142 



LLOYD M. BEIDLER 



initial transient response is determined by the time constant of the elec- 

 tronic integrator and thus varies in published results from one laboratory 

 to another. 



— =20 Sec. 

 Fig. 3. (A) Continuous response to 0.1 m NaCl followed by water rinses and 

 two additional responses to 0.1 m NaCl. (B) Response to 0.1 m NaCI followed 

 by continuous response to 0.1 m CaClg with two responses to 0.1 m NaCl inter- 

 posed before rinsing with water. (C) Response to 0.1 m K benzoate. Note 

 negative response followed by a positive transient response during water rinse. 

 (D) Response to 0.05 m HCl. Note increased transient response during 



water rinse. 



Although the temporal pattern of the response to many stimuli is 

 similar to that to NaCl, differences do exist. The rat response to sucrose 

 may be slow in starting and show grouped nerve impulses when recording 

 from single taste fibers (Beidler, 1951 ; Fishman, 1957). The response 

 to CaClg never reaches a steady state but continually declines toward 

 zero over a period of several minutes (see Fig. 3). High concentrations 

 of BaCl2 produces a response that is slow in starting, steadily increases, 

 shows a sharp initial increase when water is applied and only decreases 

 several minutes later. The response to some acids also shows an additional 

 transient increase when the tongue is rinsed with water followed by a rapid 

 decrease. Low concentrations of potassium benzoate, on the other hand, 

 depress any resting activity of the rat, but produce a large transient positive 

 response when water is again applied to the tongue. Some of these fast 

 transient responses may be of particular importance to the animal during 

 normal eating since the concentration of the stimulus applied to any given 

 taste bud varies continually as the animal moves the food about the 



