Scientist whose work led to the development of drugs for Parkinson's disease

Born: January 25, 1923;

Died: June 29, 2018

ARVID Carlsson, who has died aged 95, was a scientist whose discoveries about the brain and the working of the chemical dopamine led to the development of drugs for Parkinson's disease. His work earned him a Nobel prize.

Starting his research in the 1950s, Carlsson discovered that dopamine, which had been thought to have little significance, was in fact an important neurotransmitter - a chemical that transmits signals across the brain. He then found that dopamine is concentrated in the basal ganglia, the region of the brain that controls movement.

Investigating further through experiments on rabbits, Carlsson observed that the animals lost their ability to move when their levels of dopamine were lowered and recovered their mobility when they were given L-dopa, a drug which can increase levels of dopamine. This led Carlsson to conclude that Parkinson's disease, which can lead to people losing the ability to move, was related to the loss of dopamine. All Parkinson's drugs still work today by increasing dopamine in the brain.

Carlsson was recognised by the Nobel Prize committee for his work in 2000, sharing the prize in physiology or medicine with two American researchers Eric Kandel and Paul Greengard.

Speaking about the prize in 2016, Carlsson said recognition of the importance of dopamine had felt inevitable. "Dopamine is involved in everything that happens in our brain, all the important functions" he said. "If you look at the number of citations dealing with dopamine over the decades, it was going up all the time, dramatically, and finally it was so high that the Nobel assembly couldn't avoid me."

The third of four children, Avrid Carlsson was born in Uppsala, Sweden, to a historian father and scholar mother. From the start though, Carlsson was interested in science and studied medicine and pharmacology at the University of Lund.

He had just begun his clinical training when in 1944 he was recruited to help treat thousands of prisoners from Nazi concentration camps who had been evacuated to Sweden. Carlsson found it a traumatic experience. "Most shocking was their mental status," he said. "They behaved like wild animals, obviously suffering from severe anguish and suspiciousness and trusting nobody."

Carlsson received his medical degree and a doctorate in pharmacology in 1951 and remained at the University of Lund as an associate professor. However, it was on moving to the National Heart Institute in the US that he started the work that would led to his Nobel prize.

He became a professor at the University of Gothenburg in 1959 and a professor emeritus in 1989. He was admitted to the Royal Swedish Academy of Science in 1975 and received the Japan prize in 1994.

In his later years, Carlsson was a critic of the flouridation of water supplies because he said there was no way to regulate the dose.

Arvid Carlsson was married and had five children.