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.
Mild Cognitive Impairment and Dementia. Some people have memory loss but do not have dementia. They have what is known as mild cognitive impairment, a middle ground between normal aging and dementia. People with this condition are at risk for developing dementia. But not all people with mild cognitive impairment will progress to dementia. People with mild cognitive impairment often know that they have lost memory, and tests can confirm some loss. But they have normal overall mental functioning and can carry out normal activities of daily living.