Building new connections
By Sol Inés Peca
In the 1980s, Dr. Albert Aguayo and his colleagues at McGill’s Centre for Research in Neuroscience were the first to show that injured nerve fibres could regenerate and reconnect in the central nervous system of adult mammals. Since then, Aguayo has been a leader in neural regeneration research and education. Last week, under the under the category of Excellence in Health Research, Aguayo became an inductee of the Canadian Medical Hall of Fame.
It was the mid 1950s and a young Albert Aguayo was considering applying to university in his native Argentina – architecture had always attracted him so it seemed like a natural career choice. Two weeks before the deadline for registration he switched to medicine.
“I still don’t know why I decided to do that – but I’m very glad I did, as there is such beauty in biology too!” says Aguayo. That unexplained last-minute decision has led him to nearly fifty years of exploring the architecture of the nervous system. His journey is still being recognized: this year he became the most recent in a cohort of highly distinguished inductees into the Canadian Medical Hall of Fame.
“The brain is a fascinating organ. Probably the most complex of them all,” says Aguayo. “Its components hide the secrets of what we are as human beings.” When Aguayo talks about the brain, his sense of marvel is still fresh and his excitement palpable. “Think for a moment about what the brain is like,” he says. “Billions of tiny cells that process the information we need to live, think and behave.”
After graduating in medicine from the National University of Córdoba in Argentina, Aguayo trained in neurology at both Toronto and McGill universities. “As others of my generation, I was trained as a ‘physician scientist’,” explains Aguayo. “The idea was that medical doctors involved in patient care and teaching needed to become part of the revolution in knowledge that was gaining momentum in biology during the second half of the 20th century.”
Career beginnings at McGill
In the 1960s, Dr. Donald W. Baxter was a strong advocate of this integrated drive towards scientific discovery in the clinical neurosciences at McGill. He recruited Aguayo, who, in addition to his training in neurology, wanted to pursue a career in basic research.
“Dr. Baxter’s vision, and that of others here and elsewhere in Canada, helped create conditions in this University and the rest of the country,” remembers Aguayo. “Those conditions provided the needed incentives and support for a balanced and effective commitment to those of us who elected this path,” he adds. “It was a very exciting time to be around!”
A few years after being appointed an Assistant Professor at McGill’s Department of Neurology and Neurosurgery in 1967, Aguayo became the founding Director of the Centre for Research in Neuroscience at McGill University, a role he assumed with great accomplishment for fifteen years. Involved nationally and internationally in research and teaching, he was elected President of the Washington-based Society for Neuroscience in 1987 and has since served in many other Canadian and foreign organizations.
Most recently, he helped implement new policies in world neuroscience as secretary general, and then president of the International Brain Research Organization (IBRO), a UNESCO association with over 50,000 members in 84 countries.
A time of breakthrough
In the late 1970s, after devoting several years to the study of peripheral nerve disorders both in Canada and the United Kingdom, Aguayo, together with other young McGill investigators at the Montreal General Hospital, decided to challenge one of the key scientific notions of the time – the belief that neurons could not regenerate after brain or spinal cord injury.
At the start, some of the techniques they used to investigate this problem in laboratory animals were those they had learned and applied in the clinic for the diagnosis of human nerve diseases (e.g., nerve microscopy and electrophysiology). Subsequently, new tools and an influx of capable and dedicated trainees and technicians built the research momentum. “A wonderful crowd!” recalls Aguayo.
He describes why nerve cells are so unique using creative imagery. “They have a small cell body, and often very long arms that reach out to other cells located far away, and at the end of those arms, there is a hand that makes things happen. The arms are the axons, and the hands are the synapses,” he explains. “The music of the cell is programmed in its body and played out there, in the synapse.”
“The intricate circuitry made by such a multitude of interconnecting nerve cells is “wired” early on in development when the organism is very small, but, with body growth, many axons must stretch a great deal as cells move away from each other. Some axons can measure half of your body’s length!”
Usually, when injuries from a fall or a car accident take place, axons may be cut and the cells no longer communicate with each other. “Repair requires axonal re-growth and enough of an appropriate re-wiring to restore useful function,” explains Aguayo.
“We were able to prove in the 1980s that injured nerve cells in the adult central nerve system retain the capacity to re-grow long distances and form new connections. By now, research in a number of laboratories has greatly advanced our understanding of the cellular mechanisms that inhibit or facilitate axonal regeneration,” says Aguayo. “Much remains to be done, however, to recreate the neural circuits required to restore complex functions. Advances along these lines are needed for these discoveries to be applied clinically,” he adds.
Aguayo sees opportunities for the field. “Great challenges have already been met in the medical and surgical management of spinal cord and brain injuries. Indeed, until 50 or 60 years ago, no one with a serious spinal cord injury would have survived for very long,” says Aguayo. Now, millions of these patients can live a happy, useful and sometimes exemplary life.
“In Canada, Rick Hansen is a wonderful example and a great role model for all of us! It is a sign of progress that basic research is now also able to tackle the biological mechanisms involved in neural injury and repair, with the hope of restoring neural function,” he says.
Impacting the world
As Aguayo explains the neurosciences issues that he has grown to know so well, and that continue to harbour so many challenging mysteries, his longstanding appreciation for accessible learning becomes more evident. Aguayo is not only a researcher and a clinician; he is also a teacher and avid promoter of international science education. In fact, he admits that some of the best years of his professional life have been spent working with IBRO and its training programs worldwide. “These programs build new connections between scientists!” he adds.
Through this involvement, he has helped to promote the neurosciences in countries where few resources are available for biomedical research. “It’s very inspiring to witness the efforts made around the world to acquire and apply knowledge to solve some of the major health problems faced by the population,” says Aguayo.
Six years ago, with the support of IBRO, Canadian investigators created the Canada-IBRO International School of Neuroscience, where Aguayo and others have been actively involved in the training of promising young student-researchers from Africa, Latin America and the Pacific rim of Asia. The next session will take place in Montreal and Quebec City at the end of May in conjunction with the Annual Meeting of the Canadian Association of Neuroscience. This timing will allow the trainees to connect with many Canadian colleagues at the meeting. Most of their stay at the School will involve labs and lectures at McGill and Laval.
“Being involved at this stage of my life in this sort of international teaching is great fun,” says Aguayo. “One of the wonderful things about science is the unique feelings it brings,” he explains. Experienced in savouring moments of breakthrough, he’s inspired to share the marvels of science with others by strengthening communication, collaboration and mentoring. “When you discover something new, however small it may be, you know something that, at least for a moment or two, no one else in the world knows.”