Laser Sheds Light on Mitochondrial Response to Calcium Ions
Some researchers believe that malfunctioning in the mitochondria (the cell’s energy supplier) are at least partially responsible for the loss of neurons that is associated with the degenerative effects of HD. To learn more about mitochondria please click here.
In order to study mitochondria, which are extremely small, researchers need to use laser technology. The Sandia National Laboratories, run by the Department of Energy (DOE), have developed a laser that allows scientists to study individual mitochondria in vitro (in a test tube, as opposed to inside a living organism). This laser acts as a light probe, measuring the size of the mitochondria by the spontaneous bursts of light they emit (each mitochondrion acts like a lens concentrating the light passing through it from a solid, light-emitting material and a reflective mirror; in essence, the light refracted into the mitochondria is amplified). The laser can also be used to measure the swelling effect of calcium ions when they are introduced to the mitochondria. Calcium ions may cause the death of the mitochondria, as well as the death of the entire cell.
Neuroprotectant drugs literally “waterproof”
the neurons’ mitochondria from an excess of calcium ions that penetrate the organelles when a neuron is marked for destruction (the process of programmed cell death is called “apoptosis”). The calcium ions enter a mitochondrion by opening a large pore in its inner membrane. As a result of this invasion, the pore releases a chemical that kills the cell. Since the breakdown of mitochondria is associated with cell death in HD, researchers are hopeful that neuroprotectant drugs could prevent cell death from occurring. A benefit of using lasers to study the ability of new drugs to protect mitochondria is that only small amounts of mitochondria and the drug are necessary. Calcium ions are then introduced to the drug-coated mitochondria to test the organelles’ permeability.
Cyclosporin A, a current neuroprotectant drug, is not entirely effective in waterproofing the mitochondria. Additionally, it may suppress the immune system. Researchers are in the process of developing more successful waterproofing drugs with fewer side effects.
To learn more about the use of lasers in HD research, please go here.
Last Modified: 5-10-04
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