How does caffeine affect the central nervous system?

Caffeine is widely recognized for its role as a central nervous system stimulant. When consumed, caffeine primarily works by blocking the action of adenosine, a neurotransmitter that promotes sleepiness. This inhibition leads to increased neuronal firing and the release of other neurotransmitters such as dopamine and norepinephrine, which enhances alertness, concentration, and overall cognitive function.

The stimulant properties of caffeine are what make it popular for helping individuals feel more awake and attentive, particularly in situations requiring sustained attention or during periods of fatigue. Through these mechanisms, caffeine effectively heightens alertness and can reduce feelings of fatigue, which is why it is often used by people looking to improve their performance during work or study.

In contrast, other options suggest a calming effect or an increase in fatigue, which do not align with the well-established effects of caffeine on brain function.