Spontaneous and repetitive driver potentials in crab cardiac ganglion neurons

Berlind, Allan

doi:10.1007/bf00619219

Cited by 18 publications

(18 citation statements)

References 33 publications

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“…For this, it was necessary at the outset to confirm the basic functional topography of the Callinectes cardiac system, even though this could be expected to be in many ways similar to that studied in other crab species. Indeed, the general morphological and physiological features of the Callinectes CG that we have described here (see also Hawkins and House 1978) are in agreement with descriptions in other crabs, including Eriocher japonicus (Tazaki 1972), Podophthalmus vigil (Berlind 1982), and Carcinus maenas (Saver et al 1999). In particular, our characterization enables us to conclude that the number (5), position (3 anterior and 2 posterior), and physiological properties of the motor neurons in the Callinectes system correspond to the previous detailed description of crab cardiac functional anatomy in Portunus sanguinolentus (Tazaki andCooke 1979a,b, 1983a).…”

Section: Functional Topography Of the Callinectes Cardiac Systemsupporting

confidence: 90%

“…In the crab cardiac ganglia that have been investigated to date, the spatiotemporal properties of the electrical coupling and synaptic signaling result in precise synchrony of the motor neuron firing (Berlind 1982;Mirolli et al 1987;Tazaki 1972;Tazaki andCooke 1979a,b, 1983a,b). Simultaneous recording from an anterior motor neuron, a posterior motor neuron, a branch of the anterior connective, and a branch of the posterior connective revealed that such synchrony of firing is also a property of the Callinectes CG (Fig.…”

Section: Functional Topography Of the Callinectes Cardiac Systemmentioning

confidence: 99%

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Modulation of an Integrated Central Pattern Generator–Effector System: Dopaminergic Regulation of Cardiac Activity in the Blue CrabCallinectes sapidus

Fort

Březina²,

Miller³

2004

Journal of Neurophysiology

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Fort, Timothy J., Vladimir Brezina, and Mark W. Miller. Modulation of an integrated central pattern generator-effector system: dopaminergic regulation of cardiac activity in the blue crab Callinectes sapidus. J Neurophysiol 92: 3455-3470, 2004; doi:10.1152/ jn.00550.2004. Theoretical studies have suggested that the output of a central pattern generator (CPG) must be matched to the properties of its peripheral effector system to ensure production of functional behavior. One way that such matching could be achieved is through coordinated central and peripheral modulation. In this study, morphological and physiological methods were used to examine the sources and actions of dopaminergic modulation in the cardiac system of the blue crab, Callinectes sapidus. Immunohistochemical localization of tyrosine hydroxylase (TH) revealed a prominent neuron in the commissural ganglion, the L-cell, that projected a large-diameter axon to the pericardial organ (PO) by an indirect and circuitous route. Within the PO, the L-cell axon gave rise to fine varicose fibers, suggesting that it releases dopamine in a neurohormonal fashion onto the heart musculature. In addition, one branch of the axon continued beyond the PO to the heart, where it innervated the anterior motor neurons and the posterior pacemaker region of the cardiac ganglion (CG). In physiological experiments, exogenous dopamine produced multiple effects on contraction and motor neuron burst parameters that corresponded to the dual central-peripheral modulation suggested by the L-cell morphology. Interestingly, parameters of the ganglionic motor output were modulated differently in the isolated CG and in a novel semiintact system where the CG remained embedded within the heart musculature. These observations suggest a critical role of feedback from the periphery to the CG and underscore the requirement for integration of peripheral (neurohormonal) actions and direct ganglionic modulation in the regulation of this exceptionally simple system.

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Section: Functional Topography Of the Callinectes Cardiac Systemsupporting

confidence: 90%

Section: Functional Topography Of the Callinectes Cardiac Systemmentioning

confidence: 99%

Modulation of an Integrated Central Pattern Generator–Effector System: Dopaminergic Regulation of Cardiac Activity in the Blue CrabCallinectes sapidus

Fort

Březina²,

Miller³

2004

Journal of Neurophysiology

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“…A similar effect of low Ca + +, high Mg ++ saline with added Cd + + is seen on small cell bursting isolated in ligatured Portunus ganglia (Tazaki and Cooke 1983b, c). However, in a second crab species, Podophthalmus vigil, clear small cell bursting persists in 4 mmol/1 Mn + § (Berlind 1982), as it does in the Homarus ganglion. Even in a Portunus ganglion exhibiting repetitive spiking in Mn + +, it is possible to evoke vigorous bursting by perfusion with dopamine (Miller et al 1984).…”

Section: D~cus~onmentioning

confidence: 91%

“…These ions are known to block voltage-dependent Ca ++ channels in many neuronal and non-neuronal systems. When perfused over a normally bursting Portunus ganglion, Mn + + at a concentration of 4 mmol/1 eliminates the bursting behavior, and converts the activity of the large cells to repetitive spike activity at constant frequency (Tazaki and Cooke 1979a, c;Berlind 1982;Miller et al 1984). In preliminary experiments on the cardiac ganglion of the lobster, Mn + + at 4 mmol/1 did not eliminate bursting.…”

