Unit activity in the isolated spinal cord of chick embryo, in situ

Unit electrical activity was recorded from single neurons in the isolated lumbo-sacral spinal cord of 14- to 19-day chick embryos, in situ. Spinal cord transection was combined with transection of all lumbo-sacral dorsal roots. The spontaneous discharge of cells is confined, for the most part, to the lower two thirds of the cord. A quasilinear reduction in the number of spontaneously active units was found during the developmental period studied. Comparable results were obtained in decentralized cord with sensory inputs blocked by xylocaine.