scholarly journals Invertebrate central pattern generator circuits

2010 ◽  
Vol 365 (1551) ◽  
pp. 2329-2345 ◽  
Author(s):  
Allen I. Selverston
Keyword(s):  
Central Pattern Generator ◽  
Computational Models ◽  
Mechanistic Explanation ◽  
Pattern Generator ◽  
Individual Organism ◽  
Multiple Phase ◽  
Brain Circuits ◽  
Sufficient Detail ◽  
Cellular Components ◽  
The Brain

There are now a reasonable number of invertebrate central pattern generator (CPG) circuits described in sufficient detail that a mechanistic explanation of how they work is possible. These small circuits represent the best-understood neural circuits with which to investigate how cell-to-cell synaptic connections and individual channel conductances combine to generate rhythmic and patterned output. In this review, some of the main lessons that have appeared from this analysis are discussed and concrete examples of circuits ranging from single phase to multiple phase patterns are described. While it is clear that the cellular components of any CPG are basically the same, the topology of the circuits have evolved independently to meet the particular motor requirements of each individual organism and only a few general principles of circuit operation have emerged. The principal usefulness of small systems in relation to the brain is to demonstrate in detail how cellular infrastructure can be used to generate rhythmicity and form specialized patterns in a way that may suggest how similar processes might occur in more complex systems. But some of the problems and challenges associated with applying data from invertebrate preparations to the brain are also discussed. Finally, I discuss why it is useful to have well-defined circuits with which to examine various computational models that can be validated experimentally and possibly applied to brain circuits when the details of such circuits become available.

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 Computational Modelling of Cerebellar Magnetic Stimulation: The Effect of Washout

2021 ◽  
pp. 35-46
Author(s):  
Alberto Antonietti ◽  
Claudia Casellato ◽  
Egidio D’Angelo ◽  
Alessandra Pedrocchi
Keyword(s):  
Washout Period ◽  
Magnetic Stimulation ◽  
Computational Models ◽  
Computational Modelling ◽  
Mechanistic Explanation ◽  
Neural Responses ◽  
External Stimulation ◽  
Associative Conditioning ◽  
Underlying Mechanisms ◽  
The Brain

AbstractNowadays, clinicians have multiple tools that they can use to stimulate the brain, by means of electric or magnetic fields that can interfere with the bio-electrical behaviour of neurons. However, it is still unclear which are the neural mechanisms that are involved and how the external stimulation changes the neural responses at network-level. In this paper, we have exploited the simulations carried out using a spiking neural network model, which reconstructed the cerebellar system, to shed light on the underlying mechanisms of cerebellar Transcranial Magnetic Stimulation affecting specific task behaviour. Namely, two computational studies have been merged and compared. The two studies employed a very similar experimental protocol: a first session of Pavlovian associative conditioning, the administration of the TMS (effective or sham), a washout period, and a second session of Pavlovian associative conditioning. In one study, the washout period between the two sessions was long (1 week), while the other study foresaw a very short washout (15 min). Computational models suggested a mechanistic explanation for the TMS effect on the cerebellum. In this work, we have found that the duration of the washout strongly changes the modification of plasticity mechanisms in the cerebellar network, then reflected in the learning behaviour.

scholarly journals The Fruit Fly Brain Observatory: From Structure to Function

2019 ◽  
Author(s):  
Nikul H. Ukani ◽  
Chung-Heng Yeh ◽  
Adam Tomkins ◽  
Yiyin Zhou ◽  
Dorian Florescu ◽  
...  
Keyword(s):  
Computational Models ◽  
Brain Research ◽  
Model Organism ◽  
Fruit Fly ◽  
Data Repositories ◽  
Brain Circuits ◽  
Multiple Data ◽  
Computer Scientists ◽  
Brain Data ◽  
The Brain

AbstractThe fruit fly is a key model organism for studying the activity of interconnected brain circuits. A large scattered global research community of neurobiologists and neurogeneticists, computational and theoretical neuroscientists, and computer scientists and engineers has been developing a vast trove of experimental and modeling data that has yet to be distilled into new knowledge and understanding of the functional logic of the brain. Developing open shared models, modelling tools and data repositories that can be accessed from anywhere in the world is the necessary engine for accelerating our understanding of how the brain works.To that end we developed the Fruit Fly Brain Observatory (FFBO), the next generation open-source platform to support open, collaborative Drosophila neuroscience research. FFBO provides a (i) hub for storing and integrating fruit fly brain research data from multiple data sources worldwide, (ii) unified repository of tools and methods to build, emulate and compare fruit fly brain models in health and disease, and (iii) an open framework for fruit fly brain data processing and model execution. FFBO provides access to application tools for visualizing, configuring, simulating and analyzing computational models of brain circuits of the (i) cell type map, (ii) connectome, (iii) synaptome, and (iv) activity map using intuitive queries in plain English. Tools are provided to extract the function inherent in these structural maps. All applications can be accessed with any modern browser.

