The effect of memory blocking antibiotics and their analogs on acetylcholinesterase.

The ability of antibiotics to inhibit acetylcholinesterase was measured in homogenates of goldfish brain. Puromycin aminonucleoside was the most potent inhibitor followed by puromycin, cycloheximide and acetoxycycloheximide. Puromycin effectively impaired retention of active-avoidance learning in goldfish when injected either immediately before or after training, while puromycin aminonucleoside did not regardless of injection time. These results suggest that the known amnestic effects of puromycin, cycloheximide and acetoxycycloheximide are not a consequence of interference with acetylcholinesterase.