IIT Mathematics : Co-ordinate Geometry Review Course by Prof M L Khanna for JEE/IIT-JEE /Advanced Mathematics by Balaji's BookAt just a few hours of age, animals born with defects are doomed to a lifelong struggle to cope with their fate. Now, scientists have mapped a gene that plays a critical role in the nervous system's ability to learn and recover from injury. The findings, published in Nature, provide the first clear evidence of the role of a single gene in maintaining a brain's ability to repair itself after insult.
"Our research shows that Tx3 (for Thioredoxin 3) is critical for the nervous system to regenerate after injury. This is the first time that a single gene has been shown to play such a vital role," said study leader Michael Greenberg, Ph.D., a postdoctoral fellow at the University of California-Davis.
Humans and other animals have a remarkable ability to heal and regenerate damaged tissues after injury. For example, if an adult skin is injured by an insect bite or a burn, the area immediately surrounding the wound usually regrows. In the brain, the injury might involve the death of an important part of the brain's circuitry. It could lead to symptoms such as memory loss, tremors or seizures. However, these symptoms may be easily reversible if the injured part of the brain can repair itself.
In a series of experiments, Greenberg and colleagues, including the senior author, found that when newborn rodents had severe injuries, their ability to repair these injuries in the brain was significantly less. In these animals, Tx3 levels decreased dramatically within days of birth, and they were permanently lower than normal by the end of the first week. The animals that survived had lower levels of Tx3 and showed less recovery than those born with normal levels.
Txs are small, multi-functional proteins that regulate the activity of other proteins inside cells. The expression of Tx3 in humans and other mammals is relatively low, making it difficult to detect. But when the researchers searched the rodent genome, they found that Tx3 is located in the same chromosomal area as a group of genes that are important in regeneration.
The researchers found that neurons and glial cells, two kinds of cells that support and protect nerve cells, expressed Tx3 at very high levels. In addition, when the newborns were injured, the expression of Tx3 in the neurons and glial cells was increased. be359ba680
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