A social transmission of depression (STD) score was calculated based on all 6 different behavioral tests, including open field test, elevated plus maze, tail suspension test, forced swimming test, sucrose preference test, novelty-suppressed feeding test. social interaction ratio, sucrose preference, and forced swim immobility. All behavioral tests were performed during the light cycle. Mice were anesthetized by isoflurane and brains were removed. mPFC tissue was quickly hand dissected and frozen with liquid nitrogen. Three pairs of mPFC samples from STDs mice and STDi mice were used for proteomic analysis.