A mouse model of myotonic dystrophy type 1 exhibits pain-like behavior and peripheral nociceptor hyperexcitability

Pain is a prevalent and disabling symptom of myotonic dystrophy type 1 (DM1), yet its underlying mechanisms remain poorly understood. Using HSA LR20b transgenic mice, we found multimodal mechanical and thermal hypersensitivity. Whole-cell electrophysiological recordings demonstrated depolarized resting membrane potentials and increased action potential firing selectively in small- and medium-diameter dorsal root ganglion neurons. These findings identify peripheral nociceptor sensitization as a potential mechanism contributing to pain in DM1.