Mysterious brain cells called microglia are starting to reveal their secrets thanks to research conducted at the Weizmann Institute of Science.
Until recently, most of the glory in brain research went to neurons. For more than a century, these electrically excitable cells were believed to perform the entirety of the information processing that makes the brain such an amazing machine. In contrast, cells called glia which together account for about half of the brain's volume were thought to be mere fillers that provided the neurons with support and protection but performed no vital function of their own. In fact, they had been named glia, the Greek for "glue," precisely because they were considered so unsophisticated.
But in the past few years, the glia cells particularly the tiny microglia that make up about one-tenth of the brain cells have been shown to play critical roles both in the healthy and in the diseased brain.
The octopi-like microglia are immune cells that conduct ongoing surveillance, swallowing cellular debris or, in the case of infection, microbes, to protect the brain from injury or disease. But these remarkable cells are more than cleaners: In the past few years, they have been found to be involved in shaping neuronal networks by pruning excessive synapses the contact points that allow neurons to transmit signals during embryonic development. They are probably also involved in reshaping the synapses as learning and memory occurs in the adult brain. Defects in microglia are believed to contribute to various neurological diseases, among them Alzheimer's disease and amyotrophic lateral sclerosis, or ALS. By clarifying how exactly the microglia operate on the molecular level, scientists might be able to develop new therapies for these disorders.
More than a decade ago, Weizmann Institute's Prof. Steffen Jung developed a transgenic mouse model that for the first time enabled scientists to visualize the high
|Contact: Yivsam Azgad|
Weizmann Institute of Science