Which of the following neurotransmitters are categorized as monoamines?

The selection is accurate as dopamine, norepinephrine, and serotonin are indeed categorized as monoamines. Monoamines are a class of neurotransmitters that contain one amino group and are derived from aromatic amino acids. This group primarily includes neurotransmitters that are significant in regulating mood, arousal, and various cognitive functions.

Dopamine plays a crucial role in the brain's reward system and is involved in movement and motivation. Norepinephrine is important for attention and responding actions in the brain, influencing arousal and mood regulation. Serotonin is well known for its role in mood stabilization and is linked to feelings of well-being and happiness.

In contrast, the other options included neurotransmitters that are not classified as monoamines. For example, glutamate and gamma-aminobutyric acid (GABA) are classified as amino acids and play significant roles in excitation and inhibition within the brain, respectively. Acetylcholine, while crucial for many functions including muscle activation and memory, is categorized as a different type of neurotransmitter. Glycine, similar to GABA, serves primarily as an inhibitory neurotransmitter and does not fall under the monoamine category.