Effect of physostigmine on Y-maze discrimination retention in the rat.

A series of experiments was designed to assess the effect of physostigmine on the retention of an appetitively-reinforced Y-maze discrimination. The results supported in part the model of cholinergic involvement in long-term memory as proposed by Deutsch, in that physostigmine respectively impaired and enhanced well-remembered and poorly-remembered responses. However a modification of the model was presented to accommodate futher findings that variations in both dose-level of administered physostigmine and initial leraning ability influenced subsequent retention, depending on the training-testing interval.