Conducted by Dr John Peever and his team from the University of Toronto, the studies helped in further understanding the subconscious state of the brain. These results added on to their previous research on how dreams occur and the role of REM-active neurons in the brain in reaching the dream state.
Brainstem plays a key role in controlling dreams
In the 1960s, it was discovered that dreams play out during the rapid eye movement (REM) sleep. They also found out that the brainstem plays a key role in controlling dreams. It communicates with the hypothalamus to enable the transition from wakefulness to sleep and vice versa.
REM-active ‘SubC’ neurons initiate a chain reaction to release the GABA neurotransmitter, which subsequently, reduces the levels of arousal in both the brainstem and hypothalamus. SubC neurons are named as such due to their location in brain, the subcoeruleus nucleus.
The part of the brain that produces GABAergic neurons also controls the timing of REM sleep and its features including muscle paralysis. “When we switch on these cells, it causes a rapid transition into REM sleep,” explains Peever. The signals are sent from the brainstem to the relevant muscles to ensure that we do not carry out our dreams in actual reality.
With this knowledge, Peever and his team studied sleep disorders such as narcolepsy, cataplexy and REM sleep behaviour disorders.
Early warning sign of neurodegenerative disorders
During investigations into a breakdown in brain circuits, Peever and his team stumbled upon an interesting result. “We observed that more than 80 percent of people who suffer from REM sleep disorder eventually develop synucleinopathies, such as Parkinson's disease, and Lewy body dementia,” wrote Peever in the publication.
“Our research suggests sleep disorders may be an early warning sign for diseases that may appear some 15 years later in life.”
Several neurodegenerative conditions that tend to occur in old age are linked to REM sleep disorders. Peever added, “This link suggests that neurodegenerative processes initially target the circuits controlling REM sleep and specifically SubC neurons.”
Peever and his colleagues hope to use this new data for neuroprotective therapies in the future. “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.
Dreams affected by radiation
An interesting case report was published recently whereby an Australian man receiving radiotherapy noted a significant change in his dream features after the treatment. The 59-year-old, who had previously only dreamed in black and white, said that after radiotherapy to the front and side of his head for eye cancer, he started dreaming in vivid colour.
His dreams became very strange and he reported mentally flicking through coloured pictures of former girlfriends, a timeline of cars he owned and saw colourful algebraic symbols bounce off a blackboard and whizzed towards him. He even dreamt about various species of fish he had caught.
The reason behind his prior black and white dreams could be because of the type of television he grew up watching. Prior investigations regarding this noted that those who saw only black-and-white film and television as kids were more prone to dreaming in greyscale throughout their lives.
Doctors at the North Coast Institute where the patient received the treatment said, “The neurological events were dreams rather than hallucinations, since they immediately stopped when the patient woke up.”
The radiation oncologist, Michael McKay said that his switch to colour dreaming may have been sparked by the radiation’s effect on electrical brain activity. However, EEG tests were not done for the patient to properly study the effects.
Researchers discussed explanations for this phenomenon and conjured up a few hypotheses. The possibility of tissue irritation and swelling from radiation could have contributed to the man's symptoms because a few days after the treatment had ended, the colour dreams stopped too. Another theory could be that the radiation caused the man to wake up at several stages during his sleep, triggering his subconscious to recollect the colours of the real world in his dreams.
Further studies are needed to truly substantiate this link to aid in understanding how the brain generates consciousness. MIMS
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