ACUTE EFFECTS OF MORPHINE ON THE EXPRESSION OF MESSENGER-RNAS FOR NMDA RECEPTOR SUBUNITS IN THE RAT HIPPOCAMPUS, HYPOTHALAMUS AND SPINAL-CORD

The acute effects of subcutaneously injected morphine on transcripts o f the NMDA receptor subunits NR1, NR2A and NR2B in certain areas of th e central nervous system of male rats were examined by Northern blot a nalysis. The result clearly indicated that a single dose (10 mg/kg) of the opioid alters the expression of the mRNA for receptor subunits in the hippocampus and hypothalamus 4 h after drug injection. No change in the mRNA levels was observed 30 min following injection, and after 24 h most of the levels were restored to control values. The observati on suggests that morphine affects this type of glutamate receptor alre ady in the acute phase of its administration. (C) 1998 Elsevier Scienc e B.V.