Planning and execution of multijoint movements

1988 ◽  
Vol 66 (4) ◽  
pp. 508-517 ◽  
Author(s):  
Neville Hogan
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Computational Complexity ◽  
Internal Representation ◽  
Arm Movements ◽  
Neuromuscular System ◽  
External Space ◽  
The Central Nervous System ◽  
Multijoint Movements

This paper reviews some recent studies related to the generation of simple multijoint arm movements. Two principal issues are considered. The first concern is how movements are represented internally by the central nervous system. There are many possible sets of coordinates that could be used to represent arm movements. Two of the possibilities are reviewed: representation in terms of joint angular motions versus representation in terms of motions of the hand in external space coordinates. A second concern is the transformation from intention to action: how is an internal representation of motion expressed by the neuromuscular system? The computational complexity of this problem is reviewed. A way in which the mechanics of the neuromuscular system could be exploited to simplify this problem is discussed.

Serotonin Syndrome

2019 ◽  
pp. 467-471
Author(s):  
Kevin T. Gobeske ◽  
Eelco F. M. Wijdicks
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Serotonin Syndrome ◽  
Neuromuscular System ◽  
Autonomic Nervous ◽  
Life Threatening ◽  
The Central Nervous System ◽  
Serotonin Toxicity

Serotonin syndrome affects the central nervous system, the autonomic nervous system, and the neuromuscular system and can have acute and potentially life-threatening manifestations. By definition, serotonin syndrome is associated with changes in serotonin exposure and thus might be described more accurately as serotonergic excess or serotonin toxicity. The central nervous system effects of serotonin involve regulation of attention, arousal, mood, learning, appetite, and temperature.

Sensorimotor adaptation of point-to-point arm movements after spaceflight: the role of internal representation of gravity force in trajectory planning

2011 ◽  
Vol 106 (2) ◽  
pp. 620-629 ◽  
Author(s):  
Jérémie Gaveau ◽  
Christos Paizis ◽  
Bastien Berret ◽  
Thierry Pozzo ◽  
Charalambos Papaxanthis
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Arm Movements ◽  
The Body ◽  
Sensorimotor Adaptation ◽  
Subjective Feeling ◽  
Gravity Level ◽  
The Central Nervous System ◽  
Path Curvature ◽  
Point To Point

After an exposure to weightlessness, the central nervous system operates under new dynamic and sensory contexts. To find optimal solutions for rapid adaptation, cosmonauts have to decide whether parameters from the world or their body have changed and to estimate their properties. Here, we investigated sensorimotor adaptation after a spaceflight of 10 days. Five cosmonauts performed forward point-to-point arm movements in the sagittal plane 40 days before and 24 and 72 h after the spaceflight. We found that, whereas the shape of hand velocity profiles remained unaffected after the spaceflight, hand path curvature significantly increased 1 day after landing and returned to the preflight level on the third day. Control experiments, carried out by 10 subjects under normal gravity conditions, showed that loading the arm with varying loads (from 0.3 to 1.350 kg) did not affect path curvature. Therefore, changes in path curvature after spaceflight cannot be the outcome of a control process based on the subjective feeling that arm inertia was increased. By performing optimal control simulations, we found that arm kinematics after exposure to microgravity corresponded to a planning process that overestimated the gravity level and optimized movements in a hypergravity environment (∼1.4 g). With time and practice, the sensorimotor system was recalibrated to Earth's gravity conditions, and cosmonauts progressively generated accurate estimations of the body state, gravity level, and sensory consequences of the motor commands (72 h). These observations provide novel insights into how the central nervous system evaluates body (inertia) and environmental (gravity) states during sensorimotor adaptation of point-to-point arm movements after an exposure to weightlessness.

Transformation from Head- to Shoulder-Centered Representation of Target Direction in Arm Movements

1990 ◽  
Vol 2 (1) ◽  
pp. 32-43 ◽  
Author(s):  
J. F. Soechting ◽  
S. I. H. Tillery ◽  
M. Flanders
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Coordinate System ◽  
Target Location ◽  
Arm Movements ◽  
Target Direction ◽  
Pointing Movement ◽  
Extrapersonal Space ◽  
The Central Nervous System

In a previous study (Soechting and Flanders 1990a) we suggested that subjects used a coordinate system centered at the shoulder while pointing to targets in extrapersonal space. In particular, we suggested that this coordinate system was used to define target location in terms of its distance and the direction from the shoulder. In this paper we examine this suggestion in more detail. We show that when subjects make errors in the distance of a pointing movement, the computed errors in direction will depend on the origin of the coordinate system chosen to measure direction. From an analysis of the computed error, we estimate the origin of each subject's coordinate system. We artificially induced large errors in pointing distance by asking subjects to point half-way to a target on a line from the shoulder or from the head, that is, in directions from two possible centers. The subjects' performance on both these tasks was comparable to the performance of subjects asked to point directly to the target. From this finding we argue that there exists both a head-centered and a shoulder-centered representation of target location within the central nervous system.

