The cell death

[Asexperia]

In Alzheimer the brain cells die and don't regenerate.
Does something similar happen in other organs of the body?

 

[Hercules Rockefeller]

Many, but not all, tissues and organs of the body can continue to regenerate by virtue of stem cells, immortal cells that remain undifferentiated and proliferative. Stem cells (in muscle, skin, GI tract, bone marrow, liver and more) divide to create new cells – new for old replacement. The activity of stem cells gradually slows as we age through accumulation of mutations. Unfortunately, neural stem cells are active only during embryonic nervous system development and early childhood. Once you reach late teens, your capacity to replace damaged/dead brain cells has ceased. (This isn’t strictly true. There are some neural stem cells that remain active in areas associated with memory and olfaction, but not outside of these limited areas.)

https://stemcells.nih.gov/info/2001report/chapter4.htm

 

[Asexperia]

Many, but not all, tissues and organs of the body can continue to regenerate by virtue of stem cells, immortal cells that remain undifferentiated and proliferative. Stem cells (in muscle, skin, GI tract, bone marrow, liver and more) divide to create new cells – new for old replacement. The activity of stem cells gradually slows as we age through accumulation of mutations. Unfortunately, neural stem cells are active only during embryonic nervous system development and early childhood. Once you reach late teens, your capacity to replace damaged/dead brain cells has ceased. (This isn’t strictly true. There are some neural stem cells that remain active in areas associated with memory and olfaction, but not outside of these limited areas.)

https://stemcells.nih.gov/info/2001report/chapter4.htm

There are people who are 80 or 90 years old and still retain their mental faculties.

 

[Hercules Rockefeller]

There are people who are 80 or 90 years old and still retain their mental faculties.

Indeed. In fact, you could raise that to 100-110 yo. Nothing I said precludes that.

Every human is a mixture of nature and nurture, genetics and environment. Depending on your genes (out of your control) and your lifestyle choices (in your control), you might still be fully cognisant at 100yo, or fully dependent by 50yo.

We didn’t evolve to be 80+ yo; perhaps that’s one of the reasons behind the lack of neural stem cell activity into adulthood. Our longevity is the product of a wide range of modern technologies. I think it’s a testament to the resilience of human biology that most people do remain relatively cognisant until old age.

 

[Write4U]

In Alzheimer the brain cells die and don't regenerate.
Does something similar happen in other organs of the body?

Yep, the human body has several trillions of cells each undergoing mitosis (cell division), except for certain brain cells, which are used for memory storage.

It is true that individual cells have a finite life span, and when they die off they are replaced with new cells. As The New York Public Library's Science Desk Reference (Stonesong Press, 1995) notes, "There are between 50 and 75 trillion cells in the body.... Each type of cell has its own life span, and when a human dies it may take hours or day before all the cells in the body die." (Forensic investigators take advantage of this vaguely morbid fact when determining the cause and time of death of homicide victims.)

Red blood cells live for about four months, while white blood cells live on average more than a year. Skin cells live about two or three weeks. Colon cells have it rough: They die off after about four days. Sperm cells have a life span of only about three days, while brain cells typically last an entire lifetime (neurons in the cerebral cortex, for example, are not replaced when they die).

https://www.livescience.com/33179-does-human-body-replace-cells-seven-years.html#

Perhaps the most amazing thing about mitosis is its precision, a feature that has intrigued biologists since Walther Flemming first described chromosomes in the late 1800s (Paweletz, 2001). Although Flemming was able to correctly deduce the sequence of events in mitosis, this sequence could not be experimentally verified for several decades, until advances in light microscopy made it possible to observe chromosome movements in living cells. Researchers now know that mitosis is a highly regulated process involving hundreds of different cellular proteins. The dynamic nature of mitosis is best appreciated when this process is viewed in living cells.

Mitosis ends with telophase, or the stage at which the chromosomes reach the poles. The nuclear membrane then reforms, and the chromosomes begin to decondense into their interphase conformations. Telophase is followed by cytokinesis, or the division of the cytoplasm into two daughter cells.

https://www.nature.com/scitable/topicpage/mitosis-and-cell-division-205/#

 

[Write4U]

This maybe of interest.

Adult Brain Cells Do Keep Growing

An illustration of a synapse, which won first prize in the illustration category in the 2005 Science Magazine and NSF Science and Engineering Visualization Challenge.(Image credit: Graham Johnson/NSF)

The apocryphal tale that you can't grow new brain cells just isn't true. Neurons continue to grow and change beyond the first years of development and well into adulthood, according to a new study.
The finding challenges the traditional belief that adult brain cells, or neurons, are largely static and unable to change their structures in response to new experiences.

The study, performed in adult mice, found that the branch-like projections on some neurons, called "dendrites," were still physically malleable. Dendrites conduct electrical signals received from other neurons to the parent neuron's cell body. The changes occurred both incrementally and in short bursts, and involved both growth and shrinkage.......more

https://www.livescience.com/505-adult-brain-cells-growing.html#

 

[Hercules Rockefeller]

The study, performed in adult mice, found that the branch-like projections on some neurons, called "dendrites," were still physically malleable.

Yes, adult neurons retain the ability to produce new dendrites and axons. This has been known for quite a while. This is why a brain, in some instances, can ‘re-wire’ itself after brain injury and regain lost functionality. But this is not the same thing as replacement of brain cells through stem cell division. A neuron may be able to send out new dendrites if the old dendrites are degraded, but if the neuron itself dies it is not replaced (with the exception of those areas of the brain I mentioned above).

 

[Write4U]

A neuron may be able to send out new dendrites if the old dendrites are degraded, but if the neuron itself dies it is not replaced (with the exception of those areas of the brain I mentioned above)

I agree, when a neuron dies it is called "microtubule catastrophe" which stops mitosis.

Occasionally this is desirable as in the case of stopping cancerous cells from duplicating.
I am prohibited from quoting pertinent information.

So just check out this link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4563776/

 

[Write4U]

An ocean dweller organism.