Lack of facilitation in maze learning by picrotoxin and strychnine sulfate

Abstract

The purpose of this experiment was to determine the effects of subconvulsant doses of strychnine sulfate and picrotoxin, on maze learning in the hooded rat. At 100 days of age 100 female hooded rats were randomly divided into ten groups of ten animals each. Groups 1, 3, 5, 7, and 9 were injected intraperitoneally with the appropriate solution 20 min prior to each daily trial. Groups 2, 4, 6, 8, and 10 received intraperitoneal injections 1 min after each daily trial. Groups 1 and 2 received 1.00 mg/kg of strychnine sulfate; groups 3 and 4, 0.75 mg/kg of strychnine sulfate; groups 5 and 6, 0.75 mg/kg of picrotoxin; groups 7 and 8, 0.50 mg/kg of picrotoxin; and groups 9 and 10, 1.00 ml/kg of distilled water. Each animal was run one trial a day for 15 days on a 32-unit elevated T maze. A daily record of maze errors was kept for each animal. The results and statistical analyses of this study show that neither strychnine sulfate nor picrotoxin administered before or immediately after training trials affects learning. The results are discussed in terms of their implications for J. L. McGaugh's recent modification of the neural perseveration-consolidation hypothesis.