Infrared photons generated by voltage-gated sodium channel dynamics: a hypothesis for cooperative electrodynamic interactions at the axon initial segment.

Abstract

Voltage-gated sodium (NaV) channels are essential for neuronal excitability and action-potential generation, yet the electrodynamic consequences of voltage-sensor motion remain largely unexplored. Here, we propose a biophysically grounded hypothesis in which transient electromechanical dynamics of NaV-channel voltage sensors give rise to weak cooperative electrodynamic interactions at the axon initial segment (AIS). Specifically, we consider the behavior of conserved arginine gating charges within the S4 voltage-sensor segment as they traverse the hydrophobic constriction site (HCS) and charge-transfer center (CTC) during membrane depolarization. Under subthreshold conditions, local electrostatic and π-cation interactions may transiently stabilize intermediate states of S4 motion, permitting brief reversible excursions ("micro-reversals") of gating charges within the confined high-field environment of the HCS. Based on known structural properties of the voltage-sensing domain and experimentally characterized vibrational modes of the arginine guanidinium group, we propose that these micro-reversal dynamics may generate transient oscillating dipoles capable of weak electromagnetic emission in the mid-infrared range. Because NaV channels are densely organized within the AIS and occupy a subwavelength volume relative to the predicted emission wavelength, subsets of emitters may experience similar local electric fields, orientations, and transition frequencies. Under these conditions, transient phase alignment and weak field-mediated coupling among neighboring emitters could, in principle, produce extremely weak time-locked mid-infrared emission and, under conditions supporting transient cooperative emission, potentially exhibit nonclassical photon statistics. These proposed signatures are hypothetical predictions of the present framework and require experimental verification. The proposed mechanism does not require long-lived quantum coherence, sustained entanglement, or quantum computation. Rather, it provides a testable framework that links established NaV-channel biophysics with experimentally accessible electromagnetic observables. We present order-of-magnitude estimates of charge acceleration, radiated energy, and potential cooperative enhancement and outline experimentally testable predictions, including time-locked mid-infrared emission, nonclassical photon statistics, dependence on AIS organization, and sensitivity to pharmacological or genetic perturbation of NaV-channel function. Collectively, these predictions provide a basis for evaluating whether transient cooperative electrodynamic interactions occur during neuronal activity and, if so, whether they have any functional relevance for neural information processing, including feature integration, perceptual awareness, or voluntary motor control.