Another step towards solving Alzheimer's disease
Beta-amyloid peptides are notorious for the fact that its fragments are able to accumulate in the form of plaques in the brain of people, which is a possible cause of Alzheimer's disease – a neurodegenerative disease expressed in the extinction of memory and intelligence caused by the death of neurons.
A group of bioengineers from the Jacobs Graduate School of Engineering at the University of California, San Diego, working under the guidance of Professor Gabriel Silva, found that the addition of beta-amyloid to the medium with cultured astrocytes (cells of the cerebral cortex, performing mainly a supporting function for neurons) of transgenic rats suffering from Alzheimer's disease, induces the release of calcium by cells, undulating between cells like a chain reaction: the release of calcium by one cell causes the release of calcium into the environment by neighboring cells, which, in turn, induce the release of calcium by the cells of their environment. One such "calcium wave" involves the simultaneous release of calcium by 150-200 cells. The effect was detected using fluorescent imaging, a new technique for studying the activity of brain cells, which makes it possible to trace the pathways of information distribution in a network of neurons.
In the culture of astrocytes taken from healthy rats, no such phenomenon was observed.
The finding that beta-amyloid causes a wave-like release of calcium by astrocytes of rats suffering from Alzheimer's disease opens up new functions of these cells (except for the known reference), as well as a possible connection with the causes of Alzheimer's disease. By tracing calcium waves propagating between brain cells, scientists can register changes in the potential of cell membranes, which, in turn, will allow us to judge how neurons and other brain cells, including astrocytes, interact with each other.
The article by Siu-Kei Chow et al. "Amyloid β-peptide directly induces spontaneous calcium transitions, delayed intercellular calcium waves and gliosis in rat cortical astrocytes" is published in the January issue of the journal ASN NEURO.
Portal "Eternal youth" http://vechnayamolodost.ru based on EurekAlert: Catching calcium waves could provide Alzheimer's insights.
15.02.2010