By mapping the molecular effects of electroacupuncture in mice with fibromyalgia, a research team suggested that the molecule ASIC3 might be a suitable target for the development of treatments for pain sensitivity in fibromyalgia.
The experiments, led by a research team at China Medical University in Taiwan, also showed that the molecular pathways modulated by electroacupuncture involved opioid and adenosine receptors — known players in pain signaling.
By explaining how electroacupuncture controls pain on a molecular level, the research may pave the way for more targeted treatments for fibromyalgia pain.
The study, “Targeting ASIC3 for Relieving Mice Fibromyalgia Pain: Roles of Electroacupuncture, Opioid, and Adenosine,” particularly focused on mechanical hyperalgesia — the scientific term for increased pain sensitivity to touch. The work was published in the journal Scientific Reports.
ASIC3 (acid-sensing ion channel 3) is a cellular ion channel that senses acid levels and has been linked to pain in earlier research. Since electroacupuncture is often used to relieve pain, the research team investigated if the molecular component was involved in the actions of the method.
Their experiments with electroacupuncture in a mouse model of fibromyalgia showed that indeed, it was. When the researchers injected a salt solution into a calf muscle, nothing happened. But when the salt solution was acidic, the mice developed pain sensitivity, which lasted longer after repeated injections.
The pain sensitivity was relieved after four days of electroacupuncture. The team also noted that when they blocked opioid and adenosine receptors at the site of acupuncture, the method did not improve the mice’s sensitivity to pain.
The same thing happened when they tested mice that lacked ASIC3, or used drugs that blocked the acid sensor.
When the team instead treated the mice with drugs that stimulated the opioid and adenosine receptors, they observed similar benefits to those seen when using electroacupuncture.
Examining other molecular factors offered them an even more detailed picture of what was going on with molecules in the spinal cord and brains of the mice. The researchers were able to build a map of molecular players in the brain and spinal cord that could be targeted to relieve pain sensitivity.
Several earlier studies showed that electroacupuncture reduces fibromyalgia-related pain, and a recent review of previously published studies recommended the method for pain relief in fibromyalgia. Now, the new research explains how the method can control pain.