Sodium specificity of salt appetite in the fischer-344 and wistar
strains is impaired by chorda tympani nerve transection.
Breslin, P. A. S., A. C. Spector, and H. J. Grill.
Monell Chemical Senses Center, 3500 Market Street, Philadelphia,
Pennsylvania, 19104-3308; Department of Psychology, University of
Florida, Gainesville, Florida, 32611; and Department of Psychology,
University of Pennsylvania, Philadelphia, Pennsylvania 19104
APStracts 2:0070R, 1995.
Unlike other rat strains, the sodium-replete Fischer-344 (F344) shows
no innate preference for NaCl, and displays more aversive and fewer
ingestive oral motor responses to orally infused NaCl when tested in
sodium balance. Despite these differences, F344s show an increase in
preference for NaCl in response to sodium depletion. The present
study was designed to determine whether the salt-appetite of sodium
-depleted F344s is cation specific, and whether such selectivity is
mediated in part by an intact chorda tympani nerve. Sodium-depleted
(10 mg furosemide) F-344 (n=13) and Wistar (n=16) rats were permitted
repeated access to nine stimuli (water, 0.05 and 0.3M NaCl, KCl,
NH4Cl, and CaCl2), presented randomly in 10 sec trials. Half of the
rats had their chorda tympani nerve sectioned (CTX). Under conditions
of sodium depletion, both strains discriminated NaCl from other
chloride salts. CTX significantly impaired the selectivity of the
licking behavior in both strains suggesting that sodium-specific
licking is partially mediated by anterior tongue taste receptors.
These findings suggest that both sodium-depleted F344 and Wistar rats
are comparable in their abilities to recognize NaCl, to distinguish
it from other salts, and to respond selectively to it, despite the
fact that sodium-replete F344 and Wistar rats differ greatly in their
NaCl preference.
Received 4 October 1994; accepted in final form 15 March 1995.
APS Manuscript Number R575-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 April 1995.