  We address the question how the spin-dependent nucleon structure function
g1(x,Q**2) gets modified when the nucleon is bound inside a nucleus. We analyze
the influence of nuclear interactions using the delta-pion model, known to
describe well the unpolarized effect, and the free polarized parton
distributions. The results for the neutron in 3-He and proton in 3-H, 7-Li and
19-F are presented, showing significant changes in the parton spin
distributions and in their moments. Scattering processes off polarized 7-Li are
suggested which could justify these theoretical calculations and shed more
light on both nuclear spin structure and short distance QCD.
