Two researchers from the U.S. who described the genes that give us our sense of smell have won the 2004 Nobel Prize for Physiology or Medicine.

Richard Axel, 58, of Columbia University in New York, and Linda Buck, 57, of the Fred Hutchinson Cancer Research Center in Seattle will be awarded the $1.3-million US prize.

The pair found a family of 1,000 genes and receptors for the sense of smell, which the jury said clarified the olfactory system from the molecular to cellular level.

Linda Buck (file photo)

"A good wine or a sun-ripe wild strawberry activates a whole array of odorant receptors, helping us to perceive the different odorant molecules," the Nobel Assembly at the Karolinska Institutet in Sweden said in its citation.

The scent of a flower, for example, brings a mix of molecules into the nose, turning on odour receptors. Our brains interpret the pattern to recognize and form memories of about 10,000 different odours, the assembly said.

"A unique odour can trigger distinct memories from our childhood or from emotional moments – positive or negative – later in life," the jury said.

Richard Axel (file photo)

The research may not have any medical or scientific applications, but the studies could explain why scents often remind us of childhood.

Scientists needed the tools of DNA technology to find the microscopic cells and proteins behind our sense of smell.

The sense of smell is essential for newborn mammals to find their mother's teat and feed on milk.

In 1991, Axel and Buck published a study on the 1,000 odour receptors in mice. Humans have far fewer receptors for our more limited sense of smell.

Axel and Buck are both investigators with the Howard Hughes Medical Institute.

The award is named for Alfred Nobel, the Swedish inventor of dynamite, who left an endowment to fund the prize.

The Nobel Prize for physics will be announced on Tuesday, followed by chemistry on Wednesday, literature likely on Thursday, peace on Friday and economics next Monday.

The awards are always presented on Dec. 10, the anniversary of Nobel's death in 1896.