scholarly journals Central pattern generation underlying Limulus rhythmic behavior patterns

2010 ◽  
Vol 56 (5) ◽  
pp. 537-549 ◽  
Author(s):  
Gordon A. Wyse
Keyword(s):  
Sensory Input ◽  
Horseshoe Crab ◽  
Neural Circuits ◽  
Activity Patterns ◽  
Central Pattern Generators ◽  
Pattern Generation ◽  
Rhythmic Behavior ◽  
Behavioral Activities ◽  
Pattern Generators ◽  
Rhythmic Behaviors

Abstract Many behavioral activities of the horseshoe crab Limulus are rhythmic, and most of these are produced in large part by central pattern generators within the CNS. The chain of opisthosomal ('abdominal') ganglia controls gill movements of ventilation and gill cleaning, and the prosomal ring of fused ganglia (brain and segmental 'thoracic' ganglia) controls generation of feeding and locomotor movements of the legs. Both the opisthosomal CNS and the prosomal CNS can generate behaviorally appropriate patterns of motor output in isolation, without movements or sensory input. Preparations of the isolated opisthosomal CNS generate rhythmic output patterns of motor activity characterized as fictive ventilatory and gill cleaning rhythms. Moreover, CNS preparations also express longer-term patterns, such as intermittent ventilation or sequential bouts of ventilation and gill cleaning. Such longer-term patterns are commonly observed in intact animals. The isolated prosomal CNS does not spontaneously generate the activity patterns characteristic of walking, swimming, and feeding. However, perfusion of octopamine in the isolated prosomal CNS activates central pattern generators underlying rhythmic chewing movements, and injection of octopamine into intact Limulus promotes the chewing pattern of feeding, whether or not food is presented. Our understanding of the ability of neuromodulators such as octopamine to elicit or alter central motor programs may help to clarify the central neural circuits of pattern generation that produce and coordinate these rhythmic behaviors.

Intrinsic and Extrinsic Modulation of a Single Central Pattern Generating Circuit

2000 ◽  
Vol 84 (3) ◽  
pp. 1186-1193 ◽  
Author(s):  
Peter T. Morgan ◽  
Ray Perrins ◽  
Philip E. Lloyd ◽  
Klaudiusz R. Weiss
Keyword(s):  
Neural Circuits ◽  
Central Pattern Generators ◽  
Motor Program ◽  
Pattern Generator ◽  
Motor Programs ◽  
Appetitive Behavior ◽  
Protraction Phase ◽  
Pattern Generators ◽  
Rhythmic Behaviors ◽  
Appetitive Behaviors

Intrinsic and extrinsic neuromodulation are both thought to be responsible for the flexibility of the neural circuits (central pattern generators) that control rhythmic behaviors. Because the two forms of modulation have been studied in different circuits, it has been difficult to compare them directly. We find that the central pattern generator for biting in Aplysia is modulated both extrinsically and intrinsically. Both forms of modulation increase the frequency of motor programs and shorten the duration of the protraction phase. Extrinsic modulation is mediated by the serotonergic metacerebral cell (MCC) neurons and is mimicked by application of serotonin. Intrinsic modulation is mediated by the cerebral peptide-2 (CP-2) containing CBI-2 interneurons and is mimicked by application of CP-2. Since the effects of CBI-2 and CP-2 occlude each other, the modulatory actions of CBI-2 may be mediated by CP-2 release. Although the effects of intrinsic and extrinsic modulation are similar, the neurons that mediate them are active predominantly at different times, suggesting a specialized role for each system. Metacerebral cell (MCC) activity predominates in the preparatory (appetitive) phase and thus precedes the activation of CBI-2 and biting motor programs. Once the CBI-2s are activated and the biting motor program is initiated, MCC activity declines precipitously. Hence extrinsic modulation prefacilitates biting, whereas intrinsic modulation occurs during biting. Since biting inhibits appetitive behavior, intrinsic modulation cannot be used to prefacilitate biting in the appetitive phase. Thus the sequential use of extrinsic and intrinsic modulation may provide a means for premodulation of biting without the concomitant disruption of appetitive behaviors.

scholarly journals Diversity of molecularly defined spinal interneurons engaged in mammalian locomotor pattern generation

