Sexually dimorphic expression of the NGF receptor gene in the developing rat brain.

To define relations between trophic molecules and known sexually dimorphic traits in brain, we examined possible sex differences in nerve growth factor (NGF) and NGF receptor (NGF-R) gene expression in the rat cholinergic basal forebrain (BF)-hippocampal system. Hippocampal NGF mRNA levels did not differ between sexes; in contrast, BF NGF-R mRNA levels were greater in neonatal females than males, paralleling the known dimorphic development of cholinergic enzyme activity. Cerebellar NGF-R mRNA levels were also dimorphic in the neonate, suggesting that sex-specific influences may regulate trophic receptor gene expression in diverse brain systems.