scholarly journals Distinct Proximal and Distal Corticospinal Signals Embed Limb Dynamics Through the Modulation of Stiffness

2019 ◽  
Author(s):  
R. L. Hardesty ◽  
P. H. Ellaway ◽  
V. Gritsenko
Keyword(s):  
Nervous System ◽  
Physical Properties ◽  
Neural Control ◽  
Primary Motor Cortex ◽  
Equations Of Motion ◽  
Task Demands ◽  
The Body ◽  
Control Mechanisms ◽  
Neural Signals ◽  
Limb Dynamics

AbstractThe complexities of the human musculoskeletal system and its interactions with the environment creates a difficult challenge for the neural control of movement. The consensus is that the nervous system solves this challenge by embedding the dynamical properties of the body and the environment. However, the modality of control signals and how they are generated appropriately for the task demands are a matter of active debate. We used transcranial magnetic stimulation over the primary motor cortex to show that the excitability of the corticospinal tract is modulated to compensate for limb dynamics during reaching tasks in humans. Surprisingly, few profiles of corticospinal modulation in some muscles and conditions reflected Newtonian parameters of movement, such as kinematics or active torques. Instead, the overall corticospinal excitability was differentially modulated in proximal and distal muscles, which corresponded to different stiffness at proximal and distal joints. This suggests that the descending corticospinal signal determines the proximal and distal impedance of the arm for independent functional control of reaching and grasping.Significance StatementThe nervous system integrates both the physical properties of the human body and the environment to create a rich repertoire of actions. How these calculations are happening remains poorly understood. Neural activity is known to be correlated with different variables from the Newtonian equations of motion that describe forces acting on the body. In contrast, our data show that the overall activity of the descending neural signals is less related to the individual Newtonian variables and more related to limb impedance. We show that the physical properties of the arm are controlled by two distinct proximal and distal descending neural signals modulating components of limb stiffness. This identifies distinct neural control mechanisms for the transport and manipulation actions of reach.

Physiology in perspective: The Wisdom of the Body. Neural control of the kidney

2005 ◽  
Vol 289 (3) ◽  
pp. R633-R641 ◽  
Author(s):  
Gerald F. DiBona
Keyword(s):  
Nervous System ◽  
Renal Function ◽  
Autonomic Nervous System ◽  
Neural Control ◽  
Sympathetic Nerves ◽  
The Body ◽  
Regulatory Agencies ◽  
Internal Environment ◽  
Renal Sympathetic

Cannon equated the fluid matrix of the body with Bernard’s concept of the internal environment and emphasized the importance of “the safe-guarding of an effective fluid matrix.” He further emphasized the important role of the autonomic nervous system in the establishment and maintenance of homeostasis in the internal environment. This year’s Cannon Lecture discusses the important role of the renal sympathetic nerves to regulate various aspects of overall renal function and to serve as one of the major “self-regulatory agencies which operate to preserve the constancy of the fluid matrix.”

scholarly journals Neural Control of Immunity in Hypertension: Council on Hypertension Mid Career Award for Research Excellence, 2019

Hypertension ◽  
2020 ◽  
Vol 76 (3) ◽  
pp. 622-628
Author(s):  
Daniela Carnevale
Keyword(s):  
Immune Response ◽  
Nervous System ◽  
Neural Control ◽  
Neural Signals ◽  
The Past ◽  
Target Organs ◽  
Long Time ◽  
The Common ◽  
The Brain

The nervous system and the immune system share the common ability to exert gatekeeper roles at the interfaces between internal and external environment. Although interaction between these 2 evolutionarily highly conserved systems has been recognized for long time, the investigation into the pathophysiological mechanisms underlying their crosstalk has been tackled only in recent decades. Recent work of the past years elucidated how the autonomic nervous system controls the splenic immunity recruited by hypertensive challenges. This review will focus on the neural mechanisms regulating the immune response and the role of this neuroimmune crosstalk in hypertension. In this context, the review highlights the components of the brain-spleen axis with a focus on the neuroimmune interface established in the spleen, where neural signals shape the immune response recruited to target organs of high blood pressure.

