Olfactory experience modulates Bcl-2 expression in the developing olfactory bulb.

The effect of olfactory deprivation on cellular expression of the Bcl-2 gene in the olfactory bulb of young rats was investigated. Restriction of olfactory stimuli caused an overall increase in Bcl-2 mRNA expression, with increases seen in the lateral aspects of glomerular, external plexiform, mitral and granule cell layers, as well as the medial aspects of external plexiform layer. No differences were found in the unoperated control group. In addition, we found an inverse relationship between the incidence of apoptosis induced by olfactory deprivation and the magnitude of increase in Bcl-2 mRNA expression in the glomerular layer. These data raise the possibility that Bcl-2 may be involved in olfactory experience-related neural plasticity by regulating cell survival.