Mini-Brains? Scientists Grow Rice Grain-Sized Brains to Aid Parkinson’s Research

Scientists from Singapore grew "mini-brains" the size of rice grains to aid in Parkinson's research.

The miniature versions of the human midbrain measure about 2 mm to 3 mm long, about the size of a grain of rice, and are said to help scientists in developing treatments for Parkinson's disease and other aging-related brain diseases.

The mini midbrains are made of laboratory-grown tissues, known as brain organoids, containing certain properties of specific parts of the human brain. The three-dimensional tissue is composed of functionally active neurons, with cells than can divide or cluster together, and become electrically or chemically active, just like an actual human brain, The Straits Times Singapore reports.

The study is the first to create a midbrain tissue and the first to create neuromelanin, the black pigment found in the human brain.

The human midbrain is the body's "information superhighway" and controls vision, auditory and body movements. It contains dopaminergic neurons that produce dopamine, which is responsible for some executive functions, motor control, motivation, reinforcement and reward. Low levels of dopamine lead to slowed reactions and Parkinson's disease, which is often characterized by difficulty in moving.

Parkinson's disease is also caused by the decrease in neuromelanin production, which leads to tremors and impaired motor skills.

The scientists said in a press release that the development could provide researchers with material that is affected by the disease itself and enable them to conduct studies in the laboratory instead of relying on simulations and animal experiments.

"Considering one of the biggest challenges we face in PD research is the lack of accessibility to the human brains, we have achieved a significant step forward," Prof. Ng Huck Hui, executive director of A*STAR's Genome Institute of Singapore (GIS) and lead author of the study, said in a statement.

"The midbrain organoids display great potential in replacing animals' brains which are currently used in research; we can now use these midbrains in culture instead to advance our understanding and future studies for the disease, and perhaps even other related diseases."