Consequences of damage to the sensorimotor cortex in neonatal and adult cats. I. Sparing and recovery of function.

Postural reflexes and locomotion were studied in order to assess the effects of unilateral sensorimotor cortical ablations in neonatal (1 day old) and adult cats. To document the infant lesion effect and to distinguish recovery from sparing of function, development of motor function was studied in neonatal operates and in normal littermates. Once neonatal operates achieved maturity, their motor performance was compared with that of chronic adult operates. The emergence of motor behavior during development in neonatal operates appeared to follow the same pattern as in normal animals although with a protracted time course and motor behavior did not attain the level of maturity of normal animals. Some deficits were not apparent immediately but evolved with time. Adult operates exhibited recovery of function of some behavior but neonatal operates exhibited greater recovery and sparing. Adult operates, like neonatal operates, were able to mask certain deficits by compensatory mechanisms. Kinematic analysis revealed that neonatal and adult operates often executed movements abnormally. It is hypothesized that somewhat different mechanisms underlie recovery in neonatal and adult operated animals.