Control of the motor pattern generator in the VIIth abdominal ganglion of Locusta: Descending neural inhibition and coordination with the oviposition hole digging central pattern generator

1996 ◽  
Vol 42 (8) ◽  
pp. 791-798 ◽  
Author(s):  
Giovanni Facciponte ◽  
Angela B. Lange
Keyword(s):  
Central Pattern Generator ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Abdominal Ganglion ◽  
Neural Inhibition

scholarly journals Lesions of abdominal connectives reveal a conserved organization of the calling song central pattern generator (CPG) network in different cricket species

2021 ◽  
Author(s):  
Chu-Cheng Lin ◽  
Berthold Hedwig
Keyword(s):  
Central Pattern Generator ◽  
Sound Production ◽  
Motor Pattern ◽  
Phrase Structure ◽  
Pattern Generator ◽  
Abdominal Ganglion ◽  
Calling Song ◽  
Metathoracic Ganglion ◽  
Singing Activity ◽  
Species Specific

AbstractAlthough crickets move their front wings for sound production, the abdominal ganglia house the network of the singing central pattern generator. We compared the effects of specific lesions to the connectives of the abdominal ganglion chain on calling song activity in four different species of crickets, generating very different pulse patterns in their calling songs. In all species, singing activity was abolished after the connectives between the metathoracic ganglion complex and the first abdominal ganglion A3 were severed. The song structure was lost and males generated only single sound pulses when connectives between A3 and A4 were cut. Severing connectives between A4 and A5 had no effect in the trilling species, it led to an extension of chirps in a chirping species and to a loss of the phrase structure in two Teleogryllus species. Cutting the connectives between A5 and A6 caused no or minor changes in singing activity. In spite of the species-specific pulse patterns of calling songs, our data indicate a conserved organisation of the calling song motor pattern generating network. The generation of pulses is controlled by ganglia A3 and A4 while A4 and A5 provide the timing information for the chirp and/or phrase structure of the song.

Gating of Afferent Input by a Central Pattern Generator

1999 ◽  
Vol 81 (2) ◽  
pp. 950-953 ◽  
Author(s):  
Ralph A. DiCaprio
Keyword(s):  
Central Pattern Generator ◽  
Sensory Input ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Afferent Input ◽  
Inhibitory Input ◽  
Cycle Period ◽  
Intracellular Recordings ◽  
Afferent Fibers ◽  
Sufficient Magnitude

Gating of afferent input by a central pattern generator. Intracellular recordings from the sole proprioceptor (the oval organ) in the crab ventilatory system show that the nonspiking afferent fibers from this organ receive a cyclic hyperpolarizing inhibition in phase with the ventilatory motor pattern. Although depolarizing and hyperpolarizing current pulses injected into a single afferent will reset the ventilatory motor pattern, the inhibitory input is of sufficient magnitude to block afferent input to the ventilatory central pattern generator (CPG) for ∼50% of the cycle period. It is proposed that this inhibitory input serves to gate sensory input to the ventilatory CPG to provide an unambiguous input to the ventilatory CPG.

Fast Synaptic Connections From CBIs to Pattern-Generating Neurons in Aplysia: Initiation and Modification of Motor Programs

2003 ◽  
Vol 89 (4) ◽  
pp. 2120-2136 ◽  
Author(s):  
Itay Hurwitz ◽  
Irving Kupfermann ◽  
Klaudiusz R. Weiss
Keyword(s):  
Central Pattern Generator ◽  
Motor Pattern ◽  
Aplysia Californica ◽  
Pattern Generator ◽  
Synaptic Connections ◽  
Motor Patterns ◽  
Motor Programs ◽  
Postsynaptic Potentials ◽  
Buccal Ganglia ◽  
Very High

