The effects of acupuncture (PC6) on chronic mild stress-induced memory loss.

A previous study reported that the PC6 acupuncture point can alleviate chronic mild stress (CMS)-induced anxiety [17]. Following the previous study, this study examined the effects of the PC6 acupuncture point on CMS-induced memory loss. The memory storage and acetylcholinesterase (AchE) activity in the hippocampus were measured, respectively, using a passive avoidance test (PAT) and AchE immunohistochemistry. In the PAT (retention test), the CMS group showed a markedly lower latency time than the control (post (72h): P<0.01, post (96h): P<0.05, post (120h): P<0.001). However, acupuncture at PC6 significantly recovered the impairment of memory compared to the CMS group (post (120h): P<0.001). Exposure to CMS also significantly decreased the AchE activity in the hippocampus compared to the control rats. Acupuncture stimulation at the PC6 point on the pericardium channels (3min), but not at other points (TE5), produced memory improvements and an increase in AchE reactivity in the hippocampus compared to the CMS group. These results show that the acupuncture point is effective in restoring the CMS-related biochemical and behavioral impairments, such as learning and memory.