A breakthrough in the treatment of schizophrenia has been heralded by a discovery about the way human brain cells influence each others' behaviour.

The findings of scientists at the University of Toronto, the Centre for Addicition and Mental Health, and the Hospital for Sick Children, has altered the understanding of the way that brain cells accept or reject the neurotransmitter dopamine.

Dopamine is a chemical found naturally in the brain, which in excess or deficiency is associated with schizophrenia and addiction.

Different types of neurotransmitter

Brain cells communicate with each other via neurotransmitters - natural chemicals that interact with proteins, or receptors, on adjacent cells.

There are many different types of receptors in the brain, some of which only respond to dopamine, and some which only respond to the neurotransmitter GABA (g-aminobutryic acid).

One of the many dopamine receptors, D5, has been found to be able to directly modify the function of a GABA receptor by binding with it.

Crucially for the possible future treatment of schizophrenia, scientists believe that they may be able to either halt or prompt the interaction, therefore affecting the amount of dopamine absorbed.

Senior author of a report of the findings, to be published in the scientific journal Nature on Thursday, Dr Hyman Niznik, said: "This may provide us with a new therapeutic window on how to restore normal cellular function in diseases like schizophrenia with the right medication that can either block this interaction or make it happen."

Search for malfunction

Lead author Dr Fang Liu added: "Our next step will be to demonstrate that there is a malfunction in this coupling phenomenon between the neurotransmitter receptor proteins in the brains of schizophrenics."

Spokesman for the UK charity, the National Schizophrenia Fellowship, Paul Corry, said that any advancements were welcome.

He said that current medications for the condition worked by barring the re-absorption of dopamine in the brain, and could sometimes have debilitating side-effects.

But he warned that new treatments from this particular finding could take years to achieve.

He said: "Any research breakthrough of this kind is very welcome in the field of schizophrenia, and that's because so little is known about the causes of it.

"But the immediate priorities are for increasing awareness and improving care in the community."