Quick Answer. Voltaire wrote Candide as a satire of the then-prevalent philosophical optimism advanced by Gottfried Wilhelm Leibniz. Voltaire, moved by contemporary events like the Seven Years' War and the 1755 Lisbon earthquake, felt that optimism was a naive way of viewing the world.
Neurons carry impulses from one place to another, around the many parts of the nervous system. They connect receptors to the central nervous system and also connect one part of the nervous system to another, for example in the brain and spinal cord.
Each neuron consists of a cell body or perikaryon, from which arise the nerve fibers. And each neuron has two kinds of fibers: a single axon, which conveys nerve impulses away from the cell body, and one or more dendrites, which convey nerve impulses towards the cell body. Neurons are functionally linked by their fibers at connections called synapses. All neurons are post-mitotic.