scholarly journals Current Principles of Motor Control, with Special Reference to Vertebrate Locomotion

2020 ◽  
Vol 100 (1) ◽  
pp. 271-320 ◽  
Author(s):  
Sten Grillner ◽  
Abdeljabbar El Manira
Keyword(s):  
Spinal Cord ◽  
Control System ◽  
High Speed ◽  
Postural Control System ◽  
The Core ◽  
Level Of Activity ◽  
The Subject ◽  
Command Systems ◽  
The Brain ◽  
Sensory Compensation

The vertebrate control of locomotion involves all levels of the nervous system from cortex to the spinal cord. Here, we aim to cover all main aspects of this complex behavior, from the operation of the microcircuits in the spinal cord to the systems and behavioral levels and extend from mammalian locomotion to the basic undulatory movements of lamprey and fish. The cellular basis of propulsion represents the core of the control system, and it involves the spinal central pattern generator networks (CPGs) controlling the timing of different muscles, the sensory compensation for perturbations, and the brain stem command systems controlling the level of activity of the CPGs and the speed of locomotion. The forebrain and in particular the basal ganglia are involved in determining which motor programs should be recruited at a given point of time and can both initiate and stop locomotor activity. The propulsive control system needs to be integrated with the postural control system to maintain body orientation. Moreover, the locomotor movements need to be steered so that the subject approaches the goal of the locomotor episode, or avoids colliding with elements in the environment or simply escapes at high speed. These different aspects will all be covered in the review.

scholarly journals Context-Based Filtering for Assisted Brain-Actuated Wheelchair Driving

2007 ◽  
Vol 2007 ◽  
pp. 1-12 ◽  
Author(s):  
Gerolf Vanacker ◽  
José del R. Millán ◽  
Eileen Lew ◽  
Pierre W. Ferrez ◽  
Ferran Galán Moles ◽  
...  
Keyword(s):  
Control System ◽  
Shared Control ◽  
Eeg Signals ◽  
Intelligent Processing ◽  
Intelligent Wheelchair ◽  
Brain Signals ◽  
Brain Interface ◽  
The Subject ◽  
Electroencephalogram Eeg ◽  
The Brain

Controlling a robotic device by using human brain signals is an interesting and challenging task. The device may be complicated to control and the nonstationary nature of the brain signals provides for a rather unstable input. With the use of intelligent processing algorithms adapted to the task at hand, however, the performance can be increased. This paper introduces a shared control system that helps the subject in driving an intelligent wheelchair with a noninvasive brain interface. The subject's steering intentions are estimated from electroencephalogram (EEG) signals and passed through to the shared control system before being sent to the wheelchair motors. Experimental results show a possibility for significant improvement in the overall driving performance when using the shared control system compared to driving without it. These results have been obtained with 2 healthy subjects during their first day of training with the brain-actuated wheelchair.

Modifications of Vestibular Responses of Individual Reticulospinal Neurons in Lamprey Caused by Unilateral Labyrinthectomy

2002 ◽  
Vol 87 (1) ◽  
pp. 1-14 ◽  
Author(s):  
T. G. Deliagina ◽  
E. L. Pavlova
Keyword(s):  
Spinal Cord ◽  
Control System ◽  
Vestibular Stimulation ◽  
Dorsal Side ◽  
Vestibular Compensation ◽  
Directional Sensitivity ◽  
Vestibular Input ◽  
Population Activity ◽  
Postural Control System ◽  
Unilateral Labyrinthectomy

