Behavioural effects of anatoxin, a potent nicotinic agonist, in rats.

Preliminary behavioural studies with the nicotinic agonist (+)-anatoxin have been carried with procedures sensitive to (-)-nicotine. In experimentally naive rats, (+)-anatoxin decreased locomotor activity; this effect resembled that of (-)-nicotine, but it was not blocked by mecamylamine. In nicotine-tolerant rats, (+)-anatoxin differed from (-)-nicotine because it did not increase locomotion. However, in rats trained to discriminate nicotine from saline in an operant conditioning procedure, (+)-anatoxin produced a partial nicotine-like discriminative stimulus effect that was blocked by mecamylamine, and a decreased rate of responding that was insensitive to mecamylamine. The behavioural profile of (+)-anatoxin differs from that of (-)-nicotine and it can be used for further investigations of CNS nicotinic receptors.