A 2011 study found that when a free rat came in contact with a rat trapped in a container, the free rat was empathically motivated to release the distressed rat from its cell. But a new study, published in Frontiers in Psychology, noted that a rat put in a similar scenario but given an anti-anxiety medication, was less likely to free its trapped peer.
Both studies were led in part by Peggy Mason, professor of neurobiology from the University of Chicago. In the most recent study, Mason discovered that rats given the antidepressant midazolam were less likely to free a fellow rat from a locked compartment, but would, however, open the same restrainer device when it contained chocolate instead.
via The Verge
