Researchers at the University of California - San Diego have developed biological cells that can give insight into the chemistry of the brain, in a breakthrough study.
The scientists used the cells, which change color when exposed to specific chemicals, to show how a class of schizophrenia drug works.
The team is hopeful that the discovery could help shed light on many other drugs work on the brain. class of drugs called atypical neuroleptics has become commonly prescribed for schizophrenia, in part because they seem to improve problems like delusions, hallucinations and dementia linked with the neurodegenerative disease.
But, not much was known about how they altered brain chemistry.
It was known that the drugs trigger the release of a large amount of a chemical called acetylcholine, which enables brain cells to communicate with each other.
However, the drugs have also been shown to hobble a receptor on the surface of the receiving cell, which would effectively block the message.
The San Diego team designed biological cells - called CNiFERs - which changed colour when acetylcholine latched onto this particular class of receptors.
It was the first time that scientists observed such an event in a living brain.
They implanted the cells into rat brains, and then stimulated a deeper part of the brain in a way known to release acetylcholine nearby.
This made CNiFERs change colour, proving that they were working.
They then gave the rats one of two atypical neuroleptics and found that in both cases the drug severely depressed the response from the CNiFERs.
This suggested that the drugs' receptor-blocking action over-rides the increase they trigger in acetylcholine.
Researcher Professor David Kleinfeld said the new cells had great potential to reveal the mysteries of chemical action in the brain.
"It's a world of signalling between cells that we were blind to before," the BBC quoted him as saying.
The study has been published in Nature Neuroscience.