Spiky: An ImageJ Plugin for Data Analysis of Functional Cardiac and Cardiomyocyte Studies

Figures

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  Figure 1. Flow diagram of the Spiky algorithm. Pk2Pk, Time2Pk, FWHM and PkArea correspond respectively to the parameters peak to peak, time to peak, full width at half maximum and area of the peak.

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  Figure 2. Workflow example of a Spiky XT analysis. The experiment output showed the effect of acetylcholine on rat isolated left atria action potentials recorded with a sharp microelectrode. At 600 s, 100 nM acetylcholine (ACh) was added to the superfusion solution (red arrow). The reduction of the duration of the action potential after acetylcholine superfusion is clearly visible on the second plot obtained from the output analysis values. Symbols on computing plots: red triangle: peak, blue circle: baseline, green circle: threshold, pink circle: max positive/negative slope. Output plots: Left: Amplitude, Center: peak width at 10% of peak amplitude, Right: max slope from baseline to peak.

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  Figure 3. Examples of analysis of XYT data leading to single peak parameter maps as outputs. (A) Single rat cardiomyocyte evoked calcium transient recorded with confocal microscopy. The image sequence (left to right and top to bottom) shows a selection of images of the stack with a time interval of 20 ms. Output consists of three maps of relevant parameters of the calcium transient. (B) Propagation of an evoked action potential across a rat whole heart. Input image is an image stack obtained from an optical mapping experiment. The position of the stimulation electrodes is indicated by the lightning symbol. The two-colored points illustrate the Spiky software processing occurred for each pixel of the image. After processing, FWHM and FW10 (action potential durations at respectively 50% and 90% of repolarization) are displayed in different areas of the heart as pseudo-colored maps.

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  Figure 4. Examples of analysis of XYT data leading to isochronal (a) and vector (b) maps as outputs. (A) Propagation of a spontaneous calcium wave in an isolated cardiomyocyte. Input data is an image stack of the wave recorded by confocal fluorescence microscopy. The image sequence (left to right and top to bottom) shows a selection of images of the stack with a time interval of 20 ms. (B) The same heart as in Figure 3B is shown here. The isochronal map (Ba) can be overlaid on the original image.