Strychnine sulfate and piracetam: lack of effect on learning in the rat. The effects of post-trial administration of piracetam and strychnine sulfate were examined using learning tasks. In the first procedure, a discrimination task was employed. In terms of two parameters used to assess drug effects on the acquisition of the discrimination, neither strychnine nor piracetam facilitated learning. The second task used to assess learning was acquisition of a conditioned avoidance response. Rats were trained in a shuttle box to avoid electric shock upon the presentation of an auditory stimulus. Six experiments were performed in an attempt to demonstrate facilitation of learning by post-trial injection of strychnine. Drug-treated animals did not differ significantly from controls in their acquisition of the avoidance response in any of the six experiments. Because control groups from the individual experiments did not differ significantly among themselves, data from all experiments were combined. In all, 8 doses of strychnine were tested, ranging from 0.005 to 0.60 mg/kg. Analysis of variance showed no significant differences between any of the treatment conditions, nor was there evidence of a graded dose-effect relationship. The present results do not support the conclusion that strychnine or piracetam facilitate learning.
- Post-Trial Injection