scholarly journals Two distinct proprioceptive representations of voluntary movements in primate spinal neurons

2018 ◽  
Author(s):  
Saeka Tomatsu ◽  
Geehee Kim ◽  
Joachim Confais ◽  
Tomohiko Takei ◽  
Kazuhiko Seki
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Afferent Input ◽  
Proprioceptive Information ◽  
Voluntary Movements ◽  
Input Output ◽  
Spinal Neurons ◽  
Muscle Spindle Afferents ◽  
The Central Nervous System ◽  
Firing Irregularity

AbstractWhen willingly setting our body in motion, we simultaneously know where and how our limbs are moving. While this indicates that proprioceptive information is readily represented in the neurons of the central nervous system, it is still unclear how. We recorded the activity of spinal neurons with direct projections from muscle spindle afferents in four monkeys, while they performed simple wrist movements. Against the assumption that these spinal neurons act as a simple relay of afferent input, we found the majority (56%) of neurons had firing patterns incongruent with a simple representation of spindle activity, and the minority had congruent patterns. Two groups of neurons showed distinct intrinsic characteristics (spike width, base firing rate and firing irregularity), and distinct control of their input-output gain. These results are the first demonstration that proprioceptive representation is achieved by the coordinated activity of distinct groups of neurons during volitional movement.

Secondary changes after damage of the central nervous system Significance of spastic muscle tone in rehabilitation

2020 ◽  
pp. 95-110
Author(s):  
Volker Dietz ◽  
Thomas Sinkjaer
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Movement Disorder ◽  
Muscle Tone ◽  
Clinical Signs ◽  
Movement Pattern ◽  
Afferent Input ◽  
Human Adults ◽  
The Central Nervous System ◽  
Tendon Tap

The relationship between clinical spasticity and spastic movement disorder in human adults is covered in this chapter. Exaggerated tendon tap reflexes associated with muscle hypertonia are the clinical signs of central nervous system lesions. Therefore, most antispastic treatments are directed at the reduction of reflex activity. However, a discrepancy exists between spasticity as measured in the clinic and movement disorder. Central motor lesions are associated with a loss of supraspinal drive and defective use of afferent input. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fibre and collagen tissue result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organization. In mobile patients, functional training should be applied to improve both function and spasticity. Antispastic drugs can accentuate paresis and should primarily only be applied in non-ambulatory subjects.

scholarly journals Role of uncertainty in sensorimotor control

2002 ◽  
Vol 357 (1424) ◽  
pp. 1137-1145 ◽  
Author(s):  
Robert J. van Beers ◽  
Pierre Baraduc ◽  
Daniel M. Wolpert
Keyword(s):  
Central Nervous System ◽  
Optimal Control ◽  
Nervous System ◽  
Proprioceptive Information ◽  
Neural Signals ◽  
Neural Noise ◽  
Control Framework ◽  
The Central Nervous System ◽  
State Models

Neural signals are corrupted by noise and this places limits on information processing. We review the processes involved in goal–directed movements and how neural noise and uncertainty determine aspects of our behaviour. First, noise in sensory signals limits perception. We show that, when localizing our hand, the central nervous system (CNS) integrates visual and proprioceptive information, each with different noise properties, in a way that minimizes the uncertainty in the overall estimate. Second, noise in motor commands leads to inaccurate movements. We review an optimal–control framework, known as ‘task optimization in the presence of signal–dependent noise’, which assumes that movements are planned so as to minimize the deleterious consequences of noise and thereby minimize inaccuracy. Third, during movement, sensory and motor signals have to be integrated to allow estimation of the body's state. Models are presented that show how these signals are optimally combined. Finally, we review how the CNS deals with noise at the neural and network levels. In all of these processes, the CNS carries out the tasks in such a way that the detrimental effects of noise are minimized. This shows that it is important to consider effects at the neural level in order to understand performance at the behavioural level.

Control of Man-Machine FES Systems

2011 ◽  
pp. 263-280
Author(s):  
Rahman Davoodi ◽  
Gerald E. Loeb
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Cooperative Control ◽  
Voluntary Movements ◽  
Cord Injury ◽  
The Central Nervous System ◽  
Movement System

Movement disabilities due to spinal cord injury (SCI) are usually incomplete, leaving the patients with partially functioning movement system. As a result, functional electrical stimulation (FES) systems for restoration of movement to the paralyzed limbs must operate in parallel with the residual voluntary movements of the patient. In the resulting man-machine system, the central nervous system (CNS) controls the residual voluntary movements while the FES system controls the paralyzed muscles of the same limbs. Clearly, these two control systems must work in synchrony to benefit the patient. In this chapter we will discuss different methods for cooperative control of man-machine FES systems and use a clinical FES system to demonstrate the successful application of these strategies.

Secondary changes after damage of the central nervous system: significance of spastic muscle tone in rehabilitation

2015 ◽  
pp. 76-88
Author(s):  
Volker Dietz ◽  
Thomas Sinkjaer
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Movement Disorder ◽  
Muscle Tone ◽  
Movement Pattern ◽  
Afferent Input ◽  
The Central Nervous System ◽  
Tendon Tap ◽  
Muscle Hypertonia ◽  
The Relationship

The relationship between clinical spasticity and spastic movement disorder in human adultsis covered in this chapter. Signs of exaggerated tendon tap reflexes with muscle hypertonia are the consequence of central nervous system lesions. Most antispastic treatments are directed at the reduction of reflex activity. In recent years, a discrepancy between spasticity as measured in the clinic and movement disorder was noticed. Central motor lesions are associated with a loss of supraspinal drive and defective use of afferent input. These changes lead to paresis and maladaptation of the movement pattern. Secondary changes in mechanical muscle fibre and collagen tissue result in spastic muscle tone, which in part compensates for paresis and allows functional movements on a simpler level of organization. In mobile patients functional training should be applied to improve both function and spasticity. Antispastic drugs can accentuate paresis and should primarily only be applied in non-ambulatory subjects.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Emigration of neutrophils in the central nervous system

1983 ◽  
Vol 41 ◽  
pp. 788-789
Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
White Blood Cells ◽  
Arterial Perfusion ◽  
E Coli ◽  
Intracisternal Injection ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

Mammalian Bone Marrow Acetylcholinesterase

1982 ◽  
Vol 40 ◽  
pp. 44-45
Author(s):  
Ezzatollah Keyhani
Keyword(s):  
Central Nervous System ◽  
Bone Marrow ◽  
Nervous System ◽  
Common Property ◽  
Extracellular Medium ◽  
The Central Nervous System ◽  
The Common ◽  
Mammalian Bone

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.

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