Visually mediated trace conditioning in young rats: Evidence for cholinergic involvement in the development of associative memory

Abstract

Between 21 and 25 days of age, rats show considerable improvement in their ability to associate temporally separated events in a Pavlovian trace fear conditioning situation (Moye & Rudy, in press). In the present study, it was shown that an appropriate dose of the cholinergic agonist physostigmine facilitated the otherwise poor, visually mediated trace conditioning performance of 21-day-old rats. In 25-day-old rats, the cholinergic antagonist scopolamine was shown to disrupt the otherwise strong trace conditioning performance exhibited by rats of this age. It is suggested that the development of associative memory processes that allow rats to integrate events separated in time may reflect the maturation of central cholinergic mechanisms. © 1987, Psychonomic Society, Inc.. All rights reserved.