Although the conference will need to develop over the few days and I am majorly jet-lagged, here are a few highlights from the first day:
Helene Langevin has found an interesting puzzle in the areolar tissue where the cells, small but rich in lamellopodia (they are start-shaped) depolymerize (disassemble) their microtubules (cytoskeleton) and organize actin microfilaments (cytomuscle) to flatten outward like a pancake, collapsing vertically to help the fascil medium spread out. There is still viscoelasticity in the matrix, but it is helped by fibroblasts pancakizing in the subcutaenous tissue (but hindered, as we learned last time, by the myofibroblasts in the denser fascial sheets. My conclusion: the mesodermal cells are more a spectrum of a single cell type than than distinctly muscle or connective tissue.
More evidence from Hicks: Muscle cells are syncitia, each muscle fiber is originally many cells that blend, so each muscle fiber is multinucleated into a myotubule – at which point it starts becoming responive to acetylcholine and therefore conractile. No strain is needed to form a glom of muscle cells into a functioning myotubule, the presence of fibroblasts is enough. More evidence of the guiding role of the fascia in movement morphogenesis.
Lots of new evidence supporting Huijing’s contention of stress and strain being carried across muscle boundaries, and even how the intra-muscular stress is acrried by the endomysium.
Tomorrow the coup de grace to the concept of ‘muscle’ – stay tuned for the iconoclast Jaap van der Woll.
Google any of these names to follow the work, but I will publish full references when I get sorted.