ACTION POTENTIALS OF COLD FIBRES AND INTRACUTANEOUS TEMPERATURE GRADIENT

Abstract

Small strands of the lingual nerve, supplying fibers for cold sensation to small circumscribed areas of the dorsum of the cat''s tongue, were isolated by a previously descr. method. Potentials elicited in these fibers by application of a cold stimulus to the dorsum of the tongue were compared with those elicited by cold applications to the ventral surface. In the one instance the receptors were cooled from above, and in the other from below, providing an opportunity to test theories as to the importance of the intracutaneous temp. gradient. The receptors apparently react according to the degree of cooling regardless of the gradient in the surrounding tissues. The cold receptors were activated by injn. of cold soln. into the lingual artery. The possibility that vascular factors played a role in the results obtained by the method of surface cooling was controlled by occlusion of the lingual arteries in some expts.