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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 28 (1994), S. 333-345 
    ISSN: 0886-1544
    Keywords: ciliary beat frequency ; metachronal wave ; ciliary coupling ; extracellular ATP ; acetylcholine ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In the present work we measured in real time the metachronism and degree of correlation between beating cilia from cultured mucociliary epithelium. The method is based on simultaneous measurement of ciliary beat frequency, phase shifts, and correlation factors in two directions: parallel and perpendicular to the effective stroke direction (ESD). From the phase shifts the lengths of wave components, and consequently the metachronal wavelength and direction, were evaluated.On active ciliary areas of cultured frog esophagus under normal conditions, a relatively high degree of correlation is observed, but cilia are more correlated in direction parallel to ESD which is also the direction of the mucus propulsion. The length of the wave component parallel to ESD is more than twice as large as that of the perpendicular component. The metachronal wavelength was found to be in the range of 5-9 μm, and the direction of the wave propagation was in the range of 90°-125° clockwise to the ESD.When ciliary beat frequency was rapidly increased by extracellular ATP or acetylcholine, only minor effects were observed on the degree of correlation between beating cilia. The length of the wave component parallel to ESD showed the most dramatic effect increasing up to tenfold. The perpendicular to ESD component was not affected by the stimulation. Consequently, the metachronism became more laeoplectic with the angle between the ESD and the wave directions decreasing by 10°-30°, and the metachronal wavelength remained unaltered. © 1994 Wiley-Liss, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 16 (1990), S. 167-181 
    ISSN: 0886-1544
    Keywords: metachronal wavelength ; metachronal wave direction ; asymmetry of beating ; ciliary beating ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A mathematical model is proposed to explain the dependence of the direction and the length of the metachronal wave on parameters that characterize the ciliary beat, the dimensions of the cilia, and the geometry of their arrangement on the ciliated surface. The metach/onal wave is decomposed into two mutually perpendicular components, which are chosen in such a way that the direction of one of them is in the direction of the effective stroke. The magnitudes of the two components are determined by using the concept of the time of delay between adjacent cilia. The properties of the metachronal wave are then calculated as a function of the ciliary parameters.The results obtained with the present model predict that the direction of the wave propagation is strongly dependent on the type of metachronism in the direction of the effective stroke and the polarization in time and in space of the ciliary beat. The metachronal wavelength is found to depend on four parameters: the ciliary length, the angle of the arc projected on the cell surface by the ciliary tip during the recovery stroke, the degree of asymmetry of ciliary beat, and the portion of the cycle occupied by the pause. The metachronal wavelength is also found to be only weakly dependent on the ciliary frequency.At this stage there exists relatively little experimental information with which t o characterize fully the metachronal properties of ciliary systems. Even when only partial information exists, the model allows prediction, to within a certain range, of the direction of the wave propagation. It also suggests a possible mechanism for the influence of changes in environmental conditions on wave direction and wavelength. In severalcases in which full information does exist, good agreement between the experimental findings and the predictions of the model is found. According to this model it will be worthwhile to invest more effort in measuring the time and space polarization of ciliary beating and the times of delay between cilia.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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