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| | Motoneuron - Wikipedia, the free encyclopedia |
 | | In vertebrates, motoneurons (also called motor neurons) are efferent neurons that originate in the spinal cord and synapse with muscle fibers to facilitate muscle contraction and with muscle spindles to modify proprioceptive sensitivity. | | | This is why muscle relaxants work by acting on the nerves that innervate muscles (by decreasing their electrophysiological activity) or on cholinergic neuromuscular junctions, rather than on the muscles themselves. | | | In addition to voluntary skeletal muscle contraction, alpha motoneurons also contribute to muscle tone, the continuous force generated by noncontracting muscle to oppose stretching. |
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http://en.wikipedia.org/wiki/Motoneuron
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| | BASIC MOTOR PATHWAY |
| | The motor pathways are pathways which originate in the brain or brainstem and descend down the spinal cord to control the | | | Therefore it is crucial to understand the anatomy of the motor pathway. | | | The motor pathways can control posture, reflexes, and muscle tone, as well as the conscious voluntary movements that we think of when we hear "motor system". |
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http://thalamus.wustl.edu/course/basmot.html
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| | Motor Neurons Grown From Stem Cells |
| | Motor neurons transmit messages from the brain and spinal cord, dictating almost every movement in the body from the wiggling of a toe to the rolling of an eyeball. | | | Rather, a series of complex overlapping changes may well be the developmental norm in higher vertebrates such as humans. |
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http://www.scienceagogo.com/news/20050030232521data_trunc_sys.shtml
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| | Motor Neuron Disease |
| | Motor Neuron Diseases may affect the upper motor neurons, nerves that lead from the brain to the medulla (a part of the brain stem) or to the spinal cord, or the lower motor neurons, nerves that lead from the spinal cord to the muscles of the body, or both. | | | The muscles of the eye, heart, and anal sphincter (ring of muscles that prevents passage of feces) may be affected causing vision problems, irregular heartbeat, and loss of bowel control. | | | It is characterized by weakness, twitching, and wasting of the muscles of the body. |
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http://hw.healthdialog.com/kbase/nord/nord656.htm
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| | [No title] |
| | The motor neuron and all the muscle fibers that it innervates behaves as a unit. | | | Motor neuron and their connections to the muscle Please look fig 15.4 from book (not shown but is helpful) Here is a motor neuron in the spinal cord. | | | This can be done at the level of single motor units by stimulating from inside a motor neuron or you can stimulate a whole muscle and see the same thing but in a whole muscle the tension will be greater. |
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http://www.uhmc.sunysb.edu/som/students/2003/Lectures/neu28.doc
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| | Motor system |
| | In particular, skeletal muscle contracts when motor neurons leaving the spinal cord or medulla release ACh on the muscle. | | | The simplest reflex circuit is the stretch reflex (e.g., the knee jerk reflex). | | | These neurons allow the spinal cord to coordinate movements even without a brain. |
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http://www.vancouver.wsu.edu/fac/morgan/lecture/motor.html
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| | BrainConnection: The Brain and Learning |
| | Mirror neurons may thus facilitate the preliminary motor neuron simulation, priming, programming, and rehearsing that occurs in children, and this process obviously enhances our eventual mastery of complex motor behaviors, and our ability to read the minds of others. | | | Mirror neurons may thus eventually help to explain many teaching and learning mysteries in which modeling provides children with an effective behavioral pattern to follow — and to explain disabilities (such as autism) in which children can't read the minds of others. | | | A smoothly coordinated motor sequence involves the typically unconscious preparation for a movement followed by the actual movement. |
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http://www.brainconnection.com/content/181_1/printable
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| | Developmental Biology Online: Multiple Guidance Cues in the Motor Neurons Innervating Skeletal Muscles |
| | Axonal outgrowth of motor neurons occurs very early in development, before the soma of the motor neurons have migrated to their definitive positions in the spinal cord and before the muscles have condensed out of mesenchyme (Landmesser, 1978; Hollyday, 1980a). | | | For example, in Figure 1, motor neurons for different muscles diverge into the appropriate nerve trunks and eventually project into single muscles. | | | These experiments present a paradox that has yet to be resolved; "Particular axons are biased to grow to specific places, yet axons from different motor neuron pools can substitute for one another in the establishment of normal nerve patterns" (Purves and Lichtman, 1985). |
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http://www.devbio.com/article.php?ch=13&id=140
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| | [No title] |