Cardiovascular and respiratory control mechanisms during exercise: an integrated view

1991 ◽  
Vol 160 (1) ◽  
pp. 309-340
Author(s):  
D. L. Turner
Keyword(s):  
Nervous System ◽  
Neural Coding ◽  
Phase 1 ◽  
Sensory Information ◽  
Respiratory Control ◽  
Motor Command ◽  
The Body ◽  
Control Mechanisms ◽  
Parasympathetic Nerves ◽  
Sites Of Action

Exercise can impose an immense stress upon many physiological systems throughout the body. In order that exercise performance may be optimally maintained, it is essential that a profound and complex series of responses is coordinated and controlled. The primary site for coordination is the central nervous system, whereas control mechanisms (both feedback loops and feedforward activation) involve complex sensory information, often in the form of neural coding but also in the form of blood-borne chemical signals, a number of levels of peripheral and central integration and, finally, the efferent branches of the nervous system coursing via sympathetic and parasympathetic nerves to target sites of action. The neurohumoral control of the cardiorespiratory responses to exercise has received intense attention for over two decades and some particularly important steps forward in its understanding have occurred within the last 10 years. The initial fast increase (phase 1) in cardiovascular and ventilatory flow parameters are brought about by neurally mediated muscle mechanoreceptor feedback reflexes and a feedforward ‘central motor command’. The blood pressure operating point is also raised by a combination of these two neural mechanisms. Fine control of the matching of cardiac output to ventilation may occur by means of a feedforward ventilatory control of cardiac origin. During the slower phase of adjustment (phase 2), the neurally mediated mechanisms are augmented by a cohort of humorally mediated feedback reflexes involving muscle and vascular chemoreceptors as well as being supported by central neural reverberation.(ABSTRACT TRUNCATED AT 250 WORDS)

Interlimb Coordination During Locomotion: What Can be Adapted and Stored?

2005 ◽  
Vol 94 (4) ◽  
pp. 2403-2415 ◽  
Author(s):  
Darcy S. Reisman ◽  
Hannah J. Block ◽  
Amy J. Bastian
Keyword(s):  
Nervous System ◽  
Healthy Subjects ◽  
Neural Control ◽  
Motor Pattern ◽  
Interlimb Coordination ◽  
Task Demands ◽  
Bipedal Locomotion ◽  
Gait Parameters ◽  
Human Adults

Interlimb coordination is critically important during bipedal locomotion and often must be adapted to account for varying environmental circumstances. Here we studied adaptation of human interlimb coordination using a split-belt treadmill, where the legs can be made to move at different speeds. Human adults, infants, and spinal cats can alter walking patterns on a split-belt treadmill by prolonging stance and shortening swing on the slower limb and vice versa on the faster limb. It is not known whether other locomotor parameters change or if there is a capacity for storage of a new motor pattern after training. We asked whether adults adapt both intra- and interlimb gait parameters during split-belt walking and show aftereffects from training. Healthy subjects were tested walking with belts tied (baseline), then belts split (adaptation), and again tied (postadaptation). Walking parameters that directly relate to the interlimb relationship changed slowly during adaptation and showed robust aftereffects during postadaptation. These changes paralleled subjective impressions of limping versus no limping. In contrast, parameters calculated from an individual leg changed rapidly to accommodate split-belts and showed no aftereffects. These results suggest some independence of neural control of intra- versus interlimb parameters during walking. They also show that the adult nervous system can adapt and store new interlimb patterns after short bouts of training. The differences in intra- versus interlimb control may be related to the varying complexity of the parameters, task demands, and/or the level of neural control necessary for their adaptation.

scholarly journals Altered cardiorespiratory regulation during exercise in patients with Parkinson’s disease: A challenging non-motor feature

2020 ◽  
Vol 8 ◽  
pp. 205031212092160 ◽  
Author(s):  
Jeann L Sabino-Carvalho ◽  
Lauro C Vianna
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neural Control ◽  
Current Knowledge ◽  
Cardiovascular Response ◽  
Cardiovascular Responses ◽  
The Body ◽  
Control Mechanisms ◽  
Motor Impairments ◽  
Patients Experience

The incidence of Parkinson’s disease is increasing worldwide. The motor dysfunctions are the hallmark of the disease, but patients also experience non-motor impairments, and over 40% of the patients experience coexistent abnormalities, such as orthostatic hypotension. Exercise training has been suggested as a coping resource to alleviate Parkinson’s disease symptoms and delay disease progression. However, the body of knowledge is showing that the cardiovascular response to exercise in patients with Parkinson’s disease is altered. Adequate cardiovascular and hemodynamic adjustments to exercise are necessary to meet the metabolic demands of working skeletal muscle properly. Therefore, since Parkinson’s disease affects parasympathetic and sympathetic branches of the autonomic nervous system and the latter are crucial in ensuring these adjustments are adequately made, the understanding of these responses during exercise in this population is necessary. Several neural control mechanisms are responsible for the autonomic changes in the cardiovascular and hemodynamic systems seen during exercise. In this sense, the purpose of the present work is to review the current knowledge regarding the cardiovascular responses to dynamic and isometric/resistance exercise as well as the mechanisms by which the body maintains appropriate perfusion pressure to all organs during exercise in patients with Parkinson’s disease. Results from patients with Parkinson’s disease and animal models of Parkinson’s disease provide the reader with a well-rounded knowledge base. Through this, we will highlight what is known and not known about how the neural control of circulation is responding during exercise and the adaptations that occur when individuals exercise regularly.

