Scots scientists have helped to unlock a secret of the brain that could lead to drug treatments for millions of people living with conditions such as Alzheimer’s Disease and autism.

Scientists from Edinburgh University and the Wellcome Trust Sanger Institute in Hinxton, Cambridgeshire, discovered a collection of 1461 proteins that account for more than 130 brain diseases.

The scientists said their research provides for the first time a comprehensive list of the proteins that set the “centre stage” for common conditions affecting millions of people and could also usher in genetic tests to diagnose certain diseases.

Professor Jonathan Seckl, professor of molecular medicine at the Queen’s Medical Research Institute in Edinburgh, said: “This splendid collaborative study is a major step forward which will surely illuminate the causes of many of the major mental health and neurological disorders that are so common in Britain, as well as indicating ways to develop treatments for these most disabling diseases.”

The brain is the most complex organ in the body, with millions of nerve cells linked by neural connection points called synapses. Inside the synapses, certain proteins bind together to form a bundle of molecules known as the postsynaptic density (PSD).

The scientists studied synapses extracted from people undergoing brain surgery and found that 1461 proteins, each of which is encoded by a different gene, were active inside the connection points.

Studies of animals had indicated that the PSD could be important in human diseases, but until now nothing had been confirmed by tests and this research has allowed researchers to systematically identify the conditions involved.

Professor Seth Grant, of the Wellcome Trust, who led the team, said: “We found that more than 130 brain diseases involve the PSD – far more than expected. These diseases include common debilitating diseases such as Alzheimer’s disease, Parkinson’s disease and other neurodegenerative disorders, as well as epilepsies and childhood developmental diseases including forms of autism and learning disability.

“Our findings have shown that the human PSD is at centre stage of a large range of human diseases affecting many millions of people.”

The study paves the way for others to develop treatments for the most disabling diseases, according to the scientists.

“To help in this objective, the scientists have created a roadmap of the synapses, which shows how the proteins and diseases are connected.

Professor Jeffrey L Noebels, professor of neurology, neuroscience and human genetics at Baylor College of Medicine, said: “Rather than ‘rounding up the usual suspects’, we now have a comprehensive molecular playlist of 1000 suspects.

“Every seventh protein in this line-up is involved in a known clinical disorder, and over half of them are repeat offenders.

“Mining the postsynaptic proteome now gives researchers a strategic entry point, and the rest of us a front-row seat to witness neuroscience unravel the complexity of human brain disorders.”

The research, which is published in Nature Neuroscience, has also shed light on the role the proteins play in learning, memory, emotion and mood, as well as social behaviours and addiction.