  Neutrino radiation takes a major role in the momentum, heat, and lepton
transports in proto-neutron stars (PNSs). These diffusive processes affect the
growth of magnetorotational instability (MRI) in PNSs. We perform a local
linear analysis for the axisymmetric and nonaxisymmetric MRI including the
effects of neutrino transports and ohmic dissipation. We find that the MRI can
grow even in the multi-diffusive situations that are realized in neutrino
loaded PNSs. When the toroidal magnetic component dominates over the poloidal
one, nonaxisymmetric MRI modes grow much faster than axisymmetric modes. These
results suggest the importance of the nonaxisymmetric MRI in PNSs. Thus the
understandings of three-dimensional nonlinear evolutions of the MRI are
necessary to reveal the explosion mechanism of core-collapse supernovae.
