An artificial ‘brain in a dish’ is created that matures ‘just like a human brain’ and can shed light on conditions such as Alzheimer’s and schizophrenia
- Organoids are simplified miniature versions of real organs grown in the laboratory
- They are made from stem cells with the potential to form different cell types
- Brain organoids have already helped experts learn more about autism and epilepsy
- However, it was thought that they would not progress beyond the fetal stage
- This meant that organoids were unsuitable for studying adult diseases such as dementia
- But experts have shown that they can mature and track an internal clock like ours
A “brain in a shell” grown from stem cells in the lab can develop “just like a human brain” – and help shed light on conditions like Alzheimer’s and schizophrenia.
Researchers from the US conducted extensive genetic analyzes of so-called ‘organoids’ that were allowed to grow in experimental dishes for up to 20 months.
They found that the artificial brain appears to grow in stages in accordance with an internal clock – a clock that corresponds to the development of a real baby brain.
The findings suggest that organoids may develop beyond a ‘fetal’ stage, contrary to what was previously believed.
Given this, organoids in the brain could mature so well that they could be used by scientists to study adult-onset diseases such as dementia.
A brain organoid ‘(photo) grown from stem cells in the lab can develop’ just like a human brain ‘- and help shed light on conditions such as Alzheimer’s disease and schizophrenia
US researchers conducted extensive genetic analyzes of so-called ‘organoids’ that were allowed to grow in experimental dishes for up to 20 months
“Until now, no one has grown and characterized these organoids during this time,” said paper author and neurologist Daniel Geschwind of the University of California Los Angeles (UCLA).
“Nor have they been shown to largely recapitulate human brain development in a laboratory setting.”
‘This will be a major boost for the field. We have shown that these organoids can mature and replicate many aspects of normal human development, making them a good model for studying human disease in a dish, ‘he said.
In their study, the team created their brain organoids using so-called induced pluripotent stem cells, which are capable of causing many different cell types.
The stem cells themselves came from skin and blood cells reprogrammed into an embryonic state.
When subjected to the right mix of chemicals in the right environment, the stem cells grow into brain cells and organize themselves to produce three-dimensional structures that faithfully mimic certain aspects of real human brain development.
Researchers are interested in growing organoids from stem cells because they have the potential to revolutionize the way we study how complex organs – such as the brain – both develop and respond to disease.
In fact, scientists are already using human brain organoids to study neurological and neurodevelopmental disorders, including autism, epilepsy and schizophrenia.
However, it has hitherto been believed that the cells in the form of the organoids cannot develop beyond a state similar to that observed during fetal development, limiting the extent to which these models can be used.
The findings of this new study suggest that it might, in fact, be possible for the cells of the organoids to mature enough to allow researchers to also study diseases that start in adulthood, such as dementia and schizophrenia.
“There is enormous interest in stem cell models of human diseases,” says Dr. Geschwind.
“Until now, no one has grown and characterized these organoids during this time,” said paper author and UCLA neurologist Daniel Geschwind. ‘Nor have they been shown to largely recapitulate human brain development in a lab setting’ Pictured, an organoid
“This work represents an important milestone by showing which aspects of human brain development are modeled with the highest fidelity and which specific genes behave well in vitro and when they can best be modeled.”
‘Equally important, we provide a framework based on unbiased genomic analyzes to assess how well in vitro models model in vivo development and function.’
“We show that these 3D brain organoids follow an internal clock, which in a laboratory setting parallels what happens in a living organism,” said author and biologist Aaron Gordon, also from UCLA.
“This is a remarkable finding – we show that they reach post-natal maturity around 280 days in culture, and then they start to model aspects of the early childhood brain, including known physiological changes in neurotransmitter signaling.”
The full findings of the study are published in the journal Nature Neuroscience.