Table of ContentsView AllTable of ContentsComponents of the RASSleep RegulationRAS DysfunctionTreatment
Table of ContentsView All
View All
Table of Contents
Components of the RAS
Sleep Regulation
RAS Dysfunction
Treatment
The reticular activating system (RAS) is a complex bundle of nerves in the brain that’s responsible for regulating wakefulness andsleep-wake transitions. It functions as a filter out unnecessary noise that can interfere with the processing of messages or slow the processing of messages during sleep.
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If the system is damaged, it can result in sleep problems, lethargy, or coma. It also can play a role innarcolepsyand degenerative brain disorders such asParkinson’s diseaseandprogressive supranuclear palsy (PSP).
Most Common Sleep Disorders
The RAS is composed of interlinked pathways that start in the brainstem located at the back of the brain. It then continues upward through the thalamus in the center of the brain and further on to the cerebral cortex (the thin layer of neural tissue on the surface of the brain).
Other components of the RAS situated deep within the brain include the midbrain reticular formation, mesencephalic nucleus, thalamic intralaminar nucleus, dorsal hypothalamus, and tegmentum.
The RAS releases chemicals that regulate motor function (movement) as well as emotions, wakefulness, and memories on the other.
Those involved in motor function is composed primarily of an organic chemical called acetylcholine, while those associated with consciousness and feelings are mainly composed of monoamine neurotransmitters such as dopamine, norepinephrine, and serotonin.
The RAS helps the brain gear up for a higher level of activity so that you can arise in the morning.Think of it as the brain’s attention center in which external stimulus is systematically organized into conscious thought. In order to get you up in the morning, the RAS responds to various triggers, such as the sun, sounds, and other external stimuli.
During the sleep-wake transition, the neurons will fire at a much slower rate, making organizing thoughts less coherent. This will give way to high-voltage, slow-firing brain waves that facilitatenon-REMsleep.
How the Loss of REM Sleep Affects Your Health
If the RAS becomes damaged in any way, it can affect both wakefulness and sleep.Such damage is often the result of atraumatic brain injury, such as anischemic strokeor a severe blow to the head injury.
Progressive supranuclear palsy (PSP),a degenerative brain disease often mistaken for Parkinson’s or Alzheimer’s disease, is also believed linked to RAS dysfunction.
With PSP, neurons in the brainstem and cerebral cortex develop abnormal clumps of protein called tangles. These tangles interfere with RAS pathways and contribute to cognitive impairment and sleep-wake dysregulation in people with PSP.
7 Diagnostic Tests for Sleep Disorders
People with narcolepsy are often treated with stimulants such as modafinil or armodafinil. Newer stimulants include solriamfetol and pitolisant. Less often, older stimulants that are used in people with attention-deficit hyperactivity disorder (ADHD) may be prescribed. Sodium oxybate is highly effective for treatment ofcataplexy, a feature of narcolepsy. Sometimes selective serotonin reuptake inhibitors (SSRI) antidepressants are used to suppress REM sleep to help alleviate symptoms of narcolepsy.
15 Sources
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