Figure 4. CMS decreased I_h currents in VTA dopamine neurons that project to the lateral shell of the NAc (LAcbSh).

(A) Left: Voltage protocol for recording I_h current. Right: Representative I_h current recorded from NAc-projecting VTA dopamine neurons in control and CMS mice. (B) Compared with the control group, I_h amplitude was significantly decreased in the CMS group at corresponding hyperpolarization potentials (*p<0.05, **p<0.01, ***p<0.001, control, n = 15 cells from five mice; CMS, 13 cells from three mice from B to G). I_h amplitude was calculated by subtracting the instantaneous current from the steady-state current achieved during the voltage step. (C) The membrane capacitance (C_m) was not significantly different between control and CMS mice (p=0.273). (D) I_h current density was significantly decreased in the CMS group compared with the control group (**p=0.009). (E) I_h activation curves in the control and CMS groups generated by the tail current protocol. Tail current amplitudes were fitted with a Boltzmann function. (F) CMS led to a significant hyperpolarizing shift of the half-activation potential (V_1/2) compared with that of control (**p=0.007). (G) The resting membrane conductance (G_resting) was not significantly different between control and CMS mice (p=0.107).

Figure 4—figure supplement 1. The measurement of resting membrane conductance.

(A) The instantaneous inward current (I_ins) was measured as indicated by the dashed lines. (B) A representative example for calculating resting membrane conductance. I_ins was plotted against the hyperpolarizing voltage steps. The slope of these I-V curves is indicative of the resting membrane conductance shown in Figure 4G.