Presynaptic D1 dopamine receptors facilitate glutamatergic neurotransmission in the rat globus pallidus.
The effects of D1/5 dopamine agonists on spontaneous excitatory postsynaptic currents (sEPSCs) were studied in neurons of the rat globus pallidus using whole-cell recordings in the presence of TTX and bicuculline. In this condition, CNQX abolished the sEPSCs, indicating that they were solely mediated by AMPA receptors. SKF 38393, a D1-like agonist, increased the frequency but not the amplitude of the sEPSCs, suggesting a presynaptic site of action. The increase in frequency was blocked by SCH 23390, a D1/5 antagonist. Quinpirole, a D2-like agonist, decreased the frequency but did not affect the amplitude of the synaptic currents. SKF 38393 increased the frequency of sEPSCs currents, even in presence of quinpirole, indicating that D1/5- and D2-like receptors independently modulate glutamate release upon a single neuron. The results suggest that the dopaminergic control of the glutamate transmission in the globus pallidus may play a role in processing cortical information in the indirect pathway of the basal ganglia.
Hernández
Adán
A
Departamento de Fisiología, Biofísica y Neurociencias, CINVESTAV-IPN, Apartado postal 14-740, México 07000, DF, Mexico.
Sierra
Arturo
A
Valdiosera
René
R
Florán
Benjamin
B
Erlij
David
D
Aceves
Jorge
J
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D005917:Globus Pallidus / Q000187:drug effects / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000187:drug effects / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism; D026941:Sodium Channel Blockers / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D018756:GABA Antagonists; D018091:Receptors, AMPA; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D026941:Sodium Channel Blockers; D018698:Glutamic Acid; D004298:Dopamine