This supplementary application requests funds for a new electron microscope. The Main Grant has been funded and its objectives are stated below. This project proposes enquiries into the ultrastructure of the atrium and, for comparative reasons, of the ventricles of mammalian hearts and the hearts of other vertebrate species. The artrium is chosen as the main topic of study because of its importance for impulse generation, and because of the interesting phenomena of impulse conduction encountered in the atrium. Since the atria, especially of mammals, are morphologically quite heterogenous it is important to define the anatomical details of the heterogeneity. New advances in contrasting procedures have made it possible to ask interesting questions regarding the geometry and quantity of structural features of cardiac cells. In this proposal we shall study such matters with conventional and high voltage electron microscopy, as well as with the freeze fracture method and scanning electron microscopy. Specifically we shall study the distribution of transverse tubules and sarcoplasmic reticulum in the common and specialized atrial cells, the distribution and configuration of the nexuses and the anatomy and distribution of the cytoskeleton and of the microfibrils at the surface of cardiac cells. Finally, we shall study with serial sections the geometry of cell appositions in bundles of atrial and ventricular fibers for modelling current distribution in such bundles.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL012486-19
Application #
3334477
Study Section
(SSS)
Project Start
1978-02-01
Project End
1990-02-28
Budget Start
1988-03-01
Budget End
1989-02-28
Support Year
19
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Duke University
Department
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
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