Roland M. Bagby

University of Tennessee at Knoxville

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James Martin

University of Colorado Boulder

Bruce A. Fisher

URSA Institute

Robert K. Abercrombie

Oak Ridge National Laboratory

Toshihisa Tomie

Changchun University of Science and Technology

Linda J. McGuffee

Magee-Womens Research Institute

E. Miura

National Institute of Advanced Industrial Science and Technology

Sally A. Little

Marshall Space Flight Center

D. Neely

Central Laser Facility

G.H. Bourne

Emory University

Sumito Shimizu

Nikon (Japan)

Cooperative Institutions

University of Tennessee at Knoxville

University of London

Royal Holloway University of London

National Institute of Advanced Industrial Science and Technology

Electrotechnical Institute

University of Oxford

Japan Science and Technology Agency

Lawrence Livermore National Laboratory

Rutherford Appleton Laboratory

University of New Mexico

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Properties of rattlesnake shaker muscle

Journal of Experimental Zoology (1973)

James Martin Roland M. Bagby

Abstract The goals of this study were to learn something of the physiology of the rattlesnake's rattling mechanism and the mechanical properties of tension development. Using the rattlesnakes, Crotalus atrox and Crotalus scutulatus , it was found that the rattling motion is a complex oscillation rather than the simple back and forth motion often described. Rattling is accomplished by “doublet” contractions, i.e., if the shaker muscles on one side of the tail contract, then so do the muscles on the other side. The time interval between the two members of a doublet is temperature dependent and is the ultimate determinant of maximum rattling speed. The rattling is not produced by asynchronous type muscle such as found in insects. The isometric twitch is extremely fast at 18°C, and the contraction time is on the order of 8–10 msec. The rattlesnake shaker muscle at 18°C produces 0.3 kg/cm 2 tension and has a twitch‐tetanus ratio of 0.19. The length‐tension curve for the active muscle is typical for skeletal muscle, but there is a larger passive resistance to stretch like that found in insect fibrillar flight muscle or cardiac muscle.

Shaker

Muscle tension

Cardiac muscle

Tension (geology)

10.1002/jez.1401850303

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Citations (22)

Reorientation of myofilaments during contraction of a vertebrate smooth muscle

AJP Cell Physiology (1977)

Bruce A. Fisher Roland M. Bagby

The purpose of the investigation was to determine whether filaments within smooth muscle cells changed their orientation (with respect to the main axis of the cell) during contraction. The stomach muscle of Bufo marinus was used, since its cells may be easily isolated, enabling direct observation in living cells. In addition to still micrography, cinemicrography was used to record continuously during contraction. Polarization microscopy revealed a change in birefringence after contraction, with relaxed cells exhibiting uniform birefringence while contracted cells displayed a discontinuous pattern. Movies revealed a progressive change in orientation of birefringent elements from nearly parallel to the cell's main axis in relaxed cells to increasingly larger angles to the cell's axis as contraction progressed. Phase-contrast microscopy revealed a change in filamentous components, from being parallel to the cell's axis in relaxed cells to being in an undulating or helical pattern during concentration. Cell shape tended to follow the configuration of the filamentous component. Electron microscopy of muscle strips corroborated the observations of living cells and substantiated the conclusion that filaments change their orientation from parallel to oblique (with respect to the cell's axis) during shortening with an undulating or helical pattern of filaments in shortened muscles.

Myofilament

10.1152/ajpcell.1977.232.1.c5

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Citations (94)

MAMMALIAN MUSCLE RECEPTORS AND THEIR CENTRAL ACTIONS

Medicine & Science in Sports & Exercise (1974)

P. B. C. Matthews Roland M. Bagby

10.1249/00005768-197400620-00005

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Citations (963)

Modifications for soft x-ray contact microscopy: quantification of carbon density discrimination and stereo imaging

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1995)