A postural control system in the lamprey is driven by vestibular input and maintains the dorsal-side-up orientation of the animal during swimming. After a unilateral labyrinthectomy (UL), the lamprey continuously rolls toward the damaged side. Normally, a recovery of postural equilibrium (“vestibular compensation”) takes about 1 mo. However, illumination of the eye contralateral to UL results in an immediate and reversible restoration of equilibrium. Here we used eye illumination as a tool to examine a functional recovery of the postural network. Important elements of this network are the reticulospinal (RS) neurons, which are driven by vestibular input and transmit commands for postural corrections to the spinal cord. In this study, we characterized modifications of the vestibular responses in individual RS neurons caused by UL and the effect exerted on these responses by eye illumination. The activity of RS neurons was recorded from their axons in the spinal cord by chronically implanted electrodes, and spikes in individual axons were extracted from the population activity signals. The same neurons were recorded both before and after UL. Vestibular stimulation (rotation in the roll plane through 360°) and eye illumination were performed in quiescent animals. It was found that the vestibular responses on the UL-side changed only slightly, whereas the responses on the opposite side disappeared almost completely. This asymmetry in the bilateral activity of RS neurons is the most likely cause for the loss of equilibrium in UL animals. Illumination of the eye contralateral to UL resulted, first, in a restoration of vestibular responses in the neurons inactivated by UL and in an appearance of vestibular responses in some other neurons that did not respond to vestibular input before UL. These responses had directional sensitivity and zones of spatial sensitivity similar to those observed before UL. However, their magnitude was smaller than before UL. Second, the eye illumination caused a reduction of the magnitude of vestibular responses on the UL side. These two factors tend to restore symmetry in bilateral activity of RS neurons, which is the most likely cause for the recovery of equilibrium in the swimming UL lamprey. Results of this study are discussed in relation to the model of the roll control system proposed in our previous studies as well as in relation to the vestibular compensation.

The Efficacy of Impact-Absorbing Materials during Collision with a Soccer Ball

2013 ◽  
Vol 440 ◽  
pp. 363-368
Author(s):  
Zahari Taha ◽  
Mohd Hasnun Arif Hassan ◽  
Mohd Azri Aris
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Coefficient Of Restitution ◽  
Soccer Ball ◽  
Absorbing Materials ◽  
The Subject ◽  
The Impact ◽  
The Brain ◽  
Peak Impact Force ◽  
Impact Duration

The uniqueness of soccer is that the players are allowed to use their head to pass the ball to a teammate of even try to score goal. Studies have shown that heading in soccer might be dangerous to the brain and could lead to brain trauma. There are headgears available for soccer players to protect their head, but studies have proven that currently available headgears are ineffective in reducing the impact caused by a soccer ball. The objective of this study is to test the efficacy of six different types of impact-absorbing materials in reducing the linear impact force from a soccer ball. The soccer ball was dropped from the height of 2.3 m onto a force platform to measure the impact force. A high-speed camera is used to record the motion and the impact duration, and then the coefficient of restitution for each impact was determined. Polyurethane (PU) comb-gel was found to be the most effective material in reducing the peak impact force and impulse compared with other materials. The reduction in peak force was associated with longer impact duration between the soccer ball and the PU comb-gel. However, the coefficient of restitution was reduced by 21.7%, implying that using the gel alone will reduce the speed of the ball after heading, thus reducing the performance of a player wearing it. A combination of PU gel and another stiffer material is suggested and the effectiveness of the composite will be the subject of future investigation.

Electrophysiology of the central and peripheral nervous systems

2020 ◽  
pp. 5785-5802
Author(s):  
Christian Krarup
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Nerve Conduction Studies ◽  
Brain Diseases ◽  
The Core ◽  
Electrophysiological Studies ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
The Brain

This chapter looks at electrophysiological studies of the central nervous system and peripheral nervous system—the core investigations in clinical neurophysiology. These include electroencephalography, which is of value to diagnose epilepsy caused by focal or diffuse brain diseases, electromyography and nerve conduction studies, which are of value to diagnose diseases in nerves and muscles, and evoked potentials, which are of value to diagnose diseases of white matter in the brain and spinal cord.

Disruption of Left–Right Reciprocal Coupling in the Spinal Cord of Larval Lamprey Abolishes Brain-Initiated Locomotor Activity

2005 ◽  
Vol 94 (3) ◽  
pp. 2031-2044 ◽  
Author(s):  
Adam W. Jackson ◽  
Dustin F. Horinek ◽  
Malinda R. Boyd ◽  
Andrew D. McClellan
Keyword(s):  
Spinal Cord ◽  
Locomotor Activity ◽  
Burst Activity ◽  
Experimental Conditions ◽  
Left And Right ◽  
Command Systems ◽  
Rhythmic Burst ◽  
The Brain ◽  
Caudal Spinal Cord