| | Clinical significance - Clasped knife reflex: In Upper Motor neuron lesions, tonus may increase and resistance of muscle to stretch increases; if sufficient force is applied, limb resistance suddenly decreases (like a pocket knife snapping shut); thought to be mediated by reflexes of Golgi tendon organs. | | | Muscle Tonus - The ongoing activity in muscle spindles is important in maintaining the desired activity of motor neurons to muscles (because the connection is monosynaptic). | | | motor neurons - (termed efferent arm of reflex) produce muscle contraction, motor response. |
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http://musom.marshall.edu/anatomy/grosshom/spinalreflexes.html
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| | HHMI News: Researchers Produce Motor Neurons from Embryonic Stem Cells |
| | They are also developing collaborations with neurologists to explore in mouse models whether their motor neurons can regenerate spinal cords that have been damaged by trauma or neurodegenerative diseases, such as amyotrophic lateral sclerosis. | | | The fluorescent tagging enabled Jessell and his colleagues to monitor, isolate and purify the specific motor neurons they had induced — a technique that Jessell believes will be crucial to further attempts to define the signaling pathways involved in neuronal differentiation. | | | “This is just the starting point for trying to take a rational approach to studying the ability of ES-cell-derived motor neurons to restore function, not just in an embryonic context, but in a more relevant adult context,” he said. |
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http://www.hhmi.org/news/jessell2.html
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| | Specific Genes Identified in Developing Motor Neurons - The ALS Association |
| | Two types of neurons – those in the brain’s cortex and spinal motor neurons in the spinal cord – are linked and are affected by the disease process in ALS. | | | A critical aspect of motor neurons is their “ability to extend an extremely long axon to precise locations within the spinal cord. | | | Progress from a number of labs shows “how the motor neurons in the spinal cord itself develop and, more recently, how they might be replaced,” Macklis noted. |
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http://www.alsa.org/research/article.cfm?id=578&CFID=69892&CFTOKEN=53880976
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| | Neurons |
| | The diagram is a simplified view of the relationship between sensory and motor neurons running to and from the spinal cord. | | | The cell bodies of the sensory neurons leading to the spinal cord are located in clusters, called ganglia, next to the spinal cord. | | | These are found exclusively within the spinal cord and brain. |
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http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/Neurons.html
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| | U-WIRE.com/U. Wisconsin lab creates motor neurons from stem cells |
| | According to a release, the key to the researchers' success was the specific time they coached their cells to change into motor neuron cells. | | | Zhang explained that his team of researchers originally applied knowledge from animal studies to attempt the creation of motor neuron cells, but the method did not work, and the scientists had to change the way they previously thought about development. | | | "Motor neurons control all muscles of our body," said UW professor of anatomy and neurology and lead researcher Su-Chun Zhang. |
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http://www.uwire.com/content/topnews020105003.html
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| | [No title] |
| | Thus, the neuron is involved in preparation for the movement, not the execution of the movement itself. | | | Neurons with different tuning curves of flexion and extension have a certain activity for certain movements. | | | Controlling the amount of firing by particular M1 neurons that are tuned to different directions of movement, the vector forces can add up and give you movement in the desired direction. |
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http://www.uhmc.sunysb.edu/som/students/2003/Lectures/neu31.doc
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| | Neuroscience for Kids - Neurons |
| | Neurons can be quite large - in some neurons, such as corticospinal neurons (from motor cortex to spinal cord) or primary afferent neurons (neurons that extend from the skin into the spinal cord and up to the brain stem), can be several feet long! | | | - system of transport for materials within a neuron and may be used for structural support. | | | You have many of the same neurons for your whole life. |
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http://faculty.washington.edu/chudler/cells.html
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| | Chapter 6: Motor Neurons |
| | Three examples of reflexes are the stretch reflex, the withdrawal reflex, and the gamma loop reflex. | | | Key point: Motor units are recruited through their terminating points in the specific muscles needed to execute a movement. | | | Key point: force can also be increased by manipulating the rate of firing, synchronizing the rate of firing (as in strength training), using the most effective initial body position, and using more joints and their corresponding muscles. |
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http://clem.mscd.edu/~broida/hps450/chapter_outlines/chapter6.html
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| | The Peripheral Nervous System |
| | The preganglionic motor neurons of the sympathetic system arise in the spinal cord. | | | Other preganglionic parasympathetic neurons also extend from the brain as well as from the lower tip of the spinal cord. | | | All of the spinal nerves are "mixed"; that is, they contain both sensory and motor neurons. |
