How newly discovered brain cells have made us rethink the human mind

It’s strange to think that we still don’t know what our brain is made of. Yet, despite decades of research and the development of high-tech scanning techniques, it remains true. Sure, we know the basics. The average human brain weighs about 1.4 kg and has the consistency of soft tofu. It is made up of two general cell types: neurons, which think, and glia, which support them. But beneath this simple description lies a mind-boggling complexity—a complexity that continues to baffle even neuroscientists.

Everyone knows neurons, the cells that send electrical impulses between different parts of the brain. There are about 86 billion of them in your brain and they come in many different types depending on their shape, function and properties. But there’s still a lot we don’t know about them. Take it rosehip neuronswhich were discovered in 2018. Because of their shape, these cells appear to dampen the electrical activity of other neurons. Interestingly, no equivalent cells exist in the brain of mice, despite the fact that mice resemble other cells in the human brain. We don’t really know much about what they do in the human brain, he says. Rebecca Hodge at the Allen Institute for Brain Sciences in Seattle, Washington, who was part of the team that discovered the cells.

Glia, which Also about 86 billion In the human brain, it’s even harder to pin down…