1 DNA and proteins are key molecules of the cell nucleus. 2  One gene makes one protein. 3  A gene is made of DNA. 4  Bacteria and viruses have DNA too. 5  The DNA molecule is shaped like a twisted ladder. 6  A half DNA ladder is a template for copying the whole.  RNA is an intermediary between DNA and protein.
1 Another theory holds that depression may directly damage the brain, leading to dementia. âSimply put, chronic stress and/or depression may result in the release of cortisol,â Gorman says. Over time, this stress hormone can harm the brain, she says.  A third theory points to reduced brain volume.
Severe stress in middle age can lead to Alzheimer's by damaging the brain, experts warn. 1  Canadian scientists believe neurons involved in chronic anxiety and fear 'extensively overlap' in areas also associated with Alzheimer's disease.  Stress in middle age could cause dementia by damaging the brain, new research suggests. Neurons involved in chronic anxiety and fear 'extensively overlap' in areas also associated with Alzheimer's disease, say scientists. Mid-life stress has been previously linked to a higher risk of Alzheimer's disease.