Study of Beloussov’s Hyper-Restoration Hypothesis for Regulation of Embryonic Heart Bending

2010 ◽  
Author(s):  
Ashok Ramasubramanian ◽  
Larry A. Taber
Keyword(s):  
Heart Development ◽  
Embryonic Heart ◽  
Developmental Phase ◽  
Heart Tube ◽  
Shaped Tube

During cardiac c-looping, an important developmental phase in early heart development, the initially straight heart tube (HT) is transformed into a c-shaped tube. Two distinct processes, ventral bending and dextral rotation, constitute c-looping. Previous research suggests that ventral bending is likely driven by forces that are intrinsic to the heart while dextral rotation is driven by forces applied by a pair of omphalomesenteric veins that flank the heart tube and a membrane called the splanchnopleure that lies on top of the heart.

Wall Motion Influences Flow Pattern in the Outflow Tract of the Chick Embryonic Heart Tube

2010 ◽  
Author(s):  
Aiping Liu ◽  
Ruikang Wang ◽  
Kent Thornburg ◽  
Sandra Rugonyi
Keyword(s):  
Blood Flow ◽  
Heart Development ◽  
Muscle Layer ◽  
Distal Region ◽  
Embryonic Heart ◽  
Outflow Tract ◽  
Flow Dynamics ◽  
Heart Tube ◽  
Blood Flow Dynamics ◽  
Heart Functions

The outflow tract (OFT) of the chick embryonic heart offers a good model system to study the association between blood flow dynamics and cardiac morphogenesis in early heart development. At early stages, the chick heart is a looped tube without valves. The OFT, the distal region of the heart, functions as a primitive valve [1]. The OFT is a slightly curved tube with three-layered wall (Fig. 1 (A) and (B)): the myocardium, an external muscle layer that actively contracts; the endocardium, an inner endothelial layer that directly contacts blood; in between the cardiac jelly, an extracellular matrix layer. The OFT undergoes complex morphogenesis, eventually leading to the development of semilunar valves, and this morphogenesis is sensitive to blood flow dynamics.

Role of Mechanical Feedback in Restoration of Normal Cardiac C-Looping Following Perturbed Loading

2007 ◽  
Author(s):  
Ashok Ramasubramanian ◽  
Nandan L. Nerurkar ◽  
Kate H. Achtien ◽  
Larry A. Taber
Keyword(s):  
Actin Polymerization ◽  
Ventral Side ◽  
The Body ◽  
Developmental Phase ◽  
Heart Tube ◽  
Shaped Tube ◽  
Dorsal Mesocardium ◽  
External Forces ◽  
The Right

Cardiac c-looping is an important developmental phase, as the initially straight heart tube (HT) is transformed into a c-shaped tube. Looping consists of two distinct processes: ventral bending, which is likely driven by actin polymerization, and dextral torsion, which is likely due to external forces. These forces are applied by a membrane enveloping the ventral side of the heart, the splanchnopleure (SPL, Fig. 2A) and a pair of atria that flank the caudal end of the heart tube (HT, Fig 1A). In particular, the atria provide the initial push, biasing the HT towards the right while the SPL applies a ventrally directed force, which causes the HT to rotate using the dorsal mesocardium (DM, Fig. 2A) as a pivot (the DM attaches the dorsal length of the heart to the body of the embryo).

scholarly journals On Modeling Morphogenesis of the Looping Heart Following Mechanical Perturbations

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Ashok Ramasubramanian ◽  
Nandan L. Nerurkar ◽  
Kate H. Achtien ◽  
Benjamen A. Filas ◽  
Dmitry A. Voronov ◽  
...  
Keyword(s):  
Heart Development ◽  
Three Dimensional ◽  
Ventral Surface ◽  
Feedback Mechanism ◽  
Qualitative Behavior ◽  
Dimensional Model ◽  
Heart Tube ◽  
Three Dimensional Model ◽  
Shaped Tube ◽  
External Forces