scholarly journals ON THE RESPECTIVE PARTS PLAYED BY NEURAL AND HUMORAL INFLUENCES IN ANIMAL REACTIONS

1927 ◽  
Vol 8 (6) ◽  
pp. 645-651 ◽  
Author(s):  
E. Sharpey-Schafer
Keyword(s):  
Nervous System ◽  
Neural Control ◽  
The Body ◽  
Dual Control ◽  
Nervous Influence ◽  
Humoral Control

1. In the higher animals control of the functions of the body is dual, being partly neural and partly humoral. 2. When the control of any function is single and not dual, it is entirely neural. Exceptions to this statement appear to occur in connexion with the secretion of urine and milk, since these functions have not hitherto been shown to be under direct neural control. The mamma, and perhaps the kidney also, is, however, influenced by certain internal secretions which are themselves subJect both to neural and to humoral control. 3. The functions which are controlled both neurally and humorally are initiated by direct nervous influence: the humoral influence succeeds this. 4. In the lowest organisms possessed of a nervous system there is no evidence of humoral control, and no probability that this could be exercised, since there is no circulatory fluid, and the fluid which bathes the tissue has a composition appreciably the same as that of the environment. 5. It is, therefore, inferred that in all cases in which a dual control exists the neural, which is more rapid in its action, is primary, and the humoral secondary; and that the object of the humoral influence is to continue and prolong the effect of the neural influence, and thus to effect an economy of nervous energy.

scholarly journals Attentional Modulation of Neural Dynamics in Tactile Perception of Complex Regional Pain Syndrome Patients

2020 ◽  
Author(s):  
Serena Defina ◽  
Maria Niedernhuber ◽  
Nicholas Shenker ◽  
Christopher Brown ◽  
Tristan A. Bekinschtein
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Stimulus Onset ◽  
Task Demands ◽  
The Body ◽  
Neural Representation ◽  
Neural Dynamics ◽  
Control Mechanisms ◽  
Clinical Markers ◽  
Unaffected Side

AbstractBody perceptual disturbances are an increasingly acknowledged set of symptoms and possible clinical markers of Complex Regional Pain Syndrome (CRPS), but the neurophysiological and neurocognitive changes that underlie them are still far from being clear. We adopted a novel multivariate and neurodynamical approach to the analysis of EEG modulations evoked by touch, to highlight differences between patients and healthy controls, between affected and unaffected side of the body, and between “passive” (i.e. no task demands and equiprobable digit stimulation) and “active” tactile processing (i.e. where a digit discrimination task was administered and spatial probability manipulated). Contrary to our expectations we found no support for early differences in neural processing between CRPS and healthy participants, however, there was increased decodability in the CRPS group compared to healthy volunteers between 280 and 320 ms after stimulus onset. This group difference seemed to be driven by the affected rather than the unaffected side and was enhanced by attentional demands. These results found support in the exploratory analysis of neural representation dynamics and behavioural modelling, highlighting the need for single participant analyses. Although several limitations impacted the robustness and generalizability of our comparisons, the proposed novel analytical approach yielded promising insights (as well as possible biomarkers based on neural dynamics) into the relatively unexplored alterations of tactile decision-making and attentional control mechanisms in chronic CRPS.

scholarly journals Fifty years of microneurography: learning the language of the peripheral sympathetic nervous system in humans

2018 ◽  
Vol 119 (5) ◽  
pp. 1731-1744 ◽  
Author(s):  
J. Kevin Shoemaker ◽  
Stephen A. Klassen ◽  
Mark B. Badrov ◽  
Paul J. Fadel
Keyword(s):  
Nervous System ◽  
Sympathetic Nervous System ◽  
Neural Control ◽  
Primary Component ◽  
Communication Strategy ◽  
Communication Model ◽  
Neural Signals ◽  
Health And Disease ◽  
Sympathetic Nervous ◽  
Peripheral Sympathetic Nervous System

