Activation of D1 dopamine receptors stimulates the release of GABA in the basal ganglia of the rat.
Here we have explored whether dopamine is able to modulate the release of gamma-aminobutyric acid (GABA) from striatal terminals to substantia nigra pars reticulata, entopeduncular nucleus, globus pallidus and caudate-putamen. The type of dopamine receptors involved was assessed by the blocking effect of either SCH 23390 (D1 antagonist) or (-)-sulpiride (D2 antagonist) of the dopamine effect. Dopamine stimulated (EC50 3.2 microM) the depolarization-induced release of [3H]GABA from slices isolated from all of the above mentioned nuclei. SCH 23390 dose-dependently blocked the dopamine stimulation, but (-)-sulpiride did not show any blocking effect. The results suggest that dopamine via D1 receptors modulates the release of GABA from striatal GABAergic terminals.
Floran
B
B
Department of Physiology, Biophysics and Neurosciences, Instituto Politecnico Nacional, Mexico, D.F.
Aceves
J
J
Sierra
A
A
Martinez-Fong
D
D
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000502:physiology*; D001552:Benzazepines / Q000494:pharmacology; D002421:Caudate Nucleus / Q000187:drug effects / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000494:pharmacology*; D005917:Globus Pallidus / Q000187:drug effects / Q000502:physiology; D006892:Hydroxydopamines; D066298:In Vitro Techniques; D008297:Male; D016627:Oxidopamine; D011699:Putamen / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D017447:Receptors, Dopamine D1; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001552:Benzazepines; D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D005680:gamma-Aminobutyric Acid; D013469:Sulpiride; D016627:Oxidopamine; D004298:Dopamine