Puromycin was injected bitemporally in mice one day after training in a Y-maze. Eight days later various psychotropic drugs were injected intraperitoneally or subcutaneously at maximum tolerable doses. Ten days after the drug injection the mice were tested for their memory of the maze-learning. Memory was lost in control animals injected with saline but restored in most of the animals injected with imipramine, tranylcypromine, or D-amphetamine. Some indication of restoration was observed after injection of reserpine or L-dopa. These results suggest that the blockage caused by puromycin is due to adsorption of peptidyl-puromycin to adrenergic sites and that these sites may be involved in the memory trace.