| 1. |
- Adden, Andrea, et al.
(författare)
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The brain of a nocturnal migratory insect, the Australian Bogong moth
- 2020
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 528:11, s. 1942-1963
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Tidskriftsartikel (refereegranskat)abstract
- Every year, millions of Australian Bogong moths (Agrotis infusa) complete an astonishing journey: In Spring, they migrate over 1,000 km from their breeding grounds to the alpine regions of the Snowy Mountains, where they endure the hot summer in the cool climate of alpine caves. In autumn, the moths return to their breeding grounds, where they mate, lay eggs and die. These moths can use visual cues in combination with the geomagnetic field to guide their flight, but how these cues are processed and integrated into the brain to drive migratory behavior is unknown. To generate an access point for functional studies, we provide a detailed description of the Bogong moth's brain. Based on immunohistochemical stainings against synapsin and serotonin (5HT), we describe the overall layout as well as the fine structure of all major neuropils, including the regions that have previously been implicated in compass-based navigation. The resulting average brain atlas consists of 3D reconstructions of 25 separate neuropils, comprising the most detailed account of a moth brain to date. Our results show that the Bogong moth brain follows the typical lepidopteran ground pattern, with no major specializations that can be attributed to their spectacular migratory lifestyle. These findings suggest that migratory behavior does not require widespread modifications of brain structure, but might be achievable via small adjustments of neural circuitry in key brain areas. Locating these subtle changes will be a challenging task for the future, for which our study provides an essential anatomical framework.
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| 2. |
- Agardh, E., et al.
(författare)
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Gamma‐aminobutyric acid‐ and glutamic acid decarboxylase‐immunoreactive neurons in the retina of different vertebrates
- 1987
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967. ; 258:4, s. 622-630
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Tidskriftsartikel (refereegranskat)abstract
- The localization of gamma‐aminobutyric acid (GABA)‐ and L‐glutamate 1 carboxy‐lyase (GAD)‐immunoreactive neurons was compared in the skate, frog, pigeon, chicken, rabbit, and man. Horizontal cells show both GABA and GAD immunoreactivity in the skate, frog, and bird. Certain amacrine cells show GABA and GAD immunoreactivity in all species. The distribution of GABA‐ and GAD‐immunoreactive cell bodies and cell processes was very similar, if not identical, in the skate and man. In the other species, cell populations with GAD immunoreactivity also showed GABA immunoreactivity. However, in the bird, frog, and rabbit, the GABA‐immunoreactive amacrine cells were at least twice as numerous as the GAD‐immunoreactive cells. In birds, the distributions of the GAD and GABA immunoreactivities were different in the sublayers of the inner plexiform layer. The reason for the difference is currently unknown. GABA‐immunoreactive bipolar‐like cells were seen in the frog.
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| 3. |
- Beetz, M Jerome, et al.
(författare)
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Topographic organization and possible function of the posterior optic tubercles in the brain of the desert locust Schistocerca gregaria
- 2015
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 1096-9861 .- 0021-9967. ; 523:11, s. 1589-1607
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Tidskriftsartikel (refereegranskat)abstract
- Migrating desert locusts, Schistocerca gregaria, are able to use the skylight polarization pattern for navigation. They detect polarized light with a specialized dorsal rim area in their compound eye. After multistage processing, polarization signals are transferred to the central complex, a midline-spanning brain area involved in locomotor control. Polarization-sensitive tangential neurons (TB-neurons) of the protocerebral bridge, a part of the central complex, give rise to a topographic arrangement of preferred polarization angles in the bridge, suggesting that the central complex acts as an internal sky compass. TB-neurons connect the protocerebral bridge with two adjacent brain areas, the posterior optic tubercles. To analyze the polarotopic organization of the central complex further, we investigated the number and morphologies of TB-neurons and the presence and colocalization of three neuroactive substances in these neurons. Triple immunostaining with antisera against Diploptera punctata allatostatin (Dip-AST), Manduca sexta allatotropin (Mas-AT), and serotonin (5HT) raised in the same host species revealed three spatially distinct TB-neuron clusters, each consisting of 10 neurons per hemisphere: cluster 1 and 3 showed Dip-AST/5HT immunostaining, whereas cluster 2 showed Dip-AST/Mas-AT immunostaining. Five subtypes of TB-neuron could be distinguished based on ramification patterns. Corresponding to ramification domains in the protocerebral bridge, the neurons invaded distinct but overlapping layers within the posterior optic tubercle. Similarly, neurons interconnecting the tubercles of the two hemispheres also targeted distinct layers of these neuropils. From these data we propose a neuronal circuit that may be suited to stabilize the internal sky compass in the central complex of the locust
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| 4. |
- Broms, Jonas, et al.
(författare)
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Conserved expression of the GPR151 receptor in habenular axonal projections of vertebrates.
