Impairment of acquisition of learning by inhibitors of RNA or protein synthesis.

The effects of inhibitors of RNA or protein synthesis (cycloheximide, puromycin and actinomycin D) on acquisition of learning in mice were investigated using various types of shock avoidance tasks. Mice having uniform and superior learning ability were used as subjects. Drugs were injected into the lateral ventricle 1 hr before training for avoidance tasks in three different shapes of maze and in a one-way shuttle box and for those based on light-dark discrimination. In all cases of training, the drugs were found to impair the acquisition of learning. The impairment was pronounced in a relatively complicated task such as H-maze learning as compared to a simple task such as T-maze learning. The drugs never affected the performance of pretrained animals. During the discussion, the acquisition of learning would be related to some specific process of RNA and protein synthesis in the brain.