Supported by USPHS Grants EY-00596 and GM-00136 from the National Institutes of Health.
Development of the geniculocortical pathway in rat†
Article first published online: 9 OCT 2004
Copyright © 1977 The Wistar Institute Press
Journal of Comparative Neurology
Volume 173, Issue 2, pages 289–305, 15 May 1977
How to Cite
Lund, R. D. and Mustari, M. J. (1977), Development of the geniculocortical pathway in rat. J. Comp. Neurol., 173: 289–305. doi: 10.1002/cne.901730206
- Issue published online: 9 OCT 2004
- Article first published online: 9 OCT 2004
Most cells of the dorsal lateral geniculate nucleus of rats are generated of fetal days 12 to 14. Their axons invade the telencephalon on fetal day 16 and run in the intermediate zone just below the cortical plate, reaching the visual area on fetal day 18. The axons do not invade the cortical plate significantly until close to birth (day 22 of gestation) and reach their zone of terminal distribution between postnatal days 1 and 4. In subsequent days the projection becomes progressively more heavily distributed in layers IV and I, and synapses of thalamic origin can be identified in these layers. While cells destined for layers IV cross the intermediaste zone at the time that thalamic axons first arrive, this coincidence of growth does not seem to be a factor which determines the specificity of patterns of thalamocortical connections since the cells reach layer IV several days before the axons. It is unclear why the axons should wait several days in the region immediately below the cortical plate before invading, although there is a parallel in previous studies on the development of the chick retinotectal pathway (Crossland et al., '75).