[en] Extracellular recordings were obtained from spontaneously active, presumed dopaminergic neurons of the ventral tegmental area (VTA) of the rat in a slice preparation. Bath-applied N-methyl-D-aspartate (NMDA) (1-20 microM) activated all neurons tested (n = 36). This effect was clearly concentration-dependent (n = 14), quickly reversible and reproducible. No bursting type of discharge was observed during NMDA infusion. The NMDA receptor blocker DL-2-amino-5-phosphonovaleric acid (50 microM) reversibly antagonized the increase in cell firing produced with 10 microM NMDA by 83.5 +/- 3% (mean +/- S.E.M.) (n = 8, P less than 0.05). Lowering the Mg2+ concentration of the perfusion fluid to one-third of its normal value significantly enhanced the excitatory effect of 5 microM NMDA (n = 7, P less than 0.05), but not of 500 nM carbachol (n = 6). Finally, NMDA did not modify the sensitivity of dopaminergic autoreceptors of VTA neurons (n = 8), when compared to controls (n = 10). These observations strongly support the presence of specific NMDA receptors in the VTA.
Disciplines :
Pharmacy, pharmacology & toxicology
Author, co-author :
Seutin, Vincent ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Pharmacologie
Verbanck, Paul
Massotte, Laurent ; Université de Liège - ULiège > Département des sciences biomédicales et précliniques > Département des sciences biomédicales et précliniques
Dresse, Albert ; Université de Liège - ULiège > Services généraux (Faculté de médecine) > Relations académiques et scientifiques (Médecine)
Language :
English
Title :
Evidence for the presence of N-methyl-D-aspartate receptors in the ventral tegmental area of the rat : an electrophysiological in vitro study
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