Expression of stathmin and SCG10 proteins in the olfactory neurogenesis during development and after lesion in the adulthood

Stathmin and SCG10 belong to a family of phosphoproteins associated to cell proliferation and differentiation. In the present study, we have analyzed immunocytochemically the distribution of these proteins during neurogenesis in the mouse olfactory system, from midgestation to adulthood. Data show t hat already at embryonic day 12, stathmin and SCG10 immunoreactivities were present in the olfactory and vomeronasal neurons, and their number increas ed greatly, colocalizing with neuronal specific tubulin, a marker of immatu re neurons. Later on up to adulthood, the distribution of stathmin and SCG1 0 became progressively restricted to a few immature receptor and chemosenso ry neurons. Significantly, in the olfactory epithelium, stathmin was seen i n immature neurons and also in basal cells representing precursors of neuro nal elements. Interestingly, before birth stathmin and SCG10 immunopositive cells were seen outside the olfactory epithelium, seemingly migrating towa rd the olfactory bulb. After regeneration in the adult following peripheral lesion of the olfactory epithelium, stathmin and SCG10 were again strongly expressed and generally colocalized with neuronal specific tubulin immunor eactivity. Overall these results indicate that stathmin and SCG10 are expre ssed in immature olfactory neurons as well as in the migrating cells genera ted from the olfactory epithelium, supporting the role of these proteins in neurogenesis and cell migration. (C) 2001 Elsevier Science Inc.