Regional variations in NMDA receptor downregulation in streptozotocin-diabetic rat brain

Insulin insufficiency has multiple actions on the CNS. Three weeks after streptozotocin-induced diabetes in rats, we found a preferential downregulation of l-[(3)H]glutamate-labeled NMDA receptors in primary sensory cortical regions. Layers I-III of the parietal cortex and superficial piriform cortex were the most sensitive followed by other cortical regions and, in turn, deeper brain structures. These effects on NMDA receptors can potentially explain some of the known CNS effects of diabetes.