Development of Specific Connectivity Between Premotor Neurons and Motoneurons in the Brain Stem and Spinal Cord

2000 ◽  
Vol 80 (2) ◽  
pp. 615-647 ◽  
Author(s):  
Joel C. Glover
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Brain Stem ◽  
Sensory Afferents ◽  
Precise Control ◽  
Axonal Projections ◽  
Skeletal Musculature ◽  
Premotor Neurons ◽  
Molecular Guidance ◽  
The Brain

Astounding progress has been made during the past decade in understanding the general principles governing the development of the nervous system. An area of prime physiological interest that is being elucidated is how the neural circuitry that governs movement is established. The concerted application of molecular biological, anatomical, and electrophysiological techniques to this problem is yielding gratifying insight into how motoneuron, interneuron, and sensory neuron identities are determined, how these different neuron types establish specific axonal projections, and how they recognize and synapse upon each other in patterns that enable the nervous system to exercise precise control over skeletal musculature. This review is an attempt to convey to the physiologist some of the exciting discoveries that have been made, within a context that is intended to link molecular mechanism to behavioral realization. The focus is restricted to the development of monosynaptic connections onto skeletal motoneurons. Principal topics include the inductive mechanisms that pattern the placement and differentiation of motoneurons, Ia sensory afferents, and premotor interneurons; the molecular guidance mechanisms that pattern the projection of premotor axons in the brain stem and spinal cord; and the precision with which initial synaptic connections onto motoneurons are established, with emphasis on the relative roles played by cellular recognition versus electrical activity. It is hoped that this review will provide a guide to understanding both the existing literature and the advances that await this rapidly developing topic.

Symptoms, Related Brain Regions, and Diagnosis

2013 ◽  
Author(s):  
J. Eric Ahlskog
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Basal Ganglia ◽  
Brain Stem ◽  
Muscle Activation ◽  
Sensory Information ◽  
Brain Regions ◽  
Electrical Signal ◽  
Brain And Spinal Cord ◽  
The Brain

As a prelude to the treatment chapters that follow, we need to define and describe the types of problems and symptoms encountered in DLB and PDD. The clinical picture can be quite varied: problems encountered by one person may be quite different from those encountered by another person, and symptoms that are problematic in one individual may be minimal in another. In these disorders, the Lewy neurodegenerative process potentially affects certain nervous system regions but spares others. Affected areas include thinking and memory circuits, as well as movement (motor) function and the autonomic nervous system, which regulates primary functions such as bladder, bowel, and blood pressure control. Many other brain regions, by contrast, are spared or minimally involved, such as vision and sensation. The brain and spinal cord constitute the central nervous system. The interface between the brain and spinal cord is by way of the brain stem, as shown in Figure 4.1. Thought, memory, and reasoning are primarily organized in the thick layers of cortex overlying lower brain levels. Volitional movements, such as writing, throwing, or kicking, also emanate from the cortex and integrate with circuits just below, including those in the basal ganglia, shown in Figure 4.2. The basal ganglia includes the striatum, globus pallidus, subthalamic nucleus, and substantia nigra, as illustrated in Figure 4.2. Movement information is integrated and modulated in these basal ganglia nuclei and then transmitted down the brain stem to the spinal cord. At spinal cord levels the correct sequence of muscle activation that has been programmed is accomplished. Activated nerves from appropriate regions of the spinal cord relay the signals to the proper muscles. Sensory information from the periphery (limbs) travels in the opposite direction. How are these signals transmitted? Brain cells called neurons have long, wire-like extensions that interface with other neurons, effectively making up circuits that are slightly similar to computer circuits; this is illustrated in Figure 4.3. At the end of these wire-like extensions are tiny enlargements (terminals) that contain specific biological chemicals called neurotransmitters. Neurotransmitters are released when the electrical signal travels down that neuron to the end of that wire-like process.