2017 ◽  
Vol 118 (6) ◽  
pp. 2956-2974 ◽  
Author(s):  
Lea Ziskind-Conhaim ◽  
Shawn Hochman
Keyword(s):  
Activity Patterns ◽  
Central Pattern Generators ◽  
Pattern Generation ◽  
Model Systems ◽  
Locomotor Rhythm ◽  
Spinal Interneurons ◽  
Adult Mice ◽  
Descending Fibers ◽  
Experimental Model Systems ◽  
Pattern Generators

Mapping the expression of transcription factors in the mouse spinal cord has identified ten progenitor domains, four of which are cardinal classes of molecularly defined, ventrally located interneurons that are integrated in the locomotor circuitry. This review focuses on the properties of these interneuronal populations and their contribution to hindlimb locomotor central pattern generation. Interneuronal populations are categorized based on their excitatory or inhibitory functions and their axonal projections as predictors of their role in locomotor rhythm generation and coordination. The synaptic connectivity and functions of these interneurons in the locomotor central pattern generators (CPGs) have been assessed by correlating their activity patterns with motor output responses to rhythmogenic neurochemicals and sensory and descending fibers stimulations as well as analyzing kinematic gait patterns in adult mice. The observed complex organization of interneurons in the locomotor CPG circuitry, some with seemingly similar physiological functions, reflects the intricate repertoire associated with mammalian motor control and is consistent with high transcriptional heterogeneity arising from cardinal interneuronal classes. This review discusses insights derived from recent studies to describe innovative approaches and limitations in experimental model systems and to identify missing links in current investigational enterprise.

Rhythmic Pattern Generation in Invertebrates

2018 ◽  
pp. 390-400
Author(s):  
Astrid A. Prinz
Keyword(s):  
Central Pattern Generators ◽  
Pattern Generation ◽  
Rhythmic Pattern ◽  
Neuronal Circuit ◽  
Neuronal Circuits ◽  
Timing Circuit ◽  
Core Components ◽  
Pattern Generators

This chapter begins by defining central pattern generators (CPGs) and proceeds to focus on one of their core components, the timing circuit. After arguing why invertebrate CPGs are particularly useful for the study of neuronal circuit operation in general, the bulk of the chapter then describes basic mechanisms of CPG operation at the cellular, synaptic, and network levels, and how different CPGs combine these mechanisms in various ways. Finally, the chapter takes a semihistorical perspective to discuss whether or not the study of invertebrate CPGs has seen its prime and what it has contributed—and may continue to offer—to a wider understanding of neuronal circuits in general.

scholarly journals Augmenting Flexibility: Mutual Inhibition Between Inhibitory Neurons Expands Functional Diversity

2020 ◽  
Author(s):  
Belle Liu ◽  
Alexander James White ◽  
Chung-Chuan Lo
Keyword(s):  
Dynamical Systems ◽  
Bifurcation Theory ◽  
Neural Circuits ◽  
Feedback Inhibition ◽  
Central Pattern Generators ◽  
Recurrent Network ◽  
Inhibitory Neurons ◽  
Mutual Inhibition ◽  
Input Type ◽  
Pattern Generators

AbstractOne of the most intriguing observations of recurrent neural circuits is their flexibility. Seemingly, this flexibility extends far beyond the ability to learn, but includes the ability to use learned procedures to respond to novel situations. Here, we report that this flexibility arises from the synergistic interplay between recurrent mutual excitation and recurrent mutual inhibition. Specifically, we show that mutual inhibition is critical in expanding the functionality of the circuit, far beyond what feedback inhibition alone can accomplish. By taking advantage of dynamical systems theory and bifurcation analysis, we show mutual inhibition doubles the number of cusp bifurcations in the system in small neural circuits. As a concrete example, we build a simulation model of a class of functional motifs we call Coupled Recurrent inhibitory and Recurrent excitatory Loops (CRIRELs). These CRIRELs have the advantage of being multi-functional, performing a plethora of functions, including decisions, switches, toggles, central pattern generators, depending solely on the input type. We then use bifurcation theory to show how mutual inhibition gives rise to this broad repertoire of possible functions. Finally, we demonstrate how this trend also holds for larger networks, and how mutual inhibition greatly expands the amount of information a recurrent network can hold.

