The brain is actually a collection of cells. There are two groups of brain cells, neurons and glia cells. These two groups of cells work together to make sure that our brain can do its job. The brain cells are very tiny, smaller than the eye can see. There are billions of cells in the brain!
Neurons are often thought of as the main cells in the brain because they have a very important job. Neurons communicate with each other so that the brain can do its job.
In some ways neurons are similar to other cells because they have a soma (or a cell body) and a nucleus. The nucleus is very important because it holds the genetic information of a cell.
Neurons are also very different from other cells. All neurons have dendrites and axons, which help neurons communicate with each other.
How do neurons communicate?
Neurons communicate using electricity. A neuron receives information at the dendrites, which builds up electricity in the cell body. If the electric charge is strong enough the neuron will release an action potential. An action potential is a big electric current that flows through the axon, all the way from the cell body to the axon terminals. When the electric current reaches the axon terminals, they release chemicals that send information to the dendrites of other nearby neurons.
Another important part of neural communication are the myelin sheaths. Myelin is a fatty material that is coated around sections of the axon. Myelin insulates the axon so that the electricity can travel through the neuron more efficiently. Sort of like when we cover wires in rubber material to keep all the electricity flowing through the wire.
Types of Neurons
There are different types of neurons depending on where they are located and what type of information they communicate. Three types of neurons are motor neurons, sensory neurons, and interneurons.
- Motor neurons are in the brain and send information to the body to tell us how to move.
- Sensory neurons are in the spinal cord and communicate with the brain to tell us information about our senses.
- Interneurons are like relay neurons, they combine information coming from multiple sources. They also help the motor and sensory neurons communicate.
Neurons are very important, but they wouldn't be able to do their jobs and communicate without the help of glia cells!
Glia cells are the supportive cells in the brain. They don't communicate like neurons, but they have a bunch of other jobs to make sure that the brain is healthy. Sometimes people think that glia cells are less important than neurons, but that isn't true. Without glia cells and a healthy brain, neurons wouldn't be able to communicate!
Three important types of glia cells are microglia, oligodendrocytes, and astrocytes.
Microglia are the immune system of the brain. They protect the brain from disease, locate areas where the brain is damaged, and clear away any waste in the brain.
Astrocytes are large glia cells that help provide structural support to the brain. They also help heal the brain if it is injured.
Oligodendrocytes have one very important job, they coat neuron axons with myelin sheaths in order to speed up the electric currents in neurons.
Goldstein, E.B. (2019). Cognitive psychology: Connecting mind, research, and everyday experience (5th ed.). Cengage.
Kolb, B., Whishaw, I. Q., Campbell Teskey, G. (2000). An introduction to brain and behaviour (6th ed.). Worth Publishers.
Try these activities to go along with what you've learned: