Facilitation of memory performance by a novel muscarinic agonist in young and old rats.
AF150(S), a partial M1 muscarinic receptor agonist, was tested for its ability to improve performance in rats in a delayed matching-to-position task. Young and old rats received intraperitoneal injections of 0, 1, and 4 mg/kg of AF150(S). AF150(S) significantly enhanced matching accuracy for both young and old rats. Fits of exponential functions to discriminability measures showed that the enhancement was manifest as a reduction in the rate of forgetting. These results indicate that AF150(S) may be a useful therapeutic agent for improving cognitive function.