Ligand-induced LC activation in the Tg mice. A, Schematic illustration of strategy for a whole-cell current-clamp recording of a brain slice preparation. Inset shows a typical waveform of NE neurons showing a wide action potential with large afterhyperpolarization. B, Excitatory effect of 0.1% (7.3 mm) PhAc on the membrane potential of a NE neuron obtained from a Tg mouse. C, Depolarization block after excitatory response to PhAc in another neuron in a Tg mouse. D, Lack of effect of PhAc (0.2%) on the membrane potential of a neuron from a non-Tg mouse. E, Bar graphs showing the firing frequency before (pre) and after (post) PhAc application and amplitude of PhAc-induced depolarization of NE neurons in the Tg (n = 12 for firing frequency and n = 17 for depolarization amplitude) and the non-Tg (n = 4) mice. *p < 0.05 vs pretreatment in the Tg mice (paired two-tailed t test), ***p < 0.001 vs the non-Tg mice (unpaired two-tailed t test). F, Expression of IR84a/IR8a complex in HEK293 T cells transduced by a lentiviral vector. Immunohistochemistry for GFP and HA tag detected expression of the two receptor subunits. Scale bar, 50 μm. G, Bar graph showing the current amplitude in GFP⁺ (n = 14) and GFP^– (n = 11) cells. Inset shows mean current traces of the PhAc-induced inward current waveform. Solid and dotted lines indicate the waveform of GFP⁺ and GFP^– cells, respectively. **p < 0.01 versus GFP^– cells. H, Ligand dose responses of the GFP⁺ (n = 12) and GFP^– (n = 8) cells. The amplitudes of the ligand-induced currents were normalized in each cell to the amplitude at 0.01% PhAc. **p < 0.01, ***p < 0.001 versus GFP^– cells at the corresponding ligand concentrations. Data are presented as the mean ± SEM. Individual data points are overlaid.