Pyloric Neuron Morphology in the Stomatogastric Ganglion of the Lobster, Panulirus interruptus

2009 ◽  
Vol 73 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Jeffrey B. Thuma ◽  
William E. White ◽  
Kevin H. Hobbs ◽  
Scott L. Hooper
Keyword(s):  
Stomatogastric Ganglion ◽  
Neuron Morphology ◽  
Panulirus Interruptus

Synaptic regulation of cellular properties and burst oscillations of neurons in gastric mill system of spiny lobsters, Panulirus interruptus

1984 ◽  
Vol 52 (1) ◽  
pp. 54-73 ◽  
Author(s):  
D. F. Russell ◽  
D. K. Hartline
Keyword(s):  
Motor Neurons ◽  
Pattern Generator ◽  
Stomatogastric Ganglion ◽  
Gastric Mill ◽  
Panulirus Interruptus ◽  
Synaptic Regulation ◽  
Gastric Cells ◽  
Current Pulses ◽  
Regenerative Property ◽  
Stimulation Of

The properties of neurons in the stomatogastric ganglion (STG) participating in the pattern generator for the gastric mill rhythm were studied by intracellular current injection under several conditions: during ongoing gastric rhythms, in the nonrhythmic isolated STG, after stimulation of the nerve carrying central nervous system (CNS) inputs to the STG, or under Ba2+ or Sr2+. Slow regenerative depolarizations during ongoing rhythms were demonstrated in the anterior median, cardiopyloric, lateral cardiac, gastropyloric, and continuous inhibitor (AM, CP, LC, GP, and CI) neurons according to criteria such as voltage dependency, burst triggering, and termination by brief current pulses, etc. Experiments showed that regenerative-like behavior was not due to synaptic network interactions. The slow regenerative responses were abolished by isolating the stomatogastric ganglion but could be reestablished by stimulating the input nerve. This indicates that certain CNS inputs synaptically induce the regenerative property in specific gastric neurons. Slow regenerative depolarizations were not demonstrable in gastric mill (GM) motor neurons. Their burst oscillations and firing rate were instead proportional to injected current. CNS inputs evoked a prolonged depolarization in GM motor neurons, apparently by a nonregenerative mechanism. All the gastric cells showed prolonged regenerative potentials under 0.5-1.5 mM Ba2+. We conclude that the gastric neurons of the STG can be divided into three types according to their properties: those with a regenerative capability, a repetitively firing type, and a nonregenerative "proportional" type. The cells are strongly influenced by several types of CNS inputs, including "gastric command fibers."

Properties of synapses made by IVN command-interneurones in the stomatogastric ganglion of the spiny lobster Panulirus interruptus

1982 ◽  
Vol 97 (1) ◽  
pp. 153-168
Author(s):  
K. A. Sigvardt ◽  
B. Mulloney
Keyword(s):  
Membrane Potential ◽  
High Frequency ◽  
Spiny Lobster ◽  
Postsynaptic Membrane ◽  
Stomatogastric Ganglion ◽  
Gastric Mill ◽  
Panulirus Interruptus ◽  
Postsynaptic Potential ◽  
Lateral Posterior ◽  
Conductance Increase

1. The IVN command interneurones synapse directly onto 11 identified neurones in the stomatogastric ganglion: the two pyloric dilators (PDs), the anterior burster (AB), ventricular dilator (VD), the four gastric mill neurones (GMs), the two lateral posterior gastric neurones (LPGNs), and Interneurone I (Int 1). 2. The IVN p.s.p.s in PD and AB are biphasic, and consist of a fast depolarizing component followed by a slower hyperpolarizing component. 3. The hyperpolarizing component of this biphasic postsynaptic potential is inhibitory, and appears to be the result of a conductance increase to K+ and Cl-. 4. The IVN p.s.p. in VD is excitatory and can drive VD one-for-one. 5. The IVN p.s.p.s in GM and LPGN are inhibitory. The amplitude of a single p.s.p. is small but, at high frequency, summation of p.s.p.s holds the postsynaptic membrane potential below threshold. 6. The facilitation characteristics of the p.s.p.s in each neurone are described. 7. The functional significance of these synaptic characteristics is discussed in terms of the modification of motor output caused by a burst of the IVN interneurones.

