A characteristic feature of the mammalian primary somatosensory cortex is an ordered representation of the contralateral body surface. The long term objective of this research project is an understanding of the ontogenetic events which contribute to the formation of these somatotopic maps. The research is focussed on this problem in the somatosensory system of the rat because of the discrete and easily visualized somatotopic organization within its central nervous system. Attention will be centered on an earlier period when primary afferents are first contacting their central targets. The research proposes to determine the role of the periphery in establishing boundaries between neocortical areas and delimiting the subcortical events which play a role in this process. This problem will be approached at the light microscopic level of analysis in both normal and fetally manipulated rats with a variety of anatomical methods. This research should contribute to our understanding of the factors which regulate the formation of discrete neocortical areas.
