Eli5: Why are some cells permanent(like fat cells), regenerative(like skin cells) or lost permanently (brain cells)



I just wish my brain cells were permanent like my fat cells I’d be smart until I die

In: Biology

1) Fat cells are permanent as we don’t always know when our next meal is, this means they need to be around when we need them, we can’t have food and just wait for fat cells to form-storage is needed immediately.

2) Skin is external-it is subject the most to environmental damage-UV, water, heat, scratches, etc. If they didn’t regenerate DNA and other damage would pile up leading to higher cancer incidence and poorer protection from the environment.

3) Brain cells regarding memory (“smarts”) and movement are actually regenerative though at very low levels and decreasing as you age. Use it or lose it.