Fig. 2From: Intracellular Ca2+-handling differs markedly between intact human muscle fibers and myotubesPharmacological activation of the RyR markedly increases [Ca2+]i but does not cause contractions in myotubes. a, b Typical example of changes in fluorescent signal induced by selective activation of the RyR1 by 4-CmC in myotubes; note the lack of contraction despite robust [Ca2+]i increase and lack of [Ca2+]i increase in surrounding mononuclear cellsBack to article page