NIMH-supported scientists at the Johns Hopkins University School of Medicine, led by Mikhail V. Pletnikov, in collaboration with the laboratory of Solomon H. Snyder, explored whether DISC1 might have an impact on a molecule that plays a role in glutamate signaling—D-serine. There is evidence for a connection between D-serine and schizophrenia; in people with the disease, the level of D-serine is reduced and mutations in the gene for an enzyme that produces D-serine have been associated with schizophrenia. D-serine is found largely in cells called glia that surround and support neurons. Earlier work on DISC1 focused primarily on neurons, not glia. Findings in recent years, however, have suggested that these support cells, like the neurons themselves, are involved in the signaling that takes place in the brain.