Lateral habenula lesions improve the behavioral response in depressed rats via increasing the serotonin level in dorsal raphe nucleus.
The dorsal raphe nucleus (DRN)-serotonin (5-HT) system plays a key role in stress-related psychiatric disorders such as anxiety and depression. The habenular nucleus (Hb) is closely connected with the DRN both morphologically and functionally. Here, we used two types of depressive animal models by exposing rats to chronic mild stress (CMS) and by chronically administering the tricyclic antidepressant clomipramine (CLI) in the rat during the neonatal state of life to produce adult depressed rats. We investigated the effects of lateral habenular nucleus (LHb) lesions on the behavioral response and on the level of 5-HT in DRN in the depressed rats. Forced-swimming test (FST) showed that the immobility time decreased, and the climbing time increased after lesioning LHb of depressed rats. Microdialysis results indicated that the 5-HT level in DRN in depressed rats was lower than that of the control group. Lesion of the LHb was followed by an increased 5-HT turnover in the DRN. Our results suggested that the lesion of the LHb could improve the behavioral response of the depressed rats and the 5-HT level of the DRN increased by LHb lesions could be involved in the effects.
Yang
Li-Min
LM
Department of Physiology, School of Basic Medical Sciences, Jilin University, 2 Xinmin Street, Changchun 130021, China.
Hu
Bing
B
Xia
Ying-Hong
YH
Zhang
Bei-Lin
BL
Zhao
Hua
H
D000818:Animals; D000928:Antidepressive Agents; D002908:Chronic Disease; D002997:Clomipramine; D003866:Depressive Disorder / Q000139:chemically induced / Q000209:etiology / Q000503:physiopathology*; D004195:Disease Models, Animal; D019262:Habenula / Q000502:physiology* / Q000503:physiopathology; D046353:Immobility Response, Tonic / Q000502:physiology; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D011903:Raphe Nuclei / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D013315:Stress, Psychological / Q000150:complications / Q000378:metabolism*
D000928:Antidepressive Agents; D012701:Serotonin; D002997:Clomipramine