The mechanism of the burst formation in the cardiac ganglion of the lobster (Panulirus japonicus): A re-examination
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Electrical interaction among the ganglion cells in the heart of the lobster (Panulirus japonicus) was studied using intracellular microelectrodes, attention being focused on the identification of the direct driver of the anterior four large cells, i.e. the presynaptic cell responsible for the large EPSPs seen in these cells.
The direct driver was thought to be Cell 5, the most posterior large cell, since (1) spike-like potentials were recorded from Cell 5, just preceding the large EPSPs (Fig.1), (2) intracellular stimulation of Cell 5 caused the large EPSPs (Fig.3), and (3) intracellular stimulation of Cell 6, which was reported to be the direct driver by Friesen (1975b), caused small EPSPs (Fig.4).
Depolarization imposed on an anterior large cell induced a slow potential followed by an after-hyperpolarization in the adjacent large cell. Strong depolarization resulted in the large EPSPs super-imposed on the slow potential (Fig.8), suggesting that the imposed depolarization with the induced slow potential elicited spikes of the direct driver. This result implies a possible feedback from the anterior large cells to their direct driver, Cell 5, through electrotonic spread of slow potential changes.
Simultaneous recordings from the ganglion cells suggested that the small cell was innervated by more posterior cells and by one of the more anterior small cells (Figs. 5 and 6).
Cell 9 showed EPSPs with marked antifacilitation (Fig. 5), resembling the anterior large cells rather than the other small cells.
The large cells did not show any burst activity when the activity of the small pacemaker cell was inhibited by injecting a long hyperpolarizing current into Cell 5 or a small cell (Fig.9), suggesting that the large cells are not the endogenous bursters under the experimental conditions used. Based on these results, the mechanism of the burst formation was considered.
KeywordsGanglion Cell Large Cell Pacemaker Cell Slow Potential Direct Driver
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- Alexandrowicz JS (1932) The innervation of the heart of the Crustacea. I. Decapoda. Q J Microsc Sci 75:181–249Google Scholar
- Bullock TH, Terzuolo C (1957) Diverse forms of activity in the somata of spontaneous and integrating ganglion cells. J Physiol 138:341–364Google Scholar
- Friesen WD (1975a) Physiological anatomy and burst pattern in the cardiac ganglion of the spiny lobsterPanulirus interruptus. J Comp Physiol 101:173–189Google Scholar
- Friesen WD (1975b) Synaptic interaction in the cardiac ganglion of the spiny lobsterPanulirus interruptus. J Comp Physiol 101:191–205Google Scholar
- Hagiwara S, Bullock TH (1957) Intracellular potentials in pacemaker and integrative neurons of the lobster cardiac ganglion. J Cell Comp Physiol 50:25–47Google Scholar
- Hagiwara S, Watanabe A, Saito N (1959) Potential changes in syncytial neurons of the lobster cardiac ganglion. J Neurophysiol 22:554–572Google Scholar
- Hartline DK (1979) Integrative neurophysiology of the lobster cardiac ganglion. Am Zool 19:53–65Google Scholar
- Kuramoto T, Kuwasawa K (1980) Ganglionic activation of the myocardium of the lobster,Panulirus japonicus. J Comp Physiol 139:67–76Google Scholar
- Matsui K (1955) Spontaneous discharges of the isolated ganglionic trunk of the lobster heart (Panulirus japonicus). Sci Rep Tokyo Kyoiku Daigaku B 7:257–268Google Scholar
- Matsui K, Ebara A, Ai N (1972) Changes in the electrical activity of the lobster cardiac ganglion caused by local application of high calcium or high potassium solutions. Jpn J Physiol 22:121–134Google Scholar
- Matsui K, Kuwasawa K, Kuramoto T (1977) Periodic bursts in large cell preparations of the lobster cardiac ganglion (Panulirus japonicus). Comp Biochem Physiol 56 A:313–324Google Scholar
- Maynard DM (1955) Activity in a crustacean ganglion. II. Pattern and interaction in burst formation. Biol Bull 109:420–436Google Scholar
- Tameyasu T (1976) Intracellular potentials in the small cells and cellular interaction in the cardiac ganglion of the lobsterPanulirus japonicus. Comp Biochem Physiol 54A: 191–196Google Scholar
- Tazaki K (1971) Small synaptic potentials in burst activity of neurons in the lobster cardiac ganglion. Jpn J Physiol 21:645–658Google Scholar
- Watanabe A (1958) The interaction of electrical activity among neurons of lobster cardiac ganglion. Jpn J Physiol 8:305–318Google Scholar
- Watanabe A, Bullock TH (1960) Modulation of activity of one neuron by subthreshold slow potentials in another in lobster cardiac ganglion. J Gen Physiol 43:1031–1045Google Scholar