scholarly journals Evolution of central pattern generators and rhythmic behaviours

2016 ◽  
Vol 371 (1685) ◽  
pp. 20150057 ◽  
Author(s):  
Paul S. Katz
Keyword(s):  
Large Scale ◽  
Neural Circuits ◽  
Motor Pattern ◽  
Parallel Evolution ◽  
Central Pattern Generators ◽  
Neural Mechanism ◽  
Rhythmic Movements ◽  
Biological Organization ◽  
Gradual Evolution ◽  
Pattern Generators

Comparisons of rhythmic movements and the central pattern generators (CPGs) that control them uncover principles about the evolution of behaviour and neural circuits. Over the course of evolutionary history, gradual evolution of behaviours and their neural circuitry within any lineage of animals has been a predominant occurrence. Small changes in gene regulation can lead to divergence of circuit organization and corresponding changes in behaviour. However, some behavioural divergence has resulted from large-scale rewiring of the neural network. Divergence of CPG circuits has also occurred without a corresponding change in behaviour. When analogous rhythmic behaviours have evolved independently, it has generally been with different neural mechanisms. Repeated evolution of particular rhythmic behaviours has occurred within some lineages due to parallel evolution or latent CPGs. Particular motor pattern generating mechanisms have also evolved independently in separate lineages. The evolution of CPGs and rhythmic behaviours shows that although most behaviours and neural circuits are highly conserved, the nature of the behaviour does not dictate the neural mechanism and that the presence of homologous neural components does not determine the behaviour. This suggests that although behaviour is generated by neural circuits, natural selection can act separately on these two levels of biological organization.

Neuronal control of walking: studies on insects

e-Neuroforum ◽  
2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Ansgar Büschges ◽  
Joachim Schmidt
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sensory Input ◽  
Central Pattern Generators ◽  
Movement Direction ◽  
Coordination Pattern ◽  
Differential Processing ◽  
Neuronal Control ◽  
Pattern Generators ◽  
Leg Movements

AbstractThe control of walking in insects is to a substantial amount a function of neuronal networks in the thoracic ganglia. While descending signals from head ganglia provide general commands such as for walking direction and velocity, it is the thoracic central nervous system that controls movements of individual joints and legs. The coordination pattern of legs is velocity dependent. However, a clear stereotypic coordination pattern appears only at high velocities. In accordance with the unit burst oscillator concept, oscillatory networks (central pattern generators (CPGs)) interlocked with movement and load sensors control the timing and amplitude of joint movements. For a leg’s movements different joint CPGs of a leg are mainly coupled by proprioceptors. Differential processing of proprioceptive signals allows a task specific modulation of leg movements, for example, for changing movement direction. A switch between walking and searching movements of a leg is under local control. When stepping into a gap missing sensory input and the activation of a local command neuron evokes stereotypic searching movements of the leg.

scholarly journals From Spinal Central Pattern Generators to Cortical Network: Integrated BCI for Walking Rehabilitation

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
G. Cheron ◽  
M. Duvinage ◽  
C. De Saedeleer ◽  
T. Castermans ◽  
A. Bengoetxea ◽  
...  
Keyword(s):  
Brain Plasticity ◽  
Central Pattern Generators ◽  
Pattern Generation ◽  
Lower Limbs ◽  
Plantar Surface ◽  
Rehabilitation Programs ◽  
Walking Rehabilitation ◽  
Locomotor Patterns ◽  
Pattern Generators ◽  
Clinical Conditions

Success in locomotor rehabilitation programs can be improved with the use of brain-computer interfaces (BCIs). Although a wealth of research has demonstrated that locomotion is largely controlled by spinal mechanisms, the brain is of utmost importance in monitoring locomotor patterns and therefore contains information regarding central pattern generation functioning. In addition, there is also a tight coordination between the upper and lower limbs, which can also be useful in controlling locomotion. The current paper critically investigates different approaches that are applicable to this field: the use of electroencephalogram (EEG), upper limb electromyogram (EMG), or a hybrid of the two neurophysiological signals to control assistive exoskeletons used in locomotion based on programmable central pattern generators (PCPGs) or dynamic recurrent neural networks (DRNNs). Plantar surface tactile stimulation devices combined with virtual reality may provide the sensation of walking while in a supine position for use of training brain signals generated during locomotion. These methods may exploit mechanisms of brain plasticity and assist in the neurorehabilitation of gait in a variety of clinical conditions, including stroke, spinal trauma, multiple sclerosis, and cerebral palsy.