Consummatory feeding movements in Aplysia californica are organized by a central pattern generator (CPG) in the buccal ganglia. Buccal motor programs similar to those organized by the CPG are also initiated and controlled by the cerebro-buccal interneurons (CBIs), interneurons projecting from the cerebral to the buccal ganglia. To examine the mechanisms by which CBIs affect buccal motor programs, we have explored systematically the synaptic connections from three of the CBIs (CBI-1, CBI-2, CBI-3) to key buccal ganglia CPG neurons (B31/B32, B34, and B63). The CBIs were found to produce monosynaptic excitatory postsynaptic potentials (EPSPs) with both fast and slow components. In this report, we have characterized only the fast component. CBI-2 monosynaptically excites neurons B31/B32, B34, and B63, all of which can initiate motor programs when they are sufficiently stimulated. However, the ability of CBI-2 to initiate a program stems primarily from the excitation of B63. In B31/B32, the size of the EPSPs was relatively small and the threshold for excitation was very high. In addition, preventing firing in either B34 or B63 showed that only a block in B63 firing prevented CBI-2 from initiating programs in response to a brief stimulus. The connections from CBI-2 to the buccal ganglia neurons showed a prominent facilitation. The facilitation contributed to the ability of CBI-2 to initiate a BMP and also led to a change in the form of the BMP. The cholinergic blocker hexamethonium blocked the fast EPSPs induced by CBI-2 in buccal ganglia neurons and also blocked the EPSPs between a number of key CPG neurons within the buccal ganglia. CBI-2 and B63 were able to initiate motor patterns in hexamethonium, although the form of a motor pattern was changed, indicating that non-hexamethonium-sensitive receptors contribute to the ability of these cells to initiate bursts. By contrast to CBI-2, CBI-1 excited B63 but inhibited B34. CBI-3 excited B34 and not B63. The data indicate that CBI-1, -2, and -3 are components of a system that initiates and selects between buccal motor programs. Their behavioral function is likely to depend on which combination of CBIs and CPG elements are activated.

scholarly journals Output variability across animals and levels in a motor system

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Angela Wenning ◽  
Brian J Norris ◽  
Cengiz Günay ◽  
Daniel Kueh ◽  
Ronald L Calabrese
Keyword(s):  
Life History ◽  
Central Pattern Generator ◽  
Motor Neurons ◽  
Motor System ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Phase Relations ◽  
The Other ◽  
Output Variability ◽  
Rhythmic Behaviors

Rhythmic behaviors vary across individuals. We investigated the sources of this output variability across a motor system, from the central pattern generator (CPG) to the motor plant. In the bilaterally symmetric leech heartbeat system, the CPG orchestrates two coordinations in the bilateral hearts with different intersegmental phase relations (Δϕ) and periodic side-to-side switches. Population variability is large. We show that the system is precise within a coordination, that differences in repetitions of a coordination contribute little to population output variability, but that differences between bilaterally homologous cells may contribute to some of this variability. Nevertheless, much output variability is likely associated with genetic and life history differences among individuals. Variability of Δϕ were coordination-specific: similar at all levels in one, but significantly lower for the motor pattern than the CPG pattern in the other. Mechanisms that transform CPG output to motor neurons may limit output variability in the motor pattern.

Evolution of air-breathing and central CO(2)/H(+) respiratory chemosensitivity: new insights from an old fish?

2000 ◽  
Vol 203 (22) ◽  
pp. 3505-3512 ◽  
Author(s):  
R.J. Wilson ◽  
M.B. Harris ◽  
J.E. Remmers ◽  
S.F. Perry
Keyword(s):  
Central Pattern Generator ◽  
Motor Pattern ◽  
Lung Ventilation ◽  
Pattern Generator ◽  
Motor Patterns ◽  
Air Breathing ◽  
Longnose Gar ◽  
Isolated Brainstem

While little is known of the origin of air-breathing in vertebrates, primitive air breathers can be found among extant lobe-finned (Sarcopterygii) and ray-finned (Actinopterygii) fish. The descendents of Sarcopterygii, the tetrapods, generate lung ventilation using a central pattern generator, the activity of which is modulated by central and peripheral CO(2)/H(+) chemoreception. Air-breathing in Actinopterygii, in contrast, has been considered a ‘reflexive’ behaviour with little evidence for central CO(2)/H(+) respiratory chemoreceptors. Here, we describe experiments using an in vitro brainstem preparation of a primitive air-breathing actinopterygian, the longnose gar Lepisosteus osseus. Our data suggest (i) that gill and air-breathing motor patterns can be produced autonomously by the isolated brainstem, and (ii) that the frequency of the air-breathing motor pattern is increased by hypercarbia. These results are the first evidence consistent with the presence of an air-breathing central pattern generator with central CO(2)/H(+) respiratory chemosensitivity in any primitive actinopterygian fish. We speculate that the origin of the central neuronal controller for air-breathing preceded the divergence of the sarcopterygian and actinopterygian lineages and dates back to a common air-breathing ancestor.

