The development of D2 autoreceptor-mediated modulation of K(+)-evoked dopamine release in the neostriatum.
A within-subject dose-response analysis was conducted by locally perfusing increasing concentrations (0.1, 1, 10 and 100 microM) of the selective D2 agonist quinpirole via a microdialysis probe into the neostriatum of urethane-anesthetized rat pups 5, 10-11, 15-16 and 21-22 days of age and adult rats. In Expt. 1, K(+)-evoked dopamine release was significantly decreased by quinpirole relative to the vehicle control group for each age in a dose-dependent manner. The maximum effect of quinpirole was not influenced by acute tolerance or the length of the experiment (Expt. 2). Finally, the effect of quinpirole (10 microM) was blocked by the addition of the selective D2 antagonist (-)-sulpiride (100 microM) to the perfusion solution (Expt. 3). These results support and extend previous research that suggests that presynaptic D2 autoreceptors in the neostriatum are able to modulate K(+)-evoked dopamine release in vivo by postnatal day 5 in the rat.
Andersen
S L
SL
Department of Psychology, State University of New York at Binghamton 13902-6000.
Gazzara
R A
RA
D000375:Aging / Q000378:metabolism; D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D015259:Dopamine Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology; D065127:Dopamine D2 Receptor Antagonists; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D004873:Ergolines / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D017551:Microdialysis; D017072:Neostriatum / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D019257:Quinpirole; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology
D015259:Dopamine Agents; D065127:Dopamine D2 Receptor Antagonists; D004873:Ergolines; D017448:Receptors, Dopamine D2; D019257:Quinpirole; D013469:Sulpiride; D011188:Potassium; D004298:Dopamine