ACTION CURRENTS OF THE SINGLE LATERAL-LINE NERVE FIBER OF FISH

1. ON THE SPONTANEOUS DISCHARGE

抄録

1. The lateral-line nerve of Japanese eel yields vigorous spontaneous dischargesas many other fishes do.
2. These spontaneous discharges are much influenced by temperature of the externalmilieu.
3. Each fiber of this nerve refers to a certain limited skin area of 7-10mm. in length along the lateral-line. This is a sensory unit.
4. The spike discharges of a single fiber of this nerve vary in size. Some arelarge and the others are small.
5. These spontaneous discharges occur quasi-periodically and the average frequency of small spikes is higher than-that of large spikes. In stimulation of the receptor, however, the frequency of the large spikes become much higher than that of small spikes. Naturally large spikes are elicited from thick fibers and small spikes from thin fibers.
6. The statistical treatment of the spike-intervals shows that most of these spike discharges occur at random, owing to the changes of the external as well as internal environments.
7. Some of these discharges have a relatively high correlation with the heartbeat.
8. Histologically the lateral-line organ of the fish shows, even in its fine structure, a marked similarity to the Corti's organ of the higher mammal.
9. The intimate relationship between the spontaneous discharges of the fibers of this nerve and the heart-beat is suggestive of the mechanism of the human ear-tinnitus.
10. A few thicker fibers and many thinner fibers innervate together a receptor, each innervating different groups of sensory cells respectively.
11. It seems probable that the thinner fibers are related to the threshold, that is, to the perception of stimuli, and thicker fibers to the discrimination of sensation.