John, a 19 year old boy, wanted to figure out why he wasn't sleeping well at night. He normally and heads to bed by 11 pm and wa
kes up about 6 am. He works during the day, exercises after work for 1 hour, eats dinner, watches television, checks his phone for messages, and drinks a Pepsi at about 10 pm. What can you infer is keeping John awake at night.
Pepsi is a caffeinated drink that has caffeine in it. Caffeine is a stimulant which means it keeps the body awake and alert. Caffeine works by mimicking adenosine. Adenosine is produced by neuron cells and when it binds to its own receptors (autocrine signaling) it triggers the neurons cells to continue firing. As the adenosine levels fall as the day progresses, the brain is signaled that it is time rest. Adenosine levels are at the lowest when its almost bedtime. However, when Jon takes Pepsi, the caffeine in it bind to the adenosine receptors and make the brain neurons to keep ‘firing’.
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