Organoid research reveals: the brain is born with a preset "operating system"

A joint team from the University of California, Santa Cruz, Johns Hopkins University, and a number of institutions in Germany and Switzerland revealed that the brain is born with a preset "operating system" with the help of a miniature human brain tissue model called organoids. The latest study, published in Nature Neuroscience, subverts traditional cognition, showing that the brain's earliest neuronal firing occurs in a structured pattern and does not rely on any external experience at all. This finding suggests that the brain presets basic "instructions" on how to interact with the world before a person is born.

Humans have long wondered: When did thinking begin to form? Is the brain innately configured, or are thought patterns formed only gradually with sensory experience of the world around them? The brain works like a computer, relying on electrical signals from neurons to "discharge" for information transmission. However, when these signals began to be produced has been difficult to delve into because the early-developing human brain is protected in the mother's womb and cannot be directly observed.

In this study, the team guided stem cells to develop into brain tissue, which then used specialized microelectrode arrays similar to computer chips to record their electrical activity. In the process of observing brain tissue self-assembly from stem cells into complex structures capable of processing sensory information and eventually producing language and conscious thinking, it was found that in the first few months of development, long before the human brain can receive and process complex external sensory information such as vision and hearing, its internal cells have begun to spontaneously emit electrical signals with specific patterns. The patterns of these signals are strikingly similar to the characteristic patterns exhibited when processing sensory information.

While looking at the firing activity of individual neurons in organoids, the team found that even without receiving any sensory input from the outside world, the neuronal network is able to spontaneously produce complex and time-series characteristic firing activity. This strongly suggests that there is an inherent developmental blueprint determined by genetic coding in the neural structure of the living brain.

Understanding the basic neural structure of the brain that organoids can spontaneously produce opens up many possibilities for better understanding human neurodevelopment, neurological diseases, and the effects of environmental toxins on the brain. These models have the fundamental ability to capture complex neurodynamics that are likely to be closely related to certain pathogenesis. In the future, the team will explore the development of new compounds, drug therapies or gene editing tools at the preclinical level.

【Editor-in-Chief】

When the seeds are still buried deep in the soil, they have the "potential" to break through the soil. This is not the acquired "learning" of seeds, but the underlying program of life evolution written into genes. In the same way, at the beginning of the human brain's development, neurons can spontaneously emit complex electrical signals to initially interact with the world and prepare for the subsequent processing of more complex external sensory signals, which is also determined by the underlying coding of human genes. In other words, the brain of a newborn baby is not a blank sheet of paper, but a "factory setting" preset by genes for the human brain. This discovery will help scientists better understand the mechanisms of human brain development and is expected to provide inspiration for the use of gene editing and other means to treat congenital neurological diseases.