Motor activity induced by disinhibition of the primary motor cortex of the rat is blocked by a non-NMDA glutamate receptor antagonist

Neurosci Lett. 1993 Feb 19;150(2):183-6. doi: 10.1016/0304-3940(93)90531-o.


Application of a GABAA (gamma-aminobutyric acid-A) receptor antagonist through a microdialysis probe into the forelimb primary motor cortex of ketamine-anesthetized rats induced electromyographic activity in the contralateral forelimb. This activity consisted of spontaneous forelimb movements with a frequency of 0.8 +/- 0.2 Hz. The motor activity induced by GABAA receptor blockade was suppressed by application through the dialysis probe of a non-NMDA (N-methyl-D-aspartate) receptor antagonist, but not by an NMDA receptor antagonist. Glutamate eliminated the blocking effect of the non-NMDA receptor antagonist upon GABAA receptor blockade mediated activity. In conclusion, the results show that an excitatory input to the motor cortical output is mediated through a non-NMDA receptor, therefore the effects of cortical disinhibition may be controlled by non-NMDA receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Animals
  • Bicuculline / pharmacology
  • Brain Mapping
  • Dialysis
  • Electromyography
  • GABA-A Receptor Antagonists*
  • Male
  • Models, Neurological
  • Motor Activity / physiology*
  • Motor Cortex / physiology*
  • Peripheral Nerves / physiology
  • Quinoxalines / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, GABA-A / drug effects
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors*
  • Receptors, N-Methyl-D-Aspartate / drug effects


  • GABA-A Receptor Antagonists
  • Quinoxalines
  • Receptors, GABA-A
  • Receptors, N-Methyl-D-Aspartate
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Bicuculline