Low sensitivity of dorsal spinocerebellar neurons to limb movement speed

1999 ◽  
Vol 125 (3) ◽  
pp. 313-322 ◽  
Author(s):  
G. Bosco ◽  
R. E. Poppele
Keyword(s):  
Limb Movement ◽  
Movement Speed ◽  
Low Sensitivity ◽  
Spinocerebellar Neurons

Broad directional tuning in spinal projections to the cerebellum

1993 ◽  
Vol 70 (2) ◽  
pp. 863-866 ◽  
Author(s):  
G. Bosco ◽  
R. E. Poppele
Keyword(s):  
Functional Organization ◽  
Sagittal Plane ◽  
Mossy Fiber ◽  
Cerebellar Nuclei ◽  
Limb Movement ◽  
Response Patterns ◽  
Hind Foot ◽  
Limb Posture ◽  
Spinocerebellar Neurons ◽  
Tuning Function

1. Spinocerebellar neurons that project in the dorsal spinocerebellar tract (DSCT) receive mono- and polysynaptic inputs from specific sensory receptors in the hindlimb, and they project mossy fiber terminals to the cerebellar vermis. We examined the functional organization of these neurons and found that it relates to whole-limb parameters like limb posture and direction of limb movement. 2. We recorded the activity of 444 DSCT units during passive perturbations of the hind foot in anesthetized cats. The movements were either confined a single joint (the ankle; 234 cells) or involved the entire hindlimb (210 cells). The cells exhibited opposite responses for opposite directions of whole-limb movement, but a variety of response patterns for opposite directions of movement at one joint. We interpret the result to imply that the population encodes information about the whole limb rather than single joints. 3. Most of the 78 neurons recorded during passive limb placements (63%) responded to changes in limb length and also changes in limb orientation. In fact, the activity of most of the cells was broadly tuned with respect to the direction of passive limb movements generated by moving the hind foot in the sagittal plane. Changes in unit activity could be described by a cosine tuning function with respect to foot positions (72% of responses) and directions of foot movement (50%). 4. The similarity of this behavior to that of neurons in the motor cortex and cerebellar nuclei recorded during voluntary movements is consistent with a common neural code to represent the sensorimotor parameters of limb movement.

Relationship between limb movement speed and associated contraction of the trunk muscles

Ergonomics ◽  
1997 ◽  
Vol 40 (11) ◽  
pp. 1220-1230 ◽  
Author(s):  
PAUL W. HODGES ◽  
CAROLYN A. RICHARDSON
Keyword(s):  
Limb Movement ◽  
Trunk Muscles ◽  
Movement Speed

Design of Sensitive Photographic Materials for the High-Voltage Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 156-157
Author(s):  
Murray Vernon King ◽  
Donald F. Parsons
Keyword(s):  
Electron Microscope ◽  
Radiation Damage ◽  
High Voltage ◽  
Radiation Sensitivity ◽  
Fast Electrons ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Biological Studies ◽  
Low Sensitivity

Effective application of the high-voltage electron microscope to a wide variety of biological studies has been restricted by the radiation sensitivity of biological systems. The problem of radiation damage has been recognized as a serious factor influencing the amount of information attainable from biological specimens in electron microscopy at conventional voltages around 100 kV. The problem proves to be even more severe at higher voltages around 1 MV. In this range, the problem is the relatively low sensitivity of the existing recording media, which entails inordinately long exposures that give rise to severe radiation damage. This low sensitivity arises from the small linear energy transfer for fast electrons. Few developable grains are created in the emulsion per electron, while most of the energy of the electrons is wasted in the film base.

Effect of energy filtering on micro-diffraction in the SEM

1994 ◽  
Vol 52 ◽  
pp. 604-605
Author(s):  
James F. Mancuso ◽  
Leo A. Fama ◽  
William B. Maxwell ◽  
Jerry L. Lehman ◽  
Hasso Weiland ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Ccd Camera ◽  
High Gain ◽  
Microchannel Plate ◽  
Electrostatic Energy ◽  
Energy Filtering ◽  
Electron Channelling ◽  
Low Energy Electrons ◽  
Low Sensitivity ◽  
Angular Field Of View

Micro-diffraction based crystallography is essential to the design and development of many classes of ‘crafted materials’. Although the scanning electron microscope can provide crystallographic information with high spatial resolution, its current utility is severely limited by the low sensitivity of existing diffraction techniques (ref: Dingley). Previously, Joy showed that energy filtering increased contrast and pattern visibility in electron channelling. This present paper discribes the effect of energy filtering on EBSP sensitivity and backscattered SEM imaging.The EBSP detector consisted of an electron energy filter, a microchannel plate detector, a phosphor screen, optical coupler, and a slow scan CCD camera. The electrostatic energy filter used in this experiment was constructed as a cone with 5 coaxial electrodes. The angular field-of-view of the filter was approximately 38°. The microchannel plate, which was the initial sensing component, had high gain and had 50% to 80% detection efficiency for the low energy electrons that passed through the retarding field filter.

