Temperature dependence of spin-lattice relaxation time T-1* of mobile Na-23 and immobile Ga-71 in the framework of NaxTi2-xGa4+xO10 was measured in the temperature range of 4.2-900 g. The dependence is divided into four temperature regions, corresponding to different activation-type ionic motions. T-1* above about 700 K is probably dominated by the interchannel hopping of Na+. Activation energy E(NMR) in the middle temperature range below 600 K, obtained using Na-23 as the probe to observe Na+ ionic motion, is 0.069 eV and is about 1.8 times as large as the value obtained using Ga-71 as the probe. The discrepancy commonly observed in sodium titano-gallates is discussed.