Delay in Normalization of Disrupted Sleep-Wake Cycle in Mice as a Bipolar Disorder-Prone Animal Model (Bipolar Disorder-Prone Animal Model).
10.4306/jknpa.2016.55.3.209
- Author:
Soo Yeon KIM
1
;
Eunsoo MOON
;
Hee Jeong JEONG
;
Young Min LEE
;
Byung Dae LEE
;
Je Min PARK
Author Information
1. Department of Psychiatry, Pusan National University Hospital, Busan, Korea. jmback@pusan.ac.kr
- Publication Type:Original Article
- Keywords:
Bipolar disorder;
Circadian rhythm;
Quinpirole;
Open field test;
Forced swimming test
- MeSH:
Animals;
Animals*;
Bipolar Disorder;
Circadian Rhythm;
Depression;
Humans;
Male;
Mice*;
Models, Animal*;
Motor Activity;
Photoperiod;
Physical Exertion;
Quinpirole
- From:Journal of Korean Neuropsychiatric Association
2016;55(3):209-214
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES: This study was designed to test the hypothesis that delayed recovery from disrupted circadian rhythm is associated with both manic and depressive episodes in bipolar disorder. METHODS: Twenty-two male mice (age of five weeks, weight 28–30 gm) underwent three days of light-dark cycle disruption and 10 days of recovery phase. Sleep and wake state were checked every five minutes during the entire experimental period. After recovery phase, quinpirole (0.5 mg/kg, s.c.) was injected into the mice and open field locomotor activities were checked. Five days after the open field test, immobility time during the last 4 min in 6 min of forced swimming test was measured. Animals which recovered sleep-wake cycle within six days after light-dark cycle disruption were assigned to the early recovery group (n=14), and those that failed to recover in six days were assigned to the delayed recovery group (n=8). The locomotor activities and the immobility times of the two groups were compared by Mann-Whiney U test at two-tailed significance level of 0.05. RESULTS: The locomotor activities of the delayed recovery group were higher (mean rank=16.19) than those of the early recovery group (mean rank=8.82, U=18.5, p=0.008). The immobility times did not differ by recovery time (U=32.0 p=0.110). CONCLUSION: The results suggest that delayed recovery from circadian rhythm disruption raises the risk of manic symptoms rather than depressive symptoms.
