Astrocytic D-amino acid oxidase degrades D-serine in the hindbrain

D-Serine modulates excitatory neurotransmission by binding to N-methyl-D-aspartate glutamate receptors. D-Amino acid oxidase (DAO) degrades D-amino acids, such as D-serine, in the central nervous system, and is associated with neurological and psychiatric disorders. However, cell types that express brain DAO remain controversial, and whether brain DAO influences systemic D-amino acids in addition to brain D-serine remains unclear. Here, we created astrocyte-specific DAO-conditional knockout mice. Knockout in glial fibrillary acidic protein-positive cells eliminated DAO expression in the hindbrain and increased D-serine levels significantly in the cerebellum. Brain DAO did not influence levels of D-amino acids in the forebrain or periphery. These results show that astrocytic DAO regulates D-serine specifically in the hindbrain.