The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain can generate new nerve cells throughout life. One of the areas where this happens is the hippocampus, a brain structure that determines many types of learning and memory, deciding what is remembered and what is forgotten.

In a new study published in Science, researchers have shown for the first time the process by which neural stem cells divide and newborn neurons integrate in the adult mouse hippocampus. The study used in vivo 2-photon imaging and genetic labeling of neural stem cells in order to observe stem cell divisions as they happened, and to follow the maturation of new nerve cells for up to two months. By observing the cells in action and over time the team showed how most stem cells divide only for a few rounds before they mature into neurons. These results offer an explanation as to why the number of newborn cells dramatically declines with advancing age.

"In the past it was deemed technically impossible to follow single cell stem cells in the brain over time given the deep localization of the hippocampus in the brain", said the senior author.

The study answered long-standing questions in the field, but the researchers stated that this is just the beginning of many more experiments aimed at understanding how our brains are able to form new nerve cells throughout life. "In the future, we hope that we will be able to use neural stem cells for brain repair - for example for diseases such as cognitive aging, Parkinson's and Alzheimer's disease or major depression", summarizes the senior author.

http://science.sciencemag.org/content/359/6376/658

https://youtu.be/lSrLRnc3F_c