Insular muscarinic signaling regulates anxiety-like behaviors in rats on the elevated plus-maze.
Anxiety is one of the most prevalent neuropsychiatric disorders, and little is known about its pathogenesis. In order to investigate the neural mechanisms of this mental disorder, we used rat behavior in the elevated plus-maze as an animal model of anxiety and the insular cortex (insula) as a brain target. The microinjection of non-selective and selective M1 and M4 muscarinic acetylcholine receptor (mAChR) agonists or antagonists was used to explore whether the insular muscarinic receptor and its subtypes regulate levels of anxiety. The results showed that both non-selective and selective M1 and M4 mAChR agonists increased the time spent on exploring in the open arms, whereas antagonists decreased exploration. Our results indicate that activation of insular mAChRs could produce anxiolytic effects, whereas inhibition of insular mAChRs could increase anxiety. We concluded that the insular muscarinic system plays a role in the modulation of anxiety, and dysfunction of mAChR signaling may be involved in the mechanism of anxiogenesis.
National Institute on Drug Dependence, Peking University, Beijing 100191, China.
Hui
H
Li
National Institute on Drug Dependence, Peking University, Beijing 100191, China.
Lei
L
Chen
School of Chinese Meteria Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
Peng
P
Li
School of Chinese Meteria Medica, Beijing University of Chinese Medicine, Beijing 100102, China.
Xiaohong
X
Wang
National Institute on Drug Dependence, Peking University, Beijing 100191, China. Electronic address: zhaihf@hsc.pku.edu.cn.
Haifeng
H
Zhai
D000818:Animals; D001007:Anxiety / Q000188:drug therapy* / Q000523:psychology*; D001522:Behavior, Animal; D002540:Cerebral Cortex / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008845:Microinjections; D018721:Muscarinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043643:Receptor, Muscarinic M1 / Q000819:agonists / Q000037:antagonists & inhibitors; D043588:Receptor, Muscarinic M4 / Q000819:agonists / Q000037:antagonists & inhibitors
D018721:Muscarinic Agonists; D018727:Muscarinic Antagonists; D043643:Receptor, Muscarinic M1; D043588:Receptor, Muscarinic M4
Anxiety; Elevated plus-maze; Insula; Muscarinic acetylcholine receptor