How to Build a Neuron

The neuron is simply another term for a brain cell. Cells, as we know, are the teeniest components of all living animals, at least in terms of a functional unit (genes are of course smaller). Neurons are unique because they are excitable and they are found nowhere else in the body: if they were, we might have thinking body parts which would definitely upset the order of things (except for sensing neurons in our gut). Neurons constitute heterogeneous and diverse populations whose morphology (body shape) is uniquely tailored to the specific functions they perform. Their basic organisation does however generally maintain across the different varieties of neuron and includes a cell body that is the molecular factory and energy source of the neuron, an axon that is a tentacle-like structure that extends from the cell body to make contact with other neurons (although there are unique exceptions to this—VENs, see Chap. 8), and branching tree-like structures termed dendrites that form contact points for the axons of other neurons. Neurons are the elemental component of our Central Nervous System (CNS) and, importantly, the term CNS refers to both brain and spinal cord. So let’s build a neuron.