THE EFFECTS OF UNILATERAL PYRAMIDAL TRACT SECTION ON HINDLIMB MOTOR-PERFORMANCE IN THE RAT

Most investigations on selective lesions of the pyramidal tract in rod ents have focused on the functional impairment of the forelimbs. This study describes the effects of a unilateral transection of the pyramid al tract rostral to the decussation on hindlimb function. Using kinema tic locomotion analysis, the narrow beam test, open field locomotion r anking, analysis of footprints and air righting, we found severe impai rments including hypermetria, trunk instability, lateral shifts in wei ght support, toe dragging, and hindlimb exe-rotation. Most impairments recovered rapidly within the first week after operation. Slight hyper metria persisted after 4 weeks. The rather mild long term deficits aft er unilateral pyramidotomy may stress the need for extremely sensitive behavioural tasks to enable the detection. We conclude that the possi bility to correlate regenerative changes following selective pyramidal tract lesions with hindlimb function is thus limited. (C) 1998 Elsevi er Science B.V. All rights reserved.