Interactions between dopamine and amino acid-induced excitation and inhibition in the striatum.
Iontophoretic techniques were used to examine the effect of dopamine on glutamate-induced excitation and gamma-aminobutyric acid (GABA)-induced inhibition of single striatal neurons in rat brain. When dopamine was applied at concentrations that produced little or no inhibition of spontaneous firing rate, both glutamate-induced excitation and GABA-induced inhibition were enhanced. In contrast, when dopamine was applied at doses that significantly decreased spontaneous firing, glutamate-induced excitation was greatly reduced, though GABA-mediated inhibition remained enhanced. Thus, dopamine acts to modulate the efficacy of other neurotransmitters impinging on striatal neurons, but has a qualitatively different effect on the excitatory activity of striatal cells depending on its concentration.
Chiodo
L A
LA
Berger
T W
TW
D000818:Animals; D003342:Corpus Striatum / Q000166:cytology / Q000187:drug effects*; D004298:Dopamine / Q000494:pharmacology*; D004347:Drug Interactions; D005071:Evoked Potentials / Q000187:drug effects; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007478:Iontophoresis; D008297:Male; D009431:Neural Conduction / Q000187:drug effects*; D009433:Neural Inhibition / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005971:Glutamates; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D004298:Dopamine