The Importance Of Sleep For Brain Function: In Partnership With Neurohacker Collective
By Dr. Gregory Kelly, N.D.
Why Is Biohacking the Night Time Important?
In the fall of 2018, Neurohacker Collective started to turn some of our attention to sleep and nighttime physiology. We invested time learning about changes in brain neurotransmitters that occur as we transition from daytime to night, and how these impact sleep quality. We reviewed research on the circadian system, which is essential for generating robust sleep-wake rhythms. We looked into brain energy, because while we are asleep, the brain is still busy working, and work takes energy.
Long story short, we spent a lot of time learning about healthy nighttime function and the important jobs the brain does for us every night while we are asleep. We did this because about half of our lifetime will be lived during the night. We spend roughly one third of our adult hours sleeping. Yet, compared to daytime, the importance of darkness hours and sleep tend to be taken for granted.
For most of us, daytime is a period of doing. We are working, learning, exercising, eating, and interacting socially. Performing the many activities of daily life requires mental and physical energy. It’s easy to appreciate how much work the brain (and body) does during the day, because, naps aside, we are awake for every minute of it.
Compared to waking, when we are actively doing things, sleep seems like it is a time characterized by not doing. We can’t feel how active the brain is when we are asleep. But at night the brain and body are still busy, with many jobs to do, just different jobs than what takes priority during the day. And, during sleep, the brain is actively working; it’s busy doing tasks that are as essential for daytime performance as anything we do during waking hours.
“We sleep for a rich litany of functions, plural—an abundant constellation of nighttime benefits that service both our brains and our bodies. There does not seem to be one major organ within the body, or process within the brain, that isn’t optimally enhanced by sleep (and detrimentally impaired when we don’t get enough).”
Mathew Walker, PhD from Why We Sleep: Unlocking the Power of Sleep and Dreams
What Are Some of the Body Clock Changes that Prepare Us for Night … for Sleep?
Health is about what happens, and, at least as importantly, when it happens. Over the course of a day “when” will be determined by circadian rhythms (i.e., the body clock). The body clock influences cellular functions; it also controls the timing of most of the major jobs that organs and tissues do to keep us healthy.
Changes in body clock controlled functions are particularly important for shifting us into nighttime mode and for coordinating the processes that collectively produce quality sleep. Temperature, cortisol, and melatonin rhythms are body clock functions that directly impact the ability to sleep. A fourth important part of shifting into a more relaxing night is a neurotransmitter called GABA.
The early morning is when body temperature is at its lowest. It increases during the day and reaches its peak in the evening, typically about 12-14 hours after we woke in the morning. After reaching the peak, temperature starts to drop leading up to bedtime. The pre-bedtime drop in body temperature is part of the change in physiology that allows us to fall asleep naturally. This is the rationale behind taking a warm bath an hour or so before bed as a way to biohack falling to sleep—body temperature drops after getting out of the warm bath, which is a cue for sleep.
Cortisol is one of our stress hormones. It surges as we wake, reaching its peak between 7-9 am. During this early morning time window, cortisol promotes alertness, preparing us for a new day. The large rise in cortisol levels is the timing cue that informs the body and brain to get up and get going, to be ready for whatever stress the new day might bring.
In the evening, we should be winding down. Cortisol levels reflect this, falling during the evening hours and being at their lowest point in the late evening while in the beginning stages of getting a restful night’s sleep. The same is true for the fight or flight neurochemicals called epinephrine and norepinephrine, which are also part of the stress response. A key thing to keep in mind is that sleep should be a time when the brain feels safe and comfortable. Stress hormones signal that we shouldn’t be feeling either.
Not surprisingly, the stress system plays a large role in sleep. Stress leads to a state of “hyperarousal,” which means that the body, brain, or emotions are on higher alert and interfering with other processes that allow us to experience restful sleep. Some people are less, while others are more prone to stress interfering with sleep.
Taking actions to lower stress, to have a calmer more relaxed evening, can make a big difference in both the ease of falling asleep and the sleep quality we experience through the night. Adaptogenic and calming herbs can help support this lower stress state. Resting heart rate is a sign that can be used to gain insight into the stress system. A lower resting heart rate during the late evening, and an even lower heart rate during sleep, is a clue that stress chemicals are at the low levels needed for quality sleep.
