Pituitary peptides and the suppression of memory by puromycin

It has previously been shown that the expression of memory of maze-learning in mice is blocked by intracerebrally-injected puromycin one or more days after the training experience, and that bilateral adrenalectomy before training protects memory against this effect of puromycin. Purified cortrophin gel, injected subcutaneously up to 3 days before training, has now been found to give results like those obtained with adrenalectomy and, additionally, to provide a high degree of protection when injected up to 16 hr after training. Several possible explanations for these effects have been considered and found to be inadequate.