STUDY OF CENTRAL GRAY NMDA RECEPTORS IN NOCICEPTIVE BEHAVIOR IN RATS

1. Cannulae were implanted stereotaxically in the PAG area in rats. 2. Nociceptive thresholds were assessed in these rats, by measuring the tail flick latencies after post - operative recovery. 3. Micro-injecti ons of NMDA, L - aspartic acid and L - glutamic acid were made in the central gray and the effects on tail flick latencies studied. 4. Low d ose of NMDA in the FAG did not significantly alter the tail flick late ncies, higher doses produced hyperalgesia. 5. L - glutamic acid, aspar tic acid, and Mk 801 induced hyperalgesia in the doses used. Ketamine did not significantly affect the tail flick latencies.