Potassium voltage-gated channel subfamily Q (Kv7) (Kv7)

Kv7 voltage-gated potassium channels, primarily composed of subunits Kv7.2 (KCNQ2), Kv7.3 (KCNQ3), and Kv7.5 (KCNQ5), are essential regulators of excitability in nociceptive dorsal root ganglion (DRG) neurons [1, 2]. These channels generate the M-current, a subthreshold, non-inactivating outward potassium current that stabilizes the resting membrane potential and serves as a physiological brake against repetitive action potential firing [7, 10]. In pathological states such as neuropathic, inflammatory, and bone cancer pain, the expression and functional activity of these channels are frequently downregulated, leading to neuronal hyperexcitability and the transmission of ectopic pain signals [3, 6, 15]. Pharmacological activators, or openers, such as retigabine and flupirtine, enhance the M-current to hyperpolarize nociceptors and provide potent analgesia in preclinical models [4, 11]. Despite their efficacy, the clinical use of early Kv7 activators has been restricted by systemic safety concerns, including CNS depression, urinary retention, and tissue-specific toxicities [4, 12]. Consequently, current therapeutic development focuses on subunit-selective modulators and gene therapies designed to target these channels specifically within the peripheral pain pathway [12, 16].

Other names

KCNQ channelsM-channelsM-current channelsNeuronal Kv7 channels

Pharmacological activation of Kv7 channels enhances the M-current, which hyperpolarizes the resting membrane potential of nociceptive neurons and reduces their firing frequency, thereby attenuating the transmission of pain signals to the central nervous system.