The NMR spin-lattice proton relaxation dispersion T1(nL) of the liquid crystal propylcyano-phenylcyclohexane are studied over several decades of Larmor frequencies and at different temperatures in the nematic mesophase. The results show that the order fluctuation of the local nematic director contribution to T1(nL) undergoes a transition between two power regimes: from T1(nL)µnL1/2 to nLa (a» 1/3) on going from low to high Larmor frequencies.