The neurotransmitter arginine vasopressin (AVP) is a complement of oxytocin, and mediates a lot of social behaviors. Both oxytocin and vasopressin act at the v1a and v1b vasopressin receptors.
In our model, v1a is Mithra, the Persian god of kings. The v1b receptor is Mordred, King Arthur's resentful, downtrodden relative. When mice fight, the winner tends to have an increase of v1a receptors, while the loser has an increase of v1b receptors.
Which brings us to the Sardinian alcohol-preferring rats. Researchers have bred two lab strains of Sardinian rats: alcohol preferring and non-preferring.
In the alcohol-preferring rats, blocking the v1b (Mordred) receptor stopped them from drinking so much.
Study:
Zhou et al, Involvement of Arginine Vasopressin and V1b Receptor in Alcohol Drinking in Sardinian Alcohol-Preferring Rats, Alcohol, Clinical and Experimental Research (2011)
