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Buzzers and shocks were presented in random sequence and with no temporal association to rats in a shuttle-box, so that they performed pseudoconditioned barrier-crossing responses to the buzzer. Performance of these responses was enhanced by amphetamine and tyramine. The adrenergic blocking agents yohimbine and dibenamine, though ineffective on their own, antagonized the action of amphetamine and tyramine. Hexamethonium and methylatropine, also ineffective by themselves, potentiated the effect of amphetamine but not that of tyramine. Eserine depressed the performance of pseudoconditioned responses when given alone, and it antagonized the stimulant action of both amphetamine and tyramine. The results suggest that amphetamine and tyramine enhance pseudoconditioning through activation of a peripheral adrenergic mechanism and that amphetamine, in addition, triggers an opposing cholinergic mechanism, also peripheral, from which it can be released by the anticholinergic agents hexamethonium and methylatropine. The depressant action of eserine can also be explained by activation of the cholinergic mechanism.

Effects of scopolamine on avoidance conditioning of naive and previously trained mice and on habituation to the to-be-conditioned stimulus was studied by using a shuttle-box avoidance technique and a light as CS. The results show that the action of the drug depends on four major phenomena: Nicotine exerted a facilitating effect on avoidance conditioning. The action of this cholinergic agent was not state dependent. The effects of anticholinergic agents on conditioning and learning are interpreted in light of these findings.

Mice were intraperitoneally dosed with trans(−)-Δ8 tetrahydrocannabinol, various anticholinergic agents, hallucinogenics, or other behaviourally active drugs immediately prior to a habituating experience. The anticholinergic agents and trans(−)-Δ8 tetrahydrocannabinol inhibited the subsequent influence of the habituating experience relative to the other drugs and to solvent treated subjects. The habituation modifying effects of these drugs were antagonized by tacrine, but not by d-amphetamine. The results suggest that the behavioural effects of tetrahydrocannabinols might involve an anticholinergic mechanism.

The behavioral effects of JB 329 (Ditran) were compared with those of several anticholinergic agents in rats.

Effects of arecoline (0.25–4 mg/kg) were studied on several behavioral schedules in rats. It usually decreased the responses, especially at high doses, in schedules including spontaneous motor activity, FR (water and food) and FI (food) reinforcement, DRL and shock avoidance. Slight enhancement of responses was observed at low doses in spontaneous activity, FR (food) reinforcement, FI reinforcement and shock avoidance. Arecoline methiodide had negligible and insignificant effects.