Chronic nicotinic stimulation and blockade effects on working memory.
Acute and chronic nicotine treatment has been found to improve learning and memory function in a variety of tasks. In several studies we have found that chronic nicotine infusion improves working memory performance. Replicating these results, the current study showed that chronic nicotine treatment (12mg/kg/day) significantly improved working memory performance in the radial-arm maze. The nicotine effect did not diminish during the 2 weeks following withdrawal. The nicotine-induced improvement was eliminated when the nicotinic antagonist mecamylamine (3mg/kg/day) was given concurrently, suggesting that the nicotine effect was mediated via actions on the nicotinic receptor. Surprisingly, when this chronic dose of mecamylamine was given alone, it caused a transient improvement in choice accuracy during the first week of administration. This improvement subsequently became attenuated and was not evident at all by the third and fourth weeks of administration.
Department of Psychiatry, Duke University Medical Centre, Durham, NC, USA.
E.D.
ED
Levin
S.J.
SJ
Briggs
N.C.
NC
Christopher
J.E.
JE
Rose