E2 effects on delay of excitation in PVN-RVLM neurons. A, a representative image shows a delay in the onset of the first action potential expressed in PVN-RVLM neurons from the oil-group (dashed line) and the E2-group (solid line). The cells were hyperpolarized to near -90 mV to remove IA inactivation and depolarized by injecting a +45 pA current. B, The bar graph summarizes the differences in delay in the onset of the first action potential between the oil-group and the E2-group. The mean delay time of the E2-group significantly decreased, compared to that of the oil-group (*P < 0.05).