Alcohol-induced neuropathy associated downregulation of Kv7 channels in primary nociceptors

Chronic alcohol consumption is a well-known risk factor for peripheral neuropathy, often presenting with thermal hyperalgesia and mechanical allodynia. While the involvement of dorsal root ganglia (DRG) neurons in alcohol-induced neuropathy (AIN) is recognized, the molecular mechanisms-particularly the role of Kv7-KCNQ potassium channel remains insufficiently understood. This research focused on evaluating the impact ofchronic alcohol exposure on Kv7 channel function and gene expression in DRG neurons, focusing on the KCNQ2 and KCNQ5 subunits.A rat model of AIN was established via oral gavage administration of 35 % ethanol (10 g/kg, twice daily) for 10 weeks. Pain hypersensitivity was evaluated using the electronic von Frey and Hargreaves tests. Quantitative real-time PCR was used to evaluate the mRNA expression of KCNQ2 and KCNQ5 channels. M-current (IM) density and neuronal excitability were assessed through whole-cell voltage-clamp and current-clamp recordings, respectively.Chronic ethanol exposure significantly reduced both mechanical and thermal thresholds, confirming the development of neuropathic pain. We observed a marked downregulation in the mRNA expression of KCNQ2 and KCNQ5 subunits, accompanied by a diminished M-current density within DRG neurons. These alterations were linked to increased neuronal excitability and heightened pain sensitivity in rats exposed to ethanol.These findings demonstrate that AIN is marked by a significant downregulation of KCNQ2 and KCNQ5 channel expression and function, contributing to elevated neuronal excitability and the onset of thermal hyperalgesia and mechanical allodynia. The suppressed activity of KCNQ/M channels within DRG neurons of AIN rats highlights Kv7 channels as promising molecular targets for AIN therapy.