Touch, Pain and Interoception in Somatosensory and Cancer Neuroscience

24.04.2026, Friday, 11:30-13:00

General focus of the symposium:

Sensory systems of the body inform the brain on the multitude of different stimuli that come from the environment as well as from the inside. Somatosensory neuroscience is currently going through a transformative period in which we witness the emergence of technologies that allow for precise dissection of neural pathways transmitting sensory information. This is possible due to unprecedented ability to integrate anatomical, genetic and functional data on primary afferents as well as central neurons that together form circuits of touch, pain and internal feelings. Moreover, we are beginning to pinpoint mechanisms by which different elements of these circuits are able to modulate one another as a mean of maintaining homeostasis. The goal of this symposium is to highlight research that uncovers the organizational logic of painful and innocuous bodily sensations and how neural systems that process different sensory modalities affect internal states and behavior. Studies discussed here utilize state-of-the-art physiological and anatomical approaches in transgenic mouse models in pursuit of in-depth investigations on structure and function of painful, interoceptive and tactile signalling pathways. This allows for new insights on important topics, such as identity of neurons forming ascending pain pathways in the spinal cord, top-down modulation of bone cancer pain and tumor progression, hierarchical organization of peripheral nociceptive and interoceptive pathways and assessment of neurons of touch regulating sexual behavior.

Chair: Felipe Meira de-Faria (Linkoping)

11:30 Andrew Bell, PhD

School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK; School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, UK

"The Architecture of Pain: Molecular and Anatomical Insights into the Anterolateral System"

The anterolateral system (ALS) is a major ascending pathway from the spinal cord that projects to multiple brain areas. Activity in the projection neurons of the ALS underlies the perception of pain, itch, and skin temperature, and this tract therefore represents an attractive target for novel analgesics. Despite its importance, our understanding of this system has been hampered by the considerable functional and molecular diversity of its constituent cells. In particular, we have a poor understanding of how different classes of neuron within this heterogeneous pathway transmit diverse sensory modalities and drive the dimensionality of pain. Dr Andrew Bell will present recent work using single nucleus RNA sequencing to reveal the molecular architecture of the ALS in mice. The session will explore how to target specific neuronal subsets of these cells in transgenic mice and how this can permit investigation of their distinct projectome and function.

12:10 Mateusz Kucharczyk

 Cancer Neurophysiology Research Group, Łukasiewicz Research Network–PORT Polish Centre for Technology Development, Wrocław, Poland; Biophotonics and Electrophysiology Laboratory, Center for the Development of Therapies for Civilization and Age-Related Diseases, Jagiellonian University Medical College, Kraków, Poland; Wolfson Sensory, Pain, and Regeneration Centre, King’s College London, London, United Kingdom

"Gathering the periphery: Descending control of sensory input in pain and cancer."

Descending neuronal pathways shape somatosensation by regulating spinal circuits and primary sensory neuron activity, enabling the brain to modulate afferent signal flow and influence peripheral tissues through neurogenic mechanisms. Our laboratory integrates somatosensory neuroscience with cancer biology to investigate how these pathways contribute to tumorigenesis and cancer-associated pain. Using in vivo electrophysiology and calcium imaging combined with selective opto- and chemogenetic modulation of genetically and anatomically defined circuits, we record spinal and peripheral neuronal activity and relate it to behaviour through machine-learning–assisted analysis. This systems-level approach aims to link network-wide dynamics with top-down control of nociception and tumour progression. Dr. Kucharczyk will illustrate how descending pathways regulate spinal projection neurons and presynaptic terminals of primary afferents, including peptidergic and silent nociceptors in cancer-induced bone pain. He will also discuss neurogenic inflammation and introduce fiber-type–specific functional imaging strategies that reveal new opportunities to modulate nociceptive transmission through defined spinal and supraspinal pathways.

12:23 Gabriela Basile Carballo, MSc

BKV/CSAN, Linköpings Universitetet, Linköping, Sweden

"Hierarchical organization of mechano-nociceptive pathways revealed by activity labeling"

Nociception safeguards organisms from external injury and internal tissue damage by detecting and distinguishing harmful stimuli, and encoding their intensity and location, thereby driving adaptive behavioral and homeostatic responses. However, the relationship between specific function and molecular identity across nociceptors remains poorly understood.

