The distribution of pacemaker cells and atrial working cardiomyocytes in the anterior right atrial wall was studied using intracellular glass microelectrodes under conditions of short-term culturing. It was shown that the dominant pacemaker region and the functional tail are located in the lateral area of the central part of the sinoatrial node, while the medial area is occupied by latent pacemaker cells.
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http://dx.doi.org/10.1007/s10517-010-0734-5 | DOI Listing |
In the human heart, the binding of cyclic adenosine monophosphate (cAMP), a second messenger, to hyperpolarization and cyclic nucleotide-gated (HCN) regulates the automaticity of pacemaker cells. Recent single-molecule binding studies show that cAMP bound to each subunit of purified tetrameric HCN channels independently, in contrast to findings in cells. To explore the lipid membrane's role in cAMP regulation, we reconstituted purified human HCN channels in various lipid nanodiscs and resolved single molecule ligand-binding dynamics.
View Article and Find Full Text PDFCell Calcium
December 2024
Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557, USA. Electronic address:
Interstitial cells of Cajal in the plane of the myenteric plexus (ICC-MY) serve as electrical pacemakers in the stomach and small intestine. A similar population of cells is found in the colon, but these cells do not appear to generate regular slow wave potentials, as characteristic in more proximal gut regions. Ca handling mechanisms in ICC-MY of the mouse proximal colon were studied using confocal imaging of muscles from animals expressing GCaMP6f exclusively in ICC.
View Article and Find Full Text PDFShenxian-Shengmai (SXSM) is a Chinese patent medicine used in the treatment of sick sinus syndrome (SSS). However, its active chemical compounds and the underlying molecular mechanisms remain unclear. In this study, we researched the underlying mechanisms of SXSM in treating SSS.
View Article and Find Full Text PDFJ Pineal Res
November 2024
School of Neurobiology, Biochemistry and Biophysics, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel.
Located dorsally underneath a thin translucent skull in many teleosts, the pineal gland is a photoreceptive organ known as a key element of the circadian clock system. Nevertheless, the presence of additional routes of photoreception presents a challenge in determining its specific roles in regulating photic-related behavior. Here, we show the importance of the pineal gland in mediating a prolonged motor response of zebrafish larvae to sudden darkness, both as a photodetector and as a circadian pacemaker.
View Article and Find Full Text PDFPhys Rev E
November 2024
Laboratory of Dynamics in Biological Systems, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, 3000 Leuven, Belgium.
We explore a biomimetic model that simulates a cell, with the internal cytoplasm represented by a two-dimensional circular domain and the external cortex by a surrounding ring, both modeled using FitzHugh-Nagumo systems. The external ring is dynamically influenced by a pacemaker-driven wave originating from the internal domain, leading to the emergence of three distinct dynamical states based on the varying strengths of coupling. The range of dynamics observed includes phase patterning, the propagation of phase waves, and interactions between traveling and phase waves.
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