scholarly journals Distributed control of motor circuits for backward walking in Drosophila

2020 ◽  
Author(s):  
Kai Feng ◽  
Rajyashree Sen ◽  
Ryo Minegishi ◽  
Michael Dübbert ◽  
Till Bockemühl ◽  
...  
Keyword(s):  
Distributed Control ◽  
Population Coding ◽  
Power Stroke ◽  
Single Type ◽  
Level Control ◽  
Backward Walking ◽  
Motor Circuits ◽  
Descending Neurons ◽  
High Level ◽  
The Brain

How do descending inputs from the brain control leg motor circuits to change the way an animal walks? Conceptually, descending neurons are thought to function either as command-type neurons, in which a single type of descending neuron exerts a high-level control to elicit a coordinated change in motor output, or through a more distributed population coding mechanism, whereby a group of neurons, each with local effects, act in combination to elicit a global motor response. The Drosophila Moonwalker Descending Neurons (MDNs), which alter leg motor circuit dynamics so that the fly walks backwards, exemplify the command-type mechanism. Here, we identify several dozen MDN target neurons within the leg motor circuits, and show that two of them mediate distinct and highly-specific changes in leg muscle activity during backward walking: LIN156 neurons provide the hindleg power stroke during stance phase; LIN128 neurons lift the legs at the end of stance to initiate swing. Through these two effector neurons, MDN directly controls both the stance and swing phases of the backward stepping cycle. MDN exerts these changes only upon the hindlegs; the fore-and midlegs follow passively through ground contact. These findings suggest that command-type descending neurons can also operate through the distributed control of local motor circuits.

scholarly journals Distributed control of motor circuits for backward walking in Drosophila

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Kai Feng ◽  
Rajyashree Sen ◽  
Ryo Minegishi ◽  
Michael Dübbert ◽  
Till Bockemühl ◽  
...  
Keyword(s):  
Distributed Control ◽  
Population Coding ◽  
Power Stroke ◽  
Single Type ◽  
Level Control ◽  
Backward Walking ◽  
Motor Circuits ◽  
Descending Neurons ◽  
High Level ◽  
The Brain

AbstractHow do descending inputs from the brain control leg motor circuits to change how an animal walks? Conceptually, descending neurons are thought to function either as command-type neurons, in which a single type of descending neuron exerts a high-level control to elicit a coordinated change in motor output, or through a population coding mechanism, whereby a group of neurons, each with local effects, act in combination to elicit a global motor response. The Drosophila Moonwalker Descending Neurons (MDNs), which alter leg motor circuit dynamics so that the fly walks backwards, exemplify the command-type mechanism. Here, we identify several dozen MDN target neurons within the leg motor circuits, and show that two of them mediate distinct and highly-specific changes in leg muscle activity during backward walking: LBL40 neurons provide the hindleg power stroke during stance phase; LUL130 neurons lift the legs at the end of stance to initiate swing. Through these two effector neurons, MDN directly controls both the stance and swing phases of the backward stepping cycle. These findings suggest that command-type descending neurons can also operate through the distributed control of local motor circuits.

Neuronal Control of Drosophila Walking Direction

Science ◽  
2014 ◽  
Vol 344 (6179) ◽  
pp. 97-101 ◽  
Author(s):  
Salil S. Bidaye ◽  
Christian Machacek ◽  
Yang Wu ◽  
Barry J. Dickson
Keyword(s):  
Muscle Activation ◽  
Command Neurons ◽  
Backward Walking ◽  
Motor Circuits ◽  
Neuronal Control ◽  
Descending Neurons ◽  
Leg Muscle ◽  
The Brain ◽  
Local Motor

Most land animals normally walk forward but switch to backward walking upon sensing an obstacle or danger in the path ahead. A change in walking direction is likely to be triggered by descending “command” neurons from the brain that act upon local motor circuits to alter the timing of leg muscle activation. Here we identify descending neurons for backward walking in Drosophila—the MDN neurons. MDN activity is required for flies to walk backward when they encounter an impassable barrier and is sufficient to trigger backward walking under conditions in which flies would otherwise walk forward. We also identify ascending neurons, MAN, that promote persistent backward walking, possibly by inhibiting forward walking. These findings provide an initial glimpse into the circuits and logic that control walking direction in Drosophila.

Modular Distributed Control Architecture for Cooperative Soccer-Playing Robot Agents

2000 ◽  
Vol 12 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Gen'ichi Yasuda ◽  
Keyword(s):  
Distributed Control ◽  
Action Planning ◽  
Control Architecture ◽  
Level Control ◽  
Sensors And Actuators ◽  
Cooperative Action ◽  
Intelligent Sensors ◽  
Distributed Implementation ◽  
High Level ◽  
Robotic Soccer

We describe the concept and implementation of modular distributed control architecture for cooperative soccer-playing robot agents. Overall complete autonomous control for robotic soccer consists of the host and several onboard control systems. Onboard control for an autonomous mobile robot with intelligent sensors and actuators is constructed on microcontrollerbased flexible, extendable architecture whose microcontrollers are dedicated to low-level control for navigation based on multiaxis and multisensor cooperation. Operations of autonomous actuators are integrated through a serial-bus communication network. Distributed implementation reduces difficulties in complex hardware and software design of the control system. We evaluated basic control executed on microcontrollers. The host conducts high-level decision-making and cooperative action planning for robot agents. The implementation of basic skills and strategies for robotic soccer is discussed.

