- #1
black hole 123
- 36
- 2
i read somewhere the body replace itself every 7 years. does the brain also do this?
Does the brain replace itself every 7 years?
Click For Summary
Discussion Overview
The discussion centers around the claim that the brain replaces itself every seven years, exploring the validity of this idea and examining the rates of cell turnover in the brain compared to other body cells. It includes aspects of biology and neuroscience, focusing on regeneration, neurogenesis, and memory retention.
Discussion Character
- Debate/contested
- Technical explanation
Main Points Raised
- Some participants assert that the brain does not completely replace itself, with most brain cells remaining unchanged since early childhood, which is necessary for memory retention.
- Others argue that the notion of a complete cellular turnover every seven years is a myth, highlighting that different cells in the body have varying replacement rates, with neurons in the cerebral cortex not being replaced in adulthood.
- One participant provides examples of cell turnover rates for various cell types, noting that while some cells are replaced frequently, neurons may only undergo limited neurogenesis in specific brain regions like the hippocampus.
- Several participants emphasize the importance of citing reliable sources when discussing biological claims, suggesting the use of NIH resources for accurate information.
- A participant expresses a personal concern about skin cell turnover and its implications for aging, indicating a broader interest in the topic of cell regeneration.
Areas of Agreement / Disagreement
Participants generally disagree on the validity of the seven-year turnover claim, with multiple competing views on the rates of cell replacement in the brain and body. The discussion remains unresolved regarding the implications of these rates for memory and aging.
Contextual Notes
There are limitations in the discussion regarding the definitions of cell turnover and neurogenesis, as well as the varying rates of cell replacement across different tissues and individuals.
- #2
trurle
- 508
- 207
Generally no. Some regeneration and growth of brain (new synapses etc) continue for entire life, but most of the brain cells are the same since early childhood - or we would be unable to retain childhood memories which are saved as deposits of proteins within neurons.
- #3
Laroxe
Science Advisor
- 631
- 843
The whole idea is a myth, the reality is that the many different cells in the body are replaced at very different rates, and some like the neurones in the cerebral cortex are not replaced at all in adulthood.
Some examples; sperm cells only last around 3 days, cells lining the colon, 4 days, red blood cells last around 4 months, while white blood cells can live around a year. The rate also changes as we age cells in the heart (cardiomyocytes) are replaced at around 1% a year in young adults but this rate is halved by the age of 70. For most people this means that over half of these cells will never be replaced over their lifespan. It seems that few neurons are replaced over our lifespan though there may be some neurogenesis in very specific areas of the brain like the hippocampus.
Some examples; sperm cells only last around 3 days, cells lining the colon, 4 days, red blood cells last around 4 months, while white blood cells can live around a year. The rate also changes as we age cells in the heart (cardiomyocytes) are replaced at around 1% a year in young adults but this rate is halved by the age of 70. For most people this means that over half of these cells will never be replaced over their lifespan. It seems that few neurons are replaced over our lifespan though there may be some neurogenesis in very specific areas of the brain like the hippocampus.
- #4
jim mcnamara
Mentor
- 4,789
- 3,852
@black hole 123 -
The next time you pose a question please consider giving us the source. It is clear that your source was very wrong.
Also consider: when you want to find something in medicine or human biology try a search on NIH. They have wonderful high quality references there, and their general white papers for public consumption are excellent. Prepend "site:NIH" to your google search example:
"site:nih.gov your search term(s) " --- without the quotes, I had to add them to get this to display correctly
The next time you pose a question please consider giving us the source. It is clear that your source was very wrong.
Also consider: when you want to find something in medicine or human biology try a search on NIH. They have wonderful high quality references there, and their general white papers for public consumption are excellent. Prepend "site:NIH" to your google search example:
"site:nih.gov your search term(s) " --- without the quotes, I had to add them to get this to display correctly
- #5
- 3,753
- 4,198
Here's a nice source on turnover of cells in the human body: http://book.bionumbers.org/how-quickly-do-different-cells-in-the-body-replace-themselves/
- #6
nitsuj
- 1,387
- 98
I have a dry patch of skin on my face, my concern is this means a high cell turn overate and is "aging" much faster than the rest of my face! 
- #7
elusiveshame
- 170
- 35
jim mcnamara said:
Just wanted to mention you can append your google search with the site:<url> search modifier. Here's a list of other modifiers for the Google novices: https://moz.com/learn/seo/search-operators