What is a neuron?

What is a neuron?

Quick summary! A neuron is a type of cell located in the brain that transmits information to other neurons through a junction called a synapse. The communication between neurons at synapses in our brain enables us to think and carry out behaviors.


In Latin, the word “cell” means “small room”. A cell is the smallest unit of life. Some life forms, like the bacteria Salmonella, are made up of 1 cell. Other life forms like humans have trillions of cells that work together. We can think of a human as a large skyscraper made up of trillions of rooms and each room has a location and function. A neuron is like a room located in the skyscraper in the communication department. A neuron is a specialized cell that processes and sends information throughout the body.

Similar to how a room is made up of different parts like windows, walls, and floors; a neuron is composed of many parts. In a neuron, dendrites receive information from other cells. If the information in the form of electricity received from the dendrite is strong enough they are passed down a long cable-like structure of the neuron called the axon. The length of the axon can vary from one millimeter to longer than one meter. The axon concludes to the axon terminal that contains messages called neurotransmitters. If we think of a neuron as equivalent to a room in the communication department of a skyscraper, the vesicles in the axon terminal are bins that hold letters and envelopes or messages (neurotransmitters) that can travel from one room to the next.  The brain uses neurotransmitters and electricity as a way to communicate messages.

The neurotransmitters travel from the axon terminal of one cell (often a neuron), through a small gap between cells called a synapse in order to be received by another cell (often a neuron). The cell which sends the message is called the presynaptic cell. The cell which receives the message is called the postsynaptic cell. Synapses are junctions between the presynaptic cell and the postsynaptic cell where messages are sent from one cell to the next in a network of cells that allows for brain processes.  The small space of a synapse is held together by cell adhesion molecules which attach two neurons together. The message is received by molecules called receptors on the surface of the postsynaptic cell. Some of the messages and receptors are excitatory (GO) which tells the postsynaptic neuron to keep on relaying the message to other neurons or to carry out a task. Other messages and receptors are inhibitory (STOP) which tells the postsynaptic neuron to stop the message from continuing to be passed along. This balance of excitatory and inhibitory messages is important for healthy brain communication and function.

Glossary: Dendrites, Dendritic Spines, Axon, Receptors, Neurotransmitters, Neurons, Neurotransmitters, Cell Adhesion Molecules, Glia, Excitatory, Inhibitory


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