Track tracing methods using DiI and confocal microscopy will be applied to study the development of mammalian neocortex. The normal sequence of development and the pattern of thalamocortical afferents and interhemispheric projections to the neocortex in the fetal rat. In addition, the effects of removing the hindlimb in utero on the development of cortical projection neurons and and subcortical hindlimb representation pattern in brainstem and thalamus will be determined. These experiments promise to further elucidate the role of the periphery in the development of cortical specification.
