Blog #5: Dopamine

Sleepy Explorer by ZoranPhoto

Now what is dopamine? Dopamine is a chemical in the brain that becomes active when the person is feeling happy or a certain amount of pleasure – Much like adrenaline when there is a certain kind of emergency. Dopamine goes around the brain giving the person a sense of fulfillment. Now what does dopamine have to with sleeping or the circadian rhythm?

Bethany Brookshire – who is better known by her pen name: Scicurious – wrote an article entitled “Sleep Deprived? Mind your dopamine” which covers on dopamine and its effect of being sleepy and awake. Here she said that the current hypothesis for being awake that utilizes the effects of dopamine may be partly controlled by its D2 receptors.

The author also stated from an earlier study from Volkow et al. that “increased dopamine release, which would cause decreases in D2 receptors (this is a basic idea in pharmacology, when a group of receptors is overstimulated, some receptors will leave the membrane, making the membrane less sensitive to stimulation).” In a nutshell: If there is too much dopamine in the person’s system then some of the dopamine’s receptors will be lost or be less sensitive to the dopamine itself.

The experiment made by Volkow et al. resulted in showing that the decline in D2 receptors that was hypothesized with sleep deprivation is not because of the increase in dopamine release during sleep deprivation. Although as the author stated the opposite may be true that it may be the receptors themselves that make a person sleepy with the lack of dopamine.

In Krista Conger’s article entitled “Research shows dopamine plays crucial role in sleep regulation” summarizes experiments done by Stanford University Medical Center.She explains that dopamine is a neurotransmitter used for communications between brain cells. She continues and says that methamphetamine blocks the transporter complexes of dopamine and that modafinil binds to the dopamine transporter. 

In Conger's article she quoted Jonathan Wisor, PhD – a postdoctoral researcher in the laboratory of Dale Edgar, PhD, associate professor of psychiatry and behavioral science – that "Caffeine is the most widely used stimulant in the world, and it's thought to work through another neurochemical, adenosine." She continues on by saying that "Caffeine works by blocking the receptors for adenosine and preventing the sleep signal from being transmitted."

Dopamine is an important chemical towards the person's sleep and wake cycle. Certain subjects in the experiment showed that stayed up longer experienced daytime sleepiness. If this were also applied to human beings, daytime sleepiness could lead to the person missing a lot of activities during the day. this would probably be de to overfatigue from staying awake too long; the brain ignoring certain chemicals for it to work longer.