Abstract
The requirement for cerebellar cortical neuronal activity in the development of spinocerebellar afferent topography was investigated in neonatal rats. In adult rats lower thoracic-upper lumbar spinocerebellar projections are localized to sharply circumscribed patches in the granule cell layer of the cerebellar anterior lobe. In transverse sections these patches appear as sagittally oriented stripes. This pattern develops postnatally as many spinal axons which initially project between the incipient stripes are eliminated thereby sharpening the stripe boundaries. We attempted to alter cerebellar cortical neuronal activity in neonatal animals to study the effects of these changes on the development of spinocerebellar stripes. In some experiments glutaminergic excitatory synaptic transmission was chronically blocked with the N-methyl-d-aspartate (NMDA) receptor antagonist 2-aminophosphovaleric acid (APV). In other experiments postsynaptic activity was directly inhibited by the γ-aminobutyric acid agonist muscimol. Chronic exposure to APV or to muscimol did not affect the initial development of spinocerebellar projections; many spinal axons were present in the anterior lobe and arranged in incipient stripes. Both the APV and the muscimol appeared to prevent the elimination of interstripe projections; consequently the boundaries of the stripes remained poorly defined. These findings suggest that cerebellar cortical neuronal activity is a necessary requirement for the refinement of spinal afferent topography in the anterior lobe.
Original language | English |
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Pages (from-to) | 268-274 |
Number of pages | 7 |
Journal | Developmental Brain Research |
Volume | 80 |
Issue number | 1-2 |
DOIs | |
State | Published - Jul 15 1994 |
Bibliographical note
Funding Information:Supported by NIH Grant NS-20227. The authors thank the DuPont corporation for their generous gift of Elvax and C. Pollack for his assistance with photography.
Funding
Supported by NIH Grant NS-20227. The authors thank the DuPont corporation for their generous gift of Elvax and C. Pollack for his assistance with photography.
Funders | Funder number |
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National Institutes of Health (NIH) | |
National Institute of Neurological Disorders and Stroke | R01NS020227 |
Keywords
- 2-Aminophosphovalerate
- Cerebellum
- Map formation
- Muscimol
- N-Methyl-d-aspartate
- Spinocerebellar
ASJC Scopus subject areas
- Developmental Neuroscience
- Developmental Biology