[Effects of 15-day chronic stress on behavior and neurological changes in the hippocampus of ICR mice].
Numerous rodent models of depression have been reported, most requiring a long experimental period and significant effort. We explored a new potential mouse model for depression by investigating whether exposure to a 15-day chronic stress paradigm could induce depression-like behavior in ICR mice. Animals in the stress-exposed groups were subjected to 3 h of restraint while immersed in a 28°C water bath daily for 15 consecutive days. Immobility time in the forced swim test was increased in the chronic stress-exposed mice compared with the controls. Serum corticosterone levels were also much higher in the stressed mice than in the control mice. Hippocampal cell survival (BrdU-positive cells) and neurotrophic factor (NGF, TrkA) mRNA levels were significantly decreased in the chronic stress-exposed mice compared with controls. Administration of the anti-depressant drugs clomipramine (20 mg/kg/d) or imipramine (30 mg/kg/d) did not change the immobility time in the forced swim test, but treatment with lithium (100 mg/kg/d) did result in slight improvement. These results suggest that this 15-day chronic stress paradigm can induce depression-like behavior and neurological changes, in a short time and with minimal effort, facilitating the assessment of treatments for depression.
Department of Life Science, Okayama University of Science.
Yusuke
Y
Sakamoto
Takumi
T
Ogawa
Mami
M
Ogawa
Yumi
Y
Matsuo
Naoya
N
Hashikawa
Narumi
N
Hashikawa
D000818:Animals; D001522:Behavior, Animal; D002470:Cell Survival; D003863:Depression / Q000188:drug therapy; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008094:Lithium / Q000494:pharmacology; D008297:Male; D008813:Mice, Inbred ICR; D010805:Physical Conditioning, Animal; D013312:Stress, Physiological / Q000187:drug effects; D013997:Time Factors
D008094:Lithium