A Three‐Dimensional Functional Assessment of Heart and Vessel Development in the Larva of the Zebrafish (Danio rerio)

Abstract

There has been considerable recent interest in the development of the circulation in the zebrafish. Optical techniques typically used to visualize changes in heart size allow measurement of stroke volume during early vertebrate development, but this approach is complicated in zebrafish larvae because of the heart's irregular shape and its significant change in morphology during the first 6 d of development. By use of a threedimensional integration of the early zebrafish heart and vessels, we have greatly reduced measurement error of stroke volume and cardiac output and have determined the cross-sectional growth of major vessels in the developing zebrafish larvae. A dramatic 500%-600% increase in cardiac output (from 10 to 50-60 nL min Ϫ1 ) occurs on days 5 and 6 postfertilization in Danio rerio. Cross-sectional area of key vessels (dorsal artery, caudal artery, dorsal vein) as well as between-individual variation significantly decreased over the first 6 d of development. Associated with the decrease in cross-sectional area is a significant increase in red blood cell velocity on days 5 and 6 postfertilization. Together, the three-dimensional data of the cardiac and vascular systems have shown that the most profound physiological and developmental changes occur in days 5 and 6, which corresponds with the appearance of the adult form of the heart and the transition from diffusive to convective O 2 supply to internal tissues.

Physiological characterization of stolon regression in a colonial hydroid

“…Although the two-dimensional analysis of flow requires certain assumptions (e.g. Bagatto and Burggren, 2006), these assumptions seemed justifiable in this experiment.…”

Mural-Endothelial cell-cell interactions stabilize the developing zebrafish dorsal aorta

“…Previous studies have shown that the diameter of the dorsal aorta (DA) and posterior cardinal vein (PCV) decreases as development proceeds in the zebrafish (Bagatto and Burggren, 2006). During normal development, aortic diameter is inversely correlated with accumulation of mural cells over time (Fig.…”

Physiological study of larval fishes: challenges and opportunities

“…Methods for measuring vascular diameter in vivo have also been described, including digital vascular contrasting method Bagatto and Burggren, 2006), fluorescent microscopy (Isogai et al, 2001) and colour thresholding . Figure 2 shows a vascular cast of a zebrafish larva created with the digital motion analysis technique (Fritsche et al, 2000).…”

“…Figure 2 shows a vascular cast of a zebrafish larva created with the digital motion analysis technique (Fritsche et al, 2000). Much more than just producing attractive visual images of the vascular bed of the circulation, such images can be used to measure dynamic, acute changes in vessel diameter (Bagatto and Burggren, 2006). It is of course through vasoconstriction and vasodilation that vertebrates regulate regional blood flow.…”

“…The block can then be whittled down to the minimum size, and the surrounding gaseous or aquatic atmosphere adjusted to enhance oxygen diffusion through the agar and into the constrained larva. This technique allows the researcher to maintain the larva in a position favourable for micro-scopic examination without damaging the larva or significantly altering its short-term physiological status (van Raamsdonk et al, 1979;Schwerte and Pelster, 2000;Bagatto and Burggren, 2006).…”