Question: what is your brain made out of ???

Keith Brain answered on 16 Jun 2010:

Mostly salty water and fat (lipids).

The basic cells in brain are the neurons (the nerve cells) and then in between them are two other types of cells called astrocytes and oligodendrocytes. Each neurons is about 20 micrometers across … that’s 0.02 of a millimeter, so – very small. So, you can imagine that there are a lot of them. Each neuron communicates with many other neurons, using electrical and chemical signals. Some of this communication is over big distances, so the neurons have long cables called axons coming out of them. Bundles of these axons form the white bits of the brain, while the main parts of the neurons (called the cell bodies) form the grey parts of the brain. So, a living brain is a mixture of grey bits and white bits.