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http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html
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| | SPINAL MOTOR STRUCTURES |
| | One of the most familiar reflexes is the stretch reflex, also known as the knee-jerk reflex and the myotatic reflex. | | | The postural pathways do not originate in cortex; instead their function is to maintain an upright posture against gravity, a task which requires hundreds of little muscular adjustments that we are not aware of. | | | They can be roughly grouped into the voluntary motion pathways and the postural pathways. |
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http://thalamus.wustl.edu/course/spinal.html
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| | Study: New Neurons Can Get Out of Spinal Cord |
| | For example, in their experiments, even though some of the new neurons reached through the myelin coating, they didn't get much farther down the road to the real target -- muscles. | | | Furthermore, to approach therapy, Kerr says, these and other experiments need to be done with human embryonic stem (ES) cells that may one day be clinically useful. | | | In these first animal studies, however, the axons of these new neurons didn't poke through the spinal cord and out to muscle targets. |
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http://www.hopkinsmedicine.org/Press_releases/2004/04_28_04.html
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| | Molecular evidence for early activity-dependent development of hamster motor neurons. |
| | These observations suggest that motor neurons, like LGN neurons, require some pattern of neuronal activity during a critical period in development and, further, that the phenotypic changes in neurons consequent to early activity are reflected by the expression of specific molecules. | | | To determine if Cat-301 might be a general marker for experience-dependent development in other areas of the CNS we have examined antigen expression on hamster spinal cord motor neurons. | | | The identification and characterization of such molecules may yield a description of the molecular mechanisms of experience-dependent development. |
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http://www.arclab.org/medlineupdates/abstract_3249230.html
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| | Healthy neighbors rescue degenerating motor neurons |
| | Motor neurons control muscle action, and they are progressively weakened in ALS, leading to paralysis and death. | | | And I believe that this study represents an important step toward that goal." | | | The results of these studies could suggest a route to therapy for the disease, said Goldstein. |
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http://www.eurekalert.org/pub_releases/2003-10/hhmi-hnr100103.php
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| | [No title] |
| | Fasciculations may be subtle or severe to the point of "vermiculation" giving a "bag of worms" appearance, for example, the infamous "scrotal tongue" when the motor neurons of the 12th Cranial Nerve in the brainstem are affected. | | | He immediately began experiencing neck pain radiating down the left arm. | | | ALS is a system disease analagous to Parkinson's: that is, the neurons affected all participate in a related function. |
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http://www.idiom.com/~drjohn/als.html
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| | Motor - Wikipedia, the free encyclopedia |
| | Motor Neuron - neurons that originate in the spinal cord and synapse with muscle fibers | | | Motor proteins inside cells allow for the movement of objects inside cells and also the movement of cells, tissues, organs and organisms. | | | Motor (Hydraulic) - a hydraulic machine which converts energy of pressurized liquid flow into mechanical motion. |
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http://en.wikipedia.org/wiki/Motor
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| | Stem cells made into neurons that move muscle |
| | The discovery may help researchers figure out how to repair spinal cord injuries and screen new drugs for muscular diseases, such as amyotrophic lateral sclerosis, or Lou Gehrig's. | | | Success in this phase will lead to experiments with other animals and eventually to human testing. | | | Scientists transformed human embryonic stem cells into muscle-controlling motor neurons in laboratory tests for the first time, a discovery that may lead to treatments for Lou Gehrig's disease and spinal cord injuries. |
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http://www.suntimes.com/output/news/cst-nws-stem31.html
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| | Nikon MicroscopyU: Confocal Image Gallery - Mammalian Motor Neurons |
| | Because most skeletal muscle movement is under conscious control, it is also commonly referred to as voluntary muscle. | | | The average mass of the human body is comprised of about forty percent skeletal muscle. | | | Specialized nerves referred to as motor neurons transmit signals that cause skeletal muscle cells to temporarily shorten or contract. |
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http://www.microscopyu.com/galleries/confocal/mammalneuronmotornervecellssmear.html
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| | Motor Neurons |
| | The photo, published recently in the journals Nature Biotechnology and Journal of the American Medical Association, shows a cluster of motor neurons grown in a lab. | | | Motor neurons are messenger nerve cells that relay information from the brain or spinal cord to muscles. | | | Zhang and his colleagues have begun experiments implanting the neurons in animal brains and spinal cords. |
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http://www.washingtonpost.com/wp-dyn/content/article/2005/04/04/AR2005040400677.html