- 2015
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 1096-9861 .- 0021-9967. ; 523:3, s. 359-380
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Tidskriftsartikel (refereegranskat)abstract
- The habenula is a phylogenetically conserved brain structure in the epithalamus. It is a major node in the information flow between fronto-limbic brain regions and monoaminergic brainstem nuclei, thus anatomically and functionally ideally positioned to regulate emotional, motivational and cognitive behaviors. Consequently, the habenula may be critically important in the pathophysiology of psychiatric disorders such as addiction and depression. Here we investigated the expression pattern of GPR151, a G coupled-protein receptor (GPCR), whose mRNA has been identified as highly and specifically enriched in habenular neurons by in situ hybridization and Translating Ribosome Affinity Purification (TRAP). In the present immunohistochemical study we demonstrate a pronounced and highly specific expression of the GPR151 protein in the medial and lateral habenula of rodent brain. Specific expression was also seen in efferent habenular fibers projecting to the interpeduncular nucleus, the rostromedial tegmental area, the rhabdoid nucleus, the mesencephalic raphe nuclei and the dorsal tegmental nucleus. Using confocal microscopy and quantitative colocalization analysis we found that GPR151 expressing axons and terminals overlap with cholinergic, substance P-ergic and glutamatergic markers. Virtually identical expression pattern was observed in rat, mouse and zebrafish brains. Our data demonstrate that GPR151 is highly conserved, specific for a subdivision of the habenular neurocircuitry, and constitutes a promising novel target for psychiatric drug development. J. Comp. Neurol., 2014. © 2014 Wiley Periodicals, Inc.
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| 5. |
- Broms, Jonas, et al.
(författare)
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Monosynaptic retrograde tracing of neurons expressing the G-protein coupled receptor Gpr151 in the mouse brain
- 2017
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 525:15, s. 3227-3250
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Tidskriftsartikel (refereegranskat)abstract
- GPR151 is a G-protein coupled receptor for which the endogenous ligand remains unknown. In the nervous system of vertebrates, its expression is enriched in specific diencephalic structures, where the highest levels are observed in the habenular area. The habenula has been implicated in a range of different functions including behavioral flexibility, decision making, inhibitory control, and pain processing, which makes it a promising target for treating psychiatric and neurological disease. This study aimed to further characterize neurons expressing the Gpr151 gene, by tracing the afferent connectivity of this diencephalic cell population. Using pseudotyped rabies virus in a transgenic Gpr151-Cre mouse line, monosynaptic afferents of habenular and thalamic Gpr151-expressing neuronal populations could be visualized. The habenular and thalamic Gpr151 systems displayed both shared and distinct connectivity patterns. The habenular neurons primarily received input from basal forebrain structures, the bed nucleus of stria terminalis, the lateral preoptic area, the entopeduncular nucleus, and the lateral hypothalamic area. The Gpr151-expressing neurons in the paraventricular nucleus of the thalamus was primarily contacted by medial hypothalamic areas as well as the zona incerta and projected to specific forebrain areas such as the prelimbic cortex and the accumbens nucleus. Gpr151 mRNA was also detected at low levels in the lateral posterior thalamic nucleus which received input from areas associated with visual processing, including the superior colliculus, zona incerta, and the visual and retrosplenial cortices. Knowledge about the connectivity of Gpr151-expressing neurons will facilitate the interpretation of future functional studies of this receptor.
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| 6. |
- Cardoso, Tiago, et al.
(författare)
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Target-specific forebrain projections and appropriate synaptic inputs of hESC-derived dopamine neurons grafted to the midbrain of parkinsonian rats
- 2018
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Ingår i: Journal of Comparative Neurology. - 0021-9967. ; 526:13, s. 2133-2146
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Tidskriftsartikel (refereegranskat)abstract
- Dopamine (DA) neurons derived from human embryonic stem cells (hESCs) are a promising unlimited source of cells for cell replacement therapy in Parkinson's disease (PD). A number of studies have demonstrated functionality of DA neurons originating from hESCs when grafted to the striatum of rodent and non-human primate models of PD. However, several questions remain in regard to their axonal outgrowth potential and capacity to integrate into host circuitry. Here, ventral midbrain (VM) patterned hESC-derived progenitors were grafted into the midbrain of 6-hydroxydopamine-lesioned rats, and analyzed at 6, 18, and 24weeks for a time-course evaluation of specificity and extent of graft-derived fiber outgrowth as well as potential for functional recovery. To investigate synaptic integration of the transplanted cells, we used rabies-based monosynaptic tracing to reveal the origin and extent of host presynaptic inputs to grafts at 6 weeks. The results reveal the capacity of grafted neurons to extend axonal projections toward appropriate forebrain target structures progressively over 24weeks. The timing and extent of graft-derived dopaminergic fibers innervating the dorsolateral striatum matched reduction in amphetamine-induced rotational asymmetry in the animals where recovery could be observed. Monosynaptic tracing demonstrated that grafted cells integrate with host circuitry 6 weeks after transplantation, in a manner that is comparable with endogenous midbrain connectivity. Thus, we demonstrate that VM patterned hESC-derived progenitors grafted to midbrain have the capacity to extensively innervate appropriate forebrain targets, integrate into the host circuitry and that functional recovery can be achieved when grafting fetal or hESC-derived DA neurons to the midbrain.
