Selective facilitation of memory attributes by strychnine.

In two experiments, the effects of strychnine on the specific memory attributes of prior discrimination training were assessed in terms of subjects' performance under various discrimination reversal conditions. Mice were trained in a discrimination task with two redundant relevant cues. Immediately after their last training trial, subjects were administered an intraperitoneal injection of either strychnine (1.0 mg/kg) or saline. When both training cues were reversed (Experiment 1), strychnine treated subjects were observed to exhibit greater performance decrements than saline-treated subjects upon initial exposure to reversal conditions, suggesting that strychnine had enhanced the memory of a relatively specific stimulus-response association. When subjects were tested under partial cue-reveraal conditions (Experiment 2) strychnine treated animals exhibited treater utilization of one of the redundant relevant stimuli than the other, while saline-treated animals exhibited no preference.