Peripheral Gustatory Mechanisms of Salt Intake in the Rat
The focus of this research is to determine the nature of the contribution of taste sensitivity in controlling salt intake in the rat. We know that salt taste sensitivity is important to the salt intake of the rat for several reasons. First, the normal preferences for salt are reduced after severing the taste nerves1 or after gustatory thalamic lesions2; moreover, denervation of taste afferents in sodium deficient adrenalectomized rats causes them to not increase their salt intake which ultimately leads to their death3. Second, rats select sodium solutions the first time they become sodium deficient, and they do so immediately upon tasting the salt4. Third, this sodium appetite is triggered by sodium ions as rats chose sodium salts over nonsodium salt and other taste compounds; lithium salts are the only exception as sodium deficient rats can be fooled into consuming the toxic LiCl simply because it tastes similar to NaCl4. Fourth, the rat has taste receptors and fibers that are keenly sensitive to sodium (and lithium) salts; these receptors and fibers evolved presumably to protect the animal from sodium deficiency5.
KeywordsSalt Intake Taste Receptor Nerve Response Taste Intensity Chorda Tympani
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