Minimally invasive high-speed imaging of sarcomere contractile dynamics in mice and humans.

@article{citeulike:3000911, abstract = {Sarcomeres are the basic contractile units of striated muscle. Our knowledge about sarcomere dynamics has primarily come from in vitro studies of muscle fibres1 and analysis of optical diffraction patterns obtained from living muscles2, 3. Both approaches involve highly invasive procedures and neither allows examination of individual sarcomeres in live subjects. Here we report direct visualization of individual sarcomeres and their dynamical length variations using minimally invasive optical microendoscopy4 to observe second-harmonic frequencies of light generated in the muscle fibres5, 6 of live mice and humans. Using microendoscopes as small as 350 m in diameter, we imaged individual sarcomeres in both passive and activated muscle. Our measurements permit in vivo characterization of sarcomere length changes that occur with alterations in body posture and visualization of local variations in sarcomere length not apparent in aggregate length determinations. High-speed data acquisition enabled observation of sarcomere contractile dynamics with millisecond-scale resolution. These experiments point the way to in vivo imaging studies demonstrating how sarcomere performance varies with physical conditioning and physiological state, as well as imaging diagnostics revealing how neuromuscular diseases affect contractile dynamics.}, author = {Llewellyn, M. E. and Barretto, R. P. G. and Delp, S. L. and Schnitzer, M. J. }, citeulike-article-id = {3000911}, journal = {Nature}, keywords = {general-physiology, methods, musculoskeletal\_systems, neuro-mechanics}, posted-at = {2008-07-15 05:17:49}, priority = {2}, title = {Minimally invasive high-speed imaging of sarcomere contractile dynamics in mice and humans.}, volume = {doi:10.1038/nature07104} }

TY - JOUR ID - citeulike:3000911 L3 - citeulike-article-id:3000911 TI - Minimally invasive high-speed imaging of sarcomere contractile dynamics in mice and humans. JF - Nature VL - doi:10.1038/nature07104 N2 - Sarcomeres are the basic contractile units of striated muscle. Our knowledge about sarcomere dynamics has primarily come from in vitro studies of muscle fibres1 and analysis of optical diffraction patterns obtained from living muscles2, 3. Both approaches involve highly invasive procedures and neither allows examination of individual sarcomeres in live subjects. Here we report direct visualization of individual sarcomeres and their dynamical length variations using minimally invasive optical microendoscopy4 to observe second-harmonic frequencies of light generated in the muscle fibres5, 6 of live mice and humans. Using microendoscopes as small as 350 m in diameter, we imaged individual sarcomeres in both passive and activated muscle. Our measurements permit in vivo characterization of sarcomere length changes that occur with alterations in body posture and visualization of local variations in sarcomere length not apparent in aggregate length determinations. High-speed data acquisition enabled observation of sarcomere contractile dynamics with millisecond-scale resolution. These experiments point the way to in vivo imaging studies demonstrating how sarcomere performance varies with physical conditioning and physiological state, as well as imaging diagnostics revealing how neuromuscular diseases affect contractile dynamics. KW - general-physiology KW - methods KW - musculoskeletal_systems KW - neuro-mechanics AU - Llewellyn, ME AU - Barretto, RPG AU - Delp, SL AU - Schnitzer, MJ ER -