The Question: Which cells in the human body are never replaced?

Submitted by: Salha

The Short Answer: So far, the only cell type that we can confidently say is never replaced is cerebral cortex neurons. Check out my posting a couple of months ago about the research of Dr. Jonas Frisén at the Department of Cell and Molecular Biology at Karolinska Institute in Sweden. Dr. Frisén has developed a very clever way to measure the replacement of cells in the human body. Like most careful science, this research takes time, of course. So far, Dr. Frisén and his team have only gotten definitive results on cerebral cortex neurons, fat cells, and cardiomyocytes (heart muscle cells). This research suggests that cerebral cortex neurons are never replaced. Fat cells are replaced fairly regularly, and cardiomyocytes are replaced at a decreasing rate with age. Click here for the full article:

Dr. Frisén is currently working on other cell types and those results will probably be published as they become available.

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