Magic embryology: turning on a heartbeat (Introduction)

by David Turell , Sunday, October 01, 2023, 18:08 (420 days ago) @ David Turell

Based on real ion electricity:

https://www.sciencedaily.com/releases/2023/09/230927154920.htm

"Becoming a full-fledged organism out of a handful of cells, complete with functioning tissues and organs, is a messy yet highly synchronized process that requires cells to organize themselves in a precise manner and begin working together.

"This process is especially dramatic in the heart, where static cells must start beating in perfect unison.

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"In a study conducted in zebrafish, the team discovered that heart cells start beating suddenly and all at once as calcium levels and electrical signals increase. Moreover, each heart cell has the ability to beat on its own, without a pacemaker, and the heartbeat can start in different places.

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"'The heart beats about 3 billion times in a typical human lifetime, and it must never take a break," said co-senior author Adam Cohen, professor of chemistry and chemical biology and of physics at Harvard.

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"Using fluorescent proteins and high-speed microscope imaging, the researchers captured changes in calcium levels and electrical activity in heart cells of developing zebrafish embryos. To their surprise, they discovered that all the heart cells abruptly transitioned from not beating to beating -- characterized by simultaneous spikes in calcium and electrical signals -- and immediately began beating in sync.

"'It was like somebody had flipped on a switch," Cohen described.

"Further experiments revealed that for each heartbeat, one region of the heart fires first, initiating a wave of electricity that rapidly flows through the rest of the cells and prompts them to fire.

"Interestingly, the heartbeats started from different spots in different zebrafish, suggesting that there's nothing unique about the cells that fire first. This finding was counterintuitive because cells in adult hearts behave differently.

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"'The heart first learns how to keep pace without a clock, and individual cells first learn to cooperate without agreeing on what their roles are," Jia added. "It is very important for the heartbeat to be regular, but it is organized very quickly at the start of life from what seems to be a total mess."

"Developing zebrafish offer a convenient model for studying the heart because they are transparent, grow quickly -- developing a heartbeat in only 24 hours -- and can be imaged by the dozen. However, Megason thinks the same developmental process may be conserved across species, including humans."

Comment: the heart is made up from unusual muscles, has amazingly different cell parts from filamentously thin valves, specialized firing points, and conduction bundle cells to transmit electric firing signals. Blood flow is arranged in one direction. The first hearts appeared in the Cambrian explosion along with the first brains. Designed special organs requiring the existence of a designer.