Characteristics of the performance of a formed motor skill by rats with different motor preferences.

Wistar rats with different motor preferences were used to study performance of a food-procuring skill--extracting food from a narrow horizontal feeder tube. These experiments showed that when the preferred limb was used, left-handed rats performed the task more quickly (including both preliminary movements and the final successful movements) than right-handed rats. Comparison of movement performance times with the preferred and non-preferred limbs showed that the task was performed more quickly using the left paw in both left- and right-handed rats, i.e., independently of whether this was the preferred paw or not. At the final stage of task performance (grasping and extracting the food), the preferred paw was more successful than the non-preferred paw in both right- and left-handed animals. It is suggested that the organization of the overall strategy for performing this complex behavioral task in rats is determined by the functional heterogeneity of the right and left hemispheres of the brain, which is not linked with limb preference. The selected preference is based on the specific motor and precision characteristics of the preferred paw, while the contralateral hemisphere--the left in right-handed animals and the right in left-handed animals--has a special role in mediating these abilities.