CHRNA4 and neuropathic pain: For this reason, the present study was designed to observe the effect of EAS at different frequencies on pain behaviors and expressions of hippocampal muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) in CCI-induced neuropathic pain rats, thereby, to better our understanding on the mechanism of acupuncture in the management of neuropathic pain.