TRPC6 mediates neuronal hyperexcitability in the lateral habenula to drive trigeminal neuralgia-associated anxiety.

Persistent facial and oral discomfort, particularly trigeminal neuralgia (TN), is frequently accompanied by anxiety, which has been closely linked to increased excitability of neurons in the lateral habenula (LHb). However, the mechanisms underlying this hyperexcitability remain unclear. Here, we show that partial transection of the infraorbital nerve (pT-ION) significantly upregulated the expression of transient receptor potential canonical 6 (TRPC6), β isoform of calcium/calmodulin-dependent protein kinase II (βCaMKII), phosphorylated extracellular regulated kinase (p-ERK), and phosphorylated cyclic adenosine monophosphate response element-binding protein (p-CREB) in the LHb. Pharmacological blockade of either TRPC6 or βCaMKII effectively reversed pT-ION-induced mechanical hypersensitivity and anxiety-like behaviors. TRPC6 overexpression in the LHb reproduced the behavioral and electrophysiological phenotypes observed in pT-ION mice, including increased LHb neuronal excitability. In contrast, bilateral knockdown of TRPC6 attenuated both pain- and anxiety-like behaviors and normalized neuronal activity in the LHb. Our study identified TRPC6 as a key mediator of LHb neuronal hyperexcitability, contributing to trigeminal neuralgia-associated pain and anxiety via the βCaMKII/ERK/CREB pathway, and suggests its potential as a target for treatment.