Auricular acupuncture attenuates neuronal damage in kainic acid-induced epilepsy related to mGluR5 and GABAA receptor alpha1 subunit modulation.

Epilepsy affects over 50 million people worldwide, with more than one-third developing drug-resistant forms. While acupuncture is increasingly utilized for seizure management, its molecular mechanisms remain poorly understood. This study investigated the neuroprotective effects of auricular electroacupuncture (EA) in a kainic acid (KA)-induced rat model of epilepsy. Rats received EA at the heart (CO15) and liver (CO12) acupoints at 2 Hz or 15 Hz for three consecutive days. Although acute seizure behaviors remained consistent across treatment groups-ensuring a homogenous baseline of seizure insult-both EA frequencies significantly reduced KA-induced neuronal apoptosis in the hippocampal CA1, CA2, and CA3 subfields (p < 0.05). Western blot and immunohistochemical analyses showed marker-specific and region-specific changes after EA treatment, including increased hippocampal mGluR5 expression and increased dentate gyrus staining for mGluR5 and GABAA receptor alpha1 subunit. Our findings suggest that auricular EA exerts neuroprotective effects appearing to strengthen the dentate gate and restoring the hippocampal excitatory-inhibitory balance, which might involve mGluR5 and GABAA receptor alpha1 subunit modulation. These results could provide a mechanistic foundation for auricular stimulation as a potential non-pharmacological strategy for drug-resistant epilepsy.