The Synaptic Cleft Function

Amanda Robb, Lauragrace Allen
  • Author
    Amanda Robb

    Amanda has taught high school science for over 10 years. They have a Master's Degree in Cellular and Molecular Physiology from Tufts Medical School and a Master's of Teaching from Simmons College. They also are certified in secondary special education, biology, and physics in Massachusetts.

  • Instructor
    Lauragrace Allen
The synaptic cleft is vital to how information in the brain is relayed from one neuron to another. Learn the definition and all about how the synapse works. Updated: 09/09/2021

Table of Contents


Synaptic Cleft Definition

What is the synaptic cleft? The synaptic cleft, also known as the synaptic gap, is the space after the axon terminal of a neuron between the next target cell. The synaptic cleft is important for cells to be able to communicate using chemical transmission.

Synaptic Cleft Function

The main function of the synaptic cleft is to provide space for chemical transmission of messages from the nervous system. The synaptic cleft also provides opportunity for these signals to be modulated, such as increasing or decreasing the duration of the signal or summing of additional signals. The chemical nature of the synaptic cleft allows for modulation of signals, summation and a tight level of control instead of a simple on and off switch that is characteristic of electrical signals.

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  • 0:00 Your Brain
  • 0:21 Function of the Synaptic Cleft
  • 1:26 The Neuron & the Synapse
  • 2:44 Neurotransmission in Action
  • 3:17 Neurons Communicate
  • 3:39 Lesson Summary
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What is a Neuron?

Neurons are the cells of the nervous system. They are electrochemical cells and are capable of sending high speed electrical signals and transferring those signals into chemical signals that can be sent to other cells. Neurons can communicate with other neurons, and additional cells and tissues in the body such as glands and muscle. Neurons are responsible for controlling not only all of our physical actions but also our thoughts and emotions.

Neurons are highly specialized and have a unique structure to enable them to carry out their function. Neurons have a cell body that houses the important organelles. On one end of the cell body are dendrites, which are projections that receive information from the environment or from other neurons. On the other end of the cell body is the axon. This is a long projection that carries the electrical signal, called an action potential.

The axon ends in the axon terminal, also known as the synaptic terminal. This is where the electrical signal is converted to a chemical signal, called neurotransmitters. The neurotransmitters are released into the synapse to facilitate communication with other cells. What's a synapse? The synapse is the space between one neuron and a target tissue. So, where is the synapse located? The synapse is located in the space just after the axon and synaptic terminal of a neuron and the dendrites of the next neuron.

The structure of a neuron including the synapse

neuron structure

What Is a Synapse?

The synapse is an essential component in chemical communication for neurons. There are several steps that occur to facilitate synaptic activity.

  1. Action Potential
  2. Vesicle Mobilization
  3. Fusion
  4. Communication

How does a synapse work?

The first step to facilitating synaptic activity is for an action potential to travel down the axon to the synaptic terminal. At the terminal the increase in voltage from the action potential triggers voltage gated calcium channels to open. This allows calcium to rush into the cell. Calcium binds to calcium binding proteins, that allow for the mobilization of vesicles containing neurotransmitter. The vesicles move towards the membrane at the synaptic terminal and eventually fuse. This releases neurotransmitters into the synapse. In the synapse the neurotransmitters diffuse to the target cell where they are able to bind to receptors and trigger changes in the cell through chemical communication.

What Does the Synapse Do?

The process of synaptic transmission begins with the pre-synaptic cell sending an action potential, which can be converted to a chemical signal at the synapse. The steps below outline how this process happens.

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Frequently Asked Questions

Where is synapse located?

The synapse is located just after the axon terminal of a neuron and is considered the space between the neuron and the target cell.

What's another word for synaptic cleft?

Another word for synaptic cleft is the synapse. These two words are synonymous and describe the space between the neuron and the target tissue.

What is synapse and synaptic cleft?

The synapse and synaptic cleft is the space between the axon terminal of one neuron and the target cell, tissue or next neuron.

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