EVIDENCE OF THE NON-SEGMENTAL CHARACTER OF SPINAL REFLEXES FROM AN ANALYSIS OF THE CEPHALAD EFFECTS OF SPINAL TRANSECTION (SCHIFF-SHERRINGTON PHENOMENON)

Abstract

Transection of the spinal cord below the brachial enlargement induces a marked increase in the decerebrate rigidity and the stretch reflex of the fore limbs. Section of a large number of posterior roots in the lumbo-sacral region or section of the posterior columns is without cephalad effect. Section and degeneration of all Jumbo-sacral dorsal roots below the 3d lumbar does not augment fore-limb extension, nor diminish the effect of a subsequent post-brachial transection. A transection which eliminates only spinal cord segments that were previously deafferented augments the stretch reflex of the fore limbs. The inhibitory action exerted by lumbo-sacral segments on the fore limbs is subserved by an intra-spinal system of neurones, which operates in the absence of segmental afferent influx to the lumbar enlargement.