Canadian scientist Marc Tessier-Lavigne has been chosen as the next president of the prestigious Rockefeller University in New York. Dr. Tessier-Lavigne, 50, obtained his bachelor of science at McGill University in Montreal and has made important discoveries about how the developing brain and central nervous system are wired. He has held positions at the University of California and Stanford University and the biotech company Genentech.
Rockefeller has six Nobel Prize winners on staff. Is that a bit daunting even for a researcher of your status to take over as president?
Yes, it is a remarkable institution, focused exclusively on biomedical research. It has maintained an exceptional track record of accomplishment for over a century. It really is a legendary place, with 23 Nobel laureates associated with the university over the years. It is a great honour and extraordinarily humbling.
Will you keep up your own research?
The university has a tradition that the president maintains an active research lab, so I am able to enjoy that tradition. I will be maintaining my research effort.
What drew you to the developing brain and nervous system?
I started out thinking that I wanted to be a mathematician or physicist. I was fortunate enough to win a Rhodes Scholarship to go to Oxford, and the beauty of that is you are allowed to do whatever you want, so I did a second undergraduate degree in physiology and encountered the nervous system. I became more and more fascinated by the biology of the nervous system and its wiring diagram.
Tell me about that diagram.
We have a trillion nerve cells, but they are interconnected. Each nerve cell sends out a thin extension, a fibre, called an axon, that has to connect with just the right set of target neurons to form the neuronal circuits that underlie the proper functioning of the brain - for perception, motor control, thought and consciousness. I became fascinated by the problem of brain wiring. How can so many cells make all the correct decisions?
How do they decide where to go?
At the tip of each axon is a growth cone. Think of the growth cone as a little hand, with little finger-like extensions which actively probe the environment for guidance information. There are specific proteins - guidance cues or little signposts - that instruct the growth cone to grow in specific directions.
How long do some axons grow? Do they stretch from head to toe?
They don't stretch from the brain to the big toe, but almost. A neuron in the brain's motor cortex may have to send its axon through the brain down the spinal cord, and it may go as far as the base of the spinal cord. In us, an axon can be a metre in length. In a giraffe, you can imagine it will be several metres. It connects with a second neuron, a motor neuron, which sends its axons out of the spinal cord through the limb to the big toe.
Was there an actual eureka moment when you made your big discovery in the early '90s and found a protein that guides the growth of developing neurons in the spinal cord?
Yes, there was. We needed 25,000 embryonic chick brains to isolate and purify a guidance substance operating in the spinal cord. When we obtained the protein and were able to decipher its genetic code, we found it was related to a protein that guides axon growth in roundworms. This showed the same mechanisms are used in different organisms, just put to a more sophisticated use in higher organisms. That was definitely a eureka moment.
How could your work help people with spinal cord injuries?
There is substantial evidence that the environment of the brain and spinal cord is hostile to regrowth of axons after nerve fibres in the spinal cord have been severed. The program of research in the field as a whole is to identify key factors that inhibit regeneration. The idea is if we can identify those, we can block their actions. This has proven to be more difficult than we all thought. Either many of them act together or we haven't put our hands on the key inhibitors. But there has been some progress.
You were born in Trenton, Ont., but educated in London and Brussels?
My father was with the Canadian Armed Forces and posted to NATO. We moved to Europe when I was 7 and moved back again when I was 17, and [I]went to McGill.
Do you still see yourself as Canadian?
Absolutely. I have dual citizenship and maintain close ties with Canada. My mother lives in Ottawa, and I have lots of relatives across the country, as well as many friends and many other ties, including many newer connections with Canadian scientists.
Could you see yourself moving back one day?
Of course, but for now we are focused on our new adventure in New York.
This interview has been condensed and edited.