Slow Potentials in Spontaneous Ganglion Cells of the Lobster Heart
摘要
The slow potential was recorded from the large cell of the lobster cardiac ganglion, and effects of polarizing currents on its initiation were observed. 1. Depolarization of Cell 5 at a sufficient interval after the preceding slow potential elicited synaptic potentials and slow potential. Hyperpolarization impeded the development of the slow potential. 2. Synaptic potentials occurred repetitively during depolarization. They were evoked by stimulus given at varying phases during the spontaneous activity, differing from the slow potential which was elicited with a critical interval. This fact indicates that the slow potential is the independent depolarization of the membrane of large cell, separated from synaptic potentials. 3. Axon produced trains of full-sized spikes, but it did not exhibit the slow potential, suggesting that the slow potential was generated at the soma and dendrites of large cell. 4. The spontaneous burst of the large cell was composed of the slow potentials and spikes. When the small cells that induced synaptic potentials were inactive, the large cells became pacemakers which initiated only the slow potential with superimposed spikes. 5. Synchronous discharges of the cardiac ganglion are considered to be performed by the coordination of the activities of both large and small cells.