The dynamics of the accumulation of free-radical oxidation products in the
brain hemispheres of rats in rate ontogenesis was studied. Multiphase chang
es in the concentration of products in the right and left hemispheres in di
fferent age groups were registered. Significant differences in the contents
of hydroperoxides, Schiff's bases of phospholipids and lipofuscin in brain
hemispheres revealed, which correlates with different rate of ageing of he
mispheres.