scholarly journals The central pattern generator underlying swimming in Dendronotus iris: a simple half-center network oscillator with a twist

2016 ◽  
Vol 116 (4) ◽  
pp. 1728-1742 ◽  
Author(s):  
Akira Sakurai ◽  
Paul S. Katz
Keyword(s):  
Central Pattern Generator ◽  
Body Wall ◽  
Impulse Activity ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Excitatory Synapse ◽  
Dynamic Clamp ◽  
Motor Patterns ◽  
The Brain ◽  
Excitatory Drive

The nudibranch mollusc, Dendronotus iris, swims by rhythmically flexing its body from left to right. We identified a bilaterally represented interneuron, Si3, that provides strong excitatory drive to the previously identified Si2, forming a half-center oscillator, which functions as the central pattern generator (CPG) underlying swimming. As with Si2, Si3 inhibited its contralateral counterpart and exhibited rhythmic bursts in left-right alternation during the swim motor pattern. Si3 burst almost synchronously with the contralateral Si2 and was coactive with the efferent impulse activity in the contralateral body wall nerve. Perturbation of bursting in either Si3 or Si2 by current injection halted or phase-shifted the swim motor pattern, suggesting that they are both critical CPG members. Neither Si2 nor Si3 exhibited endogenous bursting properties when activated alone; activation of all four neurons was necessary to initiate and maintain the swim motor pattern. Si3 made a strong excitatory synapse onto the contralateral Si2 to which it is also electrically coupled. When Si3 was firing tonically but not exhibiting bursting, artificial enhancement of the Si3-to-Si2 synapse using dynamic clamp caused all four neurons to burst. In contrast, negation of the Si3-to-Si2 synapse by dynamic clamp blocked ongoing swim motor patterns. Together, these results suggest that the Dendronotus swim CPG is organized as a “twisted” half-center oscillator in which each “half” is composed of two excitatory-coupled neurons from both sides of the brain, each of which inhibits its contralateral counterpart. Consisting of only four neurons, this is perhaps the simplest known network oscillator for locomotion.

scholarly journals Feedback From Peripheral Musculature to Central Pattern Generator in the Neurogenic Heart of the Crab Callinectes sapidus: Role of Mechanosensitive Dendrites

2010 ◽  
Vol 103 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Keyla García-Crescioni ◽  
Timothy J. Fort ◽  
Estee Stern ◽  
Vladimir Brezina ◽  
Mark W. Miller
Keyword(s):  
Motor Neuron ◽  
Central Pattern Generator ◽  
Motor Neurons ◽  
Callinectes Sapidus ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Neuron Spike ◽  
Effector System ◽  
Spike Bursts

The neurogenic heart of decapod crustaceans is a very simple, self-contained, model central pattern generator (CPG)-effector system. The CPG, the nine-neuron cardiac ganglion (CG), is embedded in the myocardium itself; it generates bursts of spikes that are transmitted by the CG's five motor neurons to the periphery of the system, the myocardium, to produce its contractions. Considerable evidence suggests that a CPG-peripheral loop is completed by a return feedback pathway through which the contractions modify, in turn, the CG motor pattern. One likely pathway is provided by dendrites, presumably mechanosensitive, that the CG neurons project into the adjacent myocardial muscle. Here we have tested the role of this pathway in the heart of the blue crab, Callinectes sapidus . We performed “de-efferentation” experiments in which we cut the motor neuron axons to the myocardium and “de-afferentation” experiments in which we cut or ligated the dendrites. In the isolated CG, these manipulations had no effect on the CG motor pattern. When the CG remained embedded in the myocardium, however, these manipulations, interrupting either the efferent or afferent limb of the CPG-peripheral loop, decreased contraction amplitude, increased the frequency of the CG motor neuron spike bursts, and decreased the number of spikes per burst and burst duration. Finally, passive stretches of the myocardium likewise modulated the spike bursts, an effect that disappeared when the dendrites were cut. We conclude that feedback through the dendrites indeed operates in this system and suggest that it completes a loop through which the system self-regulates its activity.

