AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 1 52-R61, Copyright © 1985 by American Physiological Society

ARTICLES

Analysis of amiloride inhibition of chorda tympani taste response of rat to NaCl

J. A. DeSimone and F. Ferrell

The kinetics of inhibition by amiloride of the integrated chorda tympani response were investigated in rats subjected to lingual stimulation with NaCl. In one series of experiments the time of exposure to amiloride was varied at fixed amiloride concentration. Exposure to 10(-4) M amiloride for 2 s reduced the response to 0.5 M NaCl by approximately 50%. The time course of recovery from amiloride inhibition was first order (relaxation time approximately equal to 4 min) for all exposure times. For exposure to 10(-4) M amiloride for less than or equal to 30 s recovery was better than 90% in 20 min. Not all of the chorda tympani response was inhibited by amiloride. With 0.5 M NaCl there was a 70% reduction in response, whereas at 0.05 M NaCl the reduction was only 30%. Parallel effects of amiloride were seen in the short-circuit current of an in vitro preparation of canine lingual epithelium. Amiloride reduced the short-circuit current by the same percentage as it inhibited the chorda tympani response. These results suggest that gustatory transduction is mediated in part by an apical membrane transport system that can be inhibited by amiloride. There exists, however, a second transducing element that is amiloride insensitive. A model is developed, assuming, in part, that the neural response reflects the flows of Na through amiloride-sensitive apical pathways.

This article has been cited by other articles:

				S. D. Hillyard, V. Baula, W. Tuttle, N. J. Willumsen, and E. H. Larsen Behavioral and Neural Responses of Toads to Salt Solutions Correlate with Basolateral Membrane Potential of Epidermal Cells of the Skin Chem Senses, October 1, 2007; 32(8): 765 - 773. [Abstract] [Full Text] [PDF]

				Y. Treesukosol, V. Lyall, G. L. Heck, J. A. DeSimone, and A. C. Spector A psychophysical and electrophysiological analysis of salt taste in Trpv1 null mice Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2007; 292(5): R1799 - R1809. [Abstract] [Full Text] [PDF]

				T. Ohkuri, K. Yasumatsu, N. Shigemura, R. Yoshida, and Y. Ninomiya Amiloride Inhibition on NaCl Responses of the Chorda Tympani Nerve in Two 129 Substrains of Mice, 129P3/J and 129X1/SvJ Chem Senses, July 1, 2006; 31(6): 565 - 572. [Abstract] [Full Text] [PDF]

				S. Eylam and A. C. Spector Taste discrimination between NaCl and KCl is disrupted by amiloride in inbred mice with amiloride-insensitive chorda tympani nerves Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2005; 288(5): R1361 - R1368. [Abstract] [Full Text] [PDF]

				L. C. Geran, M. Garcea, and A. C. Spector Transecting the gustatory branches of the facial nerve impairs NH4Cl vs. KCl discrimination in rats Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2002; 283(3): R739 - R747. [Abstract] [Full Text] [PDF]

				T. Hanamori Effects of Various Ion Transport Inhibitors on the Water Response in the Superior Laryngeal Nerve in Rats Chem Senses, September 1, 2001; 26(7): 897 - 903. [Abstract] [Full Text] [PDF]

				S. J. Hendricks, R. E. Stewart, G. L. Heck, J. A. DeSimone, and D. L. Hill Development of Rat Chorda Tympani Sodium Responses: Evidence for Age-Dependent Changes in Global Amiloride-Sensitive Na+ Channel Kinetics J Neurophysiol, September 1, 2000; 84(3): 1531 - 1544. [Abstract] [Full Text] [PDF]

				S. J. St. John and D. V. Smith Neural Representation of Salts in the Rat Solitary Nucleus: Brain Stem Correlates of Taste Discrimination J Neurophysiol, August 1, 2000; 84(2): 628 - 638. [Abstract] [Full Text] [PDF]

				S. L. Kopka, L. C. Geran, and A. C. Spector Functional status of the regenerated chorda tympani nerve as assessed in a salt taste discrimination task Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2000; 278(3): R720 - R731. [Abstract] [Full Text] [PDF]

				Y. Shimizu and K. Tonosaki Low environmental temperature modulates gustatory nerve activity and behavioral responses to NaCl in rats Am J Physiol Regulatory Integrative Comp Physiol, August 1, 1999; 277(2): R368 - R373. [Abstract] [Full Text] [PDF]

				M. F. Roitman and I. L. Bernstein Amiloride-sensitive sodium signals and salt appetite: multiple gustatory pathways Am J Physiol Regulatory Integrative Comp Physiol, June 1, 1999; 276(6): R1732 - R1738. [Abstract] [Full Text] [PDF]

				M. A. Kloub, G. L. Heck, and J. A. Desimone Self-Inhibition in Ca2+-Evoked Taste Responses: A Novel Tool for Functional Dissection of Salt Taste Transduction Mechanisms J Neurophysiol, February 1, 1998; 79(2): 911 - 921. [Abstract] [Full Text] [PDF]

				R. F. Lundy Jr., D. W. Pittman, and R. J. Contreras Role for epithelial Na+ channels and putative Na+/H+ exchangers in salt taste transduction in rats Am J Physiol Regulatory Integrative Comp Physiol, December 1, 1997; 273(6): R1923 - R1931. [Abstract] [Full Text] [PDF]

				M. A. Kloub, G. L. Heck, and J. A. Desimone Chorda Tympani Responses Under Lingual Voltage Clamp: Implications for NH4 Salt Taste Transduction J Neurophysiol, March 1, 1997; 77(3): 1393 - 1406. [Abstract] [Full Text] [PDF]

				A. C. Spector, N. A. Guagliardo, and S. J. St. John Amiloride Disrupts NaCl versus KCl Discrimination Performance: Implications for Salt Taste Coding in Rats J. Neurosci., December 15, 1996; 16(24): 8115 - 8122. [Abstract] [Full Text] [PDF]