Independence of Central Controls of Vascular and Sweat Gland Responses in the Paw of the Cat.

The galvanic skin response can be recorded as a reduction of skin resistance (Fere, 1888) or as a change of skin potential (Tarchanoff, 1890). Accompanying this response there may occur a vasoconstriction of the digits, shown by reduction of volume, pulsation, and blood flow. In the past there has been discussion about the relationship between the electrical and the vascular events. Recently Lader and Montagu (1962) have used pharmacological blockades to separate the responses in man, and have shown that each may occur when the other response is blocked. Their findings imply that the peripheral pathways are separate and independent in the post-ganglionic section. This still leaves open the question whether the pathways and controls are distinct within the central nervous system. The purpose of this paper is to report findings which show that the responses can be elicited separately when activating the central paths by direct or reflex stimulations. The central controlling pathways, both excitatory and inhibitory, are individual at least up to medullary level.