Shaping the Action Potential in Dorsal Root and Trigeminal Ganglia Neurons: Relevance to Pain Mechanisms

Sensory neurons of the dorsal root ganglia (DRG) and trigeminal ganglia (TG) are critical for transmitting somatosensory information, including pain, to the central nervous system. In these neurons, as in other neurons, the shape of the action potential (AP) is a key determinant of excitability and signal transmission and is governed by the coordinated activity of voltage-gated sodium (Na V ), potassium (K V ), calcium (Ca V ), and calcium-activated potassium (BK) channels. This review synthesizes current knowledge about how these ion channels shape AP waveform and influence neuronal function across diverse DRG and TG subtypes. We outline the distinct expression patterns, intrinsic properties, and physiological roles of channel subtypes based on available data from the literature, emphasizing their influence on AP waveform shape. We discuss how ion channel dysregulation contributes to neuropathic and inflammatory pain and explore emerging therapeutic strategies, including novel analgesics like suzetrigine. By integrating electrophysiological, molecular, and computational insights, this work underscores the importance of ion channel modulation in advancing pain research and treatment.