Table of ContentsView AllTable of ContentsTypesSensory NeuronsMotor NeuronsInterneuronsNeuronal AnatomyNeuronal Repair and Replacement
Table of ContentsView All
View All
Table of Contents
Types
Sensory Neurons
Motor Neurons
Interneurons
Neuronal Anatomy
Neuronal Repair and Replacement
This article covers the different types of neurons in the body and how they help us function.
zf L / Getty Images
Types of Neurons
There are many different types of neurons, and they all have special functions in thebrain,spinal cord, and muscles that control our body.These different types of neurons are highly specialized. Some neurons are responsible for taste while others sense pain.
Traditionally, scientists classify neurons based on function into three broad types:
Sensory, motor, and interneurons are the most common neuron types, Of these, interneurons are the most abundant.
Myelinated axons are present in sensory neurons and motor neurons however, all sensory and motor neurons are not myelinated. Non-myelinated neurons transmit electrical signals more slowly than the myelinated nerves in the body.
Most neurons that carry signals regarding movement and higher-level functions, such as thinking and reading, are myelinated. Neurons that control the feelings of pain and temperature are sometimes myelinated and sometimes not.
Scientists also classify neurons into four groups based on structural differences:
Although almost any neuron falls into one of these broad categories, these seven groups are only a subset of all the neurons within the nervous system. Categorizing neurons helps us to simplify how they work and better understand their role in the body.
Sensory neurons help us feel and explore the world around us. Major senses such as touch and pain can help us to move safely through the world.
Pain is an example of an important sensory neuron. When you feel pain from a hot pan or a sharp pin, you are sending sensory information via sensory neurons up to the brain. The flow of electrical impulses is directed from the source of the pain alongnervefibers that connect to sensory neurons.
Sensory neurons are critical for informing our body about the environment around us. They can relay information on temperature and teach us when to avoid a hot item. Sensory neurons can also support complex movements like picking up utensils.
The sensory neurons provide feedback to our muscles and joints to enable precise and carefully choreographed movements.
Motor neurons carry impulses away from the central nervous system (made up of the brain and spinal cord), and control the movement of the body. These neurons coordinate our muscles and ensure that our arms and legs move together.
Motor neurons can be subdivided into lower motor neurons and upper motor neurons located in the brain and spinal cord. The differences between upper and lower motor neurons involve the level of control each exerts over functions of the body.
How Motor Neurons Work in Practice
Think of the process of standing up from a chair. Your brain tells the motor neurons in your legs to activate. Next, your motor neurons send instructions to the muscles controlling your legs to rise up. Finally, you might press your arms against the arms of the chair to provide an additional lift.
Interneurons are the most abundant neurons in the body. They act as signal controllers within the body, relaying important information from one end of the nervous system to the other.
The interneurons sit in the middle of other neurons, such as motor or sensory neurons. They are responsible for relaying electrical signals.
Interneurons can also serve to regulate the signals from neurons. They can control what is sent along and what isn’t. They have a multipolar structure that allows them to receive multiple signals and then send a unified command to another neuron.In this way, you can think of interneurons as traffic controllers, sitting in the middle of the neurologic pathway and coordinating the flow of information.
Interneurons and DepressionInterneurons are thought to play an important role in signal transmission in the brain, where they have been linked todepression.
Interneurons and Depression
Interneurons are thought to play an important role in signal transmission in the brain, where they have been linked todepression.
Neurons are the basic cellular unit of the nervous system. Neurons have different components that play integral roles in their ability to receive and transmit signals through the body.
Neuron.Donald Bliss, MAPB/National Institute on Drug Abuse
The most important components of the neuron include the following:
In addition to the billions of neurons within the nervous system, there are a host of supportive cells, calledglialcells, that regulate neuronal activity. The glia are responsible for cleaning out waste and debris from neurons, as well as responding toinflammationand invaders like viruses and bacteria.
While glia do not directly regulate signal transmission in the nervous system, increasing research has shown that they play an important role in healthy nervous system function.
Types of neurons based on structure include:
In the event of injury or disease, some neurons, such as those located in theperipheral nervous system, can slowly regenerate and repair themselves.However, neurons located in the brain and spinal cord are not able to heal or regenerate. For this reason, specific injuries to the nervous system are permanent, such as spinal cord injuries.
In some cases, neuronal plasticity within the brain can lead to healthy neurons picking up the job or function of other neurons that have been damaged.
