Chronic sleep deprivation

The chronic sleep deprivation was generated by modified multiple platform method [34]. This method has been reported to interfere with total sleep, mainly rapid eye moved sleep [35]. Rats in CSD group were deprived sleeping for 14 h per day from 18:00 to 8:00, last for 21 days, according to our previous research [36]. The equipment for modified multiple platform method was made with plastic, and there are 15 platforms placed on the bottom of the tank (110 × 60 × 40 cm); they were surrounded by water at a temperature of 20–22 °C at a depth of 1.0 cm below the platform surface; iron cages and bottles were filled with food and water, respectively, on the top of the tank. Thus, the rats could move around inside the tank by jumping from one platform to another. When rats fall asleep, they will fall into the water and wake up.