Arginine vasopressin facilitates reversal and impairs retention of a brightness discrimination in albino rats

Abstract

One microgram of arginine vasopressin (AVP) or a placebo was administered to male albino rats. Performance on the original learning, reversal learning, and retention of a black-white visual discrimination was assessed by means of both trials and errors to criterion. In Experiment 1, the rats were given AVP after original learning trials and prior to retention trials. In Experiment 2, the rats were given AVP prior to reversal trials and before retention trials. In Experiment 3, they were given AVP after original learning and then given a series of extinction trials. The results indicated that treatment with AVP after original learning trials facilitated performance during reversal learning but did not affect the rate of extinction. Treatment with AVP prior to reversal learning had no influence on performance during reversal learning. Finally, treatment with AVP impaired the 10-day retention of the discrimination learned during reversal training, that is, the black (+) discrimination. These findings are discussed in the context of their implications for the actions of vasopressin on selective attention and the possible independence of its actions on measures of attention and memory.