  We discuss the relevance of nuclear medium effects in the analysis of some
low and medium energy neutrino reactions of current interest. In particular, we
study the Quasi-Elastic (QE) process, where RPA correlations and Final State
Interactions (FSI) are shown to play a crucial role. We have also investigated
the neutrino induced coherent pion production. We find a strong reduction of
the cross section due to the distortion of the pion wave function and the
modification of the production mechanisms in the nucleus. The sensitivity of
the results to the axial $N\Delta$ coupling $C_5^A(0)$ has been also
investigated.