scholarly journals Conservation law for self-paced movements

2016 ◽  
Vol 113 (31) ◽  
pp. 8831-8836 ◽  
Author(s):  
Dongsung Huh ◽  
Terrence J. Sejnowski
Keyword(s):  
Optimal Control ◽  
Scaling Law ◽  
Control Variable ◽  
Level Control ◽  
Internal Motivation ◽  
Internal States ◽  
Motivation Level ◽  
High Level ◽  
The Brain ◽  
Biological Motor

Optimal control models of biological movements introduce external task factors to specify the pace of movements. Here, we present the dual to the principle of optimality based on a conserved quantity, called “drive,” that represents the influence of internal motivation level on movement pace. Optimal control and drive conservation provide equivalent descriptions for the regularities observed within individual movements. For regularities across movements, drive conservation predicts a previously unidentified scaling law between the overall size and speed of various self-paced hand movements in the absence of any external tasks, which we confirmed with psychophysical experiments. Drive can be interpreted as a high-level control variable that sets the overall pace of movements and may be represented in the brain as the tonic levels of neuromodulators that control the level of internal motivation, thus providing insights into how internal states affect biological motor control.

scholarly journals A neurocognitive model of ideological thinking

2021 ◽  
pp. 1-15
Author(s):  
Leor Zmigrod
Keyword(s):  
Empirical Evidence ◽  
Motivational Factors ◽  
Cognitive Systems ◽  
Social Forces ◽  
Low Level ◽  
Cognitive Principles ◽  
High Level ◽  
Ideological Attitudes ◽  
The Brain

Abstract Ideological behavior has traditionally been viewed as a product of social forces. Nonetheless, an emerging science suggests that ideological worldviews can also be understood in terms of neural and cognitive principles. The article proposes a neurocognitive model of ideological thinking, arguing that ideological worldviews may be manifestations of individuals’ perceptual and cognitive systems. This model makes two claims. First, there are neurocognitive antecedents to ideological thinking: the brain’s low-level neurocognitive dispositions influence its receptivity to ideological doctrines. Second, there are neurocognitive consequences to ideological engagement: strong exposure and adherence to ideological doctrines can shape perceptual and cognitive systems. This article details the neurocognitive model of ideological thinking and synthesizes the empirical evidence in support of its claims. The model postulates that there are bidirectional processes between the brain and the ideological environment, and so it can address the roles of situational and motivational factors in ideologically motivated action. This endeavor highlights that an interdisciplinary neurocognitive approach to ideologies can facilitate biologically informed accounts of the ideological brain and thus reveal who is most susceptible to extreme and authoritarian ideologies. By investigating the relationships between low-level perceptual processes and high-level ideological attitudes, we can develop a better grasp of our collective history as well as the mechanisms that may structure our political futures.

scholarly journals Perceptual decisions are biased toward relevant prior choices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helen Feigin ◽  
Shira Baror ◽  
Moshe Bar ◽  
Adam Zaidel
Keyword(s):  
Sensory Information ◽  
Irrelevant Stimulus ◽  
Stimulus Feature ◽  
Serial Dependence ◽  
Low Level ◽  
Subsequent Test ◽  
Key Factor ◽  
High Level ◽  
Motor Actions ◽  
The Brain

AbstractPerceptual decisions are biased by recent perceptual history—a phenomenon termed 'serial dependence.' Here, we investigated what aspects of perceptual decisions lead to serial dependence, and disambiguated the influences of low-level sensory information, prior choices and motor actions. Participants discriminated whether a brief visual stimulus lay to left/right of the screen center. Following a series of biased ‘prior’ location discriminations, subsequent ‘test’ location discriminations were biased toward the prior choices, even when these were reported via different motor actions (using different keys), and when the prior and test stimuli differed in color. By contrast, prior discriminations about an irrelevant stimulus feature (color) did not substantially influence subsequent location discriminations, even though these were reported via the same motor actions. Additionally, when color (not location) was discriminated, a bias in prior stimulus locations no longer influenced subsequent location discriminations. Although low-level stimuli and motor actions did not trigger serial-dependence on their own, similarity of these features across discriminations boosted the effect. These findings suggest that relevance across perceptual decisions is a key factor for serial dependence. Accordingly, serial dependence likely reflects a high-level mechanism by which the brain predicts and interprets new incoming sensory information in accordance with relevant prior choices.

