Connection discovered between the nervous system and the vascular system

(Press-News.org) Montréal, June 8, 2011 – Dr. Frédéric Charron, researcher at the Institut de recherches cliniques de Montréal (IRCM), and his team have shown for the first time that a key molecule of the vascular system directs axons during the formation of neural circuits. This connection between the nervous system and the vascular system could be a good starting point for the development of therapies for neurodegenerative diseases. The discovery will be published tomorrow by Neuron, a scientific journal of the Cell Press group.

"To properly form neural circuits, developing axons (long extensions of neurons that make the nerves) need molecules to guide them towards their target, in the same way that road signs guide us when we drive," explains Pierre Fabre, doctoral student in Dr. Charron's team and first co-author of the article.

The nervous system is not the only system formed during human embryo development. Blood vessels are also organized into a very complex network, which led to the idea that certain molecules could be reused by both the nervous system and the vascular system. In fact, recent studies revealed that the reference points used to guide axons also help blood vessels reach their targets.

"One of the key molecules of the vascular system is the vascular endothelial growth factor, better known as VEGF," adds Mr. Fabre. "We discovered that VEGF is able to attract nervous system axons. More specifically, we identified Flk-1 as the receptor responsible for this effect, making it a prime target for the development of therapies to re-grow axons after lesions of the central nervous system or neurodegenerative diseases."

This scientific breakthrough was possible due to an innovative technique developed by Dr. Charron's laboratory a few years ago. The system uses a microscopic device to control and observe, in real time, the axon's behaviour in response to guidance molecules. This technique allowed the researchers to follow the axon's trajectory and revealed VEGF's role in directing axons.

"This research could have an important long-term impact in the field of spinal cord repair, as the results will help us better understand the development of the spinal cord," says Dr. Charron, Director of the IRCM's Molecular Biology of Neural Development research unit. "The more we learn about the molecules needed to appropriately guide axons, the more it will become possible to develop a therapy to treat spinal cord injuries."

"These new findings are of great interest to the research community as they offer new hope for the treatment of neurodegenerative diseases," says Dr. Anthony Phillips, CIHR's Scientific Director of the Institute of Neurosciences, Mental Health and Addiction. "CIHR recognizes the important work of Dr. Charron's team and this novel discovery linking blood vessels and neurons to neural circuit formation."

### This research project was conducted in close collaboration with Dr. Peter Carmeliet's (senior co-author of the article with Dr. Charron) team at the Vesalius Research Center, in Leuven (Belgium), including Dr. Carmen Ruiz de Almodovar, first co-author of the study with Mr. Fabre.

Research carried out in Dr. Charron's laboratory was funded by the Canadian Institutes of Health Research (CIHR) and the Fonds de recherche en santé du Québec (FRSQ). Pierre Fabre also holds scholarships from the Université de Montréal and the IRCM.

For more information, please refer to the article summary published by Neuron: http://www.cell.com/neuron/abstract/S0896-6273(11)00343-6.

About Dr. Frédéric Charron Frédéric Charron obtained his PhD in experimental medicine from McGill University. He is an Associate IRCM Research Professor and Director of the Molecular Biology of Neural Development research unit. Dr. Charron is also associate researcher in the Department of Medicine at the Université de Montréal, and associate member of the Department of Medicine (Division of Experimental Medicine), the Department of Biology, and the Department of Anatomy and Cell Biology at McGill University. In addition, he is a member of the McGill Integrated Program in Neuroscience, the Montreal Regional Brain Tumor Research Group at the Montreal Neurological Institute, and the Centre of Excellence in Neurosciences (CENUM) at the Université de Montréal. Dr. Charron is a Research Scholar from the Fonds de recherche en santé du Québec (FRSQ).

About the Institut de recherches cliniques de Montréal (IRCM) Founded in 1967, the IRCM (www.ircm.qc.ca) is currently comprised of 36 research units in various fields, namely immunity and viral infections, cardiovascular and metabolic diseases, cancer, neurobiology and development, systems biology and medicinal chemistry. It also houses three specialized research clinics, seven core facilities and two research platforms with state-of-the-art equipment. The IRCM employs 425 people and is an independent institution affiliated with the Université de Montréal. The IRCM clinic is associated to the Centre hospitalier de l'Université de Montréal (CHUM). The IRCM also maintains a long-standing association with McGill University.

About the Canadian Institutes of Health Research (CIHR) CIHR (www.cihr-irsc.gc.ca) is the Government of Canada's agency for health research. CIHR's mission is to create new scientific knowledge and to enable its translation into improved health, more effective health services and products, and a strengthened Canadian health-care system. Composed of 13 Institutes, CIHR provides leadership and support to more than 13,600 health researchers and trainees across Canada.