scholarly journals From Neural Command to Robotic Use: The Role of Symmetry/Asymmetry in Postural and Locomotor Activities

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1773
Author(s):  
Mariève Blanchet ◽  
Pierre Guertin ◽  
Francine Pilon ◽  
Philippe Gorce ◽  
François Prince
Keyword(s):  
Central Pattern Generators ◽  
Movement Control ◽  
Walking Robots ◽  
Environmental Constraints ◽  
Task Requirements ◽  
Locomotor Activities ◽  
Pattern Generators ◽  
And Control ◽  
The Brain

This article deepens a reflection on why and how symmetry/asymmetry affects the motor and postural behavior from the neural source, uterine development, child maturation, and how the notion of symmetry/asymmetry has been applied to walking robot design and control. The concepts of morphology and tensegrity are also presented to illustrate how the biological structures have been used in both sciences and arts. The development of the brain and the neuro-fascia-musculoskeletal system seems to be quite symmetric from the beginning of life through to complete maturity. The neural sources of movements (i.e., central pattern generators) are able to produce both symmetric or asymmetric responses to accommodate to environmental constraints and task requirements. Despite the fact that the human development is mainly symmetric, asymmetries already regulate neurological and physiological development. Laterality and sports training could affect natural musculoskeletal symmetry. The plasticity and flexibility of the nervous system allows the abilities to adapt and compensate for environmental constraints and musculoskeletal asymmetries in order to optimize the postural and movement control. For designing humanoid walking robots, symmetry approaches have been mainly used to reduce the complexity of the online calculation. Applications in neurological retraining and rehabilitation should also be considered.

Sensory regulation of quadrupedal locomotion: a top-down or bottom-up control system?

2012 ◽  
Vol 108 (3) ◽  
pp. 709-711 ◽  
Author(s):  
Yann Thibaudier ◽  
Marie-France Hurteau
Keyword(s):  
Control System ◽  
Central Pattern Generators ◽  
Top Down ◽  
Bottom Up ◽  
Sensory Inputs ◽  
Sensory Regulation ◽  
Before And After ◽  
Pattern Generators

Propriospinal pathways are thought to be critical for quadrupedal coordination by coupling cervical and lumbar central pattern generators (CPGs). However, the mechanisms involved in relaying information between girdles remain largely unexplored. Using an in vitro spinal cord preparation in neonatal rats, Juvin and colleagues ( Juvin et al. 2012 ) have recently shown sensory inputs from the hindlimbs have greater influence on forelimb CPGs than forelimb sensory inputs on hindlimb CPGs, in other words, a bottom-up control system. However, results from decerebrate cats suggest a top-down control system. It may be that both bottom-up and top-down control systems exist and that the dominance of one over the other is task or context dependent. As such, the role of sensory inputs in controlling quadrupedal coordination before and after injury requires further investigation.

scholarly journals Simulation of Octopus Arm Based on Coupled CPGs

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Juan Tian ◽  
Qiang Lu
Keyword(s):  
Phase Diagrams ◽  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Hot Spot ◽  
Central Pattern Generators ◽  
Arm Movements ◽  
Movement Control ◽  
High Dimensionality ◽  
Neuromuscular System ◽  
Pattern Generators

The octopus arm has attracted many researchers’ interests and became a research hot spot because of its amazing features. Several dynamic models inspired by an octopus arm are presented to realize the structure with a large number of degrees of freedom. The octopus arm is made of a soft material introducing high-dimensionality, nonlinearity, and elasticity, which makes the octopus arm difficult to control. In this paper, three coupled central pattern generators (CPGs) are built and a 2-dimensional dynamic model of the octopus arm is presented to explore possible strategies of the octopus movement control. And the CPGs’ signals treated as activation are added on the ventral, dorsal, and transversal sides, respectively. The effects of the octopus arm are discussed when the parameters of the CPGs are changed. Simulations show that the octopus arm movements are mainly determined by the shapes of three CPGs’ phase diagrams. Therefore, some locomotion modes are supposed to be embedded in the neuromuscular system of the octopus arm. And the octopus arm movements can be achieved by modulating the parameters of the CPGs. The results are beneficial for researchers to understand the octopus movement further.

