The Importance of Sleep with Alzheimer’s

The brain is programmed to “clean mode” at night that washes away waste products. Poor sleep could make this cycle less effective and leave Alzheimer’s toxins to build up.

Study findings: Researchers studied the brain of 13 participants asleep and awake. They discovered that, during deep sleep, the brain is washed by coordinated waves of cerebrospinal fluid which can remove waste products. The authors noted that these waves are not as strong in people with memory impairment, and chronic sleep problems can lead to the accumulation of beta-amyloid, a protein linked to Alzheimer’s disease.

Why it matters: Alzheimer’s disease is the main form of dementia, and the number of people diagnosed with dementia is expected to grow by 204% worldwide by 2050. Understanding the role that sleep can play in healing the brain, and how it can be disrupted, are critical in the search for a cure and preventive measures.

The final word: The study’s findings reveal the synchrony of processes that enable waste clearance, and suggest how this may, in the future, help to explain what role sleep quality plays in Alzheimer’s disease. The authors recommend more probing studies to identify what may influence these nocturnal cleaning “rhythms”.

Sleep: the brain’s housekeeper

Sleep flicks the switch that allows the brain to go about maintenance work without being interrupted by the pesky activity of a conscious mind.

There are several stages and depths of sleep, and you cycle through them several times per night. When you start to nod off, you are at stage 1 of non-rapid eye movement (nREM) sleep. Once you sink a bit deeper, you’re into nREM stage 2, during which your body temperature drops and your heart rate starts to slow.

Stage 3 of nREM is one we’ll discuss in this article. It is the deepest sleep: your blood pressure drops, your muscles relax, and your breathing is slowed. And this is the time your brain has set aside to clear out the waste. It’s followed by rapid-eye movement (REM) sleep when you dream, your eyes flick around, and your brain is more active. Then it all starts again.

Deep sleep, deep clean

For many centuries, the brain had the scientific community stumped because they couldn’t figure out how it got rid of metabolic waste.

The central nervous system, which includes the brain, doesn’t have a lymphatic system like the rest of the body. Scientists found this very curious because this system is responsible for removing waste products and toxins from the body. In fact, for many centuries, it was believed that the central nervous system of mammals was simply devoid of lymphatic activity.

The idea of getting a cerebral spa treatment every night is appealing

However, that left an important question unanswered: how on earth does the brain rid itself of rubbish? Thanks to new technologies and determined scientists, we now know that the brain has its own way of doing things. Firstly, it does have lymphatic vessels, and they can be seen on a correctly tuned magnetic resonance imaging (MRI) scan.

But that’s not all, as this paper helpfully reminds us. The brain is much classier than initially thought: it repeatedly rinses itself in cerebrospinal fluid (CSF) every night. Your brain and spinal cord bathe in this clear, colourless fluid all day, and at night, waves of it surge over the brain and clear it of metabolic waste.

It takes three baby

Three synchronised actions allow the brain to clear out the byproducts of metabolism and other waste products that accumulate each day.

A team of seven researchers, led by Nina E. Fultz, looked for the missing piece of a messy puzzle that included brain waves, blood, and cerebrospinal fluid. It was already known that our thinking organ emits brain waves (tiny electrical pulses) that make our neurons fire in a specific region. The same goes for CSF — scientists already knew that it could remove metabolic waste products.

Yet, it was unclear whether these processes are related, and if so, what is their purpose. Fortunately, these intrepid scientists intervened to solve this nail-biting enigma. They put 13 slumbering (and sometimes, waking) people through their paces with new and old technology.

That cat is rolling in Delta waves

They attached electrodes to their subjects’ heads, measuring electric impulses on the outer layers of the brain (the cortex), a non-invasive technique called electroencephalography (EEG). Participants also underwent functional MRI scans that could show changes in cerebrospinal fluid and blood flow.

When the scans were in, the team compared the timing and effect of these three parameters and concluded that these features are synchronised. So, in order for the brain “washing” to function, it requires three steps. A slow brain wave breaks across a network of neurons, which triggers an increase in CSF and a decrease in blood flow (which probably makes room for the cerebrospinal fluid to wash over the brain).

What’s it got to do with Alzheimer’s?

There are brain waves for each level of cerebral activity, and they can be disturbed in patients with specific diseases.

Brain waves coordinate levels of activity in this organ, so it should come as no surprise that they can be disturbed in different diseases. People with Alzheimer’s have fewer and smaller Delta waves, the long slow waves that occur during deep sleep (nREM stage 3), and this research may help understand why.

Poor sleep quality is an important feature of Alzheimer’s, but it could be poor sleep quality and thus fewer, weaker Delta waves during a person’s lifetime that might influence clinically significant aspects, like the accumulation of specific proteins associated with this disease.

