STOCKHOLM. Oct 9: A Swede and two Americans won the 2000 Nobel prize for medicine today for studies on how-messages move around the nervous system, making It possible to develop drugs against Parkinson s disease and schizophrenia, reports Reuters.

Arvid Carlsson of Sweden and Paul Grerngard and Erick Kandel of the United States share the first Nobel prize of the millennium, worth nearly one million dollar for their discoveries, Sweden's Karolinska Instl-| tutesald.

These discoveries have been crucial for an understanding of the normal function of the brain and how' disturbances in this signal transduction can give rise to neurological and psychiatric diseases." the institute said.

Messages between nerve cells in the brain, which number more than 100 billion, are carried by chemical transmitters, with messages transmitted at special points of contact between the cells called synapses.

One of these chemical messengers is a hormone-like substance called dopamine, which when present in certain quantities allows the brain to function normally.

Carlsson. 77, former professor of Pharmacology at the University of Gothenburg. Is rewarded for his pioneering studies going back to the 1950s that dopamine is an important transmitter in the brain, the institute said.

His research led to the realisation that Parkinson's disease, in which the victim loses control of body movements. Is caused by a lack of dopamine in certain parts of the brain and that an efficient remedy, called L-dopa. could be developed.

Carlsson, the first Swedish Nobel laureate since 1982, made several other discoveries further clarifying the role of dopamine in the brain, showing how drugs that can be used to treat schizo-

phreniavvork.

Ralf Pettersson, chairman of the Karollnska Institute s Nobel committee, hailed Carlssons works as 'magical.' relieving the suffering of millions.

Parkinsons used to be a disease of which people would die. a horrible death, often by suffocation.' Pettersson said.

There are millions of Parkinson's patients around the world. These people now can get acute symptoms treated with L-dopa ... That's almost a magical thing."

Greengard. 74. and head of the Laboratory of Molecular and Cellular Neuroscience at Rockefeller University, New York, is rewarded for his discovery of how dopamine and a number of other transmitters act on the nervous system, the institute said.

Greengard studied the way chemical signals operate in something called "slow synaptic transmission" which Is important for alertness and mood. Slow synaptic transmission also controls fast synaptic transmission which makes speech, movement and sensory perception possible.

Greengard's work increased understanding of the action of several drugs and Is Important for the way antl-psychotlc drugs work, said psychiatry professor Marie Asberg.

This made it possible for the pharmaceutical Industry to discover drugs that work In tills way and don t do a lot of other things too." she said.

/Xustrian-born Kandel. 70. director of Columbia University's Center for Neuroblolo&’ and Behavior. Is rewarded for his discoveries of how the efficiency of synapses can be modified. and how changes affect learning and memory. It said.

His work derives from his research Into the way a sea slug, which has far fewer nerve cells than a mammal, develops certain refiexes, which is a form of learning.

Building on Greengard's research Into the action of proteins in synaptic transmission, Kandel demonstrated where memory Is located and how it Is lost, making It possible in future to develop new drugs for dementia diseases such as Alzheimer's.