Type 1 diabetes mellitus in mice increases hippocampal d-serine in the acute phase after streptozotocin injection

► STZ injection increased d-serine in the hippocampus in the acute phase. ► Amount of d-serine was not altered in the cerebellum. ► STZ injection didn't increase Srr expression in the hippocampus. ► Increased d-serine was restored by implantation of insulin tablets. ► Glucose concentration didn't alter extracellular amounts of d-serine in vitro.