Adrenalectomy and the suppression of memory by puromycin.

It has previously been shown that expression of memory of maze-learning in mice is blocked by puromycin injected intracerebrally one or more days after the training experience. Bilateral adrenalectomy before training has now been found to protect memory against the effects of puromycin. This protection is absent when adrenalectomy follows training. In view of control experiments, we conclude that adrenalectomy before training modifies factors necessary for the expression of memory and that this alteration makes puromycin ineffective in blocking memory.