Neurotransmitters: Types And Functions

We have all heard about how neurons communicate with each other through electrical impulses. It is true that some of the synapses are purely electrical, but chemical elements mediate most of these compounds. These chemicals are called neurotransmitters. Thanks to these, neurons are able to participate in several cognitive functions such as learning, memory and perception.

Today, neuronal synapses involve more than a dozen neurotransmitters. People have learned about the function of neurotransmission, which leads to major improvements in designing and understanding the effects of psychotropic drugs. The most well-known neurotransmitters are: serotonin, dopamine, norepinephrine, acetylcholine, glutamate and GABA.

In this article, we will explore the following aspects to better understand the principles of neurotransmission. First, we will find out the different ways neurotransmitters affect the synapse. Secondly, we are talking about the signal transduction cascade, which is the most common way neurotransmitters work.

Types of effects of neurotransmitters

The main function of neurotransmitters is to modulate the synapse between neurons. In this way, electrical connections become more complex, resulting in more possibilities. Many functions of the nervous system would not work if neurotransmitters did not exist and neurons functioned as simple wires.

The way neurotransmitters affect neurons is not always the same. Chemical effects change the synapses in two different ways – here we have two types of effects:

• Through ion channels : The possibility of a difference between the outer and inner of the neuron produces electrical impulses. The movement of ions (electrically charged particles) causes the differential to vary and the neuron to be triggered when it reaches the activation limit. Some neurotransmitters have the function of attaching to ion channels found in the membrane of the neuron. When they get stuck, they open this channel, allowing a greater movement of ions, which triggers the neuron.

• Through a metabotropic receptor : This is a more complex modulation. Here, the neurotransmitter attaches to a receptor found in the membrane of the neuron. However, this receptor is not a channel that opens or closes, but instead produces another substance inside the neuron. When attached to the neurotransmitter, the neuron releases a protein inside it, which changes its structure and function. In the next section, we will examine this type of neurotransmission in depth.

The signal transduction cascade

The signal transduction cascade is the process by which the neurotransmitter modulates the function of a neuron. In this section, we will focus on the functions of the neurotransmitters that do so through metabotropic receptors, as this is the most common way they operate.

The process consists of four different phases:

• The first messenger or neurotransmitter : First, the neurotransmitter attaches to the metabotropic receptor that changes its configuration, and now allows it to fit in with a substance called G-protein. The coupling of the receptor with the G protein induces the release of an enzyme on the inner side of the membrane, and then causes the release of the second messenger.
• The second messenger : The second messenger is the protein that releases the enzyme linked to the G protein. Its mission runs through the neuron until you find a kinase or phosphatase. These substances are activated when the other messenger attaches himself to one of them.
• The third messenger (kinase or phosphatase) : This varies depending on whether the second messenger encounters a kinase or a phosphatase. The encounter with a kinase will cause it to activate and release a process of phosphorylation in the nucleus of the nucleus, which will cause the neuron’s DNA to begin producing proteins that it did not previously. However, if the other messenger encounters a phosphatase, it will have the opposite effect: it will inactivate the phosphorylation process and stop the establishment of certain proteins.

• The fourth messenger or phosphoprotein : When the kinase is activated, it sends a phosphoprotein to the neuronal DNA to trigger the phosphorylation. The phosphorus protein will activate a transcription factor that will trigger the activation of a gene as well as the formation of a protein; This protein, depending on its qualities, will release several biological responses that will end up modifying neuronal transmission. When the phosphatase is activated, it destroys the phosphorus protein, which causes the phosphorylation process to stop.

Neurotransmitters are very important chemicals in our nervous system. They are responsible for modulating and transmitting information between the different brain nuclei. In addition, their effects on neurons can last from a few seconds to months, or even years. Thanks to their study, we can understand the connection between many complex cognitive processes, such as learning, memory and attention.