Issues

Cover picture: Cultured muscle cells respond to UTP with an increase in Ca²⁺ concentration (top left), which is blocked by 2-APB, an inhibitor of IP₃ receptors (top right). In contrast, myofibers isolated from adult mouse skeletal muscle do not display significant IP₃ -dependent Ca²⁺ changes (not depicted) but respond to caffeine (bottom left), an effect markedly inhibited by dantrolene, an inhibitor of ryanodine receptors (bottom right; see communication by Blaauw et al., 235–241).