Hit and False-Alarm Rates of Selected ABR Indices in Differentiating Cochlear Disorders From Acoustic Tumors

1996 ◽  
Vol 5 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Frank E. Musiek ◽  
Cynthia A. McCormick ◽  
Raymond M. Hurley
Keyword(s):  
False Alarm ◽  
Amplitude Ratio ◽  
High Specificity ◽  
Auditory Brainstem ◽  
Latency Difference ◽  
Cochlear Pathology ◽  
Brainstem Response ◽  
Absolute Latency ◽  
Two Indices ◽  
Low Sensitivity

We performed a retrospective study of 26 patients with acoustic tumors and 26 patients with otologically diagnosed cochlear pathology to determine the sensitivity (hit rate), specificity (false-alarm rate), and efficiency of six auditory brainstem response indices. In addition, a utility value was determined for each of these six indices. The I–V interwave interval, the interaural latency difference, and the absolute latency of wave V provided the highest hit rates, the best A’ values and good utility. The V/I amplitude ratio index provided high specificity but low sensitivity scores. In regard to sensitivity and specificity, using the combination of two indices provided little overall improvement over the best one-index measures.

The Use of Neuroplastic Principles Affects the Swallow Motor Plan of a Patient in Severe Cognitive Decline: A Case Study

2016 ◽  
Vol 1 (15) ◽  
pp. 79-83
Author(s):  
Ed Bice ◽  
Kristine E. Galek
Keyword(s):  
Central Nervous System ◽  
Cognitive Decline ◽  
Full Range ◽  
Movement Speed ◽  
Positive Outcomes ◽  
Verbal Cues ◽  
Motor Plan ◽  
Bolus Size ◽  
The Central Nervous System

Dysphagia is common in patients with dementia. Dysphagia occurs as a result of changes in the sensory and motor function of the swallow (Easterling, 2007). It is known that the central nervous system can undergo experience-dependent plasticity, even in those individuals with dementia (Park & Bischof, 2013). The purpose of this study was to explore whether or not the use of neuroplastic principles would improve the swallow motor plan and produce positive outcomes of a patient in severe cognitive decline. The disordered swallow motor plan was manipulated by focusing on a neuroplastic principles of frequency (repetition), velocity of movement (speed of presentation), reversibility (Use it or Lose it), specificity and adaptation, intensity (bolus size), and salience (Crary & Carnaby-Mann, 2008). After five therapeutic sessions, the patient progressed from holding solids in her mouth with decreased swallow initiation to independently consuming a regular diet with full range of liquids with no oral retention and no verbal cues.

Neurologisch bedingte Schlafstörungen

2014 ◽  
Vol 71 (11) ◽  
pp. 671-678
Author(s):  
Ramin Khatami
Keyword(s):  
Limb Movement ◽  
Periodic Limb Movement ◽  
Epileptische Anfälle ◽  
Eine Hohe ◽  
Restless Legs ◽  
Seltene Erkrankung ◽  
Frühzeitige Diagnose ◽  
Neuroprotektive Substanzen ◽  
Restless Legs Syndrom

Das Spektrum der schlafmedizinischen Erkrankungen umfasst eine Reihe von speziellen neurologischen Erkrankungen, die sich durch eine hohe Prävalenz kennzeichnen oder die Lebensqualität stark beeinträchtigen. Dem praktisch tätigen Arzt kommt eine Schlüsselrolle in der Erkennung und Behandlung dieser Erkrankungen zu und sollte deshalb mit den wichtigsten schlafmedizinischen neurologischen Erkrankungen vertraut sein. Im Folgenden werden als wichtigste Vertreter, das Restless Legs Syndrom (mit oder ohne Periodic Limb Movement im Schlaf), Bewegungsstörungen im Schlaf (v. a. nonREM- und REM-Schlaf-Parasomnien), epileptische Anfälle im Schlaf sowie die Narkolepsie vorgestellt. Die Narkolepsie gilt zwar als seltene Erkrankung, ermöglicht aber als Modellerkrankung physiologische bzw. pathophysiologische Vorgänge der Schlaf-/Wachregulation zu verstehen. Eine zunehmende Bedeutung gewinnt auch die REM-Schlafverhaltensstörung, die als Frühzeichen einer neurodegenerativen Erkrankung (z. B. Synukleinopathien wie Parkinson-Erkrankung) auftreten kann. Eine frühzeitige Diagnose eröffnet hier die Möglichkeit in Zukunft neuroprotektive Substanzen einzusetzen.

Schlaf und Depression

Schlaf ◽  
2012 ◽  
Vol 01 (01) ◽  
pp. 9-13
Author(s):  
Samia Little Elk
Keyword(s):  
Limb Movement ◽  
Periodic Limb Movement ◽  
Restless Legs ◽  
Affektive Störung

Die Komorbidität von Depression und Schlafstörungen ist hoch. Dabei kann die Klärung, welche Störung der anderen vorausgegangen ist, bzw. der Ausschluss einer organischen Ursache, für die weitere Behandlung von großer Wichtigkeit sein. Als besonders häufige körperliche Ursache für Schlafstörungen, die wiederum eine depressive Symptomatik bedingen können, kommt dem Periodic-Limb-Movement-, dem Restless-Legs- sowie dem obstruktiven Schlafapnoesyndrom eine besondere Bedeutung zu. Eine ausführliche Medikamenten- und Alkoholanamnese kann Hinweise auf eine substanzinduzierte Insomnie geben. Schlafanstoßende Antidepressiva können neben verhaltenstherapeutischen Maßnahmen einen positiven Effekt auf die affektive Störung wie auch die Insomnie haben.

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