382 TAKASHI HAYASHI 



(2) Nerve endings and motor end-plate. 



(3) The muscle fibre. 



Of these, the muscle fibre has a special "excitine" and "inhibitine" and the 

 motor nerve fibre also has a special "excitine (N)" and "inhibitine (N)". The 

 chemical structure of excitine (N) and inhibitine (N) is not yet known, but 

 factors extracted from muscle are quite effective on the desheathed nerve as 

 shown by the following experiment: 



A sartorius muscle was prepared with its nerve. The nerve was de-sheathed 

 and bathed with Ringer's solution. Application of excitine (carnitine plus 

 taurine) to the nerve caused a sequence of muscle contractions. If the nerve 

 was exposed to an isotonic sodium chloride solution, muscle contractions 

 resulted also and when inhibitine (carnosine plus taurine) was applied to the 

 nerve, contractions ceased at once. 



In contrast to tissues (1) and (3) in which excitation is produced in a similar 

 manner, the tissue (2) produces acetylcholine as transmitter and an end-plate 

 potential as a generator potential. 



The question is now: is there a system in the central nervous system cor- 

 responding to the above two, that is a tissue producing acetylcholine and 

 "end-plate potential"? 



(1) When an appropriate concentration of metrazol is apphed directly to 

 the grey matter of the motor cortex of the brain of dogs, a seizure occurs. If, 

 however, this drug is applied to the white matter, seizures do not occur. The 

 same was found for any other convulsants. On the other hand, it is known 

 that electrical stimulation is effective in both the grey matter as well as the 

 white matter. We have, therefore, beheved that a chemical stimulation acts 

 only on soma and dendrite but not on the pathways of the central nervous 

 system. 



(2) Soma and dendrite are characterized by "excitine (NC)" and "inhibitine 

 (NC)" as shown before. How about the pathway ? On the basis of experiments 

 in which we apphed carnitine with taurine as well as carnosine with taurine, 

 crude excitine and GABOB to the motor cortex and to the cerebral spinal 

 fluid in various combinations, we conclude that soma and dendrite have an 

 "excitine" and "inhibitine" different from that which is active in the nerve 

 fibres (the pathway). The results of the experiments follow. 



We would hke to call the excitine and inhibitine of pathways excitine (P) 

 and inhibitine (P). It can be seen that the effect of crude excitine (NC) could 

 not be inhibited by carnosine (the peripiieral inhibitine (N)) and that carnitine 

 (the peripheral excitine (N)) had an effect on central nerve tissue. The excitine 

 (NC) is neutralized only by GABOB while the carnitine-taurine complex is 

 neutrahzed only by carnosine-taurine. GABOB does not neutrahze carnitine- 

 taurine, and carnosine-taurine does not neutrahze excitine (NC). We, there- 

 fore, have a special excitine-inhibitine system for soma and dendrites and 

 another one for the pathway. 



