One of the best ways to understand a machine is to build it yourself. What if you wanted to get to know your brain that way, from the bottom up? It sounds like a tall order, yet the real brain does this automatically.

If you really want to know how to build a brain, take a lesson from the master: Just sit back and watch how nature herself does it.

Step 1: Understand the building blocks

Before you get started, pause for a second to appreciate the complex architecture of just one of them. Neurobiologist Bernd Knoll at the University of Tubingen in Germany and his collaborators used electron microscopy to picture this neuron's cobweb-like cytoskeleton (its interior scaffolding).

The cytoskeleton is made of strings of proteins that constantly stretch and shrink as the neuron sends out projections toward other neurons, making and breaking connections. This neuron is from mouse hippocampus, a part of the brain important in memory, but the ones in the human brain are constructed much the same way.

This article is a sample from DISCOVER's special issue on the brain. The issue will be on sale through December 28, only on newsstands.