Humans are born with a variety of cells. While all of them are absolutely essential for creating us, some cells are more complex and important—like the nerve cells forming our brain. After all, what is a human body is nothing if not for its brain.
Once the brain cells start to deteriorate, with ageing or injury, humans start to lose cognitive and motor functions. Often seen in cases of Alzheimer's and schizophrenia.
But looking inside a living human brain is impossible; you can only dissect a dead brain that doesn’t function. But a group of researchers have overcome this hurdle by building a ‘brain in a dish.’
Scientists have been growing living cells in Petri-dishes for a long time. But this research is leaps and bounds ahead as “organoids,” grown from stem cells, allowed them to conduct extensive genetic analyses. The organoid was allowed to grow for 20 months. They observed it developed in phases, as if on an internal clock, much like the brain of a human infant. This is beyond the former assumption that ‘dish’ brain could only develop till foetal stage.
“Until now, nobody has grown and characterized these organoids for this amount of time, Nor shown they will recapitulate human brain development in a laboratory environment for the most part,” said Daniel Geschwind, author of the study. He adds how this will be incredibly useful as models to study the human brain and diseases as the organoids “mature and replicate many aspects of normal human development.” The study can be found in the journal Nature Neuroscience.
Studying the organoids is helping them understand the physiology and development of diseases like “neurological and neurodevelopmental disorders including autism, epilepsy and schizophrenia.”
The scientists developed these organoids using pluripotent stem cells. These cells are born one but have the ability to differentiate into multiple specific cells like neurons or cardiac and so on. They induced these cells, derived from skin and blood, to grow into neurons. By manipulating the chemical balance, cell-dish environment and so on, these cells not just developed a rough neural network but self-organised into a structure similar to a 3-D brain.