[Compensation deficits in posture and kinetics following unilateral vestibular neurectomy in cats. The role of sensorimotor activity].

The role of sensorimotor activity in compensating deficits following unilateral vestibular neurectomy was studied in four adult cats using behavioral tests. Disturbances in posture and equilibrium were quantified and their subsequent compensation was described in both sensorimotor restrained and unrestrained cats. Sensorimotor restriction (S.M.R.) lasted 7 days and was performed in different postoperative periods. In the unrestrained animal, postural asymmetry compensation followed a 3-phase time course leading to preoperative criteria after about 40 days. Recovery of equilibrium developed by steps and was achieved after about 50 postoperative days. A first week applied S.M.R. was most effective in stopping postural symmetry recovery, while a later S.M.R. had no effect on the recovery time course and did not produce decompensation. On the contrary, S.M.R. (1st week or 3rd week) prevented and delayed equilibrium recovery, the earlier S.M.R. producing maximal effects. These observations suggest a CNS "sensitive period" to vicariant inputs.