Findings on how memory works earn prize for three

Three scientists who have explored the inner workings of the brain and its chemical secrets have shared this year's Nobel Prize for Medicine. The award, with a cash prize of just under £800,000, goes to Dr Arvid Carlsson, emeritus professor of pharmacology at the University of Goteborg, Sweden, Professor Paul Greengard of Rockefeller University, and Professor Eric Kandel of the Centre for Neurobiology and Behaviour at Columbia University.

Each worked independently on the processes of the brain and nervous system. Although their discoveries came in the 1960s and 1970s, their groundbreaking research has opened up many potential new avenues of treatment for conditions such as Parkinson's and Alzheimer's Diseases.

Prof Carlsson made huge strides in helping doctors understand the importance and role of dopamine in the brain. His early work opened the way to the discovery of dopamine depletion in Parkinson's, and its subsequent treatment with L-dopa.

In the 1960s his group developed a drug used for depression, the first clinically active inhibitor of another messenger chemical, or neurotransmitter, called serotonin. This work contributed to the development of similar inhibitor drugs such as Prozac.

Prof Greengard devoted more than 40 years to the study of how nerve cells communicate on a biochemical level. In the 1970s he revealed new information about how dopamine affects the brain. He tracked down the complex signalling pathways used by the chemical.

His work has had application in the treatment and study of Parkinson's, schizophrenia and Alzheimer's.

Prof Kandel helped to uncover the hidden processes behind the human mind, particularly the molecular mechanisms that underlie the acquisition of memory. In the mid-1970s his team discovered the importance of serotonin to the memory process.

The work helped to show how serotonin triggered reactions between cells in the brain. These served to strengthen the electrical connections between cells for several minutes, a process that provides the foundation of short-term memory.

He later found genes that play a key role in the conversion of short-term to long-term memory. An understanding of this process should help doctors in their attempts to understand the memory loss suffered by Alzheimer's patients.

Together their research represents a watershed in our understanding of the mind.