As a primary component of homeostasis, the sympathetic nervous system enables rapid adjustments to stress through its ability to communicate messages among organs and cause targeted and graded end organ responses. Key in this communication model is the pattern of neural signals emanating from the central to peripheral components of the sympathetic nervous system. But what is the communication strategy employed in peripheral sympathetic nerve activity (SNA)? Can we develop and interpret the system of coding in SNA that improves our understanding of the neural control of the circulation? In 1968, Hagbarth and Vallbo (Hagbarth KE, Vallbo AB. Acta Physiol Scand 74: 96–108, 1968) reported the first use of microneurographic methods to record sympathetic discharges in peripheral nerves of conscious humans, allowing quantification of SNA at rest and sympathetic responsiveness to physiological stressors in health and disease. This technique also has enabled a growing investigation into the coding patterns within, and cardiovascular outcomes associated with, postganglionic SNA. This review outlines how results obtained by microneurographic means have improved our understanding of SNA outflow patterns at the action potential level, focusing on SNA directed toward skeletal muscle in conscious humans.

scholarly journals Attentional Modulation of Neural Dynamics in Tactile Perception of Complex Regional Pain Syndrome (CRPS) Patients

2020 ◽  
Author(s):  
Serena Defina ◽  
Maria Niedernhuber ◽  
Nicholas Shenker ◽  
Christopher Brown ◽  
Tristan Bekinschtein
Keyword(s):  
Complex Regional Pain Syndrome ◽  
Pain Syndrome ◽  
Stimulus Onset ◽  
Task Demands ◽  
The Body ◽  
Neural Representation ◽  
Neural Dynamics ◽  
Control Mechanisms ◽  
Clinical Markers ◽  
Unaffected Side

Body perceptual disturbances are an increasingly acknowledged set of symptoms and possible clinical markers of Complex Regional Pain Syndrome (CRPS), but the neurophysiological and neurocognitive changes that underlie them are still far from being clear. We adopted a novel multivariate and neurodynamical approach to the analysis of EEG modulations evoked by touch, to highlight differences between patients and healthy controls, between affected and unaffected side of the body, and between “passive” (i.e. no task demands and equiprobable digit stimulation) and “active” tactile processing (i.e. where a digit discrimination task was administered and spatial probability manipulated). Contrary to our expectations we found no support for early differences in neural processing between CRPS and healthy participants, however, there was increased decodability in the CRPS group compared to healthy volunteers between 280 and 320 ms after stimulus onset. This group difference seemed to be driven by the affected rather than the unaffected side and was enhanced by attentional demands. These results found support in the exploratory analysis of neural representation dynamics and behavioural modelling, highlighting the need for single participant analyses. Although several limitations impacted the robustness and generalizability of our comparisons, the proposed novel analytical approach yielded promising insights (as well as possible biomarkers based on neural dynamics) into the relatively unexplored alterations of tactile decision-making and attentional control mechanisms in chronic CRPS.

Neuron-glia relationship during the early postembryonic development of the nervous system in some oligochaetes

1978 ◽  
Vol 36 (2) ◽  
pp. 600-601
Author(s):  
Wiktor Djaczenko ◽  
Carmen Calenda Cimmino
Keyword(s):  
Nervous System ◽  
Glial Cells ◽  
Early Period ◽  
Postembryonic Development ◽  
Ruthenium Red ◽  
The Body ◽  
Tubifex Tubifex ◽  
Growth Stages ◽  
Cell Processes ◽  
Cytoplasmic Processes

The simplicity of the developing nervous system of oligochaetes makes of it an excellent model for the study of the relationships between glia and neurons. In the present communication we describe the relationships between glia and neurons in the early periods of post-embryonic development in some species of oligochaetes.Tubifex tubifex (Mull. ) and Octolasium complanatum (Dugès) specimens starting from 0. 3 mm of body length were collected from laboratory cultures divided into three groups each group fixed separately by one of the following methods: (a) 4% glutaraldehyde and 1% acrolein fixation followed by osmium tetroxide, (b) TAPO technique, (c) ruthenium red method.Our observations concern the early period of the postembryonic development of the nervous system in oligochaetes. During this period neurons occupy fixed positions in the body the only observable change being the increase in volume of their perikaryons. Perikaryons of glial cells were located at some distance from neurons. Long cytoplasmic processes of glial cells tended to approach the neurons. The superimposed contours of glial cell processes designed from electron micrographs, taken at the same magnification, typical for five successive growth stages of the nervous system of Octolasium complanatum are shown in Fig. 1. Neuron is designed symbolically to facilitate the understanding of the kinetics of the growth process.

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