In this study, contributions of left–right reciprocal coupling mediated by commissural interneurons in spinal locomotor networks to rhythmogenesis were examined in larval lamprey that had longitudinal midline lesions in the rostral spinal cord [8 → 30% body length (BL), relative distance from the head] or caudal spinal cord (30 → 50% BL). Motor activity was initiated from brain locomotor command systems in whole animals or in vitro brain/spinal cord preparations. After midline lesions in the caudal spinal cord in whole animals and in vitro preparations, left–right alternating burst activity could be initiated in rostral and usually caudal regions of spinal motor networks. In in vitro preparations, blocking synaptic transmission in the rostral cord abolished burst activity in caudal hemi-spinal cords. After midline lesions in the rostral spinal cord in whole animals, left–right alternating muscle burst activity was present in the caudal and sometimes the rostral body. After spinal cord transections at 30% BL, rhythmic burst activity usually was no longer generated by rostral hemi-spinal cords. For in vitro preparations, very slow burst activity was sometimes present in isolated right and left rostral hemi-spinal cords, but the rhythmicity for this activity appeared to originate from the brain, and the parameters of the activity were significantly different from those for normal locomotor activity. In summary, in larval lamprey under these experimental conditions, left and right hemi-spinal cords did not generate rhythmic locomotor activity in response to descending inputs from the brain, suggesting that left–right reciprocal coupling contributes to both phase control and rhythmogenesis.

ARM Distributed Numerical Control System Design Based on CAN-Bus

2013 ◽  
Vol 415 ◽  
pp. 113-116
Author(s):  
Ji You Fei ◽  
Bin Gao ◽  
Jing Yan Wen
Keyword(s):  
Control System ◽  
System Design ◽  
Distributed Control ◽  
High Speed ◽  
Can Bus ◽  
Numerical Control ◽  
Control System Design ◽  
Numerical Control System ◽  
The Core ◽  
Hardware Circuit

This paper introduces an ARM Distributed Numerical Control System Design Based on CAN-Bus. It analyzed each parts function, hardware circuit and program. The design of interface and the driver of CAN Bus under Linux is the core of this paper. This system combines the distributed control of CAN-Bus with high-speed operation and precision of ARM. Systems resource utilization and real-time has improved. The flexibility and versatility are its advantage.

Activity of Reticulospinal Neurons During Locomotion in the Freely Behaving Lamprey

2000 ◽  
Vol 83 (2) ◽  
pp. 853-863 ◽  
Author(s):  
T. G. Deliagina ◽  
P. V. Zelenin ◽  
P. Fagerstedt ◽  
S. Grillner ◽  
G. N. Orlovsky
Keyword(s):  
Spinal Cord ◽  
Sensory Stimulation ◽  
Quiescent State ◽  
Sensory Stimuli ◽  
Equilibrium Control ◽  
Level Of Activity ◽  
Freely Behaving ◽  
Mass Activity ◽  
The Brain ◽  
Roll Tilt

The reticulospinal (RS) system is the main descending system transmitting commands from the brain to the spinal cord in the lamprey. It is responsible for initiation of locomotion, steering, and equilibrium control. In the present study, we characterize the commands that are sent by the brain to the spinal cord in intact animals via the reticulospinal pathways during locomotion. We have developed a method for recording the activity of larger RS axons in the spinal cord in freely behaving lampreys by means of chronically implanted macroelectrodes. In this paper, the mass activity in the right and left RS pathways is described and the correlations of this activity with different aspects of locomotion are discussed. In quiescent animals, the RS neurons had a low level of activity. A mild activation of RS neurons occurred in response to different sensory stimuli. Unilateral eye illumination evoked activation of the ipsilateral RS neurons. Unilateral illumination of the tail dermal photoreceptors evoked bilateral activation of RS neurons. Water vibration also evoked bilateral activation of RS neurons. Roll tilt evoked activation of the contralateral RS neurons. With longer or more intense sensory stimulation of any modality and laterality, a sharp, massive bilateral activation of the RS system occurred, and the animal started to swim. This high activity of RS neurons and swimming could last for many seconds after termination of the stimulus. There was a positive correlation between the level of activity of RS system and the intensity of locomotion. An asymmetry in the mass activity on the left and right sides occurred during lateral turns with a 30% prevalence (on average) for the ipsilateral side. Rhythmic modulation of the activity in RS pathways, related to the locomotor cycle, often was observed, with its peak coinciding with the electromyographic (EMG) burst in the ipsilateral rostral myotomes. The pattern of vestibular response of RS neurons observed in the quiescent state, that is, activation with contralateral roll tilt, was preserved during locomotion. In addition, an inhibition of their activity with ipsilateral tilt was clearly seen. In the cases when the activity of individual neurons could be traced during swimming, it was found that rhythmic modulation of their firing rate was superimposed on their tonic firing or on their vestibular responses. In conclusion, different aspects of locomotor activity—initiation and termination, vigor of locomotion, steering and equilibrium control—are well reflected in the mass activity of the larger RS neurons.

