Chemical Messenger Dopamine Moves Mice Into 'Dreamy Stage' of Sleep, What Does It Mean for Human's Behavior?

Researchers of a new study recently reported that in the brains of rodents, the chemical messenger dopamine stimulates rapid-eye-movement or REM.

As indicated in a ScienceNews report, a rapid surge of dopamine moves mice "into a dreamy stage of sleep." During a night's sleep, people and other animals are cycling between phases known as non-REM sleep and REM, a stage of sleep that typically comes with vivid dreams.

According to neurologist and sleep researcher at Harvard Medical School Thomas Scammel, what's causing such transitions is mysterious. New results of the study are some of the first to exhibit a trigger for the shifts, said Scammel. Understanding such transitions in more detail could eventually point to ways in treating sleep disorders in humans.

Dopamine Release

Certainly, certain nerve cells that reside in a portion of the mouse brain known as the ventral tegmental area can pump out dopamine, a molecule that has been associated with pleasure, learning, and movement, among others. These can send dopamine to the amygdalae, a pair of almond-shaped structures deep in the brain that is closely linked to emotions.

Using a molecular sensor that can determine exactly when and where dopamine is released, Takeshi Sakurai, a neuroscientist from the University of Tsukuba in Japan, and colleagues saw that dopamine levels rose in the amygdalae just before rodents shifted from non-REM sleep to REM sleep.

In their study published in Science, the researchers reported they forced the mice into the REM phase by controlling those dopamine-generating nerve cells with the use of lasers and genetic techniques, a method known as "optogenetics."

A 'Feel-Good' Chemical

Into Action Recovery Centers describes dopamine as one of the "feel-good chemicals" in the human brain. Interacting with the brain's pleasure and reward center, this chemical, along with other chemicals such as endorphins, oxytocin, and serotonin, plays a vital role in the happiness of a person.

On top of humans' mood, dopamine impacts memory, focus, and movement, as well. Healthy dopamine levels drive people to search for and repeat pleasurable activities, whereas low levels can have an adverse physical and psychological effects.

When the brain has a healthy dopamine level, it provides a good feeling. An individual's motivation increases, he becomes productive and is able to plan well, too.

With a healthy dopamine level, one learns fast, becomes driven and excited about life. He becomes focused too, not to mention, attentive. Lastly, healthy dopamine levels can make a person more social and extrovert, too.

Dopamine's Impact on Human Behavior

One of the most prominent neurotransmitters affecting human behavior is dopamine. When one experiences pleasurable events such as eating satisfying food or drug use, the body releases dopamine.

Additionally, the brain then links the release of dopamine with pleasure and develops a war system. For instance, when a person eats comforting food, his brain releases dopamine, which makes him feel good.

Therefore, the brain assumes this is a reward that encourages an individual to repeat the behavior, even though the comforting food may not be the body's healthiest choice. Dopamine is linked to reinforcement. It is believed to be the chemical that's motivating a person to do something repeatedly.

Related information dopamine's effects on human learning and memory is shown on Tedx Talk's YouTube vide below:

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