral condition, and a condition in which stimuli were to be actively ignored. Amplitudes were largest during the attend condition, lowest during the ignore condition, with the neutral condition in between. A Bayesian analysis resulted in strong evidence for similar effects of task across sensory modalities. We conclude that olfaction, despite its unique neural projections, does not differ from audition and vision in terms of task-dependent neural modulation of the LPC.
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| 10. |
- Andersson, Linus, et al.
(författare)
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Short-term olfactory sensitization involves brain networks relevant for pain, and indicates chemical intolerance
- 2017
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Ingår i: International journal of hygiene and environmental health. - : Elsevier. - 1438-4639 .- 1618-131X. ; 220:2, s. 503-509
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Tidskriftsartikel (refereegranskat)abstract
- Chemical intolerance is a medically unexplained affliction that implies deleterious reactions to non-toxic everyday chemical exposure. Sensitization (i.e. increased reactivity to repeated, invariant stimulation) to odorous stimulation is an important component in theoretical explanations of chemical intolerance, but empirical evidence is scarce. We hypothesized that (1) individuals who sensitize to repeated olfactory stimulation, compared with those who habituate, would express a lower blood oxygenated level dependent (BOLD) response in key inhibitory areas such as the rACC, and higher signal in pain/saliency detection regions, as well as primary and/or secondary olfactory projection areas; and (2) olfactory sensitization, compared with habituation, would be associated with greater self-reported chemical intolerance. More-over, we assessed whether olfactory sensitization was paralleled by comparable trigeminal processing - in terms of perceptual ratings and BOLD responses. We grouped women from a previous functional magnetic imaging study based on intensity ratings of repeated amyl acetate exposure over time. Fourteen women sensitized to the exposure, 15 habituated, and 20 were considered "intermediate" (i.e. neither sensitizers nor habituaters). Olfactory sensitizers, compared with habituaters, displayed a BOLD-pattern in line with the hypothesis, and reported greater problems with odours in everyday life. They also expressed greater reactions to CO2 in terms of both perceived intensity and BOLD signal. The similarities with pain are discussed.
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