Ryanodine receptors (RyR) are the Ca2+ release channel of skeletal muscle, which are responsible for rapidly releasing a large amount of Ca2+ upon electrical stimulation to evoke contraction. In the resting muscle, RyR leak Ca2+ and require the expenditure of energy to maintain steady state Ca2+ content of the intracellular Ca2+ store. It is this function that regulates multiple processes in the muscle, including the regulation of Ca2+ permeability of the plasma membrane and distribution of Ca2+ across the intracellular compartments, non-shivering thermogenesis and adaptation to changes in muscle activity. In this talk I will describe how RyR basal function controls the movements of Ca2+ between cellular compartments following changes in the RyR due to mutations, intense exercise and changes in activity. To do this I will present novel techniques for measuring Ca2+ movements and heat generation within the fibre that we have used in conjunction with muscle from transgenic mice and fibres isolated from biopsies of human muscle.

Biography: Bradley Launikonis is a Professor at The University of Queensland, Brisbane, Australia. He completed his PhD on muscle physiology, focusing on Ca2+ handling using force recordings of mechanically skinned fibres at La Trobe University, Melbourne, Australia in 2000. He followed this with a postdoctoral work at Rush University, Chicago, USA, with a focus on Ca2+ imaging in muscle fibres using confocal microscopy. He established his lab at The University of Queensland in 2007. He now combines the techniques of mechanically skinned fibres with confocal microscopy to study aspects of muscle function in RyR-related diseases, non-shivering thermogenesis and adaptation to exercise and disuse of muscle.

IPHYS contact person: Jan Kopecký, jan.kopecky@fgu.cas.cz