[Reversal of "handedness" in callosotomized rats]

Effect of callosotomy on the transfer of preference of one of the forepaws in performance of instrumental reaction of reaching pieces of food from a narrow horizontal tube was studied in rats. The transfer was carried out by means of artificial impediment of food procuring with the preferred paw. There was no significant difference between intact and callosotomized rats in the rate of initial paw preference determination and in the rate of paw preference transfer. However, the degree of the paw preference transfer preservation was lower in the callosotomized rats as compared with intact ones. The role of interhemispheric inhibition in motor learning is discussed.