On the automaticity of the respiratory centers of the catfish and crucian carp.

The problem as to whether the respiratory centers of fishes are endowed with the ability to discharge with inherent rhythmicity or not seems not to have been extensively studied. We have not been able to find any paper except that of Adrian and Buytendijk (1) in this field of research. They studied this problem on the goldfish, and recorded slow potential changes with the respiratory rhythm from the isolated brain stem (optic lobes and medulla oblongata) of the animal. They are of opinion that this slow potential change reflects a slow development and decline of the excitatory state of the nerve cells in the respiratory centers, and that the rhythmic activity of the respiratory centers can occur in the entire absence of sensory impulses. Recently we have studied the problem related to the automaticity of the respiratory centers on the catfish as well as carassius auratus by means of methods which are different from those used by the authors described above; the results of the experiments are reported in the following: