scholarly journals Control of a central pattern generator by an identified modulatory interneurone in crustacea. II. Induction and modification of plateau properties in pyloric neurones

1983 ◽  
Vol 105 (1) ◽  
pp. 59-82
Author(s):  
P. S. Dickinson ◽  
F. Nagy
Keyword(s):  
Motor Pattern ◽  
Pattern Generator ◽  
Membrane Properties ◽  
Plateau Potentials ◽  
Stomatogastric Nervous System ◽  
Experimental Conditions ◽  
Pyloric Network ◽  
Synaptic Interactions ◽  
Voltage Dependent ◽  
A Current

In the isolated stomatogastric nervous system of the lobster Fasus lalandii, the strong modifications of the pyloric motor pattern induced by firing of the single anterior pyloric modulator neurone (APM) are due primarily to modulation by APM activity of the regenerative membrane properties which are responsible for the ‘burstiness’ of all the pyloric neurones and particularly of the non-pacemaker neurones (constrictor motoneurones). This modulation has been studied under experimental conditions where the main extrinsic influences usually received by the pyloric constrictor neurones (intra-network synaptic interactions, activity of pacemaker neurones, and phasic central inputs from two premotor centres) are minimal. Under these conditions a brief discharge of neurone APM induces long plateaus of firing in all of the pyloric neurones. The non-pacemaker neurones of the pyloric network are not simply passive follower neurones, but can produce regenerative depolarizations (plateau potentials) during which the neurones fire spikes. The ability of the pyloric constrictor neurones to produce plateau potentials (plateau properties) contributes greatly to the generation of the rhythmical pyloric motor pattern. When these neurones spontaneously express their plateau properties, firing of neurone APM amplifies these properties. When most of the central inputs usually received by the pyloric constrictor neurones are experimentally suppressed, these neurones can no longer produce plateau potentials. In such conditions, firing of the single modulatory neurone APM can reinduce plateau properties of the pyloric constrictor neurones. In addition, firing in APM neurone slows down the active repolarization phase which terminates the plateau potentials of pyloric constrictor neurones. This effect is long-lasting and voltage-dependent. Modulation by APM of the plateau properties of the pyloric neurones also changes the sensitivity of these neurones to synaptic inputs. This effect can explain the strong modifications that an APM discharge exerts on a current pyloric motor pattern. Moreover, it might render the motoneurones of the pyloric pattern generator more sensitive to inputs from a command oscillator, and contribute to switching on the pyloric motor pattern.

Slow active potentials and bursting motor patterns in pyloric network of the lobster, Panulirus interruptus

1982 ◽  
Vol 48 (4) ◽  
pp. 914-937 ◽  
Author(s):  
D. F. Russell ◽  
D. K. Hartline
Keyword(s):  
Motor Pattern ◽  
Membrane Properties ◽  
Plateau Potentials ◽  
Motor Patterns ◽  
Potential Oscillations ◽  
Panulirus Interruptus ◽  
Pyloric Network ◽  
Current Pulses ◽  
Voltage Dependent ◽  
High Level

1. Neurons in the central pattern generator for the "pyloric" motor rhythm of the lobster stomatogastric ganglion were investigated for the possible involvement of regenerative membrane properties in their membrane-potential oscillations and bursting output patterns. 2. Evidence was found that each class of pyloric-system neurons can possess a capability for generating prolonged regenerative depolarizations by a voltage-dependent membrane mechanism. Such responses have been termed plateau potentials. 3. Several tests were applied to determine whether a given cell possessed a plateau capability. First among these was the ability to trigger all-or-none bursts of nerve impulses by brief depolarizing current pulses and to terminate bursts in an all-or-none fashion with brief hyperpolarizing current pulses. Tests were made under conditions of a high level of activity in the pyloric generator, often in conjunction with the use of hyperpolarizing offsets to the cell under test to suppress ongoing bursting. 4. For each class, the network of synaptic interconnections among the pyloric-system neurons was shown to not be the cause of the regenerative responses observed. 5. Plateau potentials are viewed as a driving force for axon spiking during bursts and as interacting with the synaptic network in the formation of the pyloric motor pattern.

Excitatory Postsynaptic Potentials Trigger a Plateau Potential in Rat Subthalamic Neurons at Hyperpolarized States

2001 ◽  
Vol 86 (4) ◽  
pp. 1816-1825 ◽  
Author(s):  
Takeshi Otsuka ◽  
Fujio Murakami ◽  
Wen-Jie Song
Keyword(s):  
Basal Ganglia ◽  
Membrane Properties ◽  
Dependent Manner ◽  
Excitatory Postsynaptic Potentials ◽  
Plateau Potentials ◽  
Postsynaptic Potentials ◽  
Plateau Potential ◽  
Voltage Dependent ◽  
Subthalamic Neurons ◽  
The Stability

The subthalamic nucleus (STN) directly innervates the output structures of the basal ganglia, playing a key role in basal ganglia function. It is therefore important to understand the regulatory mechanisms for the activity of STN neurons. In the present study, we aimed to investigate how the intrinsic membrane properties of STN neurons interact with their synaptic inputs, focusing on their generation and the properties of the long-lasting, plateau potential. Whole cell recordings were obtained from STN neurons in slices prepared from postnatal day 14 (P14) to P20 rats. We found that activation of glutamate receptor-mediated excitatory synaptic potentials (EPSPs) evoked a plateau potential in a subpopulation of STN neurons ( n = 13/22), in a voltage-dependent manner. Plateau potentials could be induced only when the cell was hyperpolarized to more negative than about −75 mV. Plateau potentials, evoked with a depolarizing current pulse, again only from a hyperpolarized state, were observed in about half of STN neurons tested ( n = 162/327). Only in neurons in which a plateau potential could be evoked by current injection did EPSPs evoke plateau potentials. L-type Ca2+ channels, Ca2+-dependent K+ channels, and TEA-sensitive K+ channels were found to be involved in the generation of the potential. The stability of the plateau potential, tested by the injection of a negative pulse current during the plateau phase, was found to be robust at the early phase of the potential, but decreased toward the end. As a result the early part of the plateau potential was resistant to membrane potential perturbations and would be able to support a train of action potentials. We conclude that excitatory postsynaptic potentials, evoked in a subpopulation of STN neurons at a hyperpolarized state, activate L-type Ca2+ and other channels, leading to the generation of a plateau potential. Thus about half of STN neurons can transform short-lasting synaptic excitation into a long train of output spikes by voltage-dependent generation of a plateau potential.

Detailed Model of Intersegmental Coordination in the Timing Network of the Leech Heartbeat Central Pattern Generator

2004 ◽  
Vol 91 (2) ◽  
pp. 958-977 ◽  
Author(s):  
Sami H. Jezzini ◽  
Andrew A. V. Hill ◽  
Pavlo Kuzyk ◽  
Ronald L. Calabrese
Keyword(s):  
Central Pattern Generator ◽  
Pattern Generator ◽  
Living System ◽  
Cycle Period ◽  
Intersegmental Coordination ◽  
Experimental Conditions ◽  
Detailed Model ◽  
Distributed Structure ◽  
Synaptic Interactions ◽  
Oscillatory Neuronal Networks

To address the general problem of intersegmental coordination of oscillatory neuronal networks, we have studied the leech heartbeat central pattern generator. The core of this pattern generator is a timing network that consists of two segmental oscillators, each of which comprises two identified, reciprocally inhibitory oscillator interneurons. Intersegmental coordination between the segmental oscillators is mediated by synaptic interactions between the oscillator interneurons and identified coordinating interneurons. The small number of neurons (8) and the distributed structure of the timing network have made the experimental analysis of the segmental oscillators as discrete, independent units possible. On the basis of this experimental work, we have made conductance-based models to explore how intersegmental phase and cycle period are determined. We show that although a previous simple model, which ignored many details of the living system, replicated some essential features of the living system, the incorporation of specific cellular and network properties is necessary to capture the behavior of the system seen under different experimental conditions. For example, spike frequency adaptation in the coordinating interneurons and details of asymmetries in intersegmental connectivity are necessary for replicating driving experiments in which one segmental oscillator was injected with periodic current pulses to entrain the activity of the entire network. Nevertheless, the basic mechanisms of phase and period control demonstrated here appear to be very general and could be used by other networks that produce coordinated segmental motor outflow.

scholarly journals Neuromodulator-evoked synaptic metaplasticity within a central pattern generator network

2012 ◽  
Vol 108 (10) ◽  
pp. 2846-2856 ◽  
Author(s):  
Mark D. Kvarta ◽  
Ronald M. Harris-Warrick ◽  
Bruce R. Johnson
Keyword(s):  
Central Pattern Generator ◽  
Spiny Lobster ◽  
Motor Pattern ◽  
Synaptic Depression ◽  
Pattern Generator ◽  
Chemical Synapse ◽  
Pyloric Network ◽  
Pyloric Dilator ◽  
Synaptic Dynamics ◽  
Chemical Synapses

Synapses show short-term activity-dependent dynamics that alter the strength of neuronal interactions. This synaptic plasticity can be tuned by neuromodulation as a form of metaplasticity. We examined neuromodulator-induced metaplasticity at a graded chemical synapse in a model central pattern generator (CPG), the pyloric network of the spiny lobster stomatogastric ganglion. Dopamine, serotonin, and octopamine each produce a unique motor pattern from the pyloric network, partially through their modulation of synaptic strength in the network. We characterized synaptic depression and its amine modulation at the graded synapse from the pyloric dilator neuron to the lateral pyloric neuron (PD→LP synapse), driving the PD neuron with both long square pulses and trains of realistic waveforms over a range of presynaptic voltages. We found that the three amines can differentially affect the amplitude of graded synaptic transmission independently of the synaptic dynamics. Low concentrations of dopamine had weak and variable effects on the strength of the graded inhibitory postsynaptic potentials (gIPSPs) but reliably accelerated the onset of synaptic depression and recovery from depression independently of gIPSP amplitude. Octopamine enhanced gIPSP amplitude but decreased the amount of synaptic depression; it slowed the onset of depression and accelerated its recovery during square pulse stimulation. Serotonin reduced gIPSP amplitude but increased the amount of synaptic depression and accelerated the onset of depression. These results suggest that amine-induced metaplasticity at graded chemical synapses can alter the parameters of synaptic dynamics in multiple and independent ways.

PLATEAU POTENTIALS IN AN INSECT MOTONEURONE CAN BE DRIVEN BY SYNAPTIC STIMULATION

1993 ◽  
Vol 176 (1) ◽  
pp. 307-310
Author(s):  
J. C. Hancox ◽  
R. M. Pitman
Keyword(s):  
Central Pattern Generator ◽  
Pattern Generator ◽  
Membrane Properties ◽  
Plateau Potentials ◽  
Ionic Conductances ◽  
Final Output ◽  
Motor Rhythm ◽  
Intrinsic Membrane Properties ◽  
Synaptic Drive

Cyclical patterns of behaviour such as respiration and locomotion are generated by groups of neurones whose output depends not only upon their synaptic interconnections but also on the intrinsic membrane properties of individual cells. For example, the ionic conductances of some neurones in rhythm-generating circuits allow these cells to respond to non-patterned excitatory synaptic drive with ‘plateau’ or ‘driver’ potentials: prolonged, regenerative depolarizations which can drive bursts of impulses and, thereby, contribute to characteristics of the motor rhythm (Russell and Hartline, 1978, 1982; Tazaki and Cooke, 1979a-c, 1983a-c, 1986, 1990). Plateau potentials are not restricted to interneurones of the central pattern generator; they may also be recorded from motoneurones, which form the final output to muscles. Thus, plateau potentials have been recorded from locomotor motoneurones from the crayfish (Sillar and Elson, 1986), lamprey (Wallen and Grillner, 1987), cat (Hounsgaard et al. 1988) and turtle (Hounsgaard and Kiehn, 1989) (see also review by Kiehn, 1991).

Synaptic Modulation of the Interspike Interval Signatures of Bursting Pyloric Neurons

2003 ◽  
Vol 89 (3) ◽  
pp. 1363-1377 ◽  
Author(s):  
Attila Szűcs ◽  
Reynaldo D. Pinto ◽  
Michail I. Rabinovich ◽  
Henry D. I. Abarbanel ◽  
Allen I. Selverston
Keyword(s):  
Interspike Interval ◽  
Synaptic Connectivity ◽  
Stomatogastric Nervous System ◽  
Firing Patterns ◽  
Synaptic Modulation ◽  
Pyloric Network ◽  
Synaptic Interactions ◽  
Pyloric Dilator ◽  
Temporal Structures ◽  
Spike Patterns

The pyloric network of the lobster stomatogastric nervous system is one of the best described assemblies of oscillatory neurons producing bursts of action potentials. While the temporal patterns of bursts have been investigated in detail, those of spikes have received less attention. Here we analyze the intraburst firing patterns of pyloric neurons and the synaptic interactions shaping their dynamics in millisecond time scales not performed before. We find that different pyloric neurons express characteristic, cell-specific firing patterns in their bursts. Nonlinear analysis of the interspike intervals (ISIs) reveals distinctive temporal structures (‘interspike interval signatures’), which are found to depend on the synaptic connectivity of the network. We compare ISI patterns of the pyloric dilator (PD), lateral pyloric (LP), and ventricular dilator (VD) neurons in 1) normal conditions, 2) after blocking glutamatergic synaptic connections, and 3) in various functional configurations of the three neurons. Manipulation of the synaptic connectivity results in characteristic changes in the ISI signatures of the postsynaptic neurons. The intraburst firing pattern of the PD neuron is regularized by the inhibitory synaptic connection from the LP neuron as revealed in current-clamp experiments and also as reconstructed with a dynamic clamp. On the other hand, mutual inhibition between the LP and VD neurons tend to produce more irregular bursts with increased spike jitter. The results show that synaptic interactions fine-tune the output of pyloric neurons. The present data also suggest a way of processing of synaptic information: bursting neurons are capable of encoding incoming signals by altering the fine structure of their intraburst spike patterns.

scholarly journals Control of a central pattern generator by an identified modulatory interneurone in crustacea. I. Modulation of the pyloric motor output

1983 ◽  
Vol 105 (1) ◽  
pp. 33-58 ◽  
Author(s):  
F. Nagy ◽  
P. S. Dickinson
Keyword(s):  
Cell Body ◽  
Pattern Generator ◽  
Stomatogastric Nervous System ◽  
Pyloric Network ◽  
Long Duration ◽  
Rhythmical Activity ◽  
Muscarinic Cholinergic ◽  
Behavioural Significance ◽  
Phase Relationships

In the lobsters Fasus lalandii and Palinurus vulgaris, the rhythmical activity of the pyloric pattern generator of the stomatogastric nervous system is strongly modified by the firing of a single identified interneurone, whose activity we have recorded from the cell body, in vitro. The cell body of this interneurone, the anterior pyloric modulator (APM), is located in the oesophageal ganglion and sends two axons to the stomatogastric ganglion via the inferior oesophageal nerves, the commissural ganglia, the superior oesophageal nerves and the stomatogastric nerve. Firing of neurone APM modifies the activity of all the neurones of the pyloric network, including pacemaker and follower neurones. Its effects are both quantitative (increase in the frequency of the rhythm and in the frequency of spikes within cell bursts) and qualitative (modifications in relative efficacies of the synaptic relationships within the pyloric network, which in turn lead to changes in the phase relationships between the discharges of the neurones). The effects on pyloric activity induced by firing of neurone APM are established slowly (one or two seconds) and are of long duration (ten times the duration of APM's discharge). These modifications most probably involve muscarinic cholinergic receptors. APM's influences on the activity of pyloric neurones appear to be characteristic of a neuromodulatory process and are such that they may be of behavioural significance in the intact animal.

Control of Central Pattern Generators by an Identified Neurone in Crustacea: Activation of the Gastric Mill Motor Pattern by a Neurone Known to Modulate the Pyloric Network

1988 ◽  
Vol 136 (1) ◽  
pp. 53-87
Author(s):  
PATSY S. DICKINSON ◽  
FRÉDÉRIC NAGY ◽  
MAURICE MOULINS
Keyword(s):  
Central Pattern Generator ◽  
Motor Pattern ◽  
Central Pattern Generators ◽  
Rhythmic Activity ◽  
Pattern Generator ◽  
Gastric Mill ◽  
Pyloric Network ◽  
Single Burst ◽  
Pattern Generators ◽  
Synaptic Drive

In the red lobster (Palinurus vulgaris), an identified neurone, the anterior pyloric modulator neurone (APM), which has previously been shown to modulate the output of the pyloric central pattern generator, was shown to modulate the output of the gastric mill central pattern generator. APM activity induced a rhythm when the network was silent and increased rhythmic activity when the network was already active. Rhythmic activity was induced whether APM fired in single bursts, tonically or in repetitive bursts. A single burst in APM induced a rhythm which considerably outlasted the burst, whereas repetitive bursts effectively entrained the gastric oscillator. These modulations involved two major mechanisms. (1) APM induced or enhanced plateau properties in some of the gastric mill neurones. (2) APM activated the extrinsic inputs to the network, thus increasing the excitatory synaptic drive to most of the neurones of the network. As a result, when APM was active, all the neurones of the pattern generator actively participated in the rhythmic activity. By its actions on two separate but behaviourally related neural networks, the APM neurone may be able to control an entire concert of related types of behaviour.

Neurotransmitter Interactions in the Stomatogastric System of the Spiny Lobster: One Peptide Alters the Response of a Central Pattern Generator to a Second Peptide

1997 ◽  
Vol 77 (2) ◽  
pp. 599-610 ◽  
Author(s):  
Patsy S. Dickinson ◽  
Wesley P. Fairfield ◽  
John R. Hetling ◽  
Jane Hauptman
Keyword(s):  
Central Pattern Generator ◽  
Motor Neurons ◽  
Spiny Lobster ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Stomatogastric Nervous System ◽  
Panulirus Interruptus ◽  
State Dependent ◽  
Bursting Activity ◽  
Stomatogastric System

Dickinson, Patsy S., Wesley P. Fairfield, John R. Hetling, and Jane Hauptman. Neurotransmitter interactions in the stomatogastric system of the spiny lobster: one peptide alters the response of a central pattern generator to a second peptide. J. Neurophysiol. 77: 599–610, 1997. Two of the peptides found in the stomatogastric nervous system of the spiny lobster, Panulirus interruptus, interacted to modulate the activity of the cardiac sac motor pattern. In the isolated stomatogastric ganglion, red-pigment-concentrating hormone (RPCH), but not proctolin, activated the bursting activity in the inferior ventricular (IV) neurons that drives the cardiac sac pattern. The cardiac sac pattern normally ceased within 15 min after the end of RPCH superfusion. However, when proctolin was applied within a few minutes of that time, it was likewise able to induce cardiac sac activity. Similarly, proctolin applied together with subthreshold RPCH induced cardiac sac bursting. The amplitude of the excitatory postsynaptic potentials from the IV neurons to the cardiac sac dilator neuron CD2 (1 of the 2 major motor neurons in the cardiac sac system) was potentiated in the presence of both proctolin and RPCH. The potentiation in RPCH was much greater than in proctolin alone. However, the potentiation inproctolin after RPCH was equivalent to that recorded in RPCH alone. Although we do not yet understand the mechanisms for these interactions of the two modulators, this study provides an example of one factor that can determine the “state” of the system that is critical in determining the effect of a modulator that is “state dependent,” and it provides evidence for yet another level of flexibility in the motor output of this system.

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