The effect of cycloheximide on mouse learning.

Mice were trained in an avoidance learning task. The incorporation of 3H-leucine into the hippocampal regions of trained mice was higher than that of control mice. When mice were injected with cycloheximide, a strong inhibitor of protein synthesis, impairment was evident in acquisition of learning. Cycloheximide produced morphological changes in mitochondria and microtubules of some brain axons. It is suggested that the cycloheximide-induced learning impairment may be due to the blocking of the synthesis of the specific protein necessary of neutral conductivity.