Electroacupuncture stimulation of auricular concha region improves loss of control over stress induced depression-like behavior by modulating 5-hydroxytryptamine 1A receptor.

Abstract

Objective: To observe whether electroacupuncture stimulation of auricular concha region (EA-ACR) on behavior changes of depression by loss of control over stress model (LOC), and whether its effect is improved by regulating the expression levels of hydroxytryptamine (serotonin, 5-HT) 1A receptor (5-HT_1AR)/ hydroxytryptamine (serotonin, 5-HT) 2A receptor (5-HT_2AR) in hippocampus.

Methods: LOC was prepared using a Skinner box, and EA-ACR to observe behavioral changes, and Western Blot was used to detect the changes of 5-HT_1AR/5-HT_2AR in the hippocampus, and then observe the changes of EA-ACR behavior after microinjection of 5-HT_1AR/5-HT_2AR antagonist into the hippocampus.

Results: EA-ACR improve depressive-like behavior, up-regulated 5-HT_1AR expression and down-regulated 5-HT_2AR expression in hippocampal brain area. EA-ACR did not improve depression-like behavior after hippocampal microinjection of 5-HT_1AR antagonist, while injection of 5-HT_2AR antagonists can improve depression-like behaviors.

Conclusion: EA-ACR can improve depressive-like behaviors. Loss of control over stress leads to up-regulation of 5-HT_1AR and down-regulation of 5-HT_2AR in the hippocampus, while EA-ACR mainly improves depressive behavior by regulating 5-HT_1AR in Hip.