FIXATION OF EXPERIENCE IN THE RAT SPINAL CORD

Abstract

When an asymmetry in descending physiological activity is produced by unilateral cerebellar or other lesions, the resulting asymmetrical activity in spinal motor centers is seen in postural asymmetries of the hind legs. High spinal section abolishes the descending nerve impulses and the asymmetry, providing the situation has not persisted in the rat, for 45 minutes. An asymmetry that has endured over 45 minutes remains indefinitely. This "fixation time" is comparable to that of other learning experiences; and the cord "engram" is a type of fixing of experience or learning. This prepara-tion is being studied electrically, morphologically, and behaviorally, and especially for drug effects on fixation time.