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| | Biology of Motor Neurons |
| | This project aims to examine the physiological properties of ES cell derived motor neurons after their introduction into neonatal mouse spinal cord, and to examine the capacity of these neurons to innervate target muscle after grafting into peripheral nerve. | | | Physiology and Function of ES Cell derived Motor neurons in Mammalian Spinal Cord. | | | The main aim of this project is to define conditions in which motor neuron progenitor cells in mammalian spinal cord can be isolated, grown in vitro, expanded in the presence of mitogenic factors, and then induced to differentiate into motor neurons. |
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http://cpmcnet.columbia.edu/dept/als/research/biologymn.html
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| | Scientists grow motor neurons - Science - www.smh.com.au |
| | Most motor neurons emanate from the spinal cord, where they form long connections to muscles around the body. | | | The more immediate impact of their research will be to provide a supply of motor nerve cells that can be used to test new drugs intended to treat nerve ailments. | | | Milwaukee: Using their own line of embryonic stem cells, US researchers have become the first to make human motor neurons, the spindly nerve cells that control nearly all movement in the body. |
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http://www.smh.com.au/news/Science/Scientists-grow-motor-neurons/2005/01/31/1107020330418.html
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| | Stem Cell Research |
| | To test this, Dr. Wichterle inserted the neurons into a chick embryo's spinal cord and watched. | | | Besides its impact on ALS research, the Columbia protocol can be applied to create better stem cell-derived cells for research into therapies for other neurodegenerative disorders, such as Parkinson's disease. | | | Glial cells, which surround, nourish, and protect neurons, could, perhaps, be more useful in a future therapy. |
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http://www.cumc.columbia.edu/news/in-vivo/Vol1_Iss15_sept25_02
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| | Researchers Turn Stem Cells Into Spinal Motor Neurons |
| | Motor neurons relay messages sent from the brain and the spinal cord to the rest of the body, making them largely responsible for every movement a person makes. | | | Scientists have coaxed human embryonic stem cells into becoming spinal motor neurons, which may pave the way for future treatments and cures for Lou Gehrig's disease, muscular dystrophy and spinal-cord injuries. | | | Lead researcher, Su-Chun Zhang said the next step will be to transplant the coaxed neurons into a living animal. |
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http://www.healthtalk.ca/stem_cells_013105_37773.php
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| | Generation of Human Motor Neurons from Stem Cells - The ALS Association |
| | This work will complement ongoing studies of stem cell therapy in animal models of ALS. | | | In order to promote the regeneration of motor neurons or replacement of diseased cells, it is essential to understand how motor neurons develop in man and to find a way of generating a sufficient number of human motor neurons for drug screening and transplantation therapy. | | | Although challenging and as yet not achieved, generation of motor neurons in vitro for transplantation or the discovery of appropriate cues to generate motor neurons in the human body, are exciting potential approaches to stem cell therapy for ALS. |
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http://www.alsa.org/research/grant.cfm?id=166
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| | Ciliary neurotrophic factor prevents degeneration of motor neurons in mouse mutant progressive motor neuronopathy |
| | , and prevents lesion-mediated degeneration of rat motor neurons during early post-natal stages | | | Moreover, morphological manifestations, such as loss of motor axons in the phrenic nerve and degeneration of facial motor neurons, were greatly reduced by CNTF, although the treatment did not start until the first symptoms of the disease had already become apparent and substan-tial degenerative changes were already present. | | | The protective and restorative effects of CNTF in this mouse mutant give new perspectives for the treatment of human degenerative motor neuron diseases with CNTF. |
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http://www.nature.com/doifinder/10.1038/358502a0
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| | Title page for ETD etd-07122004-095657 |
| | Modeling the Intersegmental Coordination of Heart Motor Neurons in the Medicinal Leech | | | The heart motor neuron models were conductance-based; conductances of voltage-gated and synaptic currents were adjusted to match the firing pattern of heart motor neurons from the living system. | | | Each motor neuron receives a specific pattern of inhibitory input from rhythmic premotor heart interneurons and translates this spatiotemporal pattern into the fictive heartbeat motor pattern. |
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http://etd.gatech.edu/theses/available/etd-07122004-095657
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| | Plateau potentials and their role in motor behavior |
| | Plateau potentials and their role in motor behavior | | | This situation is quite different from the one in which firing is maintained by a summed excitatory drive which is sufficiently large to move the neuron’s membrane potential above the threshold for action potentials. | | | Research over the last 15 years has shown that vertebrate spinal motor neurons in reduced preparations under some circumstances can generate prolonged plateau potentials. |
