Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 10 (1988), S. 321-330 
    ISSN: 0886-1544
    Keywords: organelle motion ; video microscopy ; computer motion analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Video-enhanced contrast techniques have been used to study fast axonal transport of organelles in diseased and normal human axons. A broad perspective on the importance of axonal transport in the pathogenesis of human neurological disorders is presented and problems in dealing with human nerve summarized. Results from analysis of organelle traffic in axons from motor nerve in patients with amyotrophic lateral sclerosis (ALS) show: (1) higher mean speed of anterograde organelles, (2) lower mean speed of retrograde organelles, and (3) lower retrograde organelle traffic density. Hyperparathyroidism, another human clinical syndrome, can mimic ALS. The effect of parathyroid hormone (PTH) on axons in vitro is to increase the mean speed of both anterograde and retrograde organelle traffic. The dose response curve and time course of the PTH effect are delineated. Dihydropyridine calcium channel antagonists block the PTH effect, implicating extracellular calcium in the alteration of organelle traffic speed. The results are discussed in relation to neuronal function and the regulation of fast axonal transport.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 339-346 
    ISSN: 0886-1544
    Keywords: axonal transport ; human nerve ; video-enhancement ; digital image processing ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mechanism by which organelles are transported bidirectionally in axoplasm is still unknown; however, evidence of a key role for microtubules in many nonmammalian models has been established. We have observed common or shared tracks within the axoplasm of human nerves along which multiple organelles of varying size and shape are bidirectionally transported. Organelles traveling anterogradely and retrogradely were visualized by video-enhanced differential interference contrast optics and analyzed with the aid of computer-image-processing techniques.Speeds of translocating organelles were determined at eight to 16 translocation points along a path or “track.” Each translocation speed was plotted against its corresponding position on the track to develop a “speed/position diagram.” Regardless of mean organelle speed or direction of motion, organelles sharing a common track exhibited similar patterns of “speeding up” and “slowing down” relative to position along the track. Speed position data for organelles translocating the local axonal region of a common track showed no unique patterns (not different from a uniform distribution, p 〈 0.05). The unique speed/position patterns exhibited by common tracks were not necessarily related to the patterns of other tracks in the immediate vicinity (distance between tracks of 〈 0.50 μm). These findings suggest that (1) there are “common tracks” shared by organelles moving retrogradely and anterogradely; (2) both the organelles and the “track” associated with its translocation play a role in the resultant motion of that organelle; (3) the influence exerted by a common track on the motion of an organelle results in a pattern of speed changes related to position along the track.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0886-1544
    Keywords: video microscopy ; axonal transport ; computer motion analysis ; giant axon ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Moving intra-axonal organelles demonstrate frequent variations in speed when viewed over several seconds. To evaluate these and other motion variations, a long-term analysis of organelle motion in isolated axoplasm of Myxicola infundibulum was carried out using differential interference contrast optics and analog and digital image enhancement techniques. Motion characteristics of individual organelles were analyzed for periods of up to 58 minutes. Three principle observations on organelle motion were made: (1) Classes of organelles of the same size demonstrated a 5- to 25-fold variation of speed, with the slowest speeds occurring most frequently; (2) organelle speeds over individual translocations (motion without stopping) are inversely proportional to their size, but the speeds calculated for the long-term analysis of organelle motion (total distance travelled/total observation time, including pauses) did not reflect this observation; and (3) organelles displayed variable trip lengths, durations, mean speeds, and pause durations, and the relationships between these variations showed no repetitive patterns. In contrast to reported observations of uniform velocities of organelles moving on isolated microtubule preparations, these observations suggest that a variety of factors must play a role in organelle translocation in Myxicola axoplasm.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...