Strychnine-insensitive glycine/NMDA sites are altered in two stress models of depression.

Chronic severe stress (CSS) and chronic mild stress (CMS) affect the properties of [3H]5,7-dichlorokynurenic acid (5,7-DCKA) binding to strychnine-insensitive glycine/NMDA sites in the rat cerebral cortex. Specifically, CSS decreases, while CMS increases, the potency of glycine to displace [3H]5,7-DCKA binding to glycine/NMDA sites. Moreover, in both models, a reduction of the specific [3H]5,7-DCKA binding was observed. The present results demonstrate the involvement of the cortical NMDA receptor complex in the animal models of depression.