Treatment of Recurrent Brain Stem Gliomas and Other Central Nervous System Tumors with 5-Fluorouracil, CCNU, Hydroxyurea, and 6-Mercaptopurine

Neurosurgery ◽  
1988 ◽  
Vol 22 (4) ◽  
pp. 691-693 ◽  
Author(s):  
Luis A. Rodriguez ◽  
Michael Prados ◽  
Dorcas Fulton ◽  
Michael S. B. Edwards ◽  
Pamela Silver ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Brain Stem ◽  
Central Nervous System Tumors ◽  
Brain Stem Glioma ◽  
Spinal Cord Tumors ◽  
The Brain ◽  
Brain Stem Gliomas ◽  
Time To Tumor Progression

Abstract Twenty-one patients with recurrent malignant central nervous system gliomas were treated with a combination of 5-fluorouracil, CCNU, hydroxyurea, and 6-mercaptopurine. Thirteen patients had brain stem gliomas, 3 patients had spinal cord gliomas, 3 patients had thalamic gliomas, and 2 patients had cerebellar astrocytomas. All patients had received radiation therapy, and 4 brain stem patients had also been treated with chemotherapy. Sixteen patients (76%) responded to treatment with either stabilization of disease or improvement. Nine of the 13 patients with brain stem gliomas (71%) had response or stabilization of disease. The median time to tumor progression (TTP) for the brain stem patients who responded or had stabilization of disease was 25 weeks. The median survival from recurrence for the brain stem glioma patients was 27 weeks. Patients with cerebellar, thalamic, and spinal cord tumors did very well, with an 87% response or stabilization of disease and a median TTP of 122 weeks.

scholarly journals Changes in the Nervous System and Musculature of Old Rats

1971 ◽  
Vol 8 (4) ◽  
pp. 320-332 ◽  
Author(s):  
G. van Steenis ◽  
R. Kroes
Keyword(s):  
Nervous System ◽  
Brain Stem ◽  
Wallerian Degeneration ◽  
Muscular Atrophy ◽  
Segmental Demyelination ◽  
Skeletal Musculature ◽  
Neurogenic Muscular Atrophy ◽  
Old Rats ◽  
Lower Brain Stem ◽  
The Brain

Changes in the nervous system and musculature of normal 34-month-old rats are described. Wallerian degeneration as well as segmental demyelination were observed in the peripheral nervous system, with changes more severe in the sciatic than in the brachial nerves. Signs of nerve-fibre degeneration were also seen in the cord and lower brain stem. The degenerative changes were usually mild, but in a number of animals there was severe degeneration of the gracile tract and lateral columns. Other changes in the nervous system included lipochrome pigment in nerve cells and other cellular elements throughout brain and cord, and eosinophilic bodies in the lower brain stem and cord. In some animals the ventricular system in the brain was dilated. Changes in the skeletal musculature were believed to represent neurogenic muscular atrophy secondary to changes in the nervous system.

scholarly journals HEME OXYGENASE-2 NEURONS BRAIN AND SPINAL CORD OF HUMAN

2012 ◽  
Vol 67 (6) ◽  
pp. 36-41 ◽  
Author(s):  
V. M. Chertok ◽  
A. E. Kotsyuba ◽  
E. P. Kotsyuba
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Methylene Blue ◽  
Nervous System ◽  
Brain Stem ◽  
Heme Oxygenase ◽  
Enzyme Reaction ◽  
Brain And Spinal Cord ◽  
The Brain ◽  
Number Of Cells

Immune localization of heme oxygenase-2 in neurons of some nuclei of the spinal cord and brain stem in 6 men 18–44 years old who died from causes unrelated to injury of central nervous system was studied. Neurons with positive reaction are determined for all studied regions of the brain where their contents in various nuclei ranging from 0,5 to 16% of the total number of cells detected by methylene blue. In all the sensory nuclei there is a high proportion of small neurons with a high or moderate density of reaction produc deposits. Large cells of motor nuclei often exhibit negative or low intensive enzyme reaction. 

