MULTIPOLAR NEURON: FUNCTIONS, TYPES, ANATOMY - GEOGRAFÍA - 2025

The multipolar neurons are a class of neurons that are characterized by a core, an axon and a lot of dendrites. The morphology these cells present allows them to integrate a large amount of information and connect with a wide variety of brain neurons.

In this sense, multipolar neurons stand out for being the most abundant neurons within the central nervous system. Likewise, these cells include both motor neurons and interneurons.

This article reviews the main properties of multipolar neurons. Their types and their functions are discussed, as well as the brain regions in which they are located.

Anatomy

Multipolar neuron. Source: BruceBlaus

Multipolar neurons are a type of neuron that contains a soma and a single axon. The axon is characterized by being long and having a length greater than that of other types of neurons (unipolar and bipolar).

The other morphological element that defines this type of cell is the presentation of numerous dendrites. These are small extensions that are responsible for receiving information from other neurons in the central nervous system.

In this sense, these types of neurons are characterized by more intense activity than the others. The fact of containing multiple dendrites allows them to connect with a wide variety of brain cells and, in this way, generate very broad neural networks.

The high amount of dendrites that multipolar neurons have are born and originate within the cell body of the neuron itself.

In summary, these cells are those that have a high amount of dendrites originating within the soma itself, as well as a large and long axon.

Characteristics of multipolar neurons

Multipolar neurons are the most classical and globally known neurons. These have a long extension on one side (axon) and a great variety of small processes on the other side (dendrites).

Likewise, the vast majority of neurons found within the central nervous system are multipolar. This fact is justified since, functionally, these are the most productive and the ones that manage to transmit the most abundant information.

In general, the main properties that characterize multipolar neurons are:

They present multiple processes

Multipolar neurons, unlike the other types, are capable of developing multiple processes together.

That is, they establish synapses with various neurons simultaneously thanks to the large number of dendrites they present. All the information collected from different neurons of the central nervous system is processed by the cell nucleus.

They have a star shape

Multipolar neurons are also distinguished from the other types of neurons through their morphology.

While unipolar neurons are round and bipolar neurons are elongated, multipolar neurons stand out for presenting a star shape where a long prolongation (the axon) and multiple small prolongations (the dendrites) of the soma or cell nucleus stand out.

They are the most abundant

Another important characteristic of multipolar neurons is that they are the most abundant in the central nervous system. In fact, in most brain structures only these types of cells are present.

For their part, unipolar and bipolar neurons are restricted to much more specific structures. The spinal cord in the case of the former and the sensory organs in the latter.

They are present in both the brain and the spinal cord

Despite the fact that multipolar neurons are mainly associated with brain regions and with the performance of complex brain processes such as memory or reasoning, these types of cells are also found within the spinal cord.

They can be motor or interneurons

Multipolar neurons include both motor cells and interneurons. However, multipolar neurons do not include sensory neurons, which are made up solely of bipolar neurons.

Features

Multipolar neurons perform two main functions within the nervous system. The first is related to motor processes and the second to associative processes.

With regard to movement processes, these types of cells are responsible for transmitting motor impulses from the cerebral cortex to the effector organs, such as muscles.

In their associative function, multipolar neurons stand out for producing multiple connections between different areas of the brain. These connections allow the formation of a large number of neural networks and brain systems that give rise to the majority of cognitive processes.

Types of multipolar neurons

Multipolar neurons stand out for being very numerous within the central nervous system, as well as highly varied. In this sense, four main types of multipolar neurons have been described. These are:

Interneurons

Interneurons are cells that are responsible for connecting sensory neurons with motor neurons. That is, they allow the efferent neurons (which travel from the nervous system to the spinal cord) to be associated with the afferent neurons (which travel from the spinal cord to the nervous system).

This type of multipolar neuron is usually characterized by having a short axon and being located in the central nervous system. Interneurons are also known as association neurons, and their main function is to examine sensory information.

Motor neuron

Motor neurons are also found within the central nervous system. Its main function is to conduct nerve impulses out of the brain (the spinal cord).

Golgi type I neurons

Golgi-type neurons stand out for having very long axons. In fact, these can measure up to a meter in length or more. These cells are found in the fiber paths that travel from the brain to the spinal cord and the nerve fibers of the peripheral nerves.

The main Golgi type I neurons are: the pyramidal cells of the cerebral cortex, the Purkinje cells of the cerebellar cortex, and the motor cells of the spinal cord.

Golgi type II neurons

Golgi type II neurons are characterized by containing a very short axon, even in some cases they may not present this prolongation. These cells are found mainly within the gray matter of the cerebellum and cerebral cortex.

References

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