Response of adrenal efferent nerve activity to non-noxious mechanical stimulation of the skin in rats.

The effects of brushing various segmental skin areas (neck, lower chest, abdomen and thigh) on adrenal sympathetic efferent nerve activity were examined in anesthetized rats. In the CNS intact rats, brushing of all areas produced a large reflex decrease in the efferent nerve activity, whereas, in the spinalized rats, brushing the lower chest or abdominal skin area produced an increased response while brushing the neck or thigh skin area produced no significant changes in the efferent nerve activity. It is suggested that the segmental excitatory organization of the adrenal nerve reflex caused by brushing within the spinal cord is modified into a non-segmental or generalized inhibitory organization by the supraspinal structure.