Feb. 5 2012 – Researchers at the Robert-Giffard Research Center of Université Laval have just shed new light on the regeneration of brain neurons. The work of Lusine Bozoyan, Jivan Khlghatyan and Armen Saghatelyan, published in the February 1st edition of the Journal of Neuroscience, demonstrates the role played by cells called astrocytes in this mechanism. This discovery represents another step towards the regeneration of targeted areas of the brain in victims of stroke or head injury or in persons suffering from neurodegenerative diseases.
Contrary to what we long believed the adult brain has some capacity for regeneration. Indeed, brain stem cells produce neuronal precursors in an area in the center of the brain. In mice, these precursors must travel to the anterior region of the brain, where differentiation occurs, to become functional neurons capable of replacing damaged or dead cells. In 2009, Armen Saghatelyan and colleagues found that these precursors find their way through a maze of cells along blood vessels that run parallel over relatively long distances and that synthesize a protein called BDNF. “It’s as if there was a BDNF highway that precursors follow to reach their destination,” he says. But how are these blood vessels, which act as migration routes, formed?
It is this question that Saghatelyan and colleagues address in their latest article. In mice, the vascular highway is formed in the first weeks of life under the guidance of astrocytes, star-shaped cells, which produce a growth factor (VEGF). “Astrocytes play a role at a specific time during normal development and in specific regions of the brain, says the researcher. They orchestrate the formation and growth of parallel blood vessels along which the neuronal precursors migrate. ”
In humans, the existence of such a migration highway is the subject of controversy. Nevertheless, Professor Saghatelyan believes that the discovery made by his team could have medical implications. “After a stroke or after a stem cell transplant, sometimes the neural precursors do not migrate to the affected areas. Our work suggests an approach to stimulate the migration of neuronal precursors to a target region of the brain and increase the chances of neuronal regeneration. ”
Source of text and image: Jean Hamann, Université Laval
Translation to English: Canadian Association for Neuroscience (J.Poupart)
Original article in Journal of Neuroscience (subscription necessary)
This research was feature in a Guardian blog post (includes a video of migrating neurons)
