Effect of Electroacupuncture on the Activity of Corticotrophin-Releasing Hormone Neurons in the Hypothalamus and Amygdala in Rats Exposed to Restraint Water-Immersion Stress

Abstract

Objective To investigate the effects of electroacupuncture (EA) treatment on gastric mucosal lesions and the activity of corticotrophin-releasing hormone (CRH) neurons in the paraventricular nucleus (PVN) of the hypothalamus and the central nucleus of the amygdala (CNA) in a rat model of restraint water-immersion stress (RWIS). Methods 24 male Wistar rats were randomly divided into three groups: normal, RWIS, and RWIS+EA (n=8 per group). Rats in the RWIS group and RWIS+EA group received RWIS for 3 hours. For rats in the RWIS+EA group, EA was applied at ST36 in the bilateral hind legs for 30 min before RWIS. Rats in the normal group did not receive stressors or EA treatment. The gastric mucosal lesions of each rat were evaluated by the erosion index (EI) according to the methods of Guth. The activity of CRH neurons in the PVN and CNA was measured by a dual immunohistochemical test for Fos and CRH in the brain sections. Results RWIS induced serious gastric mucosal lesions. The mean gastric EI was significantly decreased in the RWIS+EA group versus the RWIS group (P=0.005). Stress induced significant activation of CRH neurons in the PVN and CNA compared with the normal group (P<0.001 for both). The mean number of Fos+CRH immunoreactive neurons in the PVN and CNA were both decreased inRWIS+EA versusRWIS groups (P<0.001 and P=0.001). Conclusions EA at ST36 can ameliorate RWIS-induced gastric mucosal lesions and suppress the Fos expression of CRH neurons in the PVN and CNA, suggesting a potentially therapeutic role for EA in stress-related gastric disorders.