From what makes us right or left-handed to why we develop autism, there are many mysteries about the human brain we are yet to solve.
Some of these questions can be answered by studying the brains of other animals like mice, for example.
But this isn’t possible for other phenomena that are unique to human brains.
Researchers are now growing hundreds of tiny human brains in labs, in an attempt to understand what gives us unique disorders like autism and schizophrenia – and the method they use to create these brains is surprisingly simple.
Scientists across the world are developing cerebral organoids, or mini brains, to solve a variety of problems.
Many of these groups are trying to understand other complex neurological diseases that are unique to humans, like autism and schizophrenia.
One such researcher is Madeline Lancaster, who works at the Medical Research Council (MRC) Laboratory of Molecular Medicine in Cambridge.
The brains are created using cells. The team uses skin cells but, they could start with any cell type.
‘The brains develop in the same way you would see in an embryo,’Dr Lancaster told BBC Future.
They turn these cells into stem cells, using proteins, and as these grow, brain cells begin to develop.
The researchers starve the cells and, for an unknown reason, the brain cells seem to be the most robust ones, so they survive.
These brain cells are placed in a special jelly and put into an incubator.
The researchers in Dr Lancaster’s lab are using these brains to study a variety of conditions.
‘Our current interests focus on other neurodevelopmental disorders like autism and intellectual disability, by introducing mutations seen in these disorders and examining their roles in pathogenesis in the context of organoid development,’ Dr Lancaster says on her project page.