Collapsin-1/Semaphorin-III/D Is Regulated Developmentally in Purkinje Cells and Collapses Pontocerebellar Mossy Fiber Neuronal Growth Cones
Autor: | Douglas H. Baird, Joanna M. Solowska, Yuling Luo, Barbara Kruk, Jonathan A. Raper, Sylvia A. Rabacchi |
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Rok vydání: | 1999 |
Předmět: |
Cell type
animal structures Neurite Growth Cones In situ hybridization Olivary Nucleus Biology Article Mice Purkinje Cells Nerve Fibers Culture Techniques Pons medicine Animals Nerve Growth Factors Growth cone In Situ Hybridization Glycoproteins Neurons General Neuroscience Gene Expression Regulation Developmental Neuronal Growth Semaphorin-3A Climbing fiber SEMAPHORIN III Axons In vitro Mice Inbred C57BL medicine.anatomical_structure Animals Newborn nervous system Neuroscience |
Zdroj: | The Journal of Neuroscience. 19:4437-4448 |
ISSN: | 1529-2401 0270-6474 |
DOI: | 10.1523/jneurosci.19-11-04437.1999 |
Popis: | Most axons in the CNS innervate specific subregions or layers of their target regions and form contacts with specific types of target neurons, but the molecular basis of this process is not well understood. To determine whether collapsin-1/semaphorin-III/D, a molecule known to repel specific axons, might guide afferent axons within their cerebellar targets, we characterized its expression byin situhybridization and observed its effects on mossy and climbing fiber extension and growth cone sizein vitro. In newborn mice sema-D is expressed by cerebellar Purkinje cells in parasagittal bands located medially and in some cells of the cerebellar nuclei. Later, sema-D expression in Purkinje cells broadens such that banded expression is no longer prominent, and expression is detected in progressively more lateral regions. By postnatal day 16, expression is observed throughout the cerebellar mediolateral axis.Collapsin-1 protein, the chick ortholog of sema-D, did not inhibit the extension of neurites from explants of inferior olivary nuclei, the source of climbing fibers that innervate Purkinje cells. In contrast, when it was applied to axons extending from basilar pontine explants, a source of mossy fiber afferents of granule cells, collapsin-1 caused most pontine growth cones to collapse, as evidenced by a reduction in growth cone size of up to 59%. Moreover, 63% of pontine growth cones arrested their extension or retracted. Its effects on mossy fiber extension and its distribution suggest that sema-D prevents mossy fibers from innervating inappropriate cerebellar target regions and cell types. |
Databáze: | OpenAIRE |
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