Which part of the neuron contains chemical messengers known as neurotransmitters?

Which part of the neuron contains chemical messengers known as neurotransmitters?

In the axon terminal, neurotransmitter molecules are housed in membrane sacs called vesicles. Each vesicle includes thousands of neurotransmitter molecules. When an action potential reaches a synapse, it triggers a rapid change in size of the neurotransmitter-containing vesicles. This causes more transmitter to be released into the synaptic gap when you squeeze the endplate.

The neurotransmitters act on receptors located on the postsynaptic cell. This can either be another nerve or a muscle fiber. The neurotransmitters can either excite or inhibit the postsynaptic cell. In general, neurons that connect one portion of the brain to another are called efferent neurons. Neurons that connect two different parts of the brain themselves are called afferent neurons.

Efferent neurons release neurotransmitters that cause muscles to contract or glands to secrete. Afferent neurons receive signals from other neurons and organs such as muscles and glands. These neurons transmit information about sensations like pain and touch from the affected area back to the brain.

Neurotransmitters are released by neurons from storage sites within the presynaptic neuron. The three main classes of neurotransmitters are acetylcholine, dopamine, and serotonin.

Are neurotransmitters stored in the axon?

Neurotransmitter molecules are contained in little "packages" known as vesicles (see the picture on the right). Neurotransmitters are released from the axon terminal when their vesicles "fuse" with the axon terminal membrane, allowing the neurotransmitter to pour into the synaptic cleft. The neurotransmitter can then bind to receptors on the postsynaptic cell, causing it to react in some way.

In fact, all neurons contain neurotransmitters, which are sent out from the neuron where they are created to other neurons to communicate a message to them. There are two main classes of neurons: excitatory and inhibitory. Excitatory neurons transmit information by firing action potentials, which cause muscle cells to contract or expand. Inhibitory neurons prevent other neurons from firing by releasing chemicals that block cellular membranes near them. Both excitatory and inhibitory neurons communicate using neurotransmitters.

Excitatory neurotransmitters include glutamate, dopamine, and serotonin. These neurotransmitters play a major role in brain function by communicating messages between neurons. Dopamine is particularly important for motivating behavior. Serotonin is involved in many behaviors including anxiety, depression, sleep, appetite, and sexual desire. Glutamate is the most abundant neurotransmitter in the brain, so it plays an important role in communication between neurons. Glutamate is responsible for signaling cells together to form memories, learn new skills, and respond to danger.

Where are neurotransmitters located in a neuron?

Neurotransmitters are stored in synaptic vesicles, which are grouped near to the cell membrane at the presynaptic neuron's axon terminal. Neurotransmitters are released into the synaptic cleft and diffuse across it, where they bind to particular receptors on the postsynaptic neuron's membrane. This interaction triggers changes in its shape that lead to an increase or decrease of its activity.

Neurotransmitters can be divided into two groups on the basis of their location within neurons: excitatory and inhibitory. Excitatory neurotransmitters like glutamate cause neurons to fire by binding to receptors on the surface of the cell body and proximal dendrites. This activation can also have further effects inside the cell through multiple pathways that involve ion channels and other cellular components. Inhibitory neurotransmitters like gamma-aminobutyric acid (GABA) prevent neurons from firing by binding to receptors on the surface of the cell body and proximal dendrites. These receptors are typically composed of several subunits, one of which may be GABA receptor types A or B. There are many more neurotransmitters than just these two categories, but they function primarily as either excitatory or inhibitory molecules that control the flow of information between neurons.

Neurotransmitters are produced by neurons themselves, but sometimes also by non-neural cells called astrocytes or glial cells.

About Article Author

Romeo Crouchet

Romeo Crouchet is a dedicated teacher with an eye for detail. He has taught at the college level in both the United States and Canada, and he uses his experience to tailor individualized courses that help students meet their goals. Romeo also enjoys teaching online courses because it enables him to reach more people than ever before.

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