EFFECTS OF BILATERAL AND UNILATERAL LOCUS-COERULEUS LESIONS ON BEAM-WALKING RECOVERY AFTER SUBSEQUENT UNILATERAL SENSORIMOTOR CORTEX SUCTION-ABLATION IN THE RAT

The recovery of beam-walking ability following a unilateral sensorimot or cortex lesion in the rat is hypothesized to be noradrenergically-me diated. We carried out two experiments to further test this hypothesis . In the first experiment, bilateral 6-hydroxydopamine locus coeruleus (LC) lesions or sham LC lesions were made 2 weeks prior to a right se nsorimotor cortex suction-ablation lesion or sham cortex lesion. In th e second experiment, unilateral left or right LC lesions or sham LC le sions were made 2 weeks prior to a right sensorimotor cortex lesion or sham cortex lesion. Beam-walking recovery was measured over the 12 da ys following cortex lesioning in each experiment. Bilateral, unilatera l left, and unilateral right LC lesions resulted in impaired recovery. These data provide additional support for the hypothesis that beam-wa lking recovery after sensorimotor cortex injury is, at least in part, noradrenergically mediated. (C) 1997 Elsevier Science Ireland Ltd.