Vascular responses of dura mater

1989 ◽  
Vol 257 (1) ◽  
pp. H157-H161 ◽  
Author(s):  
F. M. Faraci ◽  
K. A. Kadel ◽  
D. D. Heistad
Keyword(s):  
Blood Flow ◽  
Substance P ◽  
Dura Mater ◽  
Sympathetic Nerves ◽  
Vascular Headache ◽  
Vascular Responses ◽  
Anesthetized Dogs ◽  
High Level ◽  
The Brain ◽  
Increased Blood Flow

The goal of this study was to examine vascular responses of the dura mater. Microspheres were used to measure blood flow to the dura and brain in anesthetized dogs. Under control conditions, blood flow to the dura was 38 +/- 3 (SE) ml.min-1.100 g-1. Values for blood flow to the dura obtained with simultaneous injection of 15- and 50-microns microspheres were similar, which suggests that shunting of 15-microns spheres was minimal. Left atrial infusion of substance P (100 ng.kg-1.min-1) and serotonin (40 micrograms.kg-1.min-1), two agonists that have been reported to increase vascular permeability in the dura, increased blood flow to the dura two- to threefold. Adenosine (iv) produced vasodilatation in the dura. Adenosine and serotonin did not affect cerebral blood flow, but substance P increased blood flow to the brain by approximately 40%. Seizures, which produce pronounced dilatation of cerebral vessels despite activation of sympathetic nerves, produced vasoconstriction in the dura. Thus 1) the dura is perfused at a relatively high level of blood flow under normal conditions and is very responsive to vasoactive stimuli, and 2) substance P and serotonin, which have been implicated in the pathogenesis of vascular headache, produce pronounced vasodilator responses in the dura mater.

scholarly journals Robust Tracking Controller for a DC/DC Buck-Boost Converter–Inverter–DC Motor System

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2500 ◽  
Author(s):  
Eduardo Hernández-Márquez ◽  
Carlos Avila-Rea ◽  
José García-Sánchez ◽  
Ramón Silva-Ortigoza ◽  
Gilberto Silva-Ortigoza ◽  
...  
Keyword(s):  
Motor System ◽  
Dc Motor ◽  
Boost Converter ◽  
Differential Flatness ◽  
Robust Tracking ◽  
Level Control ◽  
Tracking Controller ◽  
The One ◽  
High Level ◽  
Better Than

This paper has two aims. The first is to develop a robust hierarchical tracking controller for the DC/DC Buck-Boost–inverter–DC motor system. This controller considers a high level control for the inverter–DC motor subsystems and a low level control for the DC/DC Buck-Boost converter subsystem. Such controls solve the tracking task associated with the angular velocity of the motor shaft and the output voltage of the converter, respectively, via the differential flatness approach. The second aim is to present a comparison of the robust hierarchical controller to a passive controller. This, with the purpose of showing that performance achieved with the hierarchical controller proposed in this paper, is better than the one achieved with the passive controller. Both controllers are experimentally implemented on a prototype of the DC/DC Buck-Boost–inverter–DC motor system by using Matlab-Simulink along with the DS1104 board from dSPACE. According to experimental results, the proposal in the present paper achieves a better performance than the passive controller.

scholarly journals Backward walking highlights gait asymmetries in children with cerebral palsy

2018 ◽  
Vol 119 (3) ◽  
pp. 1153-1165 ◽  
Author(s):  
Germana Cappellini ◽  
Francesca Sylos-Labini ◽  
Michael J. MacLellan ◽  
Annalisa Sacco ◽  
Daniela Morelli ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Muscle Activation ◽  
Pattern Generation ◽  
Comprehensive Assessment ◽  
Emg Activity ◽  
Backward Walking ◽  
Spinal Circuitry ◽  
Children With Cerebral Palsy ◽  
Control Circuits ◽  
The Brain

To investigate how early injuries to developing motor regions of the brain affect different forms of gait, we compared the spatiotemporal locomotor patterns during forward (FW) and backward (BW) walking in children with cerebral palsy (CP). Bilateral gait kinematics and EMG activity of 11 pairs of leg muscles were recorded in 14 children with CP (9 diplegic, 5 hemiplegic; 3.0–11.1 yr) and 14 typically developing (TD) children (3.3–11.8 yr). During BW, children with CP showed a significant increase of gait asymmetry in foot trajectory characteristics and limb intersegmental coordination. Furthermore, gait asymmetries, which were not evident during FW in diplegic children, became evident during BW. Factorization of the EMG signals revealed a comparable structure of the motor output during FW and BW in all groups of children, but we found differences in the basic temporal activation patterns. Overall, the results are consistent with the idea that both forms of gait share pattern generation control circuits providing similar (though reversed) kinematic patterns. However, BW requires different muscle activation timings associated with muscle modules, highlighting subtle gait asymmetries in diplegic children, and thus provides a more comprehensive assessment of gait pathology in children with CP. The findings suggest that spatiotemporal asymmetry assessments during BW might reflect an impaired state and/or descending control of the spinal locomotor circuitry and can be used for diagnostic purposes and as complementary markers of gait recovery.NEW & NOTEWORTHY Early injuries to developing motor regions of the brain affect both forward progression and other forms of gait. In particular, backward walking highlights prominent gait asymmetries in children with hemiplegia and diplegia from cerebral palsy and can give a more comprehensive assessment of gait pathology. The observed spatiotemporal asymmetry assessments may reflect both impaired supraspinal control and impaired state of the spinal circuitry.

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