The brain, the organ that performs functions both mysterious and admirable – such as thought, intelligence, or the coordination of movement and of the senses – has more than a billion neurons. These are connected through a complex network of processes. There are chemical transmitters to send messages among themselves. The exchange of information (or ‘transduction of signals’) between cells, occurs at special points of contact, called synapses.
A neuron has 20,000 synapses, thus receiving 20,000 bits of information.
The brain does not feel pain, for lack of specific receptors. In fact, a brain operation may be performed with a fully-conscious patient, with a local anesthetic in the cranium and the meninges.
The brain’s activity is more strained and more frantic than that of the legs in the middle of a race. Only the brain runs all the time; three minutes of neuronal ‘rest’ lead to death.