Scientists develop brain organoid model to study microlytes and brain environment
Microlytes are specialized immune cells found in the brain that play a crucial role in development and disease. However, studying them has been a challenge as they lose their function outside the brain environment. But scientists from the Salka Institute have developed an organoid model to overcome this limitation. The model is a three-dimensional set of cells that imitates human tissue features, allowing them to investigate the development and functioning of microlytes in living tissue obtained from human cells.
The researchers have also studied microlytes obtained from patients with macrocephalous autism, a condition where the child’s circumference is larger than 97% of other children, to determine the relationship between immune cells and the brain in the development of more reactive microglia. The study results, published in Cell, emphasize the importance of understanding the interactions between immune cells and the brain in neurodegenerative and developing diseases like Alzheimer’s and autism.
Salka Institute’s Professor, grows Gage, who is also the senior author of the article, said: “We found a way to create a brain organoid that contains mature microlytes and allows us to study it. So we finally got a tool in order to see how a healthy and sick brain affect microlytes and vice versa.”
The scientists used a new transplant technique to create a brain organoid with microlytes and the brain environment. They found that Sall1 protein appears eleven weeks into the development, confirming the identity and maturity of microlytes. They also discovered that factors of the brain environment, such as the proteins of TMEM119 and P2RY12, are necessary for the functioning of microlytes.
Using this new model, the scientists studied the influence of the brain environment on microglia in autism. They compared the microglia obtained from skin samples of individuals with macrocephalous autism with those from neurotypical individuals. They found that those with autism had faster growth and more complex branches than their neurotypical counterparts, with such changes in the brain environment influencing microglia development and making it more reactive to damage or invasion. These findings may help understand the inflammation of the brain in some people with autism.
Although the result of the study is preliminary with a small sample size, the scientists plan to study more microlytes from additional people in the future to confirm their findings. They also intend to extend their research on other developing and neurodegenerative diseases to determine how microglia contributes to the origin of such illnesses.