Fig. 2

Increases of the excitability of nociceptive cold-sensing trigeminal neurons by inhibiting KCNQ channels. a An example shows that blocking KCNQ channels by linopirdine (20 µM) enhances excitability of nociceptive cold-sensing TG neurons. b Summary of the changes of resting membrane potentials (RMP) following the application of 20 µM linopirdine (n = 8). c Summary of the changes of rheobase for action potential firing following the application of 20 µM linopirdine (n = 7). d Behavioral cold hypersensitivity induced by linopirdine. Orofacial operant tests were performed at 12°C following the subcutaneous injection of saline or 0.39 mg linopirdine in oral facial regions. The linopirdine-injected animals (n = 4) show a significant reduction of total contact time in comparison with saline controls (n = 4). Data represent Mean ± SEM, *P < 0.05, **P < 0.01.