Touch may become a complement in pain care
Many people today live with persistent pain that healthcare finds difficult to alleviate. But a new path is starting to emerge—one that runs through the skin and the signals of pleasant touch.
At the heart of this new approach are C-tactile fibers—specialized nerve fibers in the skin that don’t transmit pain, but rather convey sensations of comfort and well-being. These fibers respond specifically to slow, gentle touch and are believed to play a key role in feelings of safety, relaxation, and social connection.
Line Löken, associate professor at the Institute of Neuroscience and Physiology at the University of Gothenburg, is one of the leading researchers exploring how these nerve fibers work.
“The signals we register through the skin aren’t just relevant to pain. We actually have a whole system of nerve fibers whose role seems to be communicating positive sensations of well-being. These signals also appear to influence the brain in ways that we believe could help ease pain,” says Line Löken.
A robot for precise touch
The research now shaping a potential new direction in pain treatment has been underway for decades. Line Löken’s interest in neuroscience and the tactile system of the body led her to pursue a PhD in a research team at the University of Gothenburg, working with the microneurography method under the supervision of Håkan Olausson and Johan Wessberg. Her discovery—that our nervous system is designed to register pleasurable touch—opened up a completely new field of study.
In collaboration with partners in the UK, the team gained access to a specially designed robot that gently stroked participants' arms while a needle inserted into a C-tactile nerve fiber recorded its signal. The robot allowed the researchers to deliver precise, consistent, and highly controlled touch—something essential when trying to understand how different types of nerve fibers respond.
“We saw clear patterns in nerve activity. The fibers were activated by soft touch moving slowly—between one and ten centimeters per second—which is typically perceived as pleasant,” says Line Löken.
Nerve pathways and brain circuits
Microneurography showed a strong link between nerve activity and how pleasant the touch felt. But what was happening in the brain—and why did the same regions light up in response to both pain and pleasure?
After several years of studying advanced brain imaging techniques in Oxford, Line Löken moved to San Francisco to conduct experiments in genetically modified mice, specially bred to help researchers answer questions about neural circuits. These animal studies allowed for a detailed examination of how signals travel through nerve pathways and how brain cells respond. This helped her begin to uncover how different areas of the brain process touch—and how those signals shape our sensory experiences.
“Since returning to Gothenburg and establishing my research group in neurophysiology in 2022, we’ve continued tracing the nerve pathways and brain circuits activated by touch, using advanced mouse models. Our goal is to understand how these circuits interact with the brain’s pain networks. If we could use that knowledge in healthcare—as part of pain rehabilitation—it could really make a difference,” she says.
Research on C-tactile fibers has already had an impact in palliative care. Scientific findings show that touch can reduce anxiety and distress while enhancing overall well-being, providing a strong foundation for including touch in caregiving.
Prescribing hugs
The clinical focus of Line Löken’s group is now being further strengthened through an upcoming PhD project in collaboration with senior university hospital physician Paulin Andréll. Mika Evert, a specialist in pain management at the Pain Center/AnOpIVA Östra, will systematically study how individuals with persistent pain perceive touch.
“Many patients don’t benefit from medication alone. In persistent pain care today, we often use non-pharmacological methods aimed at ‘retraining’ the hypersensitive pain system and breaking negative behavioral patterns,” says Line Löken.
The purpose of the project is to explore whether touch can play a role in pain rehabilitation, and to better understand the altered sensitivity that often occurs with persistent pain—does it also affect how pleasant touch is experienced? The hope is that the findings will show whether touch can be used as a complementary element in pain care—a kind of “prescribed hug.”
“We’ve made great strides in basic research. There’s still a lot to learn, but we’re starting to understand more about how the brain reacts to touch—and now we want to move forward and see what that could mean for people living with pain,” says Line.
Microneurography is a technique that allows researchers to record electrical activity from individual nerve fibers in awake human subjects. The method was developed in the 1960s by Åke Vallbo and Karl-Erik Hagbarth and has become an important tool in neurophysiological research—particularly for studying touch and pain. As a professor at the University of Gothenburg, Åke Vallbo played a central role in establishing the method as a robust research tool. It continues to be used and further developed today.