Looping is a crucial early phase during heart development, as the initially straight heart tube (HT) deforms into a curved tube to lay out the basic plan of the mature heart. This paper focuses on the first phase of looping, called c-looping, when the HT bends ventrally and twists dextrally (rightward) to create a c-shaped tube. Previous research has shown that bending is an intrinsic process, while dextral torsion is likely caused by external forces acting on the heart. However, the specific mechanisms that drive and regulate looping are not yet completely understood. Here, we present new experimental data and finite element models to help define these mechanisms for the torsional component of c-looping. First, with regions of growth and contraction specified according to experiments on chick embryos, a three-dimensional model exhibits morphogenetic deformation consistent with observations for normal looping. Next, the model is tested further using experiments in which looping is perturbed by removing structures that exert forces on the heart—a membrane (splanchnopleure (SPL)) that presses against the ventral surface of the heart and the left and right primitive atria. In all cases, the model predicts the correct qualitative behavior. Finally, a two-dimensional model of the HT cross section is used to study a feedback mechanism for stress-based regulation of looping. The model is tested using experiments in which the SPL is removed before, during, and after c-looping. In each simulation, the model predicts the correct response. Hence, these models provide new insight into the mechanical mechanisms that drive and regulate cardiac looping.

Optical approaches to ontogeny of electrical activity and related functional organization during early heart development

1991 ◽  
Vol 71 (1) ◽  
pp. 53-91 ◽  
Author(s):  
K. Kamino
Keyword(s):  
Electrical Activity ◽  
Heart Development ◽  
Functional Organization ◽  
Embryonic Heart ◽  
Optical Recording ◽  
Additional Advantage ◽  
Physiological Functions ◽  
Spontaneous Electrical Activity ◽  
Somite Stage ◽  
Voltage Sensitive Dyes

Direct intracellular measurement of electrical events in the early embryonic heart is impossible because the cells are too small and frail to be impaled with microelectrodes; it is also not possible to apply conventional electrophysiological techniques to the early embryonic heart. For these reasons, complete understanding of the ontogeny of electrical activity and related physiological functions of the heart during early development has been hampered. Optical signals from voltage-sensitive dyes have provided a new powerful tool for monitoring changes in transmembrane voltage in a wide variety of living preparations. With this technique it is possible to make optical recordings from the cells that are inaccessible to microelectrodes. An additional advantage of the optical method for recording membrane potential activity is that electrical activity can be monitored simultaneously from many sites in a preparation. Thus, applying a multiple-site optical recording method with a 100- or 144-element photodiode array and voltage-sensitive dyes, we have been able to monitor, for the first time, spontaneous electrical activity in prefused cardiac primordia in the early chick embryos at the six- and the early seven-somite stages of development. We were able to determine that the time of initiation of the contraction is the middle period of the nine-somite stage. In the rat embryonic heart, the onset of spontaneous electrical activity and contraction occurs at the three-somite stage. In this review, a new view of the ontogenetic sequence of spontaneous electrical activity and related physiological functions such as ionic properties, pacemaker function, conduction, and characteristics of excitation-contraction coupling in the early embryonic heart are discussed.

scholarly journals miR-1/133a Clusters Cooperatively Specify the Cardiomyogenic Lineage by Adjustment of Myocardin Levels during Embryonic Heart Development

PLoS Genetics ◽  
2013 ◽  
Vol 9 (9) ◽  
pp. e1003793 ◽  
Author(s):  
Katharina Wystub ◽  
Johannes Besser ◽  
Angela Bachmann ◽  
Thomas Boettger ◽  
Thomas Braun
Keyword(s):  
Heart Development ◽  
Embryonic Heart

Cardiac embryogenesis

ESC CardioMed ◽  
2018 ◽  
pp. 33-36
Author(s):  
Robert G. Kelly
Keyword(s):  
Progenitor Cells ◽  
Progenitor Cell ◽  
Congenital Heart ◽  
Heart Defects ◽  
Embryonic Heart ◽  
Heart Tube ◽  
Second Heart Field ◽  
Heart Field ◽  
Cell Niche ◽  
The Right

The embryonic heart forms in anterior lateral splanchnic mesoderm and is derived from Mesp1-expressing progenitor cells. During embryonic folding, the earliest differentiating progenitor cells form the linear heart tube in the ventral midline. The heart tube extends in length and loops to the right as new myocardium is progressively added at the venous and arterial poles from multipotent second heart field cardiovascular progenitor cells in contiguous pharyngeal mesoderm. While the linear heart tube gives rise to the left ventricle, the right ventricle, outflow tract, and a large part of atrial myocardium are derived from the second heart field. Progressive myocardial differentiation is controlled by intercellular signals within the progenitor cell niche. The embryonic heart is the template for septation and growth of the four-chambered definitive heart and defects in progenitor cell deployment result in a spectrum of common forms of congenital heart defects.

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