Abstract |
This study used microdialysis to measure changes in extracellular acetylcholine (ACh) content in the nucleus accumbens (NAC) of freely moving rats during acute and chronic morphine treatment, and following naloxone-precipitated withdrawal. Morphine injection (20 mg/kg, i.p.) caused a significant decrease in extracellular ACh which was not apparent after repeated exposure to the opiate for 7 days. Basal recovery of ACh was not altered by chronic morphine treatment. On day 8, after morphine dependence had been established, naloxone caused a large increase in ACh levels accompanied by withdrawal symptoms such as wet dog shakes, diarrhea and teeth-chattering. Pretreatment with clonidine (200 micrograms/kg, i.p.) reduced these withdrawal symptoms and eliminated the ACh response. These results suggest that accumbens ACh is involved in some of the aversive aspects of opiate withdrawal.
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Authors | P Rada, E Pothos, G P Mark, B G Hoebel |
Journal | Brain research
(Brain Res)
Vol. 561
Issue 2
Pg. 354-6
(Oct 11 1991)
ISSN: 0006-8993 [Print] Netherlands |
PMID | 1802350
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Naloxone
- Morphine
- Clonidine
- Acetylcholine
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Topics |
- Acetylcholine
(metabolism)
- Animals
- Clonidine
(pharmacology)
- Dialysis
(methods)
- Male
- Morphine
(pharmacology)
- Morphine Dependence
(physiopathology)
- Naloxone
(pharmacology)
- Nucleus Accumbens
(drug effects, physiology, physiopathology)
- Rats
- Rats, Inbred Strains
- Substance Withdrawal Syndrome
(physiopathology)
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