In superfused rat striatal slices, the electrically evoked release of dopamine was reduced by about 30% and that of [14C]acetylcholine was enhanced by about 25% no less than 3 weeks after morphine withdrawal in rats chronically treated with the opiate for 6 days. The lasting nature of the reduced dopamine release at the level of dopaminergic nerve terminals and the concomittant enhanced excitability of neurons tonically inhibited by released dopamine, such as cholinergic interneurons, could play an important role in the maintenance of opiate dependence.
- Acetylcholine release (striatal)
- Dopamine release (striatal)
- Morphine withdrawal