Systemic morphine simultaneously decreases extracellular acetylcholine and increases dopamine in the nucleus accumbens of freely moving rats.
Microdialysis was used to measure extracellular levels of acetylcholine (ACh) and dopamine (DA) simultaneously in the nucleus accumbens (NAC) of freely moving rats. Systemic injection of morphine (20 mg/kg) significantly decreased ACh (30%, p less than .01) while it increased DA (55%, p less than .01). The effects of morphine were eliminated by naloxone. The results confirm that morphine increases DA and in addition, demonstrate an inhibitory influence of this opiate on extracellular levels of ACh in the NAC.
Rada
P
P
Department of Psychology, Princeton Universityn NJ 08544-1010.
Mark
G P
GP
Pothos
E
E
Hoebel
B G
BG
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002794:Choline / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003956:Dialysis; D004298:Dopamine / Q000378:metabolism*; D004563:Electrochemistry; D006719:Homovanillic Acid / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D015102:3,4-Dihydroxyphenylacetic Acid; D009020:Morphine; D002794:Choline; D000109:Acetylcholine; D004298:Dopamine; D006719:Homovanillic Acid