The brain is a patchwork of several cell types, each with special characteristics of its own. Neurons and glia, which are non-neuron cells, make up the majority of brain cells.
An adult human brain typically has 100 billion neurons and an equal or greater number of glia.While neurons are the most well-known brain cells, glial cells are also essential for healthy brain function.
Neurons
Most likely, neurons come to mind when you think about the brain. Neurons are the cells in the brain that send and receive electrical and chemical signals.
They serve as the building blocks of your brain and carry messages from them to other neurons, muscles, and other tissues.They allow you to think, feel, move, and comprehend the world around you.
Three main components make up a neuron: the soma, or cell body; branching dendrites, which receive messages from other neurons; and the axon, which uses the axon terminal to deliver signals to neighboring neurons.
Electric and chemical impulses travel over a tiny gap known as the synapse from the axon of one neuron to the dendrites of another neuron when a neuron fires an action potential.
Labeled-neurons-basics
Glia
Glia are significant nervous system cells, much like neurons are. Scientists used to think that glia were like glue, only for holding the neurons in place.
The word “glia” means “glue” in Latin. Glial cells, however, are more than just brain glue, as we now understand. In actuality, glia are essential to the normal operation of neurons and actively take part in brain transmission.
Glial cells are not inert just because they are unable to produce action potentials to convey signals, unlike neurons. Glia communicate to each other and to neurons using chemical signals, and can even respond to many of the same chemicals that neurons can, such as ions and neurotransmitters.
This implies that glia have the ability to listen in on neurons to enhance the signals that are exchanged between them. The brain contains a wide variety of glial cell types.
Three significant glial cell types are as follows:
Oligodendrocytes:
The axons of neurons are encircled by a unique kind of glial cell called an oligodendrocyte, which forms the myelin sheath.Like insulation around an electrical wire, oligodendrocytes insulate the axon and help neurons pass electrical signals at incredible speed and over long distances.
microglia-basics-cartoonThe immune cells that make up the central nervous system are called microglia.They are continually in motion within the brain, interacting with other glia. Microglia in an adult brain in good health are continuously scanning their surroundings for indications of problems.
For instance, neurons that are killed or injured by an illness or disease will emit chemical warning signals. When other microglia in the vicinity detect these signals, they become aware of possible danger.
As a result, the nearby microglia gather in the hazardous region and start to clear the mess.
This shields the brain from chronic inflammation and stops accumulation of debris from spreading throughout the brain. Once the danger has passed, microglia go back to their resting state, continuing to survey the brain.
Astrocytes are star-shaped cells that envelop and facilitate the operation of neurons.Astrocytes mainly help regulate the brain environment.
Astrocytes help neurons communicate with each other by moving chemicals from one neuron to another. Even though microglia are the brain’s main immune cells, astrocytes can support microglia in times of need.
Research Highlight
Glial cells have been found to have new roles in illness recently. Glia normally support and shield neurons, but when they don’t work properly, they can do a lot of harm.
Animal studies have shown that inflammation caused by glia is associated with many diseases such as Parkinson’s, Alzheimer’s, and multiple sclerosis.
Because it enables researchers to study human diseases in animal models, this kind of research is crucial. We will be able to treat these illnesses using the knowledge we gain about glia as time goes on.