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| 7. |
- 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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| 8. |
- Dyakonova, Varvara, et al.
(författare)
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Anatomical basis for interactions of enkephalins with other transmitters in the CNS of a snail.
- 1995
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 361, s. 38-47
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Tidskriftsartikel (refereegranskat)abstract
- Immunocytochemical techniques for double staining were employed to investigate the morphological basis for interactions between enkephalins and other neuroactive compounds in the behavior of the gastropod mollusc Cepaea nemoralis. Coexistence of each of the two enkephalins with FMRFamide, serotonin or GABA-like immunoreactivity was found in certain neurons in cerebral, parietal, and pedal ganglia. Tyrosine hydroxylase-immunoreactive neurons were occasionally seen in close apposition to, but never colocalized with, the enkephalins. A comparison between these anatomical observations and previous behavioral studies suggests that in gastropod molluscs cotransmission of enkephalins with classical transmitters may, at least partly, reflect synergism of these substances in the control of definite behavioral programs
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| 9. |
- Eftekhari, Sajedeh, et al.
(författare)
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Localization of CGRP receptor components and receptor binding sites in rhesus monkey brainstem: A detailed study using in situ hybridization, immunofluorescence and autoradiography.
- 2016
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 1096-9861 .- 0021-9967. ; 524:1, s. 90-118
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Tidskriftsartikel (refereegranskat)abstract
- Functional imaging studies have revealed that certain brainstem areas are activated during migraine attacks. The neuropeptide calcitonin gene-related peptide (CGRP) is associated with activation of the trigeminovascular system, transmission of nociceptive information and plays a key role in migraine pathophysiology. Therefore, to elucidate the role of CGRP it is critical to identify the regions within the brainstem that processes CGRP signaling. In situ hybridization and immunofluorescence were performed to detect mRNA expression and define cellular localization of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1), respectively. To define CGRP receptor binding sites, in vitro autoradiography was performed with [(3) H]MK-3207 (a CGRP receptor antagonist). CLR and RAMP1 mRNA and protein expression were detected in the pineal gland, medial mammillary nucleus, median eminence, infundibular stem, periaqueductal gray, area postrema, pontine raphe nucleus, gracile nucleus and spinal trigeminal nucleus and the spinal cord. RAMP1 mRNA expression was also detected in the posterior hypothalamic area, trochlear nucleus, dorsal raphe nucleus, medial lemniscus, pontine nuclei, vagus nerve, inferior olive, abducens nucleus, motor trigeminal nucleus; where protein co-expression of CLR and RAMP1 was observed via immunofluorescence. [(3) H]MK-3207 showed high binding densities concordant with mRNA and protein expression. The present study suggests that several regions in the brainstem may be involved in CGRP signaling. Interestingly, we found receptor expression and antagonist binding in some areas that are not protected by the blood-brain barrier, which suggests that CGRP receptor antagonists may not need to be CNS-penetrant to antagonize receptors in these brain regions. This article is protected by copyright. All rights reserved.
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| 10. |
- Ekström, Peter, et al.
(författare)
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Antibodies against retinal photoreceptor‐specific proteins reveal axonal projections from the photosensory pineal organ in teleosts
- 1987
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967. ; 265:1, s. 25-33
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Tidskriftsartikel (refereegranskat)abstract
- With the aid of specific antisera to the retinal proteins S‐antigen and α‐transducin and to the rhodopsin apoprotein opsin, we have labeled various cell populations in the pineal organ, parapineal organ, habenular nucleus, and subcommissural organ in two teleost species: the rainbow trout and the European minnow. Although these proteins are associated with photoreceptor functions, not only photoreceptor cells but also the majority of parenchymal cells in the pineal organ were immunoreactive. Immunoreactive cells with dendrite‐ and axonlike processes were observed also in the parapineal organ and the habenular nucleus. Furthermore, S‐antigen‐immunoreactive, long, axonal processes were observed in the pineal organ and could be traced from the pineal organ to the habenular nucleus and to the pretectal area. In the light of recent HRP electron microscopical and immunocytochemical studies we propose (1) that not only the classical pineal photoreceptor cells of poikilothermic vertebrates but also other types of CSF‐contacting neurons may be the phylogenetic ancestors of mammalian pinealocytes, and (2) a close interrelationship between the pineal organ and the limbic system, effectuated by the direct projections from pineal photoreceptors/CSF‐contacting neurons/pinealocytes to the habenular nucleus, and by displaced “pinealocytelike” elements scattered in the habenular nucleus.
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