A timing device was designed that, in conjunction with an impact type of quick-freezing apparatus and an externally-triggerable stimulus generator, allows the application of an electrical stimulus to a muscle preparation at a selected time interval before quick-freezing and the measurement of the interval with submillisecond precision. This is needed for stopping fast physiological events in calcium release and excitation-contraction coupling and allows studying the morphological parameters (by freeze-fracture and freeze-substitution) and elemental distributions (by x-ray microanalysis) as a function of time after stimulation. The device should be adaptable for use with most equipment designed for quick-freezing electrically excitable tissue by impact on a cold solid surface.
Nassar, R. and Sommer, J. R.
"A Stimulus Timing Device for Capturing Fast Physiologic Events by Quick-Freezing,"
Scanning Microscopy: Vol. 6
, Article 9.
Available at: https://digitalcommons.usu.edu/microscopy/vol6/iss3/9