Autoradiographic localization of gamma-aminobutyric acidA receptors within the ventral tegmental area.
Destruction of intrinsic neurons in the ventral tegmental area (VTA) with the excitotoxin, quinolinic acid produced a significant decrease (80%) in [3H]muscimol binding to GABAA receptors within the parabrachial pigmented and paranigral nuclei of the VTA. Selective destruction of the dopaminergic neurons with 6-hydroxydopamine (6-OHDA) did not reduce [3H]muscimol binding within the VTA. However, the destruction of dopaminergic neurons did produce an increase (20%) in [3H]muscimol binding contralateral to the lesion, suggesting a reduction in the GABAergic innervation to this region. Additionally, destruction of the VTA afferents with quinolinic acid injections in the medial accumbens failed to produce alterations in [3H]muscimol binding within the VTA. These results are consistent with the predominant localization of GABAA receptors to non-dopaminergic neurons intrinsic to the VTA.
Churchill
L
L
Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.
Dilts
R P
RP
Kalivas
P W
PW
D000818:Animals; D001345:Autoradiography; D008297:Male; D009118:Muscimol / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology; D016627:Oxidopamine / Q000494:pharmacology; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000378:metabolism*; D013681:Tegmentum Mesencephali / Q000187:drug effects / Q000378:metabolism*; D014018:Tissue Distribution
D011805:Quinolinic Acids; D011963:Receptors, GABA-A; D009118:Muscimol; D016627:Oxidopamine; D017378:Quinolinic Acid