Paramyxovirus infections alter certain functional properties in cultured sensory neurons.

Functional properties of cultured mouse dorsal root ganglion cells infected with paramyxoviruses have been studied using intracellular recording techniques. Mumps virus, which causes a persistent non-lytic infection, and Sendai virus, which causes an infection that leads to cell lysis after about a week were used. In the early phase of the infection (24-48 h) both viruses caused a reduction in the influx of calcium ions during the action potential, but did not alter resting membrane potential, action potential amplitude or input resistance. At later times functional properties became normal in mumps infected neurons. In contrast, Sendai virus infected neurons showed a reduction of action potential amplitude and input resistance at 48-72 h after infection, and finally there was also a reduction of membrane potential before the cells disintegrated. These results show that different paramyxovirus infections may cause different types of alterations in the functional properties of neurons. The reduced calcium influx resulting from mumps infection suggests that a non-lytic viral infection may have selective effects on important regulators of neuronal functions. Moreover, a lethal viral infection (Sendai) may influence specific membrane properties, such as calcium channel activation, several days prior to general structural and functional degeneration.