Influence of physostigmine upon consolidation of memory in mice. 
The influence of physostigmine upon the consolidation process was investigated in a series of four experiments.  Male mice of a DBA/2J strain were trained to escape shock in a Y-maze.  In Experiment 1, physostigmine (.4 mg/kg, ip) impaired a previously learned task 2 days after initial learning but improved performance 11 days after initial learning.  In experiments 2 and 3, it was determined that the impairment of memory found on Day 3 was transitory and no longer evident once the drug was no longer active in an animal's system.  The findings of Experiment 4, in which the Day 12 facilitory effect was examined, were essentially the same as those of Experiments 2 and 3.  The results of the experimentation tend to support an inhibitory or motivational hypothesis rather than a consolidation hypothesis.