Mark received his B.S. and M.S. in Aerospace Engineering from the University of Colorado at Boulder and received his Ph.D. in Mechanical Engineering from the University of Vermont in 2002. He completed a post-doctoral position in Molecular Physiology and Biophysics at the University of Vermont, where he is currently a Research Associate.

Our lab is focused on investigating the effects of aging and exercise in human skeletal muscle at the whole body, tissue, single fiber and molecular levels. Our goal is to understand how alterations at the molecular and single fiber levels affect whole muscle contraction in order to find potential countermeasures to prevent the age-related loss of muscle performance. We combine the use of advanced engineering methods to measure muscle function at the molecular and single fiber levels with imaging techniques to examine muscle structure from the myofibril to the tissue level, biochemical techniques to quantify proteins as well as techniques to analyze the whole body skeletal muscle contractile performance.

In addition to human skeletal muscle, our lab examines more basic questions about muscle function using Drosophila (fruit flies) and mice. These studies use transgenic lines or structural perturbations to understand the role of specific myofilament proteins or alterations in myofilament lattice spacing and protein hydration.

Single human skeletal muscle fiber with fixed (blue) sections and silver t-clips for attaching to equipment

Single human skeletal muscle fiber mounted on force-velocity rig

Electron micrograph of human skeletal muscle (cross-sectional) showing thick and thin filaments

Electron micrograph of human skeletal muscle (longitudinal) showing sarcomere structure

Miller MS, Toth MJ. Myofilament protein alterations promote physical disability in aging and disease. Exercise and Sport Sciences Reviews, 41(2), 93-99, 2013.

Toth MJ, Miller MS, Callahan DM, Sweeney AP, Nunez I, Grunberg SM, Der-Torossian H, Couch ME, Dittus K. Molecular mechanisms underlying skeletal muscle weakness in human cancer: Reduced myosin-actin cross-bridge formation and kinetics. Journal of Applied Physiology 114(7), 858-868, 2013.

Toth MJ, Miller MS, Ward K, Ades PA. Skeletal muscle mitochondrial density, gene expression and enzyme activities in human heart failure: Minimal effects of the disease and resistance training. Journal of Applied Physiology 112(6), 1864-1874, 2012.

Toth MJ, Miller MS, VanBuren P, Bedrin NG, LeWinter MM, Ades PA, Palmer BM. Resistance training alters skeletal muscle structure and function in human heart failure: Effects at the tissue, cellular and molecular levels. Journal of Physiology 590(5), 1243-1259, 2012.

Tanner BCW, Farman GP, Irving TC, Maughan DW, Palmer BM, Miller MS. Thick-to-thin filament surface distance modulates cross-bridge kinetics in Drosophila flight muscle. Biophysical Journal 103(6), 1275-1284, 2012

Miller MS, VanBuren P, LeWinter MM, Braddock JM, Ades PA, Maughan DW, Palmer BM, Toth MJ. Chronic heart failure decreases cross-bridge kinetics in single skeletal muscle fibers from humans. Journal of Physiology 588(20), 4039-4053, 2010.

Miller MS, VanBuren P, LeWinter MM, Lecker SH, Selby DE, Palmer BM, Maughan DW, Ades PA, Toth MJ. Mechanisms underlying skeletal muscle weakness in human heart failure: Alterations in single fiber myosin protein content and function. Circulation: Heart Failure 2(6), 700-706, 2009.