Accession Number : ADA020975


Title :   Generator Potential Mechanisms in Mammalian Cold-Sensitive Afferents,


Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD


Personal Author(s) : Pierau,F. K. ; Torrey,P. J. ; Carpenter,D. O.


Report Date : NOV 1975


Pagination or Media Count : 25


Abstract : Studies have been performed on the afferent fibers innervating the scrotal skin of the rat to test the hypothesis that the generator potential mechanism underlying cold thermo-sensitivity of these afferent fibers is an electrogenic sodium pump. In intact rats recordings were made from afferents dissected from the pudendal nerve, and the effect of ouabain injected subcutaneously to the receptive field area was studied. In other experiments a nerve-scrotal skin preparation was isolated from the animal and maintained in oxygenated mammalian Ringer's solution where composition could be varied and drugs added. In both preparations application of ouabain resulted in an increase in the discharge of cold-sensitive afferent fibers at 36-38 C with little or no change in the discharge at 26-28 C. Transient accelerations on cooling were also reduced or abolished. The effects of ouabain administration were reversible. In the isolated preparation removal of extracellular K (+) at 35 C resulted in an increased discharge of cold-sensitive afferents. This observation is consistent with the effects of ouabain, since removal of extracellular K (+) also blocks Na (+) transport. The generator potential mechanism underlying cold sensitivity of these afferent fibers appears to be an electrogenic Na (+) pump. (Author)


Descriptors :   *SENSES(PHYSIOLOGY), *ION PUMPS, *NERVE TRANSMISSION, TEMPERATURE, RATS, SODIUM, COLD REGIONS, SENSITIVITY, TRANSPORT PROPERTIES, NERVE CELLS, MALES, POTASSIUM, ELECTROPHYSIOLOGY, APLYSIA.


Subject Categories : ANATOMY AND PHYSIOLOGY


Distribution Statement : APPROVED FOR PUBLIC RELEASE