Which neurotransmitter is primarily released during the fight-or-flight response?

The neurotransmitter primarily released during the fight-or-flight response is norepinephrine. This response is activated by the sympathetic nervous system in reaction to perceived threats or stressors. Norepinephrine plays a crucial role in preparing the body for quick action by increasing heart rate, dilating airways, and redirecting blood flow to muscles, which enhances physical performance and alertness. This neurotransmitter helps prime the body to either confront or escape from danger, which is the essence of the fight-or-flight mechanism.

While dopamine, serotonin, and acetylcholine have their important functions in the brain and body, they are not primarily responsible for the physiological changes that occur during the fight-or-flight response.