Effect of skin temperature on absolute threshold for electrical current

¹ U.S. Army Medical Research Laboratory, Fort Knox, Kentucky

The dependence of tactile sensitivity on skin temperature could be due to a central or a peripheral effect. Maximal cutaneous sensitivity for pressure or mechanical vibration is obtained at about 36 C, with a shift in either direction resulting in an elevation of threshold. In the present study, raising skin temperature of the finger or forearm to as much as 45 C had no effect on the threshold for electrical cutaneous stimulation. It is concluded that the dependence of sensitivity to pressure or mechanical vibration on skin temperature is a peripheral effect. Further, electrical current applied to the intact skin apparently affects nerves directly without requiring transduction by a chemical (or other) process at the receptor. It is suggested that the effect of temperature, with other kinds of cutaneous stimulation, is on chemical substances contained within the receptors.