Contribution of proprioception for calibrating and updating the motor space

1995 ◽  
Vol 73 (2) ◽  
pp. 246-254 ◽  
Author(s):  
Chantal Bard ◽  
Michelle Fleury ◽  
Normand Teasdale ◽  
Jacques Paillard ◽  
Vincent Nougier
Keyword(s):  
Reference Frames ◽  
Sensory Information ◽  
Force Production ◽  
Movement Control ◽  
Spatial Reference Frames ◽  
Proprioceptive Afferents ◽  
The Brain ◽  
Prismatic Adaptation ◽  
Central Level

The absence of muscular proprioception, whether at a segmental or at a central level, impairs performance in several ways. The contribution of proprioception to movement control and learning is not easily dissociated from that of other sources of sensory information (e.g., vision). Therefore, the rare clinical cases of extensive neuropathy, depriving the brain massively and permanently of its presumed main sources of dynamogenic information from skin and muscles, are of very special interest. Two such patients and controls were tested in experiments investigating (i) force production, (ii) amplitude coding, (iii) spatial reference frames in pointing, and (iv) prismatic adaptation. Overall, our results highlight the key role of proprioceptive afferents for calibrating the spatial motor frame of reference, and the powerful substitutive properties of the central nervous system.Key words: proprioception, deafferentation, space calibration, motor control.

scholarly journals Regulation of Morphological and Functional Aspects of Sexual Dimorphism in the Brain

2021 ◽  
Author(s):  
Chitose Orikasa
Keyword(s):  
Sexual Dimorphism ◽  
Sex Steroids ◽  
Perinatal Period ◽  
Adult Brain ◽  
Functional Aspects ◽  
Neuronal Functions ◽  
And Control ◽  
The Brain ◽  
Neuroendocrine Functions

Sexual dimorphism of the adult brain regulates sex-dependent functions including reproductive and neuroendocrine activities in rodents. It is determined by sex steroid hormones during a critical perinatal period in female and male rodents. Sex steroids act on each nuclear receptor in the brain and control different physiological and neuroendocrine functions and behaviors. Several regions of the brain show evident morphological sex differences that are involved in their physiological functions. This review addresses and focuses largely on the role of sex-dependent differences in the brain, and their crucial functions in animal models. Particularly, recent intriguing data concerning the diversity of neuronal functions and sexual dimorphism are discussed.

scholarly journals Potential role of a ventral nerve cord central pattern generator in forward and backward locomotion in Caenorhabditis elegans

2018 ◽  
Vol 2 (3) ◽  
pp. 323-343 ◽  
Author(s):  
Erick O. Olivares ◽  
Eduardo J. Izquierdo ◽  
Randall D. Beer
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Computational Models ◽  
Neural Circuit ◽  
Central Pattern Generators ◽  
C Elegans ◽  
Segmentation Analysis ◽  
Pattern Generators ◽  
Neural Unit

C. elegans locomotes in an undulatory fashion, generating thrust by propagating dorsoventral bends along its body. Although central pattern generators (CPGs) are typically involved in animal locomotion, their presence in C. elegans has been questioned, mainly because there has been no evident circuit that supports intrinsic network oscillations. With a fully reconstructed connectome, the question of whether it is possible to have a CPG in the ventral nerve cord (VNC) of C. elegans can be answered through computational models. We modeled a repeating neural unit based on segmentation analysis of the connectome. We then used an evolutionary algorithm to determine the unknown physiological parameters of each neuron so as to match the features of the neural traces of the worm during forward and backward locomotion. We performed 1,000 evolutionary runs and consistently found configurations of the neural circuit that produced oscillations matching the main characteristic observed in experimental recordings. In addition to providing an existence proof for the possibility of a CPG in the VNC, we suggest a series of testable hypotheses about its operation. More generally, we show the feasibility and fruitfulness of a methodology to study behavior based on a connectome, in the absence of complete neurophysiological details.

scholarly journals Rhythm generation, coordination, and initiation in the vocal pathways of male African clawed frogs

