Beaver Amphibious Car

stem cells in the adult brain signals requires

University of California, Berkeley, biologists have found a sign that keeps stem cells alive in the adult brain, providing a focus for scientists seeking ways to grow again or return to the seed of stem cells in the brain to allow the damaged areas repaired.

Researchers discovered in fruit flies to keep the accelerated insulin receptor in the brain prevents the death of neural stem cells that occurs when most brain regions mature into adult form. Whether the same technique work in humans is unknown, but the team hopes to discover Berkeley.

"This work does not point the way to take an adult who has lost the stem cells and bringing them back mysteriously, but suggests that mechanisms may be operating to get rid of them in the first place, "said K. Hariharan Iswara, UC Berkeley professor of molecular and cellular biology. "Also, if you were able to introduce neural stem cells in adult brain, suggesting that such mechanisms may need to have in place to keep them alive."
Hariharan noted
that other researchers have obtained stem cells Neural persist by blocking the genes that cause his death. However, this alone does not produce healthy cells, nerves, normal-looking mother who can make mature neurons. The new finding team of UC Berkeley shows that it is also necessary to provide a signal similar to insulin. If you stop neuronal stem cell death is analogous to taking the foot off the brake, then providing a signal similar to insulin is like stepping on the gas, he said. Both are essential.

Hariharan, post-doctoral researcher Sarah E. Siegrist y sus colegas publicaron sus hallazgos en la versión online de la revista Current Biology. Su informe aparecerá en abril de la revista 13 edición impresa.

La mayoría de las áreas del cerebro adulto de mamíferos y cerebro de la mosca de fruta carecen de las células madre neurales, las únicas células capaces de generar neuronas en toda regla. Presumiblemente, Hariharan dijo, la falta de células madre neurales es la razón por la lesión cerebral no está en condiciones de reemplazar las neuronas muertas.

En el nuevo estudio, Siegrist showed that stem cells present in the pupal stage of the fruit fly have been in the adult brain, and they die, and not only in mature neurons. Stem cells were persisted longer in the body of mushrooms, a region of fly brain responsible for memory and learning that, somehow, is like the hippocampus in humans.

In subsequent experiments, tried to prevent the death of neural stem cells in fruit flies genetically by blocking a process called programmed cell death (apoptosis). Although this allowed the stem cells to survive longer, the cells were small and did many neurons. In fact, Siegrist said, showed signs of growth retardation, suggesting the withdrawal of insulin.

then tried to mimic various genetic manipulations of the insulin signal type, this time with fruit flies with mutant genes also blocked apoptosis. Surprisingly, neural stem cells persisted for at least a month and has even spawned many mature, apparently normal nerve cells.

"These neural stem cells seem to behave properly express the proteins expected to express neural stem cells, which resemble their normal counterparts, and most importantly, have to change the EC , normal cells that develop into mature nerve cells that put out processes (axons) that in some cases, appear to be normal processes go, "said Siegrist. "We do not know whether these cells function normally or are electrically active. At least it is encouraging that we did get the nerve cells a part of the fruit fly () of the brain that normally can not make nerve cells in the adult brain. "

" Sarah had to make two manipulations together to keep these neural stem cells alive, and did not work alone, "said Hariharan. "One was to maintain the insulin signal on, and one was to block programmed cell death. Every things improved a bit, but when he did the two together, neural stem cells survived for a month when they had reneged on mature neurons or normal looking neurons sent out processes. "

Siegrist plans to continue his search through mutant fruit flies to find other genes that enhance survival in the mushroom body and leave the stem cells in other brain areas of the fly persist. She also plans to explore collaborations similar mechanisms in mammals, to see if similar manipulation could keep alive the neural stem cells in the mammalian brain.

"In fruit flies, the pathways downstream of the insulin receptor are important to maintain neural stem cells alive, "said Siegrist. "Mammals have the same genes downstream of the insulin receptor, so you can find the same response to insulin or growth factors insulin-like mammals." About 40