scholarly journals Asymmetric and transient properties of reciprocal activity of antagonists during the paw-shake response in the cat

2021 ◽  
Vol 17 (12) ◽  
pp. e1009677
Author(s):  
Jessica R. Parker ◽  
Alexander N. Klishko ◽  
Boris I. Prilutsky ◽  
Gennady S. Cymbalyuk
Keyword(s):  
Activity Patterns ◽  
Central Pattern Generators ◽  
Emg Activity ◽  
Rhythmic Movements ◽  
Related Activity ◽  
Fast Transient Response ◽  
Hindlimb Muscles ◽  
Pattern Generators ◽  
A Current

Mutually inhibitory populations of neurons, half-center oscillators (HCOs), are commonly involved in the dynamics of the central pattern generators (CPGs) driving various rhythmic movements. Previously, we developed a multifunctional, multistable symmetric HCO model which produced slow locomotor-like and fast paw-shake-like activity patterns. Here, we describe asymmetric features of paw-shake responses in a symmetric HCO model and test these predictions experimentally. We considered bursting properties of the two model half-centers during transient paw-shake-like responses to short perturbations during locomotor-like activity. We found that when a current pulse was applied during the spiking phase of one half-center, let’s call it #1, the consecutive burst durations (BDs) of that half-center increased throughout the paw-shake response, while BDs of the other half-center, let’s call it #2, only changed slightly. In contrast, the consecutive interburst intervals (IBIs) of half-center #1 changed little, while IBIs of half-center #2 increased. We demonstrated that this asymmetry between the half-centers depends on the phase of the locomotor-like rhythm at which the perturbation was applied. We suggest that the fast transient response reflects functional asymmetries of slow processes that underly the locomotor-like pattern; e.g., asymmetric levels of inactivation across the two half-centers for a slowly inactivating inward current. We compared model results with those of in-vivo paw-shake responses evoked in locomoting cats and found similar asymmetries. Electromyographic (EMG) BDs of anterior hindlimb muscles with flexor-related activity increased in consecutive paw-shake cycles, while BD of posterior muscles with extensor-related activity did not change, and vice versa for IBIs of anterior flexors and posterior extensors. We conclude that EMG activity patterns during paw-shaking are consistent with the proposed mechanism producing transient paw-shake-like bursting patterns found in our multistable HCO model. We suggest that the described asymmetry of paw-shaking responses could implicate a multifunctional CPG controlling both locomotion and paw-shaking.

scholarly journals Behavioral evidence for nested central pattern generator control of Drosophila grooming

2020 ◽  
Author(s):  
Primoz Ravbar ◽  
Neil Zhang ◽  
Julie H. Simpson
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Neural Circuits ◽  
Central Pattern Generators ◽  
Repetitive Behaviors ◽  
Short Time Scale ◽  
Behavioral Experiments ◽  
Behavioral Evidence ◽  
Pattern Generators ◽  
Short Time

AbstractCentral pattern generators (CPGs) are neurons or neural circuits that produce periodic output without requiring patterned input. More complex behaviors can be assembled from simpler subroutines, and nested CPGs have been proposed to coordinate their repetitive elements, simplifying control over different time-scales. Here, we use behavioral experiments to establish that Drosophila grooming may be controlled by nested CPGs. On the short time-scale (5-7 Hz), flies execute periodic leg sweeps and rubs. More surprisingly, transitions between bouts of head cleaning and leg rubbing are also periodic on a longer time-scale (0.3 - 0.6 Hz). We examine grooming at a range of temperatures to show that the frequencies of both oscillations increase – a hallmark of CPG control – and also that the two time-scales increase at the same rate, indicating that the nested CPGs may be linked. This relationship also holds when sensory drive is held constant using optogenetic activation, but the rhythms decouple in spontaneously grooming flies, showing that alternative control modes are possible. Nested CPGs simplify generation of complex but repetitive behaviors, and identifying them in Drosophila grooming presents an opportunity to map the neural circuits that constitute them.

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