Glial uptake of intracerebroventricularly injected D-serine in the rat brain: an immunocytochemical study.

Recent studies have shown that free D-serine, an agonist for the N-methyl-D-aspartate receptor, is present in the forebrain of rats. In present study, we raised antibodies against D-serine and examined the distribution of both endogenous and intracerebroventricularly administered D-serine in the rat forebrain by an immunocytochemical method. D-Serine-like immunoreactive cells were found in glial cells in the brains of the rats injected with D-serine into the lateral ventricle. No immunoreactive cells were seen in the brains of untreated rats. The results suggest that glial cells may accumulate and catabolize D-serine to regulate the concentration of this neuroactive amino acid in the forebrain.