Dopamine Modulates Graded and Spike-Evoked Synaptic Inhibition Independently at Single Synapses in Pyloric Network of Lobster

1998 ◽  
Vol 79 (4) ◽  
pp. 2063-2069 ◽  
Author(s):  
Amir Ayali ◽  
Bruce R. Johnson ◽  
Ronald M. Harris-Warrick
Keyword(s):  
Action Potential ◽  
Spiny Lobster ◽  
Motor Pattern ◽  
Input Resistance ◽  
Stomatogastric Ganglion ◽  
Synaptic Inhibition ◽  
Panulirus Interruptus ◽  
Pyloric Network ◽  
Bath Application ◽  
Postsynaptic Cell

Ayali, Amir, Bruce R. Johnson, and Ronald M. Harris-Warrick. Dopamine modulates graded and spike-evoked synaptic inhibition independently at single synapses in pyloric network of lobster. J. Neurophysiol. 79: 2063–2069, 1998. Bath application of dopamine (DA) modifies the rhythmic motor pattern generated by the pyloric network in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus. Synaptic transmission between network members is an important target of DA action. All pyloric neurons employ both graded transmitter release and action-potential–mediated synaptic inhibition. DA was previously shown to alter the graded synaptic strength of every pyloric synapse. In this study, we compared DA's effects on action-potential–mediated and graded synaptic inhibition at output synapses of the lateral pyloric (LP) neuron. At each synapse the postsynaptic cell tested was isolated from other descending and pyloric synaptic inputs. DA caused a reduction in the size of the LP spike-evoked inhibitory postsynaptic potentials (IPSPs) in the pyloric dilator (PD) neuron. The change in IPSP size was significantly and linearly correlated with DA-induced reduction in the input resistance of the postsynaptic PD neuron. In contrast, graded inhibition, tested in the same preparations after superfusing the stomatogastric ganglion (STG) with tetrodotoxin (TTX), was consistently enhanced by DA. DA shifted the amplitude of spike-evoked IPSPs in the same direction as the alteration of the postsynaptic cell input resistance at two additional synapses tested: DA weakened the LP spike-mediated inhibition of the ventricular dilator (VD) and reduced the VD input resistance, while strengthening the LP → pyloric constrictor (PY) synapse and increasing PY input resistance. As previously reported, graded inhibition was enhanced at these two LP output synapses. We conclude that DA can differentially modulate the spike-evoked and graded components of synapses between members of a central pattern generator network. At the synapses we studied, actions on the presynaptic cell predominate in the modulation of graded transmission, whereas effects on postsynaptic cells predominate in the regulation of spike-evoked IPSPs.

Amine Modulation of the Transient Potassium Current in Identified Cells of the Lobster Stomatogastric Ganglion

2001 ◽  
Vol 86 (6) ◽  
pp. 2957-2965 ◽  
Author(s):  
Jack H. Peck ◽  
Stan T. Nakanishi ◽  
Ross Yaple ◽  
Ronald M. Harris-Warrick
Keyword(s):  
Firing Rate ◽  
Voltage Clamp ◽  
Potassium Current ◽  
Stomatogastric Ganglion ◽  
Model System ◽  
Panulirus Interruptus ◽  
Pyloric Network ◽  
Electrode Voltage ◽  
Postinhibitory Rebound ◽  
Ionic Changes

The pyloric network of the stomatogastric ganglion of the lobster Panulirus interruptus is a model system used to understand how motor networks change their output to produce a variety of behaviors. The transient potassium current ( I A) shapes the activity of individual pyloric neurons by affecting their rate of postinhibitory rebound and spike frequency. We used two electrode voltage clamp to study the modulatory effects of dopamine (DA), octopamine (OCT), and serotonin (5-HT) on I A in the anterior burster (AB), inferior cardiac (IC), and ventricular dilator (VD) neurons of the pyloric circuit. DA significantly reduced I A in the AB and IC neurons and shifted their voltages of activation ( V act) and inactivation ( V inact) in a depolarized direction. These ionic changes contribute to the depolarization and increased firing rate of the AB and IC neurons produced by DA. Likewise, 5-HT significantly reduced I A and shifted V inact in the depolarized direction in the IC neuron, consistent with 5-HT's enhancement of IC firing. None of the amines evoked significant changes in I A in the VD neuron, suggesting that other currents mediate the amine effects on this neuron.

