A Gene May Explain Why Human Brains Take Years to Grow

Neuron Development and the SRGAP2 Gene

According to НВ — Техно: Published: September 1, 1:33 PM

At Columbia University's Zuckerman Institute, researchers have discovered that microglial cells in the human brain take four to eight years to reach maturity. That's a striking contrast with mice, where the equivalent process wraps up in roughly three weeks. A key factor appears to lie in human-specific copies of a gene called SRGAP2. This gene is highly active in microglia, encouraging the creation of more synapses while simultaneously slowing down their maturation.

SRGAP2's Role in Shaping Neural Connections

Experiments suggest SRGAP2 helps set the pace at which both neurons and microglia develop, allowing these different cell types to grow in sync. Microglia serve an essential immune role in the brain, helping decide which neural connections stay and which should be pruned away. The researchers do not believe SRGAP2 is what determines intelligence or the overall complexity of the human brain. However, they point out that the extended maturation timeline may be tied to a concept known as neoteny, where juvenile traits persist into adulthood.

Moving forward, the team plans to dig deeper into how SRGAP2 controls microglial maturation and to explore whether the gene is linked to neurological or neurodegenerative conditions. Those findings could reshape current understanding of brain development and function.

The study underscores how genetic factors contribute to the formation of the human brain. Because microglia play a central role in maintaining neural connections, this work may also offer new angles for treating neurological disorders. Further research along these lines could dramatically change how we view brain development and how it continues across the lifespan.

As researchers delve deeper into the intricacies of brain development, it's noteworthy to consider the advancements in understanding lab-grown brain structures. For instance, Harvard's ongoing work with a seven-year-old brain organoid showcases how artificial models can evolve and provide insights into human brain maturation. To explore this fascinating parallel in brain research, read more about the developments in lab-grown brain organoids.