Exposure to enriched environment restores the mRNA expression of mineralocorticoid and glucocorticoid receptors in the hippocampus and ameliorates depressive-like symptoms in chronically stressed rats.
Chronic stress can cause emotional dysfunction, but exposure to an enriched environment (EE) can benefit emotional homeostasis. Recent studies have demonstrated that EE can ameliorate stress-induced depressive-like behaviors. Whether hypothalamic-pituitary-adrenal (HPA) axis activity and corticosteroid receptors are involved in these effects of EE is not known. In our current study, we examined HPA axis activity and hippocampal mineralocorticoid receptor/glucocorticoid receptor (MR/GR) mRNA levels following chronic stress in rats. Our study showed that stress reduced body weight, decreased sucrose intake and sucrose preference, and increased immobility in a forced swimming test. These effects were ameliorated by EE. Also we found that 21 days of restraint stress resulted in low HPA axis activity, and a reduction of MR mRNA and MR/GR ratio in the hippocampus of rats, which was restored by EE. Thus, our current results emphasizes the efficiency of EE in the amelioration of stress-induced decrease in the mRNA expression of MR and MR/GR ratio as well as behavioral depression, providing initial evidence for a possible mechanism by which an enriched environment can restore stress-induced deficits.
Department of Neurology, Zhongnan Hospital, Wuhan University, Donghu Road 169#, Wuhan 430071, Hubei, China.
Lei
L
Zhang
Junjian
J
Zhang
Huimin
H
Sun
Hui
H
Liu
Ying
Y
Yang
Zhaohui
Z
Yao
D000818:Animals; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D003863:Depression / Q000097:blood / Q000209:etiology / Q000473:pathology* / Q000628:therapy; D004195:Disease Models, Animal; D004777:Environment; D005106:Exploratory Behavior; D005518:Food Preferences; D006624:Hippocampus / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism; D018161:Receptors, Mineralocorticoid / Q000235:genetics* / Q000378:metabolism; D018709:Statistics, Nonparametric; D013315:Stress, Psychological / Q000150:complications; D013395:Sucrose / Q000008:administration & dosage; D013549:Sweetening Agents / Q000008:administration & dosage; D013550:Swimming / Q000523:psychology; D013997:Time Factors
D018377:Neurotransmitter Agents; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D018161:Receptors, Mineralocorticoid; D013549:Sweetening Agents; D013395:Sucrose; D003345:Corticosterone