Aminergic modulation in lobster stomatogastric ganglion. II. Target neurons of dopamine, octopamine, and serotonin within the pyloric circuit

1986 ◽  
Vol 55 (5) ◽  
pp. 866-881 ◽  
Author(s):  
R. E. Flamm ◽  
R. M. Harris-Warrick
Keyword(s):  
Neural Circuit ◽  
Lucifer Yellow ◽  
Spiny Lobster ◽  
Motor Pattern ◽  
Preceding Paper ◽  
Cell Types ◽  
Stomatogastric Ganglion ◽  
Synaptic Organization ◽  
Potential Oscillations ◽  
Panulirus Interruptus

In the preceding paper, we describe how dopamine, octopamine, and serotonin modulate the neural circuit generating a well-described motor pattern, the pyloric rhythm of the stomatogastric ganglion in the spiny lobster, Panulirus interruptus. In this paper, we identify the neurons within the pyloric circuit that are directly affected by each amine. We accomplished this by isolating each pyloric neuron from all known synaptic input, using a combination of Lucifer yellow photoinactivation of presynaptic neurons and pharmacological blockade by pyloric neurotransmitters. Dopamine, octopamine, and serotonin were bath applied to the preparation, and the responses of synaptically isolated neurons were recorded. Each amine had a unique constellation of effects on the neurons of the pyloric circuit. Almost every neuron in the circuit was directly affected by each amine. Dopamine and octopamine modulated every neuron, whereas serotonin affected four of the six cell types. Each amine had multiple effects among pyloric neurons including the induction of endogenous rhythmic bursting activity, initiation or enhancement of tonic firing activity, and inhibition accompanied by hyperpolarization. All three amines induced rhythmic bursting in one neuron (the AB neuron), but the form of the underlying slow-wave membrane-potential oscillations was different with octopamine than with dopamine and serotonin. Our knowledge of the effects of each amine on each pyloric neuron, combined with the extensive knowledge of the synaptic organization of the pyloric circuit, has allowed us to explain qualitatively the major aspects of the unique variants of the pyloric motor rhythm that each amine produces in the synaptically intact circuit.

Pharmacological dissection of pyloric network of the lobster stomatogastric ganglion using picrotoxin

1980 ◽  
Vol 44 (6) ◽  
pp. 1089-1101 ◽  
Author(s):  
M. Bidaut
Keyword(s):  
Stomatogastric Ganglion ◽  
Inhibitory Synapses ◽  
Primary Role ◽  
Panulirus Interruptus ◽  
Pyloric Network ◽  
Pyloric Dilator ◽  
Fast Rise ◽  
Later Phase ◽  
Pyloric Rhythm

1. Picrotoxin (PTX) (10(-7)-10(-6) M) completely blocked most inhibitory synapses in the pyloric pattern generator of the lobster (Panulirus interruptus) stomatogastric ganglion. The sensitivity of synapses from most classes of identified neurons was examined. Blockade was at least partly reversible with prolonged washing. 2. The synapses from pyloric dilator (PD) neurons were the only inhibitory synapses that picrotoxin failed to block completely. 3. A correlation is derived that brief, fast-rise inhibitory postsynaptic potentials (IPSPs) are picrotoxin sensitive, whereas a slow rounded component of IPSPs from PD neurons is not picrotoxin sensitive. 4. Picrotoxin caused specific changes in the pattern of the motor rhythm produced by the 16-cell pyloric network. This sheds some light on the functional role of particular synapses in the pyloric generator. 5. The endogenously bursting neurons (PD and anterior burster (AB)), which drive the pyloric rhythm, kept a similar burst rate. 6. Under picrotoxin, the pyloric "follower" neurons all moved to later phase relative to the "driver" group. Some normally antagonistic cells, related by reciprocal inhibitor connections, became in-phase. These and other pattern changes could be related to blockade of particular synapses. 7. The pyloric rhythm was still quite recognizable under picrotoxin despite the drastically altered circuitry of the synaptic network. This supports the idea that periodic inhibition from the PD driver neurons plays a primary role in creating the pyloric pattern.

Serotonergic innervation and modulation of the stomatogastric ganglion of three decapod crustaceans (Panulirus interruptus, Homarus americanus and Cancer irroratus)

1984 ◽  
Vol 109 (1) ◽  
pp. 35-54 ◽  
Author(s):  
B. Beltz ◽  
J. S. Eisen ◽  
R. Flamm ◽  
R. M. Harris-Warrick ◽  
S. L. Hooper ◽  
...  
Keyword(s):  
High Performance ◽  
Decapod Crustacean ◽  
Homarus Americanus ◽  
Stomatogastric Ganglion ◽  
Decapod Crustaceans ◽  
Panulirus Interruptus ◽  
Cancer Irroratus ◽  
Immunohistochemical Techniques ◽  
Stomatogastric System ◽  
Serotonergic Innervation