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.

A Central Pattern Generator Producing Alternative Outputs: Temporal Pattern of Premotor Activity

2006 ◽  
Vol 96 (1) ◽  
pp. 309-326 ◽  
Author(s):  
Brian J. Norris ◽  
Adam L. Weaver ◽  
Lee G. Morris ◽  
Angela Wenning ◽  
Paul A. García ◽  
...  
Keyword(s):  
Central Pattern Generator ◽  
Motor Neurons ◽  
Coordination Mode ◽  
Motor Pattern ◽  
Quantitative Description ◽  
Extracellular Recording ◽  
Pattern Generator ◽  
Regular Feature ◽  
Phase Constancy ◽  
Activity State

The central pattern generator for heartbeat in medicinal leeches constitutes seven identified pairs of segmental heart interneurons. Four identified pairs of heart interneurons make a staggered pattern of inhibitory synaptic connections with segmental heart motor neurons. Using extracellular recording from multiple interneurons in the network in 56 isolated nerve cords, we show that this pattern generator produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons. This pattern corresponds to a similarly asymmetric fictive motor pattern in heart motor neurons and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. We provide a quantitative description of the firing pattern of all the premotor interneurons, including phase, duty cycle, and intraburst frequency of this premotor activity pattern. This analysis identifies two stereotypical coordination modes corresponding to synchronous and peristaltic, which show phase constancy over a broad range of periods as do the fictive motor pattern and the heart constriction pattern. Coordination mode is controlled through one segmental pair of heart interneurons (switch interneurons). Side-to-side switches in coordination mode are a regular feature of this pattern generator and occur with changes in activity state of these switch interneurons. Associated with synchronous coordination of premotor interneurons, the ipsilateral switch interneuron is in an active state, during which it produces rhythmic bursts, whereas associated with peristaltic coordination, the ipsilateral switch interneuron is largely silent. We argue that timing and pattern elaboration are separate functions produced by overlapping subnetworks in the heartbeat central pattern generator.

scholarly journals Animal-to-animal variability in the phasing of the crustacean cardiac motor pattern: an experimental and computational analysis

2013 ◽  
Vol 109 (10) ◽  
pp. 2451-2465 ◽  
Author(s):  
Alex H. Williams ◽  
Molly A. Kwiatkowski ◽  
Adam L. Mortimer ◽  
Eve Marder ◽  
Mary Lou Zeeman ◽  
...  
Keyword(s):  
Central Pattern Generator ◽  
Motor Pattern ◽  
Random Parameter ◽  
Homarus Americanus ◽  
Pattern Generator ◽  
Small Cells ◽  
Excitatory Synapses ◽  
Cycle Frequency ◽  
Duty Cycles

The cardiac ganglion (CG) of Homarus americanus is a central pattern generator that consists of two oscillatory groups of neurons: “small cells” (SCs) and “large cells” (LCs). We have shown that SCs and LCs begin their bursts nearly simultaneously but end their bursts at variable phases. This variability contrasts with many other central pattern generator systems in which phase is well maintained. To determine both the consequences of this variability and how CG phasing is controlled, we modeled the CG as a pair of Morris-Lecar oscillators coupled by electrical and excitatory synapses and constructed a database of 15,000 simulated networks using random parameter sets. These simulations, like our experimental results, displayed variable phase relationships, with the bursts beginning together but ending at variable phases. The model suggests that the variable phasing of the pattern has important implications for the functional role of the excitatory synapses. In networks in which the two oscillators had similar duty cycles, the excitatory coupling functioned to increase cycle frequency. In networks with disparate duty cycles, it functioned to decrease network frequency. Overall, we suggest that the phasing of the CG may vary without compromising appropriate motor output and that this variability may critically determine how the network behaves in response to manipulations.

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