The complexity of the brain is in how these cells communicate with each other and how they change as a function of experience and as a function of your genetic makeup. If we were to look inside the brain, you actually couldn't see very much because most of the brain is translucent. But if you stain the cells in a certain way, so that they take up dyes, you can see them under the microscope. The nucleus within nerve cells is where all the genetic information is contained. These genes, the DNA in the nucleus of each cell, are affected by your daily experiences and constantly keep these cells functioning, keep them alive, and keep them responding to changes in their environment.
Nerve cells are quite small.
If one were the diameter of a hair on your head, then the brain would be about four times the size of this entire medical complex. So these are tiny cells and they are packed in the brain in precise order. It is this type of incredible connectivity that we all seek to understand. These cells talk to each other by contacts called synapses-one nerve cell reaching out through a branch, called an axon, to other cells. These contacts are called synapses.