Effects of pre-training administration of scopolamine on learning and retention in the cockroach, P. americana.

The muscarinic cholinergic blocker, scopolamine, has no effect on acquisition or retention of the choice behavior of the cockroach, P. americana trained to turn right or left to avoid shock in a T-maze. Scopolamine does, however, prevent runway habituation during training, suggesting that such habituation may be dependent on central cholinergic synapses as there are no known peripheral cholinergic receptors in cockroaches. Previous work demonstrating that puromycin interferes with correct choice retention five hours after training taken together with our results demonstrating no effect of scopolamine on such retention, suggests that puromycin does not produce its amnesic effect on choice behavior by interferring with central cholinergic synaptic processes.