Microgravity enhances the viability of midbrain organoids on the International Space Station.

Currently, research groups employ complex in vitro brain organoid models, three-dimensional (3D) structures that mimic aspects of the human brain architecture. These organoids self-organize into small clusters that resemble key features of the developing brain, including functional neural networks, cortical layers, and specific brain regions.

While not perfect replicas of the human brain, organoids are valuable for studying brain development, neurodegenerative diseases, drug testing, and genetic mutations. However, their complexity and size remain limited due to the absence of blood vessels, which restricts nutrient distribution and cell maturation. Additionally, their growth on Earth is influenced by physical constraints, particularly gravity.