I am a translational scientist in human somatosensation, focusing on the peripheral nervous system’s role in acute and persistent pain using microneurography (single nerve fiber recordings in awake humans) combined with targeted pharmacological and psychophysical approaches, and studies in rare patient groups. I have extensive experience in various experimental models of pain, psychophysical techniques for pain and touch, and have contributed to pharmacological (randomized controlled) trials and functional MRI and nociceptive reflex studies. I have also worked with chronic pain populations (e.g. fibromyalgia) and rare patient groups with selective deafferentation and channelopathies.
A recent focus area of my lab is understanding how the nervous system creates and modulates perceptions linked to the activation of very fast-conducting pain-sensing neurons in health and disease. The research group consists of a senior postdoc, a staff scientist, a Ph.D. student, and a research engineer.
PhD and postdoc highlights
I received my PhD and early postdoc training at Western Sydney University, Australia, where we identified that C-tactile fibers, a class of neurons that normally signals pleasant touch, contribute to touch- and cold-evoked pain (allodynia) in ‘sensitized’ pain states, highlighting the dual nature of C-tactile function (Nagi et al. 2011, J Physiology; Nagi & Mahns 2013, J Pain; Samour, Nagi, et al. 2015, PAIN; reviewed in Larsson & Nagi 2022, Curr Opin Behav Sci).
Based on my PhD work, I received the International Association of the Study of Pain (IASP) Early Career Research Grant.
I received further postdoc training here at Linköping and was instrumental in setting up a microneurography lab and introducing the technique of ultrasound-guided microneurography. In my first postdoc project at LiU, working in collaboration with Liverpool John Moores, UK, and National Institutes of Health, USA, we identified that humans, like other mammals, are equipped with an “Ultra-Fast” pain system subserved by Nociceptors (UFNs) that signal as fast as the thickly myelinated touch neurons (Nagi*, Marshall*, et al. 2019, Science Adv), questioning the validity of the dichotomous fast touch-slow pain systems in classical literature. In my second postdoc project, in collaboration with the University of Virginia, USA, and funded by Facebook, we used machine learning to find that specific peripheral sensory neurons reliably discriminate physical, social touch expressions, with accuracies comparable to perceptual judgements, and at functionally relevant timescales (Xu*, Hauser*, Nagi*, et al. Trans Affect Comput).
Recent achievements
Through molecular profile-informed microneurography based on single-cell RNA sequencing of human dorsal root ganglia (in collaboration with Pennsylvania Univ.), we have discovered novel temperature-sensing properties of several human sensory neurons, including two types of UFNs (Yu*, Nagi*, et al. Nature Neurosci, in press). Further, in ongoing work, we have identified that a distinct UFN subtype, dependent on the PIEZO2 ion channel, mediates a specific type of mechanical pain evoked by hair pulling, exhibiting conserved behavioral, neural, and molecular features across humans and mice. This work was chosen as one of fewer than 50 out of >10,500 submissions for a press conference at the 2024 Society of Neuroscience meeting. Going forward, we will study the role of the UFN system in experimental and clinical pain conditions.
Funding support
As the PI, I’ve secured funding from the Swedish Research Council (VR), successive grants from the Swedish Society of Medicine and Region Östergötland, and foundation support. I am also a co-investigator on NIH and VR grants.
Publications and conference talks
Between 2019-24, I have published >20 peer-reviewed articles and 2 conference proceedings. I delivered 13 talks at international conferences, including 2 keynotes.
PhD supervision
My first PhD student, as Principal Supervisor, graduated in 2019 and now holds a faculty position in Sydney. My second PhD student submitted their thesis in September 2024.
