Neurotransmitters are chemicals that transmit signals between nerve cells (neurons) or between neurons and other cells in the body. They are released from the nerve ending of one neuron and act on the receptors of the next neuron or target cell, thereby transmitting a nerve signal. Major neurotransmitters include acetylcholine, gamma-aminobutyric acid (GABA), glutamate, dopamine, serotonin, norepinephrine, and many others. Each neurotransmitter performs specific functions in the body, influencing mood, emotions, attention, sleep, learning, and many other aspects of behavior and physiological processes.

Imbalances or abnormalities in the neurotransmitter system can lead to a variety of neurological and psychiatric diseases. For example, serotonin deficiency has been linked to depression, and excess dopamine may play a role in the development of schizophrenia. In medical practice, drugs that affect the levels and action of neurotransmitters are used to treat conditions such as depression, anxiety disorders, Parkinson’s disease, Alzheimer’s disease, and others. This highlights the importance of neurotransmitters in maintaining the normal functioning of the nervous system and overall human health.