Adult-Gerontology Clinical Nurse Specialist (CNS) Practice Exam

Which neurotransmitter is the main excitation neurotransmitter in the brain?

1. Dopamine

2. Peptides

3. Glutamate

4. Monoamines

The correct answer is: Glutamate

Glutamate is recognized as the principal excitatory neurotransmitter in the brain. Its primary role is to facilitate synaptic transmission by binding to its receptors on postsynaptic neurons, which leads to depolarization and the propagation of action potentials. This process is crucial for numerous brain functions, including learning and memory. The glutamatergic system is involved in various neurological processes and pathological conditions, owing to its widespread presence in the central nervous system. The action of glutamate is mediated through several receptors, including NMDA (N-methyl-D-aspartate) and AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, which play important roles in synaptic plasticity and neurodevelopment. Other neurotransmitters mentioned, such as dopamine, peptides, and monoamines, have specific roles predominantly related to mood regulation, emotional responses, and other functions rather than being the main excitatory neurotransmitter. Their primary functions do not center on mediating direct excitatory transmission in the way that glutamate does. Therefore, focusing on the established role of glutamate in synaptic signaling underscores its importance as the favorite neurotransmitter linked to excitatory processes in the brain.