DYNAMICS OF TASTE CELLS 



Lloyd M. Beidler 

 Florida State University, Tallahassee, Florida 



INTRODUCTION 



How does a chemical stimulus initiate the response of a taste receptor? 

 Direct observation is not feasible at the present time so more indirect 

 approaches must be used. One of the most quantitative and objective is to 

 measure the electrical correlates of the taste cell response and relate them 

 to the physicochemical properties of the stimulus. Chemical reactions 

 depend upon many properties of the atoms or molecule involved and there- 

 fore no single parameter can be expected to define the stimulus of the 

 chemical senses. 



The experimenter usually considers the taste cell as very stable and un- 

 changing during the course of his experiments. The biophysicist often 

 refers to it as a transducer. Recent evidence, however, has shown that the 

 taste cell is one of the fastest ageing cells in the animal body, since it may 

 only live for several days (Beidler, 1961a). It is the purpose of this com- 

 munication to summarize some of the properties of taste cells giving par- 

 ticular attention to possible functional effects due to the high turn-over 

 rate of taste cells. 



ANATOMICAL CONSIDERATIONS FOR 

 ELECTRO PHYSIOLOGISTS 



The taste buds of mammals are associated with the fungiform papillae 

 on the front two-thirds of the tongue and with the foliates and circum- 

 vallates on the back of the tongue. Those on the anterior portion of the 

 tongue are more accessible to the experimenter and therefore are much 

 more studied. 



The chorda tympani nerves innervate the taste buds of the fungiform 

 papillae. The total chorda tympani nerve is often cut and used by electro- 

 physiologists to study the taste receptor responses. This nerve contains 

 not only taste nerves but also other sensory and motor nerves as shown by 

 Foley (see Table 1). Cutting the nerve prior to electrical recording may 

 interrupt efferent pathways to the tongue. The importance of sympathetic 

 activity on taste responses of the rat was studied by Kimura and found to 

 be present but small (Kimura, personal communication). 



133 

 11 



