The brain, in some ways, is simply the biological device that keeps a body running and the mind thinking. In that way it is like a computer. An international team of scientists has discovered striking similarities between the human brain, the nervous system of a worm, and a computer chip. The finding is reported in the journal PloS Computational Biology Monday.
The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as jellyfish and starfish have a decentralized nervous system without a brain, while sponges lack any nervous system at all.
Brains can be extremely complex. The cerebral cortex of the human brain contains roughly 15 to 33 billion neurons, perhaps more, depending on gender and age, linked with up to 10,000 synaptic connections each. Each cubic millimeter of cerebral cortex contains roughly one billion synapses.