Anthony D. Stead Anton Page Robin A. Cotton D. Neely Roland M. Bagby

Soft x-ray contact microscopy successfully images hydrated biological material with resolution superior to light microscopy. Nanosecond laser pulses record the image before movement or radiation damage can occur, eliminating concerns of fixation-induced artifacts (cf electron microscopy). X-rays make the recording polymethyl methacrylate (PMMA) photoresist more soluble, thus a contour map of x-ray absorbency is produced in which relative heights, measured by atomic force microscopy, reflect specimen carbon density. Until now quantification of the carbon-density differences was impossible, neither has the minimum carbon density difference which is detectable been determined. Since biological specimens are composed of structures differing only marginally in carbon density the discrimination between carbon densitites is critical. Using SI₃N₄ windows coated with differing carbon thicknesses we have followed the rate of PMMA dissolution in order to produce calibration curves from which specimen carbon density can be determined. These experiments have also attempted to determine the minimum detectable carbon density difference. When using relatively thick (< 5micrometers ) specimens image interpretation can be difficult as spatially separated structures in the original specimen become superimposed in the x-ray image. To provide spatial resolution in three dimensions we are developing a soft x-ray stereo imaging system. Using two laser plasma x-ray sources and contoured photoresists we have obtained two simulanteous images of the same specimen from different angles. E-beam lithography, cutting and imprinting have been tested as means of producing contoured photoresists. The merits of each will be discussed and preliminary stereo images of hydrated biological specimens presented.

Carbon fibers

Photoresist

10.1117/12.220980

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Citations (2)

Striated myofibrils in anti-myosin stained, isolated chicken gizzard smooth muscle cells

Histochemistry (1978)

Roland M. Bagby Frank A. Pepe

Myofibril

Gizzard

Tropomyosin

10.1007/bf00495721

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Citations (12)

The fine structure of pinacocytes in the marine sponge Microciona prolifera (Ellis and Solander)

Cell and Tissue Research (1970)

Roland M. Bagby

Sponge

Mesenchyme

Desmosome

10.1007/bf00335430

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Citations (57)

An explanation for the folding fibers in proboscis retractor muscles of Phascolopsis ( = Golfingia) Gouldi—I. correlation between length-tension data and structure in living muscle

Comparative Biochemistry and Physiology Part A Physiology (1984)

Robert K. Abercrombie Roland M. Bagby Yorimi Matsumoto

Retractor

Folding (DSP implementation)

Proboscis

Tension (geology)

10.1016/0300-9629(84)90006-9

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Citations (3)

An explanation for the folding fibers in proboscis retractor muscles of Phascolopsis ( = Golfingia) Gouldi—II. Structural evidence from sem of teased, glycerinated muscles and light microscopy of koh-isolated fibers

Comparative Biochemistry and Physiology Part A Physiology (1984)

Robert K. Abercrombie Roland M. Bagby

Retractor

Tension (geology)

10.1016/0300-9629(84)90007-0

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Citations (2)

Formation and differentiation of the upper pinacoderm in reaggregation masses of the sponge Microciona prolifera (Ellis and Solander)

Journal of Experimental Zoology (1972)

Roland M. Bagby

Abstract The ultrastructures of gray cells and archeocytes were studied in adult Microciona prolifera to aid in their identification in reaggregation masses. Gray cells were easily identified by their uniform, densely‐stained granules and abundant glycogen particles. A small, dense nucleolus was occasionally observed. Archeocytes lacked the characteristic granules of the gray cell, and a large nucleolus with a less dense core was invariably found. To follow the stepwise formation and differentiation of the upper pinacoderm, pieces of sponge were squeezed through cloth into polyethylene dishes, and the resultant masses were fixed with 2% OsO 4 in 90% sea water at 6, 12, 24, 48, and 96 hours after dissociation. Fixation, dehydration and embedding in the same dish preserved the orientation of the masses. Reaggregation masses of less than 150 μ diameter failed to differentiate a pinacoderm while in masses greater than 250 μ virtually the entire upper surface was composed of exopinacocytes by 96 hours. The gray cells and archeocytes were little changed from their structure in the intact sponge except for a more rounded shape and a greater number of phagosomes in the archeocytes. Cells forming the surface epithelium contained large nucleoli, phagosomes and other characteristics similar to those of archeocytes, while cell types intermediate between gray cells and exopinacocytes, were not observed. It was concluded that gray cells do not form exopinacocytes, and archeocytes form the nucleolated exopinacocytes.

Sponge

10.1002/jez.1401800209

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Citations (12)

The Contractile System of Marine Sponges

Roland M. Bagby

Sponge

Source

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Citations (4)