Washington, June 1 (IANS): Scientists have perfected mini-cultured 3D structures that grow and function much like the outer tissue (cortex) of the brain of the person from whom they were harvested.

Strikingly, these "organoids" buzz with neuronal network activity where cells talk with each other in circuits much as they do in our brains.

This evolving "disease-in-a-dish" technology is bringing closer the day when patients can ask for personalised medicines, said the study, funded by the US National Institutes of Health (NIH).

"The cortex spheroids grow to a state in which they express functional connectivity, allowing for modeling and understanding of mental illnesses," said Thomas R Insel, director of the National Institute of Mental Health.

Prior to the study, scientists led by Sergiu Pasca of the Stanford University had developed a way to study neurons differentiated from stem cells derived from patients' skin cells.

They had even produced primitive "organoids" by coaxing neurons and support cells to organise themselves, mimicking the brain's own architecture.

Based on a streamlined method, Pasca's team's cortex-like spheroids harbour healthier neurons, resulting in more functional neural connections and circuitry.

Like the developing brain, the neurons form layers and talk with each other via neural networks.

"While the technology is still maturing, there is great potential for using these assays to more accurately develop, test safety and effectiveness of new treatments before they are used in individuals with a mental illness," said David Panchision, programme director for stem cell research.

The paper appeared online in the journal Nature Methods.