Abstract
Although it is known that drebrin is expressed in the rostral migratory stream (RMS), a neurogenesis region in adult rat brain, the isoform of drebrin is unknown. In this study, a drebrin A specific antibody (DAS2) and another specific antibody (M2F6) recognizing drebrin E and A were used to identify the drebrin isoform that is specifically expressed in migrating neurons. To investigate the immunocytochemical characteristics of drebrin-positive cells, we carried out double-labeling with M2F6 and an antibody of PSA-NCAM, GFAP, or Ki-67. In addition, we performed double labeling of staining of RMS with DAS2 and M2F6 to identify the drebrin isoform. We also analyzed adult rat brains whose unilateral olfactory bulb (OB) had been removed. The migrating cells in subventricular zone of RMS were strongly stained with M2F6, but not with DAS2. This indicates that drebrin E but not A is expressed in these cells. These packed, bi-polar cells expressed PSA-NCAM but not GFAP. Some of them had been undergoing proliferation because their nuclei expressed Ki-67. These findings suggest that M2F6-positive and DAS2-negative cells are migrating neuronal precursors. Unilateral olfactory bulbectomy significantly increased the total area of M2F6-positive and DAS2-negative cells in the ipsilateral RMS comparing with the contralateral side, which is consistent with the previous report about the increase of migrating neuronal precursors by the bulbectomy [J Physiol Sci. 2006;56 Suppl:S101]