scholarly journals Amygdala: Neuroanatomical and Morphophysiological Features in Terms of Neurological and Neurodegenerative Diseases

2020 ◽  
Vol 10 (8) ◽  
pp. 502
Author(s):  
Vladimir N. Nikolenko ◽  
Marine V. Oganesyan ◽  
Negoriya A. Rizaeva ◽  
Valentina A. Kudryashova ◽  
Arina T. Nikitina ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Chronic Traumatic Encephalopathy ◽  
Neurological Diseases ◽  
Hippocampal Sclerosis ◽  
Degenerative Diseases ◽  
Behavioral Synthesis ◽  
Level Of Activity ◽  
Input Signals ◽  
The Subject ◽  
The Brain

The amygdala is one of the most discussed structures of the brain. Correlations between its level of activity, size, biochemical organization, and various pathologies are the subject of many studies, and can serve as a marker of existing or future disease. It is hypothesized that the amygdala is not just a structural unit, but includes many other regions in the brain. In this review, we present the updated neuroanatomical and physiological aspects of the amygdala, discussing its involvement in neurodegenerative and neurological diseases. The amygdala plays an important role in the processing of input signals and behavioral synthesis. Lesions in the amygdala have been shown to cause neurological disfunction of ranging severity. Abnormality in the amygdala leads to conditions such as depression, anxiety, autism, and also promotes biochemical and physiological imbalance. The amygdala collects pathological proteins, and this fact can be considered to play a big role in the progression and diagnosis of many degenerative diseases, such as Alzheimer’s disease, chronic traumatic encephalopathy, Lewy body diseases, and hippocampal sclerosis. The amygdala has shown to play a crucial role as a central communication system in the brain, therefore understanding its neuroanatomical and physiological features can open a channel for targeted therapy of neurodegenerative diseases.

scholarly journals Localisation of function in the lemur’s brain

1908 ◽  
Vol 80 (537) ◽  
pp. 136-147 ◽  
Keyword(s):  
Spinal Cord ◽  
Cerebral Cortex ◽  
Experimental Methods ◽  
Histological Structure ◽  
Full Account ◽  
Cortex Cerebri ◽  
The Subject ◽  
Brain And Spinal Cord ◽  
The Brain ◽  
Stimulation Of

The brain of the Lemur, the lowest of the ape-like animals, does not appear to have been subjected previously to a thorough examination. Page May and Elliott Smith brought a brief communication on the subject before the Cambridge Meeting of the British Association in 1904. Their experiments were apparently limited to stimulation of the cerebral cortex, and they have never published a full account of their work. Brodmann has worked out some of the histological details of the structure of the cortex cerebri, and Max Volsch has performed a stimulation experiment upon one Lemur. The work of these investigators will be referred to again in the course of this paper. Our own investigation has in the main dealt with the motor centres, and the experimental methods adopted have been the usual ones of stimulation and extirpation. In animals so low in the scale, stimulation is to be regarded as the more decisive of the two methods for the purpose of localisation. The extirpation experiments have, however, confirmed the results of stimulation, and in these experiments the course of the resulting degeneration was followed by histological examination of the brain and spinal cord. The results, moreover, agree remarkably closely with those obtained by a study of the histological structure of the various regions of the cortex cerebri.

The brain: our control system

2021 ◽  
Vol 15 (7) ◽  
pp. 318-322
Author(s):  
Ian Peate
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Control System ◽  
The Body ◽  
Brain Functions ◽  
The Brain ◽  
Complex Organ ◽  
Healthcare Assistant ◽  
Assistant Practitioner

The largest and the most complex organ in the body is the brain. In this article, the healthcare assistant and assistant practitioner (HCA and AP) are introduced to the fundamental features that are associated with the anatomy of the brain. The body's central nervous system is made up of the brain, along with the spinal cord. This is the main control system for the body's functions and abilities, allowing conscious communication with the body and automatic operation of the vital organs, for example, the heart. In this article, specific functions of the brain are considered. The four lobes of the brain are reviewed and also the three coverings of the meninges. Having insight and understanding related to how the brain functions can help the HCA and AP offer people care that is founded on a sound knowledge base. A glossary of terms is provided and a short quiz has also been included.

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