Forced swim test
The FST procedure was conducted according to our previous study(Ding,
Cui et al., 2021). On the pretest day, each rat was individually placed
for 15 minutes into a 25cm diameter×60 cm high Plexiglas cylinder filled
with 24±1°C water to a depth of 40 cm. On the test day, the rat was
placed into the same cylinder again and recorded for 5 minutes. The
water was changed between testing sessions. Behavior was recorded by two
video cameras (one on top and one on the side). After the experiment,
rats were removed from the water, dried with a towel, and returned to
their home cage. The videotapes were analysed by a researcher who was
blinded to each rat’s treatment condition. Immobility was defined as the
minimum movement necessary to keep the rat’s head above the water.
Increased immobility time indicated a state of helplessness.