Abstract
The appearance of subthreshold sudomotor nerve impulses in human skin was demonstrated in a cool environment when generalized sweating was absent. Continuous recording of the rate of local sweating induced by intradermal injection of some sudorific agents showed small upward deflections of the sweat rate curve representing sweat expulsions which were synchronous in different skin areas. These sweat expulsions corresponded to electric potential changes of the adjacent skin area, which were also s nchronous with those of the palm. These observations clearly indicate that, evea in the absence of general sweating, a subthreshold amount of transmitter substance is being released at the neuroglandular junction for each nerve impulse and gives rise to a detectable rate of sweat discharge in the presence of an adequate effective amount of the sudorific agent.
Such sweat expulsions as well as the skin potential changes became progressively less distinct with a fall in environmental temperature.
