Prevention of fluphenazine-induced changes in dopaminergic and muscarinic receptors by lithium.

Co-administration of lithium carbonate to mice through their diet prevented the increase in dopamine receptor binding and the decrease in muscarinic receptor binding normally produced in striatum by chronic (12 week) administration of the neuroleptic, fluphenazine. The lithium treatment failed to prevent the muscarinic down-regulation induced by the muscarinic agonist pilocarpine in the hippocampus. These results (along with previous data) suggest that fluphenazine-induced striatal muscarinic receptor down-regulation and its reversal by lithium may be the consequence of changes in dopamine receptors in this brain region.