scholarly journals Stereotyped terminal axon branching of leg motor neurons mediated by IgSF proteins DIP-α and Dpr10

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lalanti Venkatasubramanian ◽  
Zhenhao Guo ◽  
Shuwa Xu ◽  
Liming Tan ◽  
Qi Xiao ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Neurons ◽  
Neural Circuits ◽  
Neuromuscular System ◽  
Morphological Complexity ◽  
Terminal Axon ◽  
Branching Patterns ◽  
Ig Superfamily ◽  
The Central Nervous System

For animals to perform coordinated movements requires the precise organization of neural circuits controlling motor function. Motor neurons (MNs), key components of these circuits, project their axons from the central nervous system and form precise terminal branching patterns at specific muscles. Focusing on the Drosophila leg neuromuscular system, we show that the stereotyped terminal branching of a subset of MNs is mediated by interacting transmembrane Ig superfamily proteins DIP-α and Dpr10, present in MNs and target muscles, respectively. The DIP-α/Dpr10 interaction is needed only after MN axons reach the vicinity of their muscle targets. Live imaging suggests that precise terminal branching patterns are gradually established by DIP-α/Dpr10-dependent interactions between fine axon filopodia and developing muscles. Further, different leg MNs depend on the DIP-α and Dpr10 interaction to varying degrees that correlate with the morphological complexity of the MNs and their muscle targets.

Spastic dysphonia and denervation signs in a young man with tardive dyskinesia

1989 ◽  
Vol 154 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Jeffrey A. Lieberman ◽  
Ross Reife
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Basal Ganglia ◽  
Tardive Dyskinesia ◽  
Structural Changes ◽  
Neuromuscular System ◽  
Muscle Denervation ◽  
Neurological Syndrome ◽  
The Central Nervous System

Pathophysiological theories of tardive dyskinesia (TD) suggest the possibility of structural changes in the central nervous system of patients with TD. This report describes a case of choreoathetoid dyskinesia and spastic dysphonia associated with clinical and electromyographic signs of muscle denervation. The findings of this case suggest that the neurological syndrome originates within basal ganglia nuclei but may also extend to the peripheral neuromuscular system.

Emerging Scientist: Examining Exercise-Based Therapies for Voice and Swallow Disorders With a Neuroplastic Eye

2016 ◽  
Vol 1 (3) ◽  
pp. 33-38
Author(s):  
Allison J. Schaser
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neural Substrates ◽  
Current Therapy ◽  
Neuromuscular System ◽  
Sensorimotor System ◽  
Clear Understanding ◽  
Recent Application ◽  
The Central Nervous System

Exercise-based therapies are currently used to treat voice and swallow disorders without a clear understanding of the mechanisms that alter the cranial neuromuscular system. The recent application of principles of neuroplasticity to rehabilitation has revolutionized how we think about treatment, highlighting the need for change in both behavior and neural substrates to create lasting benefits. It is difficult, however, to study neural substrates in human patients while controlling for factors that may influence plasticity, such as genetic and environmental differences. The use of a rat model allows these controls. My research aims to further our understanding of the neuroplastic potential of exercise in the cranial sensorimotor system with the ultimate long-term and future goal of guiding care of individuals with voice and swallow problems. This work is significant because it examines the neuroplastic potential of exercise in the cranial sensorimotor system in both muscle and the central nervous system, along with the enduring effects of exercise with the long-term and future goal of using my results to guide current therapy timelines and protocols used in clinical populations with voice and swallow problems.

The iroquois complex controls the somatotopy of Drosophila notum mechanosensory projections

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3563-3569 ◽  
Author(s):  
N. Grillenzoni ◽  
J. van Helden ◽  
C. Dambly-Chaudiere ◽  
A. Ghysen
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sensory Neurons ◽  
Internal Representation ◽  
External World ◽  
Model System ◽  
Gene Complex ◽  
Lateral Region ◽  
The Central Nervous System

Sensory neurons can establish topologically ordered projections in the central nervous system, thereby building an internal representation of the external world. We analyze how this ordering is genetically controlled in Drosophila, using as a model system the neurons that innervate the mechanosensory bristles on the back of the fly (the notum). Sensory neurons innervating the medially located bristles send an axonal branch that crosses the central nervous system midline, defining a ‘medial’ identity, while the ones that innervate the lateral bristles send no such branch, defining a ‘lateral’ identity. We analyze the role of the proneural genes achaete and scute, which are involved in the formation of the medial and lateral bristles, and we show that they have no effect on the ‘medial’ and ‘lateral’ identities of the neurons. We also analyze the role of the prepattern genes araucan and caupolican, two members of the iroquois gene complex which are required for the expression of achaete and scute in the lateral region of the notum, and we show that their expression is responsible for the ‘lateral’ identity of the projection.

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