For his latest research, 60 patients at Southampton General Hospital's coronary care unit were interviewed after heart attacks had left them temporarily brain-dead. Seven reported near-death experiences - defined by characteristic features such as a feeling of leaving your body, going through a tunnel and entering an area of "love, bliss and consciousness".
This is actually interesting. According to some dud doco I saw a few months ago, the heart has some brain cells that allow storage of limited information (like the brain most heart muscle cells stay with us from birth - perhaps they are not replaced because they store information). I'm wondering if these smart heartcells might be a secondary activating tool for the chemicals involved in emotions. It is possible that even a brain dead person can still feel. I can't find anything on the net about this though.
In 1999, Frisén startled the neuroscience community by announcing he had found stem cells in the brain. Stem cells create new cells — in this case, new brain cells. However, Frisén seems to have changed his thinking. "My estimate is that 100% of cortical neurons stay with us from birth," he e-mails.
That's probably true, but doesn't rule out the possibility that the brain also makes new cells. "Two very different types of cells live a lifetime. Hence, your brain has both fully differentiated neurons that live a lifetime, and stem cells that continue to make new brain cells,"
The stem cell splits into two daughter cells (as does an ordinary cell), but instead of creating two ordinary cells, it forms another stem cell and a specialized cell (for example, a heart cell). Now, the crucial difference: The stem cell retains the original DNA strands, and makes a DNA copy
I wonder if this is the method the brain uses to create memories, namely germ cells create new cells for each new and novel cognitive memory, while the cells that stay from birth are for more instinctual activities like running the body, and pre-set reactions to emotions.