Expression of Doublecortin and NeuN in Developing Neurons in the Rat Cerebellum

Abstract

Experiments were performed on the offspring of five mongrel white rats using comparative immunochemical assessments of doublecortin (DCX) and neuronal nuclear antigen (NeuN) expression in neurons in the cortex and nucleus interpositus of the cerebellum in animals during early postnatal ontogeny (days 2-15). DCX expression was seen in postmitotic neurons in the external granular layer and migrating neurons in the cerebellar cortex. DCX expression was greater in the neocerebellum than in the paleocerebellum in rat pups aged two and seven days. NeuN expression was seen in migrating granule neurons, reaching a maximum in more mature neurons in the internal granular layer. DCX expression was not seen in Purkinje cells or in neurons in the nucleus interpositus of the cerebellum. Neurons in the nucleus interpositus showed progressive increases in NeuN from day 2 to day 15 after birth. Thus, comparative immunohistochemical studies of the dynamics of the expression of this pair of molecular markers provide an effective means of evaluating the development of cerebellar granule neurons during early postnatal ontogeny.