Modification of membrane currents in mouse neuroblastoma cells following infection with rabies virus

1 The effect on membrane currents of infection of mouse neuroblastoma NA ce lls with rabies virus was studied by using the whole-cell patch clamp techn ique. 2 Three types of membrane currents, namely voltage-dependent Na+ current (I -Na), delayed rectifier K+ current (TK-DR) and inward rectifier K+ current (IK-IR) were elicited in uninfected cells. 3 In cells 3 days after infection with the virus, no detectable change was observed in morphology and membrane capacitance, but I-Na and IK-IR were si gnificantly decreased in amplitude without any appreciable difference in th e time course of current activation and inactivation. The voltage-dependenc e of I-Na activation was significantly shifted in the positive direction al ong the voltage axis with a decreased slope. IK-DR remained almost unaltere d after the viral infection. 4 The resting membrane potential, measured with a physiological K+ gradient across the cell membrane! was decreased (depolarized) after the viral infe ction. The depolarization was associated with the decreased amplitude of IK -IR. 5 These results suggest that infection of mouse neuroblastoma NA cells with rabies virus causes reduction of functional expression of ion channels res ponsible for I-Na and IK-IR, and provide evidence for possible involvement of the change in membrane properties in the pathogenesis of rabies disease.