Human Neural Tube Model Developed

A collaborative effort led by researchers from the University of Michigan has resulted in the development of a stem cell culture method that produces a full model of the early stages of the human central nervous system. Published in Nature, this innovative model offers a detailed understanding of human brain and spinal cord development, shedding light on potential implications for various disorders.

"We try to understand not only the basic biology of human brain development, but also diseases—why we have brain-related diseases, their pathology, and how we can come up with effective strategies to treat them," said Guo-Li, a co-author of the study, who also developed protocols for growing and guiding the cells and characterized the structural and cellular characteristics of the model.

Already, human brain and spinal cord organoids are used to study neurological and neuropsychiatric diseases, but they often mimic one part of the central nervous system and are disorganized. The new model, in contrast, recapitulates the development of all three sections of embryonic brain and spinal cord simultaneously, a feat the team says has not been achieved in previous models.

The model started with a row of stem cells roughly the size of the neural tube found in a 4-week-old embryo—about 4 millimeters long and 0.2 millimeters in width. The team stuck the cells to a microfluidic chip that they then used to introduce materials that enabled the stem cells to grow and guided them toward building a central nervous system.

A gel was then added to coax the cells to grow in three dimensions and chemical signals that nudged them to become the precursors of neural cells. In response, the cells formed a tubular structure. Next, the team introduced chemical signals that helped the cells identify where they were within the structure and progress to more specialized cell types. As a result, the system organized itself to mimic the forebrain, midbrain, hindbrain, and spinal cord in a way that mirrors embryonic development.

Looking ahead, the researchers aim to leverage this model to study a range of human brain diseases using patient-specific stem cells. The potential applications extend to investigating interconnections within the developing brain and understanding neural signaling pathways related to movement control.