[Late somatosympathetic reflex responses in the thoracic and lumbar white rami communicantes]

In anesthetized and immobilized cats with intact nervous system, late somato-sympathetic reflexes (LB) in T3 and L2-3 white rami elicited by stimulation of ipsi- and contralateral thoracic and lumbar segmental nerves included at least two typical waves: LR-I, LR-II, LR-I was only elicited by stimulation of corresponding and neighbouring segmental ipsilateral nerves and had equal latency at the thoracic and lumbar levels. The appearance of LR-II in thoracic and lumbar white rami did not depend on the level of spinal entrance of the stimulated afferent nerves. The LR-II latency increased in white rami originated in more caudal segments. The data obtained suggest LR-I to be the spinal reflex, and LR-II--the suprasegmental one.