2.3. Porsolt Forced Swim Test (FST)

Mice were individually transported to the testing room where they habituated for 10 minutes prior to testing. Three mice were tested at a time and were separated by an opaque barrier to obstruct viewing of other mice. Mice were removed from their transport cages by the base of their tail and slowly placed into an inescapable transparent Plexiglas cylinder (47 × 38 cm) filled to a depth of 32 cm with tap water (25–27°C). Mice were placed and released into the water at the same time. Each mouse was given a single 6-minute trial. Researchers manually recorded latency until the first period of immobility (seconds) and total duration immobile (seconds). Immobility was defined as the period of time that the mouse was not swimming, when movement was only made in order to keep the body in balance or its head above water [30]. At the end of the 6-minute trial, mice were removed from the cylinders and carefully dried and returned to their transport cages under a heat lamp positioned approximately 30 cm above the cage. Water was changed, and temperature was taken for the next trial. All mice successfully completed the 6-minute trial.