High-Throughput Characterization of Chemical Modulation in Visceral Sensation and Nociception
Nicholas Deierlein
PhD Student Biomedical Engineering
University of Connecticut
Friday, March 13, 2026 10:45am – 11:45am; PWEB 150
Abstract:Visceral pain in irritable bowel syndrome (IBS) arises from nociceptive signaling by colorectal afferent neurons, which are primarily activated by mechanical distension rather than overt inflammatory stimuli. To determine how the intestinal chemical environment modulates afferent encoding of mechanical stimuli, we performed high-throughput calcium imaging of 1,040 colorectal afferents in dorsal root ganglia from VGLUT2-Cre;GCaMP6 mice using an ex vivo colorectum–nerve–DRG preparation during zymosan-induced visceral hypersensitivity along with intraluminal chemical stimuli. Based on experimental observations, afferent responses are categorization into five functional classes based on mechanical and chemical response profiles. More than 50% of afferents were directly chemosensitive or chemically sensitized—substantially higher than prior electrophysiological estimates (~24%). Zymosan increased the total number of responsive afferents in males, whereas females exhibited a selective increase in the proportion of chemosensitive afferents. These findings demonstrate that colorectal mechanosensitivity is strongly shaped by the luminal chemical milieu and that sex is a key determinant of afferent sensitization, providing a population-level framework for visceral hypersensitivity in IBS.
Biography: Nicholas Deierlein is a fifth-year Ph.D. candidate in Dr. Bin Feng’s Neurophysiology and Pain Research (NPR) Laboratory. He earned his B.S. in Biomedical Engineering with a concentration in biomechanics from the University of Connecticut in 2021. His research focuses on functional characterization of visceral sensory neurons using GCaMP6s-based optical imaging of mouse dorsal root ganglia. He specializes in applying high-throughput calcium imaging approaches to classify colorectal afferents and investigate mechanisms of acute sensory plasticity. His work has contributed to the development of a novel protocol for profiling rapid changes in afferent neural responses to intraluminal chemical stimuli.
For additional information, please contact Dr. Visar Ajeti or Darcy Richard
