Fig. 1.

Dexmedetomidine induces an outward current in a concentration-dependent manner in SG neurons. (A) Outward currents induced by dexmedetomidine (0.1, 1 and 10 μm). Duration of drug superfusion is shown by horizontal bars above chart recordings. Holding potential = −70 mV. (B) Relative peak amplitude was calculated as an amplitude of the dexmedetomidine (0.1–30 μm)-induced current divided by that of the current produced by dexmedetomidine (30 μm). The continuous curve was drawn according to the Hill plot with an EC₅₀ value of 0.62 μm (95% confidence interval, 0.51–0.77 μm) and a Hill coefficient of 1.34. The number next to each point denotes the number of neurons examined. Holding potential = −70 mV. (C) Outward currents elicited by dexmedetomidine (0.03 μm) in the absence and presence of TTX (1 μm). These currents were obtained from the same neuron (n= 5). Holding potential = −40 mV. (D) Relative peak amplitude was calculated as an amplitude of dexmedetomidine-induced current in the presence of TTX (5.3 ± 1.3 pA) divided by that of currents produced by dexmedetomidine (5.6 ± 1.4 pA) without TTX.