NMDA, kainate, and AMPA depolarize nondopamine neurons in the rat ventral tegmentum

Brain Res Bull. 1995;36(1):39-43. doi: 10.1016/0361-9230(94)00160-3.

Abstract

The possible existence of N-methyl-D-aspartate (NMDA) and non-NMDA receptors on electrophysiologically identified nondopamine neurones in the ventral tegmental area (VTA) was tested in rat midbrain slice preparations. NMDA, kainate (KA), and AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) depolarized the membrane potential of nondopamine neurons in a dose-dependent manner. The NMDA effect was blocked by the selective NMDA receptor antagonist, CGS 19755 (cis-4-phosphonomethyl-2-piperidine carboxylate), but not by the non-NMDA receptor antagonist, NBQX [2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline]. In contrast, the effects of KA and AMPA were antagonized by NBQX, but not by CGS 19755. The rank order potency of the three agonists was AMPA > KA > NMDA, with thresholds of 0.1, 0.3, and 3 microM, respectively. These results provide clear electrophysiological evidence that nondopamine neurons in the ventral tegmental area possess both NMDA and non-NMDA receptors.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Electrophysiology
  • In Vitro Techniques
  • Kainic Acid / pharmacology*
  • Male
  • N-Methylaspartate / pharmacology*
  • Neurons / drug effects*
  • Neurons / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Tegmentum Mesencephali / cytology
  • Tegmentum Mesencephali / physiology*
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / pharmacology*

Substances

  • N-Methylaspartate
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
  • Kainic Acid