THE INFLUENCE OF EFFERENT CEREBRAL PATHWAYS UPON THE SYMPATHETIC NERVOUS SYSTEM

Using the galvanic skin response as a measure of sweat-gland activity, the controlling influences from the cortex, brain-stem and spinal cord were investigated. Definite galvanic skin responses were obtained from faradic stimulation of two areas adjacent to the motor cortex, from the floor of the third ventricle, from the cortico-spinal and rubro-spinal tracts, from the vestibular nuclei, from the posterior column nuclei and from the posterior columns of the cervical cord. It is concluded that the same cerebro-efferent pathways which influence somatic motor cells also control preganglionic sympathetic cells; this cerebral control is predominantly an inhibitory one. Any cerebral centres influencing lower centres seem to exert final control through well-known cerebro-efferent pathways.