Types of Neurotransmitters

Youlan Li

Ever you wondered the mechanisms allowing us to sense stuff and respond to them by motor movements? Well, the entirety of such, including those of prominence in one’s day-to-day life, yes—believe it or not—all are based on what we usually call neurotransmitters fundamentally. Neurotransmitters are chemical messengers that carry chemical signals from one neuron, which is a nerve cell, towards the target cell, which can be of a variety of classifications, such as a muscle cell, a gland cell, or even a neuron. Neurotransmitters may possess contrasting roles regarding what they do with respect to cells.

Neurotransmitters may possess contrasting roles regarding what they do with respect to cells. Some neurotransmitters have an excitatory function, meaning they stimulate the next cell to fire and activate receptors on the postsynaptic membrane, thereby enhancing the effect of the action potential.

On the other hand, some neurotransmitters are in charge of an inhibitory role, meaning that they prevent the cell next to it from firing and inhibit the occurrence of an action potential as the intended outcome.

In this article, with me myself as the narrator if one may consider oneself as one, several common neurotransmitters will be introduced, including acetylcholine. dopamine and serotonin, examples of some playing vital roles in our lives.

1.

To start things off, there is acetylcholine, an excitatory neurotransmitter that plays a role in muscle action, learning, and memory. One of its primary functions is to trigger muscle contractions.

Such a mechanism is initiated by the binding to the receptor sites on the membranes of muscle fibers, thereby opening the ligand-gated sodium (Na+) channels, allowing sodium ions to enter the muscle cell and stimulate muscle contraction as a result. In addition to said role paraphrased above, another of proficiency and of vitality for this substance is of memory and the management hereof.

Without acetylcholine, the results could be severe, of a case common in senile groups is Alzheimer's disease characterized by difficulties in forming and recalling memories, delusions, and frequent confusion.

On the other hand, excessive levels of acetylcholine can lead to a cholinergic crisis causing symptoms such as headache, insomnia, and also confusion, and in more severe cases, it can result in central nervous system depression, characterized by convulsions, coma, and respiratory depression. High levels of acetylcholine can also have detrimental effects on the heart, respiration, and brain, leading to potentially fatal outcomes.

2

Next on the list is dopamine, one that plays a key role in the management of our body movements, attention, and emotions.

A deficiency of such can lead to uncoordinated and unbalanced body movements, which are typical symptoms of Parkinson's Disease and tremors. These symptoms may serve as an indicator for insufficient levels of dopamine in the brain regions responsible for regulating movement.

Conversely, excessive levels of dopamine have been linked to increased aggression and impulsivity. Conditions such as schizophrenia, depression, and psychosis are associated with elevated dopamine levels.

In schizophrenia, common behaviors include delusions, positive hallucinations, and a decrease in emotional range and cognitive function, which are negative symptoms. As illustrated, imbalances in neurotransmitter levels can disrupt normal bodily functions, regardless of whether the value is on the high or low side.

Additionally, serotonin is also a role to be not ignored, playing a role in our mood, sleep, and arousal. It regulates our mood by being our natural "feel-good" chemical, and when serotonin levels are low, it can lead to depression.

Consequently, what some medications aimed towards disorderly symptoms such as anxiety and depression really do is increase serotonin levels in the brain.

Along with dopamine, in roughly the aforementioned fashion, serotonin is as well an avid contributor to sleep quality, as our brain requires serotonin to produce melatonin, a hormone that is released in response to darkness that helps in regulating our circadian rhythm.

So much about what these neurotransmitters are and what they do, but what are we and what can we do about it? Well, one thing to be certain is the necessity to take appropriate medications and substances in appropriate dosages under the guidance of a professional in the medical area, as an inaccurate application of such can disrupt the balance and function of neurotransmitters, ultimately affecting people's daily lives in ways perhaps even permanently.

References

Cholinergic Toxicity - StatPearls. (n.d.). NCBI. Retrieved June 27, 2023, from https://www.ncbi.nlm.nih.gov/books/NBK539783/

Cuncic, A. (2022, February 27). The Relationship Between Schizophrenia and Dopamine. Verywell Mind. Retrieved June 27, 2023, from https://www.verywellmind.com/the-relationship-between-schizophrenia-and-dopamine-5219904

Hasudungan, A. (n.d.). Muscle Contractions | Learn Muscular Anatomy. Visible Body. Retrieved June 27, 2023, from https://www.visiblebody.com/learn/muscular/muscle-contractions

Physiology, Acetylcholine - StatPearls. (2023, April 10). NCBI. Retrieved June 27, 2023, from https://www.ncbi.nlm.nih.gov/books/NBK557825/

Serotonin: What Is It, Function & Levels. (2022, March 18). Cleveland Clinic. Retrieved June 27, 2023, from https://my.clevelandclinic.org/health/articles/22572-serotonin