The effect of undernutrition on the postnatal development of the brain and cord in pigs

1967 ◽  
Vol 166 (1005) ◽  
pp. 396-407 ◽  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Brain Stem ◽  
The Body ◽  
Chronological Age ◽  
Absolute Amount ◽  
The Central Nervous System ◽  
One Year ◽  
The Brain

Sucking pigs about 2 weeks old were held back by undernutrition so that they weighed only 5 to 6 kg when they were a year of age. The brain and cord developed during this time to the size to be expected in a normal pig about 10 weeks old but, although they remained immature for their chronological age, the effect on the various constituents was not uniform. The accumulation of cholesterol was less retarded than that of DNA.P or the increase in brain weight. During rehabilitation on a highly satisfactory diet the final body w eight reached at 3 1/2 years was 80 % of that to be expected in an adult pig and was equivalent only to that of a normal pig two years old. The central nervous system grew to the appropriate size for the body. The percentage of cholesterol in the central nervous system rose during rehabilitation, but, particularly in the forebrain, brain stem and spinal cord, remained subnormal for the chronological age. The deficiency of DNA- P in the rehabilitated brain was even greater, and the absolute amount finally corresponded to that found in the brain of a norm alanimal only one year of age.

Central Nerve System Impairment, AMA Guides, Sixth Edition: An Overview

2018 ◽  
Vol 23 (1) ◽  
pp. 10-13
Author(s):  
James B. Talmage ◽  
Jay Blaisdell
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Neurological Impairment ◽  
Sixth Edition ◽  
Central Nerve System ◽  
The Central Nervous System ◽  
The One ◽  
Nerve System ◽  
The Brain

Abstract Injuries that affect the central nervous system (CNS) can be catastrophic because they involve the brain or spinal cord, and determining the underlying clinical cause of impairment is essential in using the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), in part because the AMA Guides addresses neurological impairment in several chapters. Unlike the musculoskeletal chapters, Chapter 13, The Central and Peripheral Nervous System, does not use grades, grade modifiers, and a net adjustment formula; rather the chapter uses an approach that is similar to that in prior editions of the AMA Guides. The following steps can be used to perform a CNS rating: 1) evaluate all four major categories of cerebral impairment, and choose the one that is most severe; 2) rate the single most severe cerebral impairment of the four major categories; 3) rate all other impairments that are due to neurogenic problems; and 4) combine the rating of the single most severe category of cerebral impairment with the ratings of all other impairments. Because some neurological dysfunctions are rated elsewhere in the AMA Guides, Sixth Edition, the evaluator may consult Table 13-1 to verify the appropriate chapter to use.

Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

Some Points in the Histology of Lymphogenous and Hæmatogenous Toxic Lesions of the Spinal Cord

1908 ◽  
Vol 54 (226) ◽  
pp. 560-561
Author(s):  
David Orr ◽  
R. G. Rows
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Sciatic Nerve ◽  
Morphological Type ◽  
Broth Culture ◽  
Anatomical Distribution ◽  
Tabes Dorsalis ◽  
The Central Nervous System ◽  
The Brain

At a quarterly meeting of this Association held last year at Nottingham, we showed the results of our experiments with toxins upon the spinal cord and brain of rabbits. Our main conclusion was, that the central nervous system could be infected by toxins passing up along the lymph channels of the perineural sheath. The method we employed in our experiments consisted in placing a celloidin capsule filled with a broth culture of an organism under the sciatic nerve or under the skin of the cheek; and we invariably found a resulting degeneration in the spinal cord or brain, according to the situation of the capsule. These lesions we found to be identical in morphological type and anatomical distribution with those found in the cord of early tabes dorsalis and in the brain and cord of general paralysis of the insane. The conclusion suggested by our work was that these two diseases, if toxic, were most probably infections of lymphogenous origin.

Ten Million and One—Neurological Disability as a National Problem

PEDIATRICS ◽  
1958 ◽  
Vol 21 (5) ◽  
pp. 871-872
Author(s):  
ERIC DENHOFF
Keyword(s):  
Spinal Cord ◽  
New York ◽  
Nervous System ◽  
Highly Qualified ◽  
Neurological Disability ◽  
The Brain

This monograph summarizes the results of the Conference on Neurological Disability as a National Problem held at Arden House, Harriman, New York, in December, 1955. It was attended by more than 50 highly qualified specialists with various interests in the field who met to explore the realistic possibilities of meeting the problems posed by more than 10 million patients suffering from more than 300 clinical entities loosely grouped together as "neurologic disabilities." Neurologic disabilities are defined as those disorders which are associated demonstrably with dysfunction, disease, or injury of the nervous system, the brain, the spinal cord, and the peripheral neuromuscular connections.

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