High resolution

Module 3: Figure Ca2+ sparklet

Visualization of the elementary events of Ca2+ signalling in a ventricular heart cell.

The three top traces on the left are spatiotemporal records of the Ca2+ events recorded in rat ventricular cells when the resting potential (RP) is depolarized by 70 mV. Opening of the CaV1.2 L-type channel is responsible for the small sparklet at the front of the comet-shaped spark. The spontaneous spark at the bottom lacks a sparklet. The surface plots on the right also reveal the small sparklet represented as a ‘foot’ (arrow) at the front of the spark. The spontaneous spark at the bottom lacks such a foot. Reproduced by permission from Macmillan Publishers Ltd: Nature, Wang, S.-Q., Song, L.-S., Lakatta, E.G. and Cheng, H. (2001) Ca2+ signaling between single L-type Ca2+ channels and ryanodine receptors in heart cells, 410:592–596. Copyright (2001); http://www.nature.com; see Wang et al. 2001.