Sucrose preference test
The SPT was used to determine anhedonia-like behavior, which is considered a core symptom of depression. Rats were habituated to drink from two bottles of 1% sucrose for 48 hours. After training, the rats were deprived of food and water for 24 hours before the test. On the test day, one bottle containing 1% sucrose solution in tap water and the other containing tap water alone were placed in the rat’s home cages simultaneously, and rats were allowed to drink freely from both bottles for 1 hour. Water and sucrose consumption was measured by comparing the weight difference of the bottles before and after the test. Anhedonia was assessed as sucrose preference, which was calculated according to the following formula: sucrose preference=sucrose intake (g)/(sucrose intake [g] + water intake [g]) × 100%. To exclude the non-specific suppression of drinking, total fluid consumption was calculated as the sum of sucrose intake and water intake.