Although we don’t remember a majority of our dreams, we all experience them usually every night. While some dreams are normal and sometimes even fairytale-like, others can seem like never ending nightmares. But for people with sleep behavior disorders, nightmares can be even more intense - both physically and mentally. Some disorders may even be an early warning sign for certain brain conditions, according to new research.

All humans, as well as other mammals and birds, experience a stage of sleeping known as rapid eye movement sleep (REM). As the name suggests, your eyes move in a quick, random motion. During this stage some people suffer from REM sleep disorder, which leads them to act out their dreams through talking, shouting, hitting and other physical motions, according to the National Sleep Foundation. The research discovered that about 80 percent of people who suffer from a REM disorder will go on to develop a neurodegenerative disorder, such as Parkinson's. 

Read: While Dreaming During REM Sleep, Brain Captures Visual Images With Darting Eyes

For decades it’s been known that the brainstem plays a key role in controlling dreaming during REM sleep. But now, a neuroscience researcher at the University of Toronto believes he’s found the cells responsible for dreaming, called REM-active neurons. Dr. John Peever and his colleagues were successfully able to use these cells to control a rodent’s dreaming process. “When we switch on these cells, it causes a rapid transition into REM sleep,” Peever said in a statement.

Upon discovering this, Peever, who has long-studied the biology of sleep, went on to explore dreaming dysfunctions in humans. He says he and his team made a connection between disorders, like REM sleep disorder, and common debilitating brain disorders.

“We observed that more than 80% of people who suffer from REM sleep disorder eventually develop synucleinopathies, such as Parkinson’s disease, and Lewy bodies dementia,” Peever said. “Our research suggests sleep disorders may be an early warning sign for diseases that may appear some fifteen years in life.”

Read: Sleep Problems In Those With Anxiety, Depression May Make Positivity Harder

Peever, who presented his research at the 2017 Canadian Neuroscience Meeting, hopes his research will help with the furture development of protective strategies to preserve neuron structures and their functions.

“Much like we see in people prone to cancer, diagnosing REM disorders may allow us to provide individuals with preventative actions to keep them healthy long before they develop these more serious neurological conditions,” he said.

During normal REM sleep, nerve pathways in the brain prevent a person from moving, causing a temporary paralysis. However, if someone suffers from REM sleep behavior disorder, these pathways aren’t active and cause you to physically act out your dream, according to Mayo Clinic. Some common symptoms include arm flailing, jumping, talking, laughing, shouting, emotional outcries, and being able to recall the dream if you are woken up during the episode.

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