Contralateral and long range ipsilateral receptive fields of fibres in the central ends of divided dorsal roots.

Action potentials were recorded in the central ends of transected feline lumbosacral dorsal rootlets after all the ipsilateral lumbar and sacral dorsal and ventral roots had been divided. A few fibres had receptive fields on the contralateral hindlimb. A smaller number had receptive fields on the ipsilateral forelimb. Percutaneous electrical stimulation was able to drive some fibres at such high frequencies that the fibres were considered to be branches of the distant afferent. Other fibres were probably synaptically coupled to the afferent. These results are discussed in the context of an hypothesis that primary afferents form many extraneous or aberrrant branches in the spinal cord.