Depression-like behavior (day 27)

The forced swim test is commonly used to assess depression-like behavior in animals. It assesses degree of learned helplessness or behavioral despair as determined by the scoring of active (swimming and climbing) versus passive (immobility) behaviors in an inescapable cylinder filled with water [91–93]. In this procedure, mice were placed in cylinders filled with water (24°C to a depth of 15 cm) for 6 minutes and recorded. For the last five minutes of the trial, mice were scored as either immobile or mobile every 5 s. The mice were considered immobile once three paws were immobile and the fourth paw exhibited only minimal movement. Behavioral despair was measured as percent time spent immobile.