2.3 Chronic unpredictable mild stress procedure

According to the previous description (Willner, 2017; Liu M. Y. et al., 2018), the CUMS procedure was conducted for 28 days. CUMS-treated mice were subjected to 14 stressors with a random schedule. These stressors include food deprivation (24 h), water deprivation (24 h), cage tilt (24 h, 45°), dark during the day (12 h), lights on at night (12 h), damp bedding (24 h), no bedding (24 h), noise stimulation (1 h, 100 dB), electric shock (1 h, 0.8 mA, 5 s/min), tail pinch (1 min), tail suspension (30 min), cage shake (1 h, 220 r/min), restrained in tube (2 h) and cold water swimming (6 min, 10 °C), the detailed schedule is shown in Table 1.

The protocol of 28 days chronic unpredictable mild stress.

FD, food deprivation (24 h); WD, water deprivation (24 h); CT, cage tilt (24 h, 45°); DD, dark during the day (12 h); LN, lights on at night (12 h); DB, damp bedding (24 h); NB, no bedding (24 h); NS, noise stimulation (1 h, 100 dB); ES, electric shock (1 h, 0.8 mA, 5 s/min), TP, tail pinch (1 min), TS, tail suspension (30 min); CS, cage shake (1 h, 220r/min); RS, restrained in tube (2 h); CW, cold water swimming (6 min, 10°C).