Brain circuit that drives sleep-wake states, sleep-preparation behavior is identified

             Scientists at Stanford University of Medicine have identified a brain circuit that is indispensable to the sleep-wake cycle. This same circuit is also in direct correlation, or a key component, to the reward system in our brain. Until this study no known connection has been proven to be in existence between these two functions.

It makes sense that the reward system, which motivates goal-directed behaviors such as fleeing from a predator and searching for food, is connected to our sleep-wake cycle. How can you look for food if you are asleep? Unless you are a very skilled and disciplined sleepwalker, you can’t. Furthermore, it will be a lot easier to get out of bed if you are excited about your day.

Reward circuitry system’s are similar no matter what animal you look at whether it be a human, fish, or bird. There is one chemical that plays a key role in this system; that chemical is called dopamine. The part of the brain called the VTA (ventral tegmental area) is the origin of numerous dopamine producing nerve fibers that run to different parts of the brain. A lot of these fibers go to a part of the brain that is implicated in generating feelings of pleasure in anticipation or response to obtaining a desired object. Due to the fact that, if this nerve is shooting dopamine throughout your brain, which in turn activates the reward system within your brain,  it will excite you and make you more goal driven keeping you awake to achieve that desired goal and not allowing your body to go to sleep. It was said before by Eban-Rothschild:

"In part due to existing technical limitations, earlier experimental literature has unearthed little evidence for the connection (between dopamine and the sleep-wake cycle) and, in fact, has suggested that this circuit probably wasn't so important."

But still the scientists and Stanford University of Medicine decided to test the hypothesis and experimented on mice. They monitored and measured their dopamine levels. The activity and levels of the dopamine-producing nerve cells emanating for the VTA rose upon waking and stayed elevated when the mice were awake. Conversely, this activity of producing dopamine dropped when the mice transitioned to sleep and remained at low levels during their slumber. Activating this dopamine secretion to the brain was enough to wake the mice from sleep and keep them awake for long periods of time. On the flip side, when they would suppress the nerve cell activity from producing during the typical wake period of the mice’s 24-hour cycle, the mice would fall asleep and stay asleep through the presence of arousal triggers such as: delicious high-fat food, a female, and even fear-inducing fox urine.

Then they tried an experiment with putting the mice in a new cage. Usually when mice are put in a new cage they will explore it. The mice that did not have their VTA suppressed did just that. But the mice that had their VTA suppressed stayed awake for 45 minutes. They spent this time building a nest and not just a quick nest, but they were careful and made sure it was satisfactory. But then the scientist took their nest and put it in a new cage then put the VTA suppressed mice in it. Those mice would walk right up to the nest and fall asleep. They knew that stimulating the brain’s dopamine would increase goal directed behaviors such as obtaining food and sex seeking. Eban-Rothschild commented:

“...the new study shows that at least one complex behavior is induced not by stimulating, but by inhibiting (hindering or restraining), this very circuit. Interestingly, this behavior -- nest building -- is essential to a mouse's preparation for sleep."

This is the first finding of a sleep-preparation starter site in the brain and it is likely we humans have it too. And if we are disrupting this preparation by, for example, reading emails or playing video games which not only give off light but more than likely charge up our dopamine level, it is no wonder why we are having trouble getting to sleep.

This article shows that to have better sleep we need to be aware of our dopamine levels. They affect us and will either help us stay awake or help us become tired and doze off. If they are high or hard to control, there are plenty of drugs to counter that. But along those lines, to get better sleep and not have our sleep-wake cycle become disoriented, we need to use that sleep preparation time to allow our body to get ready to rest and not do things that will cause our dopamine levels to go up right before we go to bed. This will inhibit our sleep.

This article is interesting because it is relevant to me. I never feel that I get a good night’s sleep. I am always exhausted and do not want to get out of bed. In fact, it is due to this feeling in the morning that I am late to work on a few occasions. I love my beauty sleep. I want my beauty sleep. I want to wake up in the morning feeling like sleeping beauty, like I just got all the sleep I needed to tackle the day. For that to happen, I have found out a couple of things that could help me and potentially anyone else that reads this article. One habit we all need to change is that of doing homework or typing up articles on a computer late at night. We should try to be more alert and ready during our awake cycle then prepare for our sleep cycle and not just try to jump right into it.

Written by: Joshua B.

Source: September 5, 2016, Biology News Net, “Brain circuit that drives sleep-wake states, sleep-preparation behavior is identified”