Jamison et al., 2013 - In Vivo Wall Shear Measurements within the Developing Zebrafish Heart. PLoS One   8(10):e75722 Full text @ PLoS One

Fig. 1

Brightfield images of a 4dpf zebrafish ventricle (a) before and (b) after cardiac-phase filtering.

(c) Map of the local signal-to-noise ratio (SNR) after processing (b).

Fig. 2

The local signal-to-noise ratio can be used to define the boundary, allowing calculation of the slope of the wall.

(a) Binary mask created by thresholding the SNR map. Colourmap of the slope at the wall in (b) the horizontal direction and (c) the vertical direction after the heart wall identification process.

Fig. 3

Calculation of the wall shear rate (s 1) from the velocity and the slope of the wall.

(a) Brightfield images of a 3dpf zebrafish ventricle during systole with overlaid with velocity vectors calculated using PIV. Contours of (b) dv/dx, (c) du/dy and (d) the calculated wall shear rate (s1) also overlaid with velocity vectors. Shear is concentrated in the region of the ventricular bulbar valve with the majority of the remainder of the heart experiencing comparatively low shear.

Fig. 4

Brightfield images of four equally spaced time points within the cardiac cycle with contours of wall shear (s 1) and vectors of velocity overlaid (Movie S1 provides all 100 times points in the cardiac cycle).

For clarity only every second vector is shown in the horizontal direction and every fifth in the vertical direction. Average velocity through the ventricular-bulbar valve is shown below the brightfield images, with red circles indicating the time points corresponding to points (a) – (d).

Fig. 6

Wall shear rate during peak systole for (a)–(d) 3dpf, (e)–(h) 4dpf, (i)–(l) 5dpf and (m)–(p) 6dpf embryonic zebrafish used in this study.

Vectors indicate the magnitude and direction of velocity while colourmap provides the wall shear rate. For clarity only every second vector is shown in the horizontal direction and every fifth in the vertical direction.

Fig. 8

Co-ordinate system used to calculate shear rate at various locations in the ventricle.

The ventricular bulbar (VB) valve acts as the reference axis (0° rotation).

Acknowledgments:
ZFIN wishes to thank the journal PLoS One for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ PLoS One