There are two proteins in the brain that were identified in the pathology of Alzheimer’s: beta-amyloid, which accumulates in plaques, and tau, a protein that is found in cerebrospinal fluid. Other studies have shown that wakefulness can increase levels of tau protein and that chronic sleep deprivation can increase beta-amyloid plaque accumulation.

Read the study here

This study postulates that disturbances in this nocturnal process of brain “cleaning” may explain why these proteins accumulate in the brain. By demonstrating that three separate actions are required for effective removal of metabolic waste during deep sleep, they suggest it might be the first step to uncovering how disturbances in this harmonious process may allow these proteins to accumulate in the first place.

TIPThe Atlas DNA Test checks for Alzheimer’s disease risks and recommends a full night’s sleep (7-9 hours) as a preventive measure.

Learn about how sound can help aid your sleep process:

Why Walnuts Are A Good Snack To Eat Before Bed

The Right Noise – Pink, White ,Brown, Blue, Black, and Red Noise: Your Guide to a Good Night’s Sleep

How to Sleep Better: Your Guide for Good ZZZ

Everything You Need To Know About Magnesium And Sleep

Optimizing the Sleep-Wake Cycle

How to Reset Your Sleep Cycle When You Live With Insomnia

The Importance of Sleep with Alzheimer’s

What You Eat Affects How You Sleep

GABA & L-theanine mix Improves REM Sleep, Stabilizes mood and helps with depression

What Happens When Circadian Rhythm Is Off? Learn More

Do You Wake Up Every Night At The Same Time? Learn More

How to Reset Your Sleep Cycle When You Live With Insomnia Learn More

What You Eat Affects How You Sleep? Learn More

GABA / L-theanine mixture Improves REM Sleep, Antidepressant, and Mood-stabilizing Study Says Learn More

Male Brain versus Female Brain

MALE BRAIN
Temporal Parietal Junction
The place where the temporal lobe (responsible for auditory functioning, memory and speech cognition) and the parietal lobe (responsible for sensory information) meet. It is more active in males, MRI’s have shown. TPJ works to cognitively process emotion, which strengthens their ability to cognitively and analytically find a solution to emotional problems as opposed to empathize – which women are more likely to do, says Louann Brizendine (author of The Female Brain).
Size
Men have 9% bigger brains, even after correcting for body size. But men and women share the same amount of neurons, they’re just more densely packed in a woman’s brain.
Gray Matter
Men have as much as 6.5 times the amount of “gray matter” as women, according to a study conducted by the University of California, Irvine. Gray matter is associated with information processing, which might explain why some men excel at spatial intelligence and mathematics. Many experts take issue with this leap in logic.
The infidelity gene?
Several studies, including one at Johns Hopkins, have found that the length of the vasopressin receptor gene, a brain hormone, corresponds to monogamy. The first study was conducted on a prairie vole, which is one of 5% of mammals who are monogamous. A closely related “cousin” called the montane vole is more of a polygamist. Scientists found that the montane vole had a short vasopressin gene while the prairie vole had a longer one. When the scientists injected the trampy montane with a longer gene, he suddenly became a one-woman vole. Scientists have extended the study to human males, finding that the longer the gene (there are 17 known lengths), the more likely a man is to be married or in a monogamous relationship; the shorter, the more likely he is to be a bachelor.
Parietal Cortex
The part of the brain responsible for spatial and somatosensory (sensations in skin and tissue) perceptions is bigger in men, according to recent studies. Some scientists believe this helps to account for better spatial intelligence in men.
Hypothalamus
Area in the hypothalamus, which among other things manages memory, controls body temperature, hunger and thirst, has a component for sexual drive that is 2 1/2 times bigger in males than females, Brizendine says. Accordingly, men are constantly bombarded by sexual images that “flicker in the visual cortex all day and night.”
Periaqueductal Gray
The PAG, known as the “central gray,” is gray matter located near the midbrain. It helps control pain. During sex, the site suppresses pain and increases pleasure. It’s more active during sex in the male brain.
Ventral Tegmental Area
The VTA is the “motivation center” of the brain, located deep at the mind’s center. It manufactures dopamine, a feel-good neurotransmitter for motivation and reward. The VTA is one of two primary sites where drugs like cocaine, heroin and other narcotics act on the brain. It’s more active in men, which may be a clue to why more alcoholics and drug addicts are male, acording to Brain Rules by John Medina.
Amygdala
Known as the “fight or flight” center, the almond-shaped amygdala – there are two, one on the right side, one on the left – is the alarm system for threats, fear and danger. It drives emotional impulses, and triggers protective aggression. It’s larger in men than in women, meaning that men are more likely to have “short fuses” and be driven to physical action, Brizendine says.
Dorsal Premammillary Nucleus
The DPN that lies deep inside the hypothalamus and contains special circuits to detect territorial defense, fear and aggresion is larger in males. The larger size might make males “more sensitive to potential turf threats”, Brizendine says.

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