The serotonergic innervation of the stomatogastric ganglion (STG) of three decapod crustacean species, Panulirus interruptus, Homarus americanus and Cancer irroratus, was studied. Immunohistochemical techniques were used to study the distribution of serotonin-like staining in regions of the stomatogastric system in the three species. In C. irroratus and H. americanus, but not in P. interruptus, serotonin-like staining was found in fibres in the stomatogastric nerve and in neuropil regions of the STG. High performance liquid chromatography confirmed the presence of serotonin in STG of C. irroratus and H. americanus, but serotonin was not found in STG of P. interruptus. Electrophysiological experiments showed that the pyloric motor output of the STG of all three species was influenced by bath applications of serotonin. The STG of P. interruptus responded to serotonin concentrations as low as 10–9M; however the STG of the other two species did not respond until serotonin concentrations in excess of 10-6M were applied. We conclude that serotonin may play a hormonal role in the control of the STG of P. interruptus, but is likely to be a neurotransmitter released by inputs to the STG of H. americanus and C. irroratus.

Aminergic modulation in lobster stomatogastric ganglion. I. Effects on motor pattern and activity of neurons within the pyloric circuit

1986 ◽  
Vol 55 (5) ◽  
pp. 847-865 ◽  
Author(s):  
R. E. Flamm ◽  
R. M. Harris-Warrick
Keyword(s):  
Biogenic Amines ◽  
Spike Activity ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Stomatogastric Ganglion ◽  
Motor Patterns ◽  
Cycle Frequency ◽  
Panulirus Interruptus ◽  
Generator Circuit ◽  
Phase Relationships

We investigated the effects of dopamine, octopamine, and serotonin on the motor output of the pyloric circuit in the stomatogastric ganglion of the lobster, Panulirus interruptus. Amines were bath applied at concentrations from 10(-8) to 10(-4) M, and the responses of the six classes of pyloric neurons were monitored both intracellularly and extracellularly. Each amine modified the pyloric motor pattern in a specific way. In addition, dopamine and octopamine were each able to produce different motor patterns at different concentrations. Amine effects on pyloric neurons included initiation and enhancement or inhibition of spike activity, changes in the phase relationships of neurons, and changes in the cycle frequency of the pyloric rhythm. These results show that the motor pattern produced by this well-studied central pattern generator circuit is highly plastic and can be modulated by endogenous biogenic amines.

KChIP1 and Frequenin Modify shal-Evoked Potassium Currents in Pyloric Neurons in the Lobster Stomatogastric Ganglion

2003 ◽  
Vol 89 (4) ◽  
pp. 1902-1909 ◽  
Author(s):  
Y. Zhang ◽  
J. N. MacLean ◽  
W. F. An ◽  
C. C. Lanning ◽  
R. M. Harris-Warrick
Keyword(s):  
Potassium Current ◽  
Time Course ◽  
Spiny Lobster ◽  
Stomatogastric Ganglion ◽  
K Channel ◽  
Panulirus Interruptus ◽  
Recovery From Inactivation ◽  
Pyloric Dilator ◽  
Ef Hand ◽  
Firing Properties

The transient potassium current ( I A) plays an important role in shaping the firing properties of pyloric neurons in the stomatogastric ganglion (STG) of the spiny lobster, Panulirus interruptus. The shal gene encodes I A in pyloric neurons. However, when we over-expressed the lobster Shal protein by shal RNA injection into the pyloric dilator (PD) neuron, the increased I A had somewhat different properties from the endogenous I A. The recently cloned K-channel interacting proteins (KChIPs) can modify vertebrate Kv4 channels in cloned cell lines. When we co-expressed hKChIP1 with lobster shal in Xenopusoocytes or lobster PD neurons, they produced A-currents resembling the endogenous I A in PD neurons; compared with currents evoked by shal alone, their voltage for half inactivation was depolarized, their kinetics of inactivation were slowed, and their recovery from inactivation was accelerated. We also co-expressed shal in PD neurons with lobster frequenin, which encodes a protein belonging to the same EF-hand family of Ca2+ sensing proteins as hKChIP. Frequenin also restored most of properties of the shal-evoked currents to those of the endogenous A-currents, but the time course of recovery from inactivation was not corrected. These results suggest that lobster shal proteins normally interact with proteins in the KChIP/frequenin family to produce the transient potassium current in pyloric neurons.

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