TOPOGRAPHICAL DISPLACEMENT OF NEUROPEPTIDE-PRODUCING NUCLEI AS AN INDICATOR OF EVOLUTIONARY BRAIN-DEVELOPMENT

The relative topographical constancy of neuropeptide-producing nuclei and the conservation of their areas of projection are indicators of evolutionary brain developments, and they enable a functional comparison of nuclear areas among different brains. The examples presented in the chapter demonstrate the possibility to deduce the evolutionary processes, which occur in the phylogenetic brain development and which are responsible for the final location of the topographically displaced npp nuclei. The evolution of brain with its intensive structural and topographical changes depends mainly on the development of these classical neuronal groups. Therefore, the topographical displacement of the projection areas of the npp nuclei is more extensive than that of the location of the npp nuclei themselves. The comparative studies, thus, represent a morphologic basis for a better understanding of the topographical changes during brain evolution and may also help for the elaboration of further experimental investigations to analyze comparatively the evolutionary development of the functional brain systems. © 1992 Academic Press Inc.