NMDA receptor blockade in the periaqueductal grey prevents stress-induced analgesia in attacked mice

Eur J Pharmacol. 1989 Sep 13;168(2):239-42. doi: 10.1016/0014-2999(89)90570-0.


Microinjections of N-methyl-D-aspartate (NMDA, 0.1 and 1.0 nmol) into the periaqueductal grey (PAG) of the mouse resulted in potential antinociception. In a social conflict situation, attacked mice exhibited a marked analgesia that was prevented by prior injection of the competitive NMDA antagonist, AP-7 (2.0 nmol) or naloxone (6.0 nmol) into the PAG and also by i.p. injection of the non-competitive NMDA antagonist, MK-801 (33 nmol). These results demonstrate that NMDA receptors are involved in endogenous analgesic mechanisms activated by stress.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analgesia*
  • Animals
  • Male
  • Mice
  • Mice, Inbred Strains
  • Periaqueductal Gray / physiology*
  • Periaqueductal Gray / ultrastructure
  • Receptors, N-Methyl-D-Aspartate
  • Receptors, Neurotransmitter / antagonists & inhibitors*
  • Receptors, Opioid / physiology
  • Social Behavior
  • Stress, Physiological / physiopathology*


  • Receptors, N-Methyl-D-Aspartate
  • Receptors, Neurotransmitter
  • Receptors, Opioid