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Autoradiographical study of postnatal neurogenesis in the periventricular regions of the avian brain.

The study of post natal neurogenesis by means of histoautoradiographical procedures has received considerable attention (Uzman 1960, Fujita 1964, 1967, Hayashi 1966, Altman and Das 1966, Pessacq et al. 1972, Pessacq et al. 1968). However, a survey of the bibliography reveals the scarcity of data on many post natal histogenetical aspects of the brain development. In avian brains it is con stantly observed the existence of closely applied neurons constituting a sort of nests of three or four elements. Although we can speculate that these associations could be originated by repeated post migrational divisions of a single neuroblast this fact cannot be clarified until the employment of histoautoradiographical pro cedures. The main purpose of the present work was to study in autoradiograms, the histogenesis of these neuronal groups in periventricular regions of the chick neostriatum, where they are particularly numerous. Although our attention was focused in this problem, some aspects of glia cells histogenesis were also analyzed.