Targeting 5-HT receptors and Kv7 channels in PFC to attenuate chronic neuropathic pain in rats using a spared nerve injury model.

Chronic pain remains a disabling disease with limited therapeutic options. Pyramidal neurons in the prefrontal cortex (PFC) express excitatory G-coupled 5-HT receptors (5-HTR) and their effector system, the inhibitory Kv7 ion channel. While recent publications show these cells innervate brainstem regions important for regulating pain, the cellular mechanisms underlying the transition to chronic pain are not well understood. The present study examined whether local blockade of 5-HTR or enhanced Kv7 ion channel activity in the PFC would attenuate mechanical allodynia associated with spared nerve injury (SNI) in rats. Following SNI, we show that inhibition of PFC 5-HTRs with M100907 or opening of PFC Kv7 channels with retigabine reduced mechanical allodynia. Parallel proteomic and RNAScope experiments evaluated 5-HTR/Kv7 channel protein and mRNA. Our results support the role of 5-HTRs and Kv7 channels in the PFC in the maintenance of chronic pain.