Fig. 4

Measurement of I_h current density in the medium-size DRG cells of the OAB and sham-intervention rats. a: The I_h current eliciting a hyperpolarization potential in the medium-size DRG cells of the sham group (left side) and OAB group (right side). The magnitude of the I_h current is the current difference corresponding to the vertical distance from the instantaneous starting point to the steady state (the two arrows in the diagram indicate the endpoints of the magnitude). The ratio of the I_h amplitude and the capacitance of the neural cells is the I_h current density. After the addition of 2 μM ZD7288 to the perfusion fluid, the I_h current of both the OAB and sham groups was significantly inhibited (middle row). The final row shows the I_h current induced by the square-wave stimulus (starting from − 110 mV, increasing in 10 mV steps). b: When said cells were clamped at − 110, − 100 and − 90 mV, the I_h current density was significantly increased. C: The I_h current density of the both the OAB and sham groups was significantly reduced by ZD7288 (*p < 0.05, sham vs OAB group; #p < 0.05, OAB vs OAB + ZD7288 group; $p < 0.05, sham vs sham+ZD7288 group; sham n = 11, sham+ZD7288 n = 11, OAB n = 13, OAB + ZD7288 n = 13)