"If we can use this light probe to understand how mitochondria in nerve cells respond to various stimuli, we may be able to understand how all cells make life or death decisions - a step on the road, perhaps, to longer lives," says Gourley.
To do that, he says, scientists must understand how a cell self-destructs, which means understanding how mitochondria send out signals that kill cells as well as energize them.
The universal energy provider
Mitochondria have long been known as the mechanism that produces ATP, the universal energy driver for animal life. ATP powers each cell similarly to the way that gas powers each automobile. But scientists have found that the tiny power plants have another function. When cells are signaled to die - acceptably, as when biomaterial is shed from a uterus during its periodic menstrual cycle, or unacceptably, as the result of certain neurological diseases - an excess of calcium ions and free radicals that result from certain chemical reactions in the body open a large pore in the inner membrane in that cell's mitochondria. The pore enables release of a protein called cytochrome C that kills the cell. Meanwhile, the mitochondrion itself swells and explodes. One way to stop this suicidal process would be to find a chemical that would shield the mitochondria from these intruders.
Unexpected bursts of light
The observation technique developed at Sandia to test for such effects came about almost by accident. In the innovative lab arrangement already developed by Gourley's group, a micropump sends fluids containing suspect material through
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Contact: Neal Singer
nsinger@sandia.gov
505-845-7078
DOE/Sandia National Laboratories
23-Sep-2003