The number of different pathways between neurons (nerve cells) in the human brain is astronomical. This is because neurons have so many interconnections; one neuron may connect up with over one hundred thousand others. “The figure of possible connections within our modern brain is as good as infinite,” states Anthony Smith in his book The Mind. It is larger “than the total number of atomic particles that make up the known universe,” says neuroscientist Thompson.

A NEURON is a nerve cell with all its processes. Your nervous system contains many types of neurons, which total about 500 billion.