Here, we mapped the peripheral architecture of nociceptive signaling by combining in vivo activity labeling of pelvic nerve afferents with single-cell RNA sequencing to understand how different classes of nociceptors encode interoceptive signals.

To create a reference atlas, freshly dissociated cells in L5-S1 DRGs from adult C57BL/6Jrj mice were manually collected and sequenced using the Smart-Seq3 method. To label noxious stimuli-activated cells, we used animals that expressed the photoconvertible calcium reporter CaMPARI2A series of nociceptive stimuli was delivered, while DRGs were exposed to conversion-inducing UV-light, fluorescently labeling activated neurons. Labelled cells were sequenced and embedded in the control cell atlas.

We developed a cell atlas with 1037 manually sorted neurons and detected 10,000 genes per cell. Sequencing of 2.997 labelled cells revealed that while nociceptive stimuli activated multiple neuronal classes, some were specific to visceral nociceptive signals. For C- nociceptors, Adra2a cells were abundant among colon-innervating neurons but nearly absent among skin-innervating populations. A-nociceptors showed clear target-specific specialization, with Adm cells preferentially responding to colorectal stroke and anorectal distension. Moreover, we identified a subpopulation of Adm neurons, marked by the Uts2b+ gene, that relates to physiological bladder stimulation specifically.

These findings reveal a hierarchical organization of peripheral mechanical pain encoding, in which increasingly specialized mechano-nociceptor populations are differentially engaged according to tissue domain and organ context.

12:36 Marek Brodzki, PhD

Center for Social and Affective Neuroscience, Department of Clinical and Biomedical Sciences, Linköping University, Linköping, Sweden

"Bridging identity and function of vaginal afferents uncovers C-LTMR control of female sexual behavior"

Sensation of touch has a complex role in sexual behavior, as it carries both tactile and emotional information, which is underlined by extremely high innervation density of genital organs by touch neurons. While previous reports indicate particular neuron types to be important for sexual behavior, the general organization of how the rich sexual experience is encoded across molecularly defined neuronal classes is unknown, especially in females.

This study aims to elucidate the functional landscape of cells that innervate female genitalia and to pinpoint the molecularly defined neuronal types that sense and control behavioral responses that are vital for reproduction.

We use anatomical assessment of nerve endings of perineal skin and genitals, in vivo calcium imaging in transgenic mice, functional labelling of neurons activated by naturalistic vaginal stimulation combined with single-cell RNA sequencing, and sexual behavior assays in animals with conditional neurotransmission block.

We find that the murine female genital organs are innervated by both myelinated and unmyelinated fibers, but it is the C-low threshold mechanoreceptors (C-LTMRs) that are most robustly responding to the stimulation of the perineum and the inside of the vagina. Moreover, we show that these neurons directly regulate behavior of female mice during coitus, by regulating their sexual receptivity.

Together, our findings identify C-LTMRs as key mediators of vaginosensation that regulates sexual behavior. These results provide a comprehensive survey of vaginal innervation and help understand the neural basis of touch that underlies mammalian reproduction.

12:49 Aleksandra Herman

Laboratory of Brain Imaging, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur Str,. 02-093 Warsaw, Poland

"When body-brain communication goes awry: Embodiment of emotions and states in nociplastic pain"

Pain is a complex, multisensory phenomenon with sensory, emotional, and motivational components. Nociplastic pain, a type of chronic pain, arises from altered nociception without clear tissue damage or nervous system lesions. In these conditions, the brain may misinterpret body signals, making pain maladaptive. Little is known, however, about whether altered body-brain communication extends to misattributing emotions as pain.

Using a cross-sectional design, we investigated how individuals with nociplastic pain perceive, identify, and interpret emotions and bodily sensations compared to pain-free controls.

Across two studies, individuals with nociplastic pain and matched pain-free controls completed the emBODY task, mapping bodily sensations for emotional, neutral, pain-, and fatigue-related states. Participants also completed measures of alexithymia, bodily sensation interpretation, and interoception.

Linear discriminant analysis showed that classification accuracy of body sensation maps was lower in the nociplastic pain group. Compared with controls, they had higher alexithymia, greater awareness of bodily signals, more negative interpretations of ambiguous sensations, and self-reported interoceptive difficulties.

Findings indicate amplified perception of bodily signals, reduced differentiation of emotions and non-emotional states, and interoceptive difficulties in nociplastic pain. Interventions targeting perception, differentiation, and interpretation of bodily sensations may improve pain symptoms and daily functioning.