University Professor and Nobel Laureate Richard Axel Combines Molecular Genetics With Neuroscience

December 12, 2012

A human nose has the remarkable ability to distinguish among more than 10,000 smells. How it does that was long an enigma until University Professor Richard Axel and his researchers discovered a 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.

medicine for that discovery, which has been described as among the most important in medicine. He shared the prize with Linda Buck, who was a postdoctoral fellow at Columbia when they jointly published a paper on the subject in 1991.

Axel has spent nearly his entire adult life at Columbia. A 1967 graduate of Columbia College, he attended medical school at Johns Hopkins University and quickly returned to Columbia as a professor of pathology and biochemistry.

“I can only accept the Nobel Prize in trust, as a representative of a culture of science in my laboratory and at Columbia University, where I have received enormous support over the years,” Axel said in 2004.

In his research, Axel explains that the sense of smell is possible because neurons directly connect the brain to the outside world. Receptors on the neurons of the nose pick up odors from the environment and send that information directly to the olfactory bulb, the first relay station in the brain.

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. Each molecule activates several odorant receptors, leading to a combined odorant pattern, which allows us to recognize and form memories of approximately 10,000 different smells. For example, the combination of receptors activated when we smell a rose tells us that it smells nice, as opposed to the feedback we would get from the combination of receptors activated by rotting fish.

The sense of smell also is essential to the survival of most species, which 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.

Dr. Axel's groundbreaking discovery solves the puzzle of how we translate the sensations around us into knowledge that is key for our survival and quality of life.

His research with Buck combined molecular genetics with neuroscience in order to approach the previously tenuous relationship between genes, perception and behavior. They asked how the brain builds an internal representation of the external sensory world and how the recognition of olfactory stimuli might lead to meaningful thoughts and behaviors.

Dr. Richard Axel is currently 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.