2017 ◽  
Vol 117 (1) ◽  
pp. 178-194 ◽  
Author(s):  
Ayako Yamaguchi ◽  
Jessica Cavin Barnes ◽  
Todd Appleby
Keyword(s):  
Brain Stem ◽  
Anterior Commissure ◽  
Temporal Structure ◽  
Central Pattern Generators ◽  
Nucleus Ambiguus ◽  
Motor Nucleus ◽  
Vertebrate Species ◽  
Extended Amygdala ◽  
Pattern Generators ◽  
The Brain

Central pattern generators (CPGs) in the brain stem are considered to underlie vocalizations in many vertebrate species, but the detailed mechanisms underlying how motor rhythms are generated, coordinated, and initiated remain unclear. We addressed these issues using isolated brain preparations of Xenopus laevis from which fictive vocalizations can be elicited. Advertisement calls of male X. laevis that consist of fast and slow trills are generated by vocal CPGs contained in the brain stem. Brain stem central vocal pathways consist of a premotor nucleus [dorsal tegmental area of medulla (DTAM)] and a laryngeal motor nucleus [a homologue of nucleus ambiguus (n.IX-X)] with extensive reciprocal connections between the nuclei. In addition, DTAM receives descending inputs from the extended amygdala. We found that unilateral transection of the projections between DTAM and n.IX-X eliminated premotor fictive fast trill patterns but did not affect fictive slow trills, suggesting that the fast and slow trill CPGs are distinct; the slow trill CPG is contained in n.IX-X, and the fast trill CPG spans DTAM and n.IX-X. Midline transections that eliminated the anterior, posterior, or both commissures caused no change in the temporal structure of fictive calls, but bilateral synchrony was lost, indicating that the vocal CPGs are contained in the lateral halves of the brain stem and that the commissures synchronize the two oscillators. Furthermore, the elimination of the inputs from extended amygdala to DTAM, in addition to the anterior commissure, resulted in autonomous initiation of fictive fast but not slow trills by each hemibrain stem, indicating that the extended amygdala provides a bilateral signal to initiate fast trills. NEW & NOTEWORTHY Central pattern generators (CPGs) are considered to underlie vocalizations in many vertebrate species, but the detailed mechanisms underlying their functions remain unclear. We addressed this question using an isolated brain preparation of African clawed frogs. We discovered that two vocal phases are mediated by anatomically distinct CPGs, that there are a pair of CPGs contained in the left and right half of the brain stem, and that mechanisms underlying initiation of the two vocal phases are distinct.

Endothelin-A receptors and NO mediate decrease in arterial pressure during recovery from restraint

2002 ◽  
Vol 282 (3) ◽  
pp. R881-R889 ◽  
Author(s):  
Avery W. C. Yip ◽  
Teresa L. Krukoff
Keyword(s):  
Arterial Pressure ◽  
Restraint Stress ◽  
No Synthase ◽  
Rest Periods ◽  
Nos Inhibitor ◽  
Baseline Levels ◽  
Endothelin A ◽  
And Control ◽  
The Brain

We investigated the role of central endothelin-A (ETA) receptors and nitric oxide (NO) in regulating arterial pressure during restraint stress and recovery from stress. Rats received intracerebroventricular (icv) injections of the ETAreceptor antagonist BQ123 (24 μg/kg) and were then subjected to two restraint-rest cycles (1 h of restraint and 1 h of rest/cycle). Although mean arterial pressure (MAP) values in BQ123-treated and control rats increased at the onset of restraint and remained elevated during restraint, MAP values in BQ123-treated rats were consistently greater than in control rats. During rest periods, MAP values in control rats decreased to below baseline levels, whereas those in BQ123-treated rats remained significantly higher. NO content was decreased in the brain stems of BQ123-treated compared with control rats after the 4-h protocol. Injections (icv) of the NO synthase (NOS) inhibitor N G-nitro-l-arginine (l-NNA) eliminated the decreases in MAP values during rest periods in both BQ123-treated and control rats. Inhibition of neuronal NOS with icv injection of 7-nitroindazole sodium salt resulted in MAP values intermediate between control rats and rats receivingl-NNA. These results support the hypothesis that endothelin acts through ETA receptors in the brain, possibly via release of NO, to decrease arterial pressure during restraint and recovery from restraint.

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