Administration of corticosterone alters intracellular localization of brain-derived neurotrophic factor-like immunoreactivity in the rat brain.

We investigated the distribution of immunoreactivity for brain-derived neurotrophic factor (BDNF) in rat brain after peripheral administration of corticosterone or vehicle. In the immunohistochemical study, BDNF-like immunoreactivity (LI) was observed predominantly in the nucleus of the cortical and hippocampal neurons in the brain of vehicle-treated rats. In corticosterone-treated rats, BDNF-LI was markedly reduced in the nucleus and concomitantly increased in cytoplasm. Western immunoblot study also demonstrated that corticosterone significantly reduced BDNF-LI in the nuclear fraction of the cerebral cortex and hippocampus. These results indicate that corticostrone regulates the intracellular localization of BDNF and/or its derivatives in the rat brain.