Registered Practical Nurse (RPN) Practice Test

Which neurotransmitter is most prevalent in the human body?

1. GABA

2. Amino acids

3. Dopamine

4. Serotonin

The correct answer is: Amino acids

Amino acids are indeed the most prevalent neurotransmitters in the human body due to their fundamental role in various physiological functions. They serve as building blocks for proteins and are involved in the synthesis of numerous neurotransmitters. Among the amino acids, glutamate is the most abundant excitatory neurotransmitter in the central nervous system, playing a crucial role in synaptic transmission, plasticity, and overall brain function. While GABA, dopamine, and serotonin each serve important functions in neurotransmission—regulating mood, movement, and various cognitive processes—amino acids represent a broader category that underpins many biological processes. Therefore, recognizing amino acids as the most prevalent helps in understanding their integral roles in the human body's overall function.