While it's true that glial cells are incredibly numerous in the brain, they don't take up half of the brain's volume.

Here's a breakdown:

* Neurons are the cells responsible for transmitting information in the brain. While there are fewer neurons than glial cells, they are larger and more complex. They also take up a significant amount of space due to their long axons and dendrites.

* Glial cells are supporting cells that play various roles, including providing structural support, regulating the environment around neurons, and supplying nutrients. While they are numerous, their smaller size means they don't occupy the same volume as neurons.

It's estimated that neurons and glial cells contribute roughly equally to the brain's volume.

So, while glial cells outnumber neurons, it's not accurate to say they take up half the brain's volume.