Results: We observed that acute administration of BCAA increased BDNF in striatum and hippocampus in 10-day-old rats. In contrast, in 30-day-old rats, BDNF were increased in striatum and cerebral cortex. Chronic administration increased BDNF in hippocampus and cerebral cortex. Conclusion: Considering that an increase in BDNF in the brain may impair memory, we speculate that the present findings may be related to brain dysfunction in MSUD.