Newswise — Hyperalgesia refers to an increased sensitivity to pain. It can occur during alcohol withdrawal, and may contribute to a relapse to drinking. Alternative therapies such as acupuncture and electroacupuncture (EA, which combines acupuncture with electrical stimulation) are effective in reducing pain and, possibly, alcohol-withdrawal symptoms. This rodent study investigated whether EA can alleviate hyperalgesia during alcohol withdrawal, potentially reducing the risk of a relapse to drinking, and whether it achieves this effect via action at mu opioid receptors (MORs) located in a brain region called the lateral habenula.
Researchers trained male rats to drink alcohol for eight weeks, after which they discontinued the alcohol supply, which led to withdrawal symptoms, including hyperalgesia. To assess whether EA alleviated the hyperalgesia, they measured pain sensitivity using radiant heat (a light beam directed at the hind paw of each rat) and measured paw withdrawal latencies to the light stimulation, with and without EA.
The study showed that EA can lessen hyperalgesia during alcohol withdrawal, and that the effect may involve MORs in the habenula. Although obtained in rodents, the findings suggest that EA is a potential therapy for hyperalgesia in humans. If shown to be effective in humans, the use of EA to alleviate pain symptoms associated with alcohol withdrawal could potentially lessen the chances of a relapse to drinking in these individuals.