Everyone dreams. We spend up to 2 hours each night dreaming but may not remember most of our dreams. The exact purpose of our dreams is not known, but dreaming may help process our emotions and consolidate our memories. Events from the day often invade our thoughts during sleep, and people suffering from stress or anxiety are more likely to have frightening dreams. Dreams can be experienced in all stages of sleep but usually are most vivid in REM sleep. Some people dream in color, while others only recall dreams in black and white. However, we are at least as dream deprived as we are sleep deprived. Many of the health concerns attributed to sleep loss result from a silent epidemic of REM sleep deprivation. REM/dream loss is an unrecognized public health hazard that silently wreaks havoc with our lives, contributing to illness, depression, and an erosion of consciousness. Emerging evidence suggests that REM/dreaming affects immune function, memory consolidation, mood regulation, as well as transpersonal, religious, or spiritual experiences. (reference)
Where do dreams come from? Researchers now say they know: A specific group of cells in the brain stem is responsible for controlling dreaming sleep, also called Rapid Eye Movement (REM) sleep, a new study says. The study also showed that damage to those cells could lead to a sleeping disorder called REM Behavior Disorder (RBD), which makes a person act out violent dreams. The findings have far broader implications than pinpointing the neurological source of dreams, though, said the study's principal investigator, John Peever, a professor of cell and systems biology at the University of Toronto. Because previous studies have shown that 80 percent of people with RBD develop incurable brain diseases, the new research could give drug companies a specific group of cells to target for therapies that slow the progression of neurodegenerative diseases. (reference)
According to Dr. John Peever, the cells in the REM sleep area are the first to be sickened, and then the neurodegenerative disease spreads up into the brain and affects the other areas that cause disorders like Parkinson's disease. During a healthy night's sleep, a person cycles through light sleep, deep sleep and REM sleep several times. During REM sleep, the neurons in the brain stem send signals to the brain's cerebral cortex as well as to the body's spinal cord, to prevent muscles from moving.
During healthy REM sleep, most people do not move around much, although some do twitch or talk. And although some people are known to walk in their sleep, sleepwalking is not a part of REM sleep, but a part of the deep-sleep cycle, when dreaming doesn't occur. In contrast, people who have RBD frequenis nottly have violent dreams and act them out during their REM sleep, injuring themselves and anyone who might be sleeping next them.
The disorder was first described by Dr. Mark Mahowald and Dr. Carlos Schenck, of the University of Minnesota. In their book, "In Principles and Practice of Sleep Medicine," published in 1985, the two doctors presented case histories of people with the disorder, including a 77-year-old minister, who behaved violently in his sleep, sometimes injuring his wife; a 60-year-old surgeon, who reported the feeling of being attacked, and who would jump out of bed during nightmares; and a 57-year old retired school principal, who mistakenly punched and kicked his wife while having nightmares.
Dr. John Peever indicates that studies done since then have showed that the vast majority of people who have RBD develop one of three progressive brain diseases. One is Parkinson's disease, which is a degenerative disorder of the central nervous system that afflicts the motor system. The second is dementia with Lewy bodies, which causes forgetfulness, fluctuations in alertness, visual hallucinations and trouble walking. The third is a disorder called multiple system atrophy, which affects the part of the nervous system that controls voluntary movement as well as involuntary movements, including blood pressure and digestion. Acoording to Dr. John Peever, REM Behavior Disorder is in fact the best-known predictor of the onset of Parkinson's disease.
See also: Bibliography, Booze and dreams, Dream cycles, Dream glossary, Dream recall, Dreams and brain disorders, Dreams as a source of inspiration, Food and dreams, Herbs for dreaming, Hypnagogic state, Lucid dreaming, Neuroprotective agents, Precognitive dreams, Recurring dreams, Shamanic dreaming, Sleeping brain, Sleep deprivation, Weed and dreams, WILD, Yoga Nidra