Characterization by stimulation of medullary mechanisms underlying gasping neurogenesis

1985 ◽  
Vol 58 (1) ◽  
pp. 121-128 ◽  
Author(s):  
W. M. St John ◽  
T. A. Bledsoe ◽  
S. M. Tenney
Keyword(s):  
Brain Stem ◽  
Central Pattern Generator ◽  
Nucleus Tractus Solitarius ◽  
Pattern Generator ◽  
Nucleus Ambiguus ◽  
Refractory Periods ◽  
Pattern Generators ◽  
The Brain ◽  
Stimulation Of

Our purpose was to evaluate the hypothesis that neurons in the lateral tegmental field of the medulla comprise a pattern generator for neurogenesis of gasping. Stimulations in this area produced changes characteristic of pattern generators in other systems. These included shifts in gasping rhythm and refractory periods for eliciting gasps; the latter varied inversely with spontaneous gasping frequency. These responses were recorded from activities of phrenic and hypoglossal nerves of decerebrate, cerebellectomized, vagotomized, paralyzed, and ventilated cats. Gasping followed freezing the brain stem between pons and medulla. In addition to lateral tegmental loci, gasps were elicited by stimulating areas extending lateral to the nucleus ambiguus and medial to the contralateral medulla. These areas are envisaged to contain axons to or from the pattern generator of lateral tegmental field. Finally, stimulations in sites approximating nucleus tractus solitarius and nucleus ambiguus delayed spontaneous gasps and terminated ongoing gasps. Current required to terminate gasps fell during neural inspiration. Our data are consistent with the lateral tegmental field of medulla comprising a central pattern generator for gasping and pacemaker elements being a component of this pattern generator.

scholarly journals Feedforward discharges couple the singing central pattern generator and ventilation central pattern generator in the cricket abdominal central nervous system

2019 ◽  
Vol 205 (6) ◽  
pp. 881-895 ◽  
Author(s):  
Stefan Schöneich ◽  
Berthold Hedwig
Keyword(s):  
Motor Activity ◽  
Central Pattern Generator ◽  
Sensory Feedback ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Abdominal Muscle ◽  
Excitatory Input ◽  
Intracellular Recordings ◽  
Motor Patterns ◽  
The Brain

Abstract We investigated the central nervous coordination between singing motor activity and abdominal ventilatory pumping in crickets. Fictive singing, with sensory feedback removed, was elicited by eserine-microinjection into the brain, and the motor activity underlying singing and abdominal ventilation was recorded with extracellular electrodes. During singing, expiratory abdominal muscle activity is tightly phase coupled to the chirping pattern. Occasional temporary desynchronization of the two motor patterns indicate discrete central pattern generator (CPG) networks that can operate independently. Intracellular recordings revealed a sub-threshold depolarization in phase with the ventilatory cycle in a singing-CPG interneuron, and in a ventilation-CPG interneuron an excitatory input in phase with each syllable of the chirps. Inhibitory synaptic inputs coupled to the syllables of the singing motor pattern were present in another ventilatory interneuron, which is not part of the ventilation-CPG. Our recordings suggest that the two centrally generated motor patterns are coordinated by reciprocal feedforward discharges from the singing-CPG to the ventilation-CPG and vice versa. Consequently, expiratory contraction of the abdomen usually occurs in phase with the chirps and ventilation accelerates during singing due to entrainment by the faster chirp cycle.

scholarly journals The Design and Building of a Hexapod Robot with Biomimetic Legs

2019 ◽  
Vol 9 (14) ◽  
pp. 2792
Author(s):  
Hwang ◽  
Liu ◽  
Yang ◽  
Lin
Keyword(s):  
Central Pattern Generator ◽  
Distributed Control ◽  
Pattern Generator ◽  
Mathematical Function ◽  
Distributed Control System ◽  
Hexapod Robot ◽  
Computational System ◽  
Computational Burden ◽  
Tripod Gait ◽  
The Brain

A hexapod robot with biomimetic legs was built to implement a distributed control system, where a mechanism is proposed to serve as the central pattern generator and a computer to act as the brain-stem, cooperating with the central pattern generator through wireless communication. The proposed mechanism is composed of two modules, i.e., the tripod gait generator and the Theo Jansen Linkage. The tripod gait generator is a device that uses a single motor to generate a tripod gait, while the Theo Jansen Linkage rhythmically executes the legged motion. In a sense, we are trying to implement the locomotion of a robot by means of a hybrid computational system, including the mechanism part and the electronic processors part. The complex mathematical function of the foot movement is realized by the ensemble of links of the Theo Jansen Linkage, so as to alleviate the computational burden. Besides, the proposed design, based on non-collocated actuators, is intended to minimize the number of actuators while reducing the building cost of the robot.

Exercise, music, and the brain: Is there a central pattern generator?

2010 ◽  
Vol 28 (12) ◽  
pp. 1337-1343 ◽  
Author(s):  
Stefan Schneider ◽  
Christopher D. Askew ◽  
Thomas Abel ◽  
Heiko K. Strüder
Keyword(s):  
Central Pattern Generator ◽  
Pattern Generator ◽  
The Brain
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