Voltage-gating and neuronal signalling in neurodegeneration: From neuropathology to therapeutic opportunities in motor neuron disease.

Voltage-gated ion channels (VGICs) are central to motor neuron excitability, governing the initiation and propagation of action potentials and synaptic transmission. Disruption of their finely tuned gating properties contributes to pathology-associated hyperexcitability, a hallmark of several neurodegenerative conditions, including motor neuron disease (MND). In this review, we examine the physiological roles of voltage-gated sodium, calcium and potassium channels in motor neurons, and evaluate how mutations, altered expression, aberrant biophysics, and maladaptive signalling impair the voltage signalling processes that drive and underlie neuronal dysfunction and degeneration. We synthesize evidence linking ion channel dysfunction to altered excitability, excitotoxicity, impaired neurotransmission, motor system instability and progressive motor neuron loss in MND, and discuss current therapies that offer modest benefit and may act directly or indirectly on neuronal excitability but with limited target specificity. Motivated by the the urgent need for effective treatments for MND, we discuss emerging strategies that leverage highly selective VGIC modulators, particularly gating-modifier peptides inhibitors, to counteract hyperexcitability in MND. We further highlight that understanding how voltage-sensing and channel gating are altered in MND offers new avenues for selective targeted intervention. Together, the evidence supports VGICs as critical yet poorly explored therapeutic targets for halting motor neurodegeneration.