(Originally published by Columbia University)
October 4, 2004
Richard Axel, M.D. of Columbia University Medical Center has won the 2004 Nobel Prize in Physiology or Medicine along with Linda B. Buck, Ph.D., of the Fred Hutchinson Cancer Research Center for clarifying how the olfactory system works. Dr. Buck was a postdoctoral fellow at Columbia when she and Dr. Axel jointly published the fundamental paper on the subject in 1991.
The sense of smell has remained the most enigmatic of the senses. The work of Drs. Axel and Buck has provided understanding on how the nose is able to distinguish more than 10,000 distinct smells. The researchers discovered a gene pool of more than 1,000 different genes that encode olfactory receptors in the nose. This is believed to be the largest gene family in the human genome.
“I'm deeply honored and very pleased,” said Dr. Axel. “This honor represents the long efforts of the many faculty, students and fellows who have worked within our laboratories at Columbia University Medical Center. I have received enormous support over the years beginning with the scholarship I received to attend Columbia College. I have to also thank the National Institutes of Health and the Howard Hughes Medical Institute that allowed the performance of truly novel experiments by our research team.”
Dr. Richard Axel is University Professor, Columbia University, Investigator, Howard Hughes Medical Institute at the College of Physicians & Surgeons, Columbia University Medical Center, Investigator, Kavli Institute for Brain Science at Columbia University, and Member of the Center for Neurobiology and Behavior, Columbia University Medical Center. He has been at Columbia University Medical Center his entire career, and was an undergraduate at Columbia College.
Axel and Buck join a group of 70 notable Columbians whose work has been recognized by the Nobel Foundation, including 19 in the category of physiology or medicine.
“Columbia University is honored that our esteemed faculty member, Richard Axel, has received the Nobel Prize for his pioneering studies clarifying how our sense of smell works,” said Columbia University President Lee C. Bollinger. “Dr. Axel’s groundbreaking research solves the puzzle of how we translate the sensations around us into knowledge that is key for our survival and quality of life.”
“Dr. Axel’s work is among the most important discoveries of the past 50 years, providing insights regarding how individuals perceive their external environment,” said Gerald D. Fischbach, executive vice president, Columbia University Medical Center. “He has been an enormously important influence for all the sciences here at Columbia University, the medical center and the College of Physicians and Surgeons. His wide range of interests and enormous skills in molecular biology have influenced faculty throughout the university.”
"We congratulate Richard and Linda for their profoundly important discovery, and for the way in which they achieved it,” said David Hirsh, executive vice president for research at Columbia University. “Their experiments represent the highest form of creativity, scientific discipline and scholarship. This is science at its most beautiful."
The sense of smell is possible because neurons directly connect the brain to the outside world. In the nose, receptors on the neurons pick up odors from the environment and send that information directly to the olfactory bulb, the first relay station in the brain. Drs. Axel and Buck determined how neurons converge in the olfactory bulb, which gave them further insights into how smell is processed in the brain. Each olfactory receptor cell possesses only one type of odorant receptor, and each receptor can detect a limited number of odorant substances, so the olfactory receptor cells are highly specialized for a few odors. Most odors are composed of multiple odorant molecules, and each odorant molecule activates several odorant receptors, leading to a combined odorant pattern, which allows us to recognize and form memories of approximately 10,000 different odors. The combination of odorant receptors activated when we smell a rose tell us that it smells nice and is different from the combination of receptors activated by rotting fish.
The sense of smell is essential to the survival of most species, who use their olfactory systems to identify food, smell predators and observe and interpret their environments. In humans, smells warn us if food has gone bad and can be powerful enough to trigger distinct memories years later.
Axel and his colleagues also developed gene transfer techniques that permit the introduction of virtually any gene into any cell, allowing the analysis of gene function in vivo. These experiments in cell transformation led to the isolation and functional analysis of the gene for the T-cell surface protein, CD4, the cellular receptor for HIV. He then began to apply the techniques of molecular biology to problems in neurobiology. He identified the peptide genes responsible for eliciting an innate behavior in a marine snail, and molecular analysis of these genes suggests how diverse behavioral patterns may be encoded in the genetic material and inherited from parent to offspring.