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http://www.formonline.se/ScanPhys2000/abstracts/abstr127.html
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| | Science News: Neural-learning ventures - research indicates motor neurons in brain coordinate during learning - Brief ... |
| | Microelectrodes implanted in the motor-control area of the rats' brains allowed neuroscientist Mark Laubach of Duke University Medical Center in Durham, N.C., and his coworkers to gauge the activity of 20 to 30 randomly selected neurons in each animal during training. | | | As trials proceeded, a trio of activity patterns changed so that the scientists were better able to predict a rat's correct or incorrect response. | | | They then learned to wait longer for the stimuli before releasing the lever. |
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http://www.findarticles.com/p/articles/mi_m1200/is_24_157/ai_63323333
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| | Lower and Upper Motor Neurons and the Internal Capsule |
| | Explain why a paraplegic can still have a patellar reflex. | | | Compare and contrast the function and dysfunction of upper and lower motor neurons. | | | Name the cranial nerve motor nuclei in the mid brain, pons, and medulla that could be involved and present with symptoms together with corticospinal tract symptoms. |
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http://www-medlib.med.utah.edu/calendar/block4/32.html
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| | Motor Neurons on Almondnet |
| | Get a quote that you can rely on with Kwik-fit. | | | Somatosensory and Motor Research is published by Taylor and Francis Group. | | | Find motor neuron disease and more at Lycos Search. |
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http://www.bizzland.co.uk/hometv/motor_neurons.html
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| | als without upper motor neurons not affected???????????? |
| | Posted: Wed Feb 16, 2005 2:02 pm Post subject: re: als without upper motor neurons not affected | | | Posted: Tue Jan 25, 2005 4:23 pm Post subject: als without upper motor neurons not affected???????????? | | | i hadn't joined the forum before reading your posting but felt compelled because my brother still does not show any signs of upper motor neuron degeneration. |
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http://www.als.ca/_forum/alstopic.php?p=1318
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| | Nervous tissue |
| | Because of their structure they are often referred to as unipolar neurons. | | | Motor neurons, which have numerous cell processes (an axon and many dendrites) are often referred to as multipolar neurons. | | | Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialised nerve cells called neurons. |
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http://www.botany.uwc.ac.za/sci_ed/grade10/mammal/nervous.htm
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| | Neurological Research: Neurotrophic effect of hepatocyte growth factor on neonatal facial motor neurons |
| | A total of 43 rat pups born from eight mothers of the Wistar strain (Japan SLC, Inc., Hamamatsu, Shizuoka, Japan) were used in this study. | | | Many researchers have therefore been paying considerable attention to the functional roles of HGF in the nervous system. | | | Our study was undertaken to provide quantitative data on motor neuron survival following local application of HGF to the injured facial nerve of neonatal rats. |
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http://www.findarticles.com/p/articles/mi_qa3909/is_200310/ai_n9313045
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| | ALS From All Angles |
| | The researchers have developed a model for studying the familial form of ALS (fALS), and have identified abnormalities linked with the reception of the neurotransmitter glutamate that likely contribute to the course of the disease. | | | Durham’s group was able to use gene transfer techniques to increase the expression of the GluR2 protein and calbindin respectively in cultured motor neurons. | | | ALS selectively affects the motor neurons, which relay signals to the muscles used in voluntary movement, causing progressive and ultimately fatal paralysis. |
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http://www.als.ca/_news/4095.aspx
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| | zebrafish staining |
| | This experiment will look at the development of motor neurons in zebrafish at the 24 | | | The migration patterns and proliferation of these motor neurons is thought to be | | | Motor neurons arise from neurons at the ventrolateral margin of the neural tube. |
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http://www.swarthmore.edu/NatSci/sgilber1/DB_lab/Fish/ZF_stain.html
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| | Science & Technology at Scientific American.com: Scientists Switch Stem Cells into Neurons |
| | But the findings could still prove useful for people: Zhang posits that motor neuron modeling systems in the laboratory could be used as proxies to screen potential new drugs. | | | Researchers are now reporting another small step toward understanding what conditions are necessary for spinal motor neurons to form: they have coaxed human embryonic stem cells to differentiate into one critical component of the nervous system. | | | Scientists have long been studying the process of how mammalian stem cells differentiate to form specific types of brain cells. |
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http://www.sciam.com/article.cfm?chanID=sa003&articleID=00048F8A-C91A-11FA-891A83414B7F0000
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