Chronic intracerebral infusions of vasopressin and vasopressin antagonist modulate social recognition in rat.

To assess the role of androgen-dependent brain vasopressinergic transmission in the modulation of social recognition, castrated male rats which are deficient in vasopressin were implanted intracerebroventricularly with an Accurel collodion mini-device containing 10 micrograms vasopressin (AVP) whereas intact male rats were implanted with a similar device containing 50 micrograms of 1-deaminopenicillamine 2-O-methyltyrosine arginine vasopressin (dPTyr(Me)AVP), a specific antagonist of the vasopressor like receptors of vasopressin. Control rats in each experimental group were implanted with an Accurel device containing water. Castrated rats treated with AVP explored familiar juvenile conspecifics in the same manner as intact male rats. Conversely, intact male rats treated with dPTyr(Me)AVP explored familiar juveniles in the same manner as castrated male rats. These results confirm the role of androgen-dependent vasopressinergic neurotransmission in social recognition.