Study on emotion by rest time in mice with repetitive sleep deprivation.

Sleep deprivation (SD) inhibits normal biorhythms, causing physical and mental problems. To solve the problems caused by SD, fundamental measures are needed. I investigated change of recovery by rest time in psychological aspect after repetitive SD. The mice were divided into four groups: control 24-hr rest after 24-hr SD group, 48-hr rest after 24-hr SD group, and 72-hr rest after 24-hr SD group (n=20 in each group). I carried out SD in the water cage included multiple platforms. Repetitive SD executes for 36 days. I measured weight every week after SD for 6 weeks. To check emotional condition, I carried out intruder-evoked aggression test and modified forced swimming test. In the present results, group treated 24-hr rest and 48-hr rest after 24-hr SD showed lower natural aggressiveness and high depression. However, group treated 72-hr rest after 24-hr SD indicated emotional changes to recover the normal conditions. In the weight change, all group showed significant decrease compared to control for 6 weeks. I suggest that appropriate rest time after SD can help to restore emotional change.