U. Kischka et al., CARBACHOL AND NALOXONE SYNERGISTICALLY ELEVATE DOPAMINE RELEASE IN RAT STRIATUM - AN INVIVO MICRODIALYSIS STUDY, Brain research, 613(2), 1993, pp. 288-290
Striatal dopamine (DA) release increased to 184% of baseline after 10-
20 min of continuous intrastriatal perfusion with 10 mM carbachol, dro
pping to 124% after 30-40 min. The addition of 100 muM naloxone amplif
ied (to 236% of baseline) and prolonged the increase in DA release, bu
t naloxone alone (up to 1 mM) had no effect. These data suggest that a
ctivation of opiate-releasing striatal neurons suppresses cholinergic
stimulation of DA release.