Section: Manganese Fails To Eliminate Bursting In Lobster Cardiac Ganmentioning

confidence: 97%

Endogenous burst-organizing potentials in two classes of neurons in the lobster cardiac ganglion respond differently to alterations in divalent ion concentration

Berlind

1985

J. Comp. Physiol.

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Summary. 1. Crustacean cardiac ganglion neurons generate endogenous burst-organizing potentials termed 'driver potentials'. In the five motorneurons ('large cells') in the system these are slow local potentials with the depolarizing current carried by calcium ions. The existence of similar endogenous potentials in the second class of neurons in the ganglion, the four small 'pacemaker' cells, has been postulated primarily on the basis of indirect evidence. The results presented here show that burst-generating mechanisms in the pacemaker neurons and motorneurons respond differently to alterations in the ionic content of the medium, and suggest that driver potentials have different ionic bases in the two cell types. (Homarus americanus) cardiac ganglia persists in altered form in salines containing high levels of manganese (Fig. 1) or reduced calcium (Figs. 3, 4). Both of these ionic alterations suppress driver potentials generated by the motorneurons (Fig. 2). Bursts generated in low-calcium salines were of very long duration. Bursting in isolated lobster3. In low-calcium salines the long-duration bursts resulted from prolonged and intensified discharge of the small pacemaker neurons; motorneuron activity was suppressed as would be predicted from blockade of the large cell driver potentials. These conclusions derive from the use of ligatured preparations, in which a large cell group was functionally isolated from the rest of the ganglion (Fig. 5); from two-pool preparations in which the two classes of cells were perfused independently in different ionic media (Fig. 6); and from ganglia in which one or the other cell type was silenced by selective application of tetrodotoxin (Figs. 7, 8).Abbreviations: DP driver potential; pln posterior lateral nerve; TTX tetrodotoxin; TEA tetraethylammonium 4. These experiments support the idea that driver potentials in the motorneurons are primarily based on inflow of calcium ions, but that a significant proportion of the inward current responsible for the driver potentials in the small pacemaker neurons is carried by an ion other than calcium.5. The results support current models for the roles of endogenous properties and network interactions in determining the pattern of impulse production by the motorneurons; however, the synaptic mechanisms by which the pacemakers influence the motorneurons, which has previously been thought to be mainly chemical in lobsters, appears to contain a significant electrical component.

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“…When the ganglionic trunk is isolated from the surrounding tissues, the system continues to be spontaneously active with each cell generating bursts Of impulses separated by silent periods. The bursts are tightly coordinated, and in some crab species the action potentials of the five large cells are synchronous (Tazaki, 1972;Tazaki & Cooke, I979a;Berlind, 1982). 0300-4864/87 $03.00 + .12 9 1987 Chapman and Hall Ltd.…”

Section: Introductionmentioning

confidence: 98%

Structure and localization of synaptic complexes in the cardiac ganglion of a portunid crab

et al. 1987

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The cardiac ganglion of Portunus sanguinolentus exhibits spontaneous rhythmic activity when isolated. The ganglion contains five large and four small intrinsic neurons and is innervated by three pairs of fibres originating in the thoracic ganglia. We have identified the processes of the large neurons in electron micrographs by injecting these cells with two electron-dense markers, horseradish peroxidase (HRP) and Procion Rubine (PR). In addition we have studied the processes of the four smaller neurons by light microscopy serial reconstructions and by electron microscopy of selected regions. Both markers were found only in neuronal processes and not in glial cells nor in the extracellular space, except close to the soma of the injected cell. We found contacts between the small secondary (collateral) processes of the large cells but not between their somata or their primary processes (axons and dendrites). Two specialized structures present at the contacts between the collateral processes were small membrane close appositions, possibly the site of electrotonic junctions, and chemical synapses. Contacts between processes marked by HRP and those marked by PR were common, as were contacts between processes marked by either HRP or PR and those of the other intrinsic neurons. Adjacent processes stained by PR could contain PR deposits of different densities, but it is unclear whether this finding was due to intercellular diffusion of the dye or to its diffusing at different rates into branches of the same process. Identified processes of all the intrinsic neurons contained the same type of vesicles, which were different from those found in processes of the extrinsic fibres. Chemical synapses were present at contacts between processes of the extrinsic and intrinsic neurons, as well as at contacts between processes of the intrinsic neurons. The axons of three small cells made a series of contacts at which extensive arrays of membrane close appositions, but not chemical synapses, were found. These three axons also formed contacts, either directly or through their collateral branches, with processes of the large cells, at which both membrane close appositions and chemical synapses were present. The axon of the fourth small cell could not be followed in our series.

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Spontaneous and repetitive driver potentials in crab cardiac ganglion neurons

Cited by 18 publications

References 33 publications

Modulation of an Integrated Central Pattern Generator–Effector System: Dopaminergic Regulation of Cardiac Activity in the Blue CrabCallinectes sapidus

Modulation of an Integrated Central Pattern Generator–Effector System: Dopaminergic Regulation of Cardiac Activity in the Blue CrabCallinectes sapidus

Endogenous burst-organizing potentials in two classes of neurons in the lobster cardiac ganglion respond differently to alterations in divalent ion concentration

Structure and localization of synaptic complexes in the cardiac ganglion of a portunid crab

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