Impulse Activity and Pattern of Large and Small Neurones in the Cardiac Ganglion of the Lobster, Panulirus Japonicus

Open Access
Publisher Website
Google Scholar
Abstract
1. Single-unit analysis was made by means of internal and external recordings in order to observe the impulse activity of the component neurones in the lobster cardiac ganglion. 2. The large cells fired a brief high-frequency train of postsynaptic impulses in the axonal region by repetitive synaptic activation from small cells which was brought about in the soma-dendritic regions. They generated slow potentials with repetitive impulses by themselves when without synaptic controls. 3. A long-lasting train of presynaptic impulses was propagated from the small pacemaker neurone to the large-cell somata, inducing small synaptic potentials. The burst activity of the ganglion was initiated by this neurone. 4. Impulses of different kinds, presynaptic or postsynaptic, were observed in small cells. This activity occurred at about the same time as that of the pacemaker neurone and was of almost the same duration. 5. Synchronizing mechanisms of all nine neurones were discussed with respect to electrotonic interaction mediated by slow potentials, compared to synaptic interaction mediated by impulses.