Neuroscientists explain why people with PTSD experience recurrent nightmares.
Sleep can sometimes cause suppressed emotions to surface in the form of nightmares. People who suffer from PTSD frequently have terrible memories return to them night after night, which severely disrupts their sleep and worsens their mental health.
Virginia Tech researchers now assert that they know why persons with post-traumatic stress disorder continue to dream about these terrible situations after publishing their research in the journal JNeurosci.
According to studies, PTSD maintains the brain in a vicious cycle. Rapid eye movement (REM) sleep causes an increase in brain activity, which may cause the brain to behave similarly to when a person is awake. Sujith Vijayan, a neurologist at Virginia Tech, claims that paradoxical sleep, also known as REM sleep, is characterised by the brain being more awake than when you are actually awake.
During REM sleep, the concentration of the neurotransmitters norepinephrine and serotonin, which are known to encourage awake, frequently declines. Vijayan and the team connected lower levels with the brain’s potential to block fear expression cells by using rhythms that were conveyed between the front of the brain and the amygdala, a part of the brain associated with emotional expression. PTSD sufferers still have elevated levels of these substances.
Researchers investigated how levels seen in PTSD patients who were sleeping would affect these cycles associated with fear.
The research models show that in PTSD patients, these elevated levels permit the unrestricted movement of traumatic memories in the brain, in contrast to what happens in healthy persons. This study provides a potential therapy target, suggesting that patients may need higher frequency rhythms in order to forget these memories.
The problem is that many sleep neuroscience studies have concentrated on non-REM sleep, which refers to the phases of going from light to deep sleep. Vijayan refers to it as the “Wild West” in light of what is known about REM sleep in relation to memory.
According to Vijayan, an assistant professor in the School of Neuroscience, a division of the Virginia Tech College of Science, “REM sleep is a lot harder to get your hands around.”
For how non-REM sleep might strengthen memories and what function it might serve in learning and memory, there are a lot of really interesting models available. However, there are no accurate, reliable models to explain how REM works.
The researchers reduced the norepinephrine and serotonin levels to simulate typical REM sleep in order to control the rhythms during these experiments. They discovered that by doing this, horror memories might be effectively blocked. More specifically, researchers found that using a specific frequency of brain rhythms was particularly effective in blocking fear-expressing cells.
Theta beats
Theta rhythms with a frequency of about four hertz—the fundamental unit of frequency—were most effective at fostering connections between the brain areas necessary for squelching memories of dread.
Theta rhythms help to synchronise the activity of the parts of the brain involved in memory and learning. In individuals, they typically fall between four and eight hertz. By replicating REM sleep in PTSD patients, the second trial replicated the first’s settings. They weren’t able to discern the same patterns, which astonished them.
Vijayan continued, “I’m a little surprised that the four hertz didn’t work. “I thought maybe it would still work, but it wasn’t at all,” the speaker said.
By concentrating just on these patterns, scientists may have uncovered a beneficial technique for helping PTSD patients get better sleep. The idea may even help with other brain problems.