  After a short introduction to the history of neutrino mixing and
oscillations, we celebrate the 50th anniversary of the first analytical
expression for the neutrino evolution probability obtained by Gribov and
Pontecorvo in 1969 by the discussion of two new phenomena in neutrino
oscillations: 1) the emergence of the neutrino spin and spin-flavour
oscillations engendered by the transversal in respect to neutrino propagation
matter currents, and 2) an inherent interplay of neutrino oscillations on the
vacuum $\omega_{vac}=\frac{\Delta m^2}{4p}$ and magnetic $\omega_{B}=\mu
B_{\perp}$ frequencies in the case of neutrino propagation in a constance
magnetics field. We also predict a new phenomena of the modification of the
flavour neutrino oscillations probability in moving matter that can be
engendered by a non-vanishing matter transversal current ${\bf j}_{\perp}=n
{\bf v}_{\perp}$.
