Thread by @ShiningScience

🧠 New research suggests that conditions like autism and schizophrenia may start developing before birth. Scientists examined nearly 1,000 donated human brains and tracked when key chemical tags on DNA — known as methylation marks — changed in the brain’s cortex. They found that most of these changes happen prenatally, especially during the early weeks of pregnancy.

These DNA changes are critical because they help brain cells specialize, connect and form networks — and some of the affected genes are linked to autism and schizophrenia. The findings suggest that the “window” for what can influence brain development is even earlier than we thought.

This gives us a new perspective on how and when such neurodevelopmental conditions may begin, and it highlights the importance of studying prenatal brain development as we look for ways to understand and potentially intervene.

#Neuroscience #Autism #sciencenews

Most of what shapes our brain may begin before we’re even born.

Researchers from the Lieber Institute for Brain Development and their collaborators analyzed DNA from nearly 1,000 human brain samples, covering both prenatal and postnatal stages. They focused on DNA methylation — tiny chemical tags that control which genes are switched on or off.

What they discovered is remarkable:

👉 The majority of DNA methylation changes happen before birth, especially during early pregnancy when brain cells are first forming.

👉 These changes differ across specific cell types in the cortex — the part of the brain responsible for memory, reasoning, and emotions.

👉 Some of the genes showing early methylation changes are strongly linked to autism and schizophrenia, suggesting that the biological roots of these conditions start developing in the womb.

In simple words, the study shows that the foundations for complex mental functions — and even the risk of certain psychiatric conditions — are built much earlier than we ever imagined. It emphasizes how crucial the prenatal environment is for lifelong brain health and opens a new window for understanding — and perhaps one day preventing — disorders like autism and schizophrenia.

What they discovered is remarkable:

👉 The majority of DNA methylation changes happen before birth, especially during early pregnancy when brain cells are first forming.

👉 These changes differ across specific cell types in the cortex — the part of the brain responsible for memory, reasoning, and emotions.

👉 Some of the genes showing early methylation changes are strongly linked to autism and schizophrenia, suggesting that the biological roots of these conditions start developing in the womb.

In simple words, the study shows that the foundations for complex mental functions — and even the risk of certain psychiatric conditions — are built much earlier than we ever imagined. It emphasizes how crucial the prenatal environment is for lifelong brain health and opens a new window for understanding — and perhaps one day preventing — disorders like autism and schizophrenia.

📘 Journal Reference:

Franklin, A., et al. (2025). Cell-type-specific DNA methylation dynamics in the prenatal and postnatal human cortex. Cell Genomics.

🔗 Read full paper:
sciencedirect.com/science/articl…