The enhanced analgesic effects of electroacupuncture and repetitive transcranial magnetic stimulation on visceral pain via ventral lateral septal nucleus.

Researchers have discovered how electroacupuncture (EA) and repetitive transcranial magnetic stimulation (rTMS) work together to relieve chronic abdominal pain associated with irritable bowel syndrome (IBS). IBS affects millions of people worldwide and causes persistent digestive discomfort and visceral pain that is often difficult to treat effectively. This study used a mouse model to identify a specific brain region called the ventral lateral septal nucleus (LSV) that plays a key role in processing visceral pain signals. Scientists found that painful stimulation of the intestines activated glutamate-releasing neurons in this brain area, which increased pain perception. When researchers tested EA and rTMS separately, both treatments reduced pain behaviors and decreased activity in these pain-processing neurons. However, the most significant finding was that combining EA with rTMS produced substantially greater pain relief than either treatment used alone. The treatments worked by decreasing glutamate release (an excitatory neurotransmitter that amplifies pain signals) while simultaneously increasing cannabinoid signaling (which naturally reduces pain). These complementary effects help explain why the combined approach was more effective. For patients with IBS or other chronic visceral pain conditions, this research suggests that integrating electroacupuncture with brain stimulation techniques may offer enhanced pain relief compared to single-therapy approaches. The study provides scientific evidence for specific brain mechanisms underlying acupuncture's pain-relieving effects and supports the potential benefits of multimodal treatment strategies. Patients interested in electroacupuncture for chronic abdominal pain should seek treatment from a licensed acupuncturist with experience in treating digestive disorders.

This preclinical study investigated neural mechanisms underlying electroacupuncture (EA) and repetitive transcranial magnetic stimulation (rTMS) analgesia in a mouse model of visceral pain. Researchers identified the ventral lateral septal nucleus (LSV) as a critical mediator, where visceral nociceptive stimulation significantly increased c-Fos expression predominantly in glutamatergic neurons. Optogenetic manipulation confirmed that LSV glutamatergic neuron inhibition attenuated visceral pain while activation exacerbated pain behaviors. Both EA and rTMS monotherapies reduced pain-induced c-Fos expression and pain behaviors; however, combined EA+rTMS treatment demonstrated superior analgesic efficacy compared to either intervention alone. Fiber photometry recordings revealed that both modalities decreased glutamate release while concurrently increasing cannabinoid signaling in the LSV, suggesting complementary neuromodulatory mechanisms. Clinical implications: This research provides mechanistic evidence supporting combined neuromodulatory approaches for chronic visceral pain conditions including IBS. The synergistic effect of EA+rTMS suggests potential therapeutic advantages of multimodal protocols targeting LSV glutamatergic circuits, warranting investigation in clinical populations with functional gastrointestinal disorders.