  In this communication we consider the doping dependence of the strong
antiferromagnetic spin fluctuations in the cuprate superconductors. We
investigate the effect of an incommensurate magnetic response, as recently
observed in inelastic neutron scattering (INS) experiments on several
YBa_2Cu_3O_{6+x} compounds, on the spin-lattice and spin-echo relaxation rates
measured in nuclear magnetic resonance (NMR) experiments. We conclude that a
consistent theoretical description of INS and NMR can be reached if one assumes
spatially inhomogeneous but locally commensurate spin correlations and that NMR
and INS experiments can be described within a single theoretical scenario. We
discuss a simple scenario of spin and charge inhomogeneities which includes the
main physical ingredients required for consistency with experiments.
