Discovery of a 'Molecular Switch' Separating Touch and Chronic Pain... Clues to Treating Intractable Pain [Reading Science]

TWIK-1 Channel: Dual Role in Tactile Sensation in the Spinal Cord and Pain Maintenance in the Periphery
Challenging Conventional Pain Modulation Concepts... A New Therapeutic Target for Neuropathic Pain

The research team at Daegu Gyeongbuk Institute of Science and Technology (DGIST) has identified a "molecular switch" that independently regulates tactile sensation and chronic pain. The team discovered that a single molecule can contribute to tactile sensation depending on its location, while also maintaining chronic pain in other locations. This finding opens up new possibilities for developing treatment strategies for intractable neuropathic pain.

On June 30, DGIST announced that Professor Hyosang Lee's neuroscience research team has identified the dual function of "TWIK-1," a potassium ion channel expressed in both the spinal cord and peripheral sensory nerves within the somatosensory system.

Schematic diagram of the mechanism and role of the TWIK-1 channel in spinal cord and sensory neurons. TWIK-1 is a type of potassium ion channel that is responsible for tactile information processing in the spinal cord and is involved in chronic pain and allodynia caused by nerve damage in peripheral sensory nerves. Provided by the research team

TWIK-1 is a potassium ion channel located in the neuronal membrane, and it regulates the flow of potassium ions in and out of cells. This control determines how easily neurons are excited and how they transmit signals. The results of this research were published in the June issue of the international journal "Signal Transduction and Targeted Therapy."

The somatosensory system is the part of the nervous system responsible for detecting touch, pain, temperature, and more. Notably, nerve damage can lead to neuropathic pain, a condition where pain persists for an extended period even without specific stimuli. Until now, the exact causes of persistent pain have not been clearly identified, limiting the effectiveness of treatments.

Tactile Sensation in the Spinal Cord, Pain Regulation in the Periphery

Through experiments using genetically engineered mice, the research team confirmed that the TWIK-1 channel regulates the activity of inhibitory neurons in the spinal cord and acts as a key molecule in processing tactile information.

In contrast, the same TWIK-1 channel in peripheral sensory nerves was found to play a role in maintaining neuropathic pain and regulating allodynia—a condition where even light touch is perceived as pain.

This demonstrates that the same molecule can perform entirely different functions within the nervous system depending on its location. The research team explained that this finding not only deepens our understanding of the mechanisms behind persistent neuropathic pain but also presents a new therapeutic target that can selectively regulate pain.

DGIST Neuroscience Research Team. (Front row from left) First, Professor Pojeong Park; second, Professor Myungin Paek; fourth, Professor Hyosang Lee; (far right) Professor Byeongchang Seo. Courtesy of DGIST

In particular, this study is significant because it provides experimental evidence to reinterpret the conventional view that potassium ion channels only suppress pain.

Professor Hyosang Lee of DGIST's Department of Neuroscience stated, "We have identified that the TWIK-1 potassium channel has distinct roles—forming tactile sensation or maintaining chronic pain—depending on its location. We hope to further elucidate the process of tactile information processing in the spinal cord and develop neuropathic pain treatments targeting TWIK-1 in the future."

This research was conducted with support from the National Research Foundation of Korea's Mid-Career Researcher Program, the Leading Convergence Brain Science Technology Development Program, and the Samsung Future Technology Development Program. Researchers from Korea University, the University of Alabama in the United States, GIST, Korea Food Research Institute, Korea Institute of Science and Technology (KIST), and Asan Medical Center in Seoul also participated in the study.

This content was produced with the assistance of AI translation services.