Effect of vasopressin on open field and activity behavior of the vasopressin-deficient (Brattleboro) rat

The effect of 1 and 5 μg AVP injections on open field and photoactivity chamber behavior of D.I. and normal Long-Evans animals was studied. Administration of 5 μg AVP (SC) resulted in a statistically significant depression of both open field and photochamber activity in the D.I. rat, but had a less pronounced effect on normal animals. However, 1 μg AVP resulted in only minor alterations of activity in both D.I. and normal animals. In terms of learned behavior, D.I. and normal animals displayed similar within-session habituation when comparisons were made following the same treatment conditions. Thus, this study supports the hypothesis that vasopressin may influence memory tasks by modulation of related states of emotionality, motivation, and/or attention rather than by direct involvement in the retrieval and/or consolidation of information.