Dynamic imaging in living cells: windows into local signaling.
Highly localized changes in intracellular calcium concentration [Ca2+]i play a critical role in regulating numerous cellular functions, ranging from muscle contraction to neurotransmitter and hormone secretion to gene transcription. Fluorescent Ca2+ indicators have been invaluable tools in elucidating the role of localized changes in [Ca2+]i in regulating ion channels and other key proteins in various signaling pathways. Other techniques used to investigate localized changes in [Ca2+]i include approaches based on fluorescence resonance energy transfer, and electrophysiological measurements of ionic flux through Ca2+-sensitive channels. This Perspective discusses research using fluorescent Ca2+ indicators to study excitation-contraction coupling in cardiac myocytes, presenting both key findings and limitations of this approach. Complementary approaches useful in studying localized changes in Ca2+ and other second messengers (such as cyclic adenosine monophosphate) are also discussed.
Bers
Donald M
DM
Department of Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, USA. dbers@lumc.edu
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002468:Cell Physiological Phenomena; D019561:Echocardiography, Four-Dimensional / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods; D015398:Signal Transduction / Q000502:physiology