Peripheral injections of vasopressin control behavior by way of interoceptive signals for hypertension.

The stimulus properties of peripheral injections of vasopressin were assessed using conditioned taste aversion techniques. Conditioned taste aversion induced by vasopressin was blocked by prior exposure to vasopressin but not to another aversive agent, apomorphine. Prior exposure to behaviorally equivalent doses of another hypertensive agent, angiotensin II, blocked also conditioned taste aversion induced by vasopressin and this effect was fully reciprocal, since prior exposure to AVP blocked the aversive effect of angiotensin II. The protection offered by prior exposure to angiotensin II was not due to an endogenous release of AVP since the aversive properties of angiotensin II were not blocked by administration of a specific antagonist of the vasopressor effects of vasopressin. These data suggest that the interoceptive cues which are responsible for the conditioned taste aversion induced by vasopressin are related to the hypertensive action of this peptide.