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Whole-Mount Immunofluorescence Staining, Confocal Imaging and 3D Reconstruction of the Sinoatrial and Atrioventricular Node in the Mouse
Published on: December 22, 2020
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Miniseries 1-Part I: the Development of the atrioventricular conduction axis
Jill P J M Hikspoors1, Yolanda Macías2,3, Justin T Tretter4
1Department of Anatomy & Embryology, Maastricht University, Maastricht, The Netherlands.
Summary
The human atrioventricular conduction axis forms from the primary interventricular ring, developing into the atrioventricular node and bundle. This process involves significant cardiac remodeling during early fetal development.
Area of Science:
- Cardiology
- Developmental Biology
- Human Embryology
Background:
- The precise formation of the atrioventricular conduction axis in human embryos is not fully understood.
- Existing research has left several details regarding the developmental origins of the atrioventricular conduction system uncertain.
Purpose of the Study:
- To elucidate the detailed process of atrioventricular conduction axis formation in human embryonic development.
- To clarify the origin and development of the atrioventricular node and bundle.
Main Methods:
- Utilized 3D reconstructions of serial histological sections and episcopic datasets from human embryos.
- Examined serially sectioned human fetal hearts (10-30 weeks gestation).
- Incorporated data from the Human Developmental Biological Resource.
Main Results:
- The conduction axis originates from the primary interventricular ring, initially positioned perpendicular to the atrioventricular canal.
- The atrioventricular node forms at the inferior transition between ventricular and atrial components of the ring.
- The penetrating atrioventricular bundle is identified at this transitional site, with the definitive node recognized after atrial septum formation.
Conclusions:
- The atrioventricular conduction axis arises from the primary interventricular ring through a complex process of bending and remodeling.
- Formation of the atrioventricular node and bundle is intricately linked to the development of the atrioventricular canal and atrial septa.
- Postnatal cardiac anatomy requires further remodeling within the first month of fetal development.
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