62 E. F. MACNICHOL, JR. 



Enough has been said today about the activation of the potential, the generated 

 potential. The slow potential in a certain part of the cells could at times initiate 

 a chain of response. But we also think that at the end of the receptor, the cells 

 are also sensitive to the action of, or combine differently with, anions as well 

 as cations. The idea that we had formerly was that the reagents which pro- 

 duced such a change at a local point did so by inducing a permeability effect. 

 Now, however, if you look back into the idea, the change of permeability would 

 not immediately cause a change in the potential because it does not change the 

 range of ionic distribution. 



Recently we have shown that the potential generated at the cell surface 

 seems to depend only upon microscopic depth. That is, that only the potassium 

 ion at the cell surface will be responsible for the potential in the muscle. Conse- 

 quently, would it be possible to think that your ions also affect this microscopic 

 area, thereby producing a local depolarization, the generating potential, which 

 in turn would bring about the activation? 



Dr. Dethier: This could initiate a long discussion. In view of the time con- 

 sideration I will not go on lengthily on this subject. Most of what I say would 

 be sheer speculation. 



Just let me say at this time, and I am willing to discuss it later at greater 

 length, that acetylcholine does nothing at all in our system. And also, we can 

 demonstrate no potassium, calcium, no ionic antagonism of any sort. Nobody 

 working with taste has been able to. With respect to your last question, all I 

 can say is that it is possible, but we have not shown it one way or the other. 