Summary
Neurons are responsible for transmitting signals throughout the body, a process that allows us to move and exist in the world around us. Different types of neurons include sensory, motor, and interneurons, as well as structurally-based neurons, which include unipolar, multipolar, bipolar, and pseudo-unipolar neurons. These cells coordinate bodily functions and movement so quickly, we don’t even notice it happening.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Jabr F, Scientific American Blog Network.Know your neurons: how to classify different types of neurons in the brain’s forest.Kenhub.Myelin sheath and myelination.Yam MF, Loh YC, Tan CS, Khadijah Adam S, Abdul Manan N, Basir R.General Pathways of Pain Sensation and the Major Neurotransmitters Involved in Pain Regulation.Int J Mol Sci. 2018;19(8):2164. Published 2018 Jul 24. doi:10.3390/ijms19082164Zayia LC, Tadi P.Neuroanatomy, Motor Neuron. StatPearls [Internet]. 2023.Gosgnach S, Bikoff JB, Dougherty KJ, El Manira A, Lanuza GM, Zhang Y.Delineating the Diversity of Spinal Interneurons in Locomotor Circuits.J Neurosci. 2017;37(45):10835-10841. doi:10.1523/JNEUROSCI.1829-17.2017Fogaça MV, Duman RS.Cortical gabaergic dysfunction in stress and depression: new insights for therapeutic interventions.Front Cell Neurosci. 2019;13:87. doi:10.3389/fncel.2019.00087Ludwig PE, Reddy V, Varacallo M.Neuroanatomy, Neurons. StatPearls [Internet]. 2023.Science in the News.Clearing Out the Junk: Healthy lifestyle choices boost brain waste disposal.Menorca RM, Fussell TS, Elfar JC.Nerve physiology: mechanisms of injury and recovery.Hand Clin. 2013;29(3):317-330. doi:10.1016/j.hcl.2013.04.002
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Jabr F, Scientific American Blog Network.Know your neurons: how to classify different types of neurons in the brain’s forest.Kenhub.Myelin sheath and myelination.Yam MF, Loh YC, Tan CS, Khadijah Adam S, Abdul Manan N, Basir R.General Pathways of Pain Sensation and the Major Neurotransmitters Involved in Pain Regulation.Int J Mol Sci. 2018;19(8):2164. Published 2018 Jul 24. doi:10.3390/ijms19082164Zayia LC, Tadi P.Neuroanatomy, Motor Neuron. StatPearls [Internet]. 2023.Gosgnach S, Bikoff JB, Dougherty KJ, El Manira A, Lanuza GM, Zhang Y.Delineating the Diversity of Spinal Interneurons in Locomotor Circuits.J Neurosci. 2017;37(45):10835-10841. doi:10.1523/JNEUROSCI.1829-17.2017Fogaça MV, Duman RS.Cortical gabaergic dysfunction in stress and depression: new insights for therapeutic interventions.Front Cell Neurosci. 2019;13:87. doi:10.3389/fncel.2019.00087Ludwig PE, Reddy V, Varacallo M.Neuroanatomy, Neurons. StatPearls [Internet]. 2023.Science in the News.Clearing Out the Junk: Healthy lifestyle choices boost brain waste disposal.Menorca RM, Fussell TS, Elfar JC.Nerve physiology: mechanisms of injury and recovery.Hand Clin. 2013;29(3):317-330. doi:10.1016/j.hcl.2013.04.002
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Jabr F, Scientific American Blog Network.Know your neurons: how to classify different types of neurons in the brain’s forest.Kenhub.Myelin sheath and myelination.Yam MF, Loh YC, Tan CS, Khadijah Adam S, Abdul Manan N, Basir R.General Pathways of Pain Sensation and the Major Neurotransmitters Involved in Pain Regulation.Int J Mol Sci. 2018;19(8):2164. Published 2018 Jul 24. doi:10.3390/ijms19082164Zayia LC, Tadi P.Neuroanatomy, Motor Neuron. StatPearls [Internet]. 2023.Gosgnach S, Bikoff JB, Dougherty KJ, El Manira A, Lanuza GM, Zhang Y.Delineating the Diversity of Spinal Interneurons in Locomotor Circuits.J Neurosci. 2017;37(45):10835-10841. doi:10.1523/JNEUROSCI.1829-17.2017Fogaça MV, Duman RS.Cortical gabaergic dysfunction in stress and depression: new insights for therapeutic interventions.Front Cell Neurosci. 2019;13:87. doi:10.3389/fncel.2019.00087Ludwig PE, Reddy V, Varacallo M.Neuroanatomy, Neurons. StatPearls [Internet]. 2023.Science in the News.Clearing Out the Junk: Healthy lifestyle choices boost brain waste disposal.Menorca RM, Fussell TS, Elfar JC.Nerve physiology: mechanisms of injury and recovery.Hand Clin. 2013;29(3):317-330. doi:10.1016/j.hcl.2013.04.002
Jabr F, Scientific American Blog Network.Know your neurons: how to classify different types of neurons in the brain’s forest.
Kenhub.Myelin sheath and myelination.
Yam MF, Loh YC, Tan CS, Khadijah Adam S, Abdul Manan N, Basir R.General Pathways of Pain Sensation and the Major Neurotransmitters Involved in Pain Regulation.Int J Mol Sci. 2018;19(8):2164. Published 2018 Jul 24. doi:10.3390/ijms19082164
Zayia LC, Tadi P.Neuroanatomy, Motor Neuron. StatPearls [Internet]. 2023.
Gosgnach S, Bikoff JB, Dougherty KJ, El Manira A, Lanuza GM, Zhang Y.Delineating the Diversity of Spinal Interneurons in Locomotor Circuits.J Neurosci. 2017;37(45):10835-10841. doi:10.1523/JNEUROSCI.1829-17.2017
Fogaça MV, Duman RS.Cortical gabaergic dysfunction in stress and depression: new insights for therapeutic interventions.Front Cell Neurosci. 2019;13:87. doi:10.3389/fncel.2019.00087
Ludwig PE, Reddy V, Varacallo M.Neuroanatomy, Neurons. StatPearls [Internet]. 2023.
Science in the News.Clearing Out the Junk: Healthy lifestyle choices boost brain waste disposal.
Menorca RM, Fussell TS, Elfar JC.Nerve physiology: mechanisms of injury and recovery.Hand Clin. 2013;29(3):317-330. doi:10.1016/j.hcl.2013.04.002
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