Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Monday, June 05, 2006

Your Brain And Space Radiation

The most damaging effect of the massive, energetic particles that make up the most dangerous component of space radiation targets the brain. To be most specific, the radiation will initially target the sensitive inner brain regions where it may do its most severe damage.
Recent studies have shown that what we were taught in school is wrong. We were taught that “brain cells cannot regenerate – that what you were born with is all you will ever have.” That is wrong. The innermost chambers of the brain in the limbic region are lined with a layer of adult stem cells. This region has become known as “brain marrow”. Just as the bone marrow generates and replaces blood cells through adult stem cell regeneration, so does the brain marrow. It is a process that was heretofore thought impossible: neurogenesis.
Space radiation will probably target these brain marrow cells first. Research is now underway using the crude approximation of space radiation from high energy particle accelerators. Initial but still inconclusive data has demonstrated these areas are highly sensitive to acute doses of space radiation. Beyond a certain range of damage – and no one knows that that means exactly – the organism will die.
The questions are important and on them depend the future of human space exploration. The questions are: how much is bad? How does time and radiation exposure together effect the body’s natural ability to heal itself? How is the normally slow process of neurogenesis affected by the onslaught? What exposure (what combination of energy and time) is the point of no return for the brain marrow? At what dose and conditions will symptoms emerge in the organism? What will those symptoms be? ALL of these questions MUST be answered before the first astronaut is committed to a Mars expedition.
Tomorrow – we will examine what we may be able to do to fix the problem – and some of those solutions are surprisingly radical!