P2X7 receptors in the auditory nerve: current insights into their localization and functional significance
DOI:
https://doi.org/10.12775/JEHS.2026.95.77242Keywords
P2X7 receptor, purinergic signalling, auditory nerve, cochlea, spiral ganglion, Schwann cells, satellite glial cells, neuroinflammation, sensorineural hearing lossAbstract
Purinergic signalling has emerged as one of the fundamental mechanisms of intercellular communication that regulates numerous physiological and pathological processes in both the central and peripheral nervous systems. Among purinergic receptors, the P2X7 receptor has attracted particular attention because of its unique structural and functional properties, including its activation by high extracellular ATP concentrations, its ability to form large membrane pores during prolonged stimulation, and its central role in neuroinflammatory responses. Recent advances in auditory neuroscience have demonstrated that purinergic signalling is widely distributed throughout the cochlea and auditory nerve, where it contributes to the regulation of sensory transmission, ion homeostasis, intercellular communication, and adaptive responses to acoustic stimulation. However, the precise cellular localization of P2X7 receptors within the auditory system has long remained controversial.
Recent studies employing transgenic animal models, high-resolution immunohistochemistry, electrophysiological recordings, and calcium imaging have substantially refined our understanding of P2X7 receptor expression and function in the peripheral auditory system. Current evidence indicates that these receptors are predominantly expressed by Schwann cells and satellite glial cells of the spiral ganglion, although their expression has also been demonstrated in specialized type II spiral ganglion neurons involved in cochlear protective responses.
This review summarizes current knowledge of the molecular characteristics of P2X7 receptors, their distribution within the inner ear, their role in neuron–glia communication and neuroinflammatory processes, and their emerging functions in auditory physiology and pathology. Particular attention is given to recent experimental findings that have reshaped current concepts of P2X7 receptor function and highlighted its potential as a promising therapeutic target for sensorineural hearing disorders.
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