Figure 6.

Na⁺–Ca²⁺ exchanger and leak K⁺ channel coupled to H1 receptor and HCN channels coupled to H2 receptor comediate the histamine‐induced excitation on inferior vestibular nucleus neurons. (A and B) The inward currents induced by histamine (30 μM) were partly blocked by ranitidine (3 μM), a highly selective H2 receptor antagonist, and the residual currents were totally blocked by combined application of Ba²⁺ and KB‐R7943 (n = 5, P = 0.0004). (C and D) The inward currents induced by histamine (30 μM) were partly blocked by mepyramine (3 μM), a highly selective H1 receptor antagonist, and the residual currents were totally blocked by ZD7288 (n = 5, P = 0.0006). (E and F) Combined application of ZD7288, KB‐R7943, and Ba²⁺ totally blocked the postsynaptic inward current induced by histamine (n = 5, P = 0.0023). Data shown are means ± SEM; **P < 0.01, ***P < 0.001.