Melatonin’s circadian rhythm is the mirror image of cortisol. Melatonin is lowest when cortisol is at its highest (i.e., in the morning). This acts as a signal that the finish line of sleep has been reached. Melatonin starts to rise sharply at about 9 pm and is at its highest shortly after we fall asleep (i.e., when cortisol should be at its lowest).
While melatonin is often thought of as a sleep hormone, it is a darkness hormone—it’s produced at night whether an animal sleeps at night (like humans) or during the day (like many big cats and rodents). Melatonin plays a vital time-keeping role, synchronizing sleep-wake cycles with other parts of physiology. In a sense, it is the signal that it’s time to begin the work that will occur during sleep.
The brain up-regulates the enzymes that produce melatonin at night: It will quite literally be doing its best to make more starting in the hours after the sun sets. Ensuring that there’s adequate amounts of what’s needed to make it—the amino acid L-tryptophan is a building block and vitamin B6 and magnesium are cofactors—supports melatonin production.
GABA (full name, gamma-aminobutyric acid) is the chief inhibitory neurotransmitter in the brain. Its principal role is in reducing neuronal excitability throughout the brain and nervous system. This means that GABA is important for promoting calmness and relaxation, decreasing stress, and inducing sleep. It can be thought of as being a braking system of sorts, slowing the brain so it can gently ease into sleep. Supporting the entire GABA braking system can help us shift gears into a relaxed evening that gets us ready for restful sleep.
What Does the Brain Do During Sleep?
Sleep is a time of work. While we are asleep, consciously unaware of our surroundings, the brain and body have lots of important jobs to do. Repair and rejuvenation processes dominate at night. Sleep is needed to recover from exercise and have the motivation to engage in activity the next day. Sleep strengthens the immune system. Good sleep is essential for looking and feeling physically younger. Sleep is a key factor that determines whether we stay in shape or get fat. All of these health areas are being influenced by work that is getting done while we sleep.
Sleep is not a uniform state. There’s non-rapid eye movement (NREM) and rapid eye movement (REM or dreaming sleep) sleep. Within NREM there are also different stages, with deep sleep being the most restorative (and the hardest to get as we age). The brain work done during both NREM and REM sleep are critical for mental performance, physical skills, and emotional wellbeing. Sleep plays a huge role in making sense of the information and experiences from the prior day and in preparing us for the next day. This sense-making and preparation relies on NREM and REM sleep.
During NREM sleep, things we learned during the day are moved from one part of the brain to other areas, shifting information from short-term memory, which is easily filled, to long-term memory. This transfer of information cements things we learned during the day. It also prepares the brain to learn new things the next day, freeing up the space in short-term memory we’ll need to temporarily store new information.
But sleep does not consolidate all the information from the day equally. Instead, during sleep the brain may choose what memories to keep … and what to actively forget … picking and choosing what’s important and what’s not. It takes a lot of work to decide what to remember, move this information around, and strengthen the related neural connections. It takes even more work to selectively strengthen some neural networks, while actively weakening others.
Sleep is essential when it comes to learning new motor skills. It’s a truism that practice makes perfect. But, sleep research strongly suggests that it’s the combination of practice during waking hours followed by sleep that makes perfect. No matter what sport, activity, or hobby, if motor skills are involved, the transition of skills from feeling effortful to effortless, from deliberate to automatic, from slow and inaccurate to fast and accurate, is enhanced during sleep.
Mastering skills and moving information around takes work and work requires energy. This is true when we are awake and equally as true during sleep. Short, powerful pulses of electrical activity during NREM sleep called sleep spindles do the work of moving memories around. The more sleep spindles an individual has at night, the greater the ability to move memories and refresh the capability to learn new information the next morning. And, the more powerful and frequent the sleep spindles, the more resilient we are to blocking out the external noises and other sensory experiences that might cause us to wake during the night.
Creating pulses of electrical energy requires work. The transition from being awake through the stages of NREM to deep sleep also has an energy cost, with many changes occuring in different parts of the brain. Not unsurprisingly, ATP—the chemical energy molecule made by cellular powerhouses called mitochondria—surges in several brain regions during the initial hours of sleep. This makes sense since, far from being inactive, the brain is preparing to do a lot of work and will need energy to do it. While we might not be actively moving muscles and thinking, mitochondria and their ability to produce ATP are not less important during sleep.
While brain activity during REM is very different than during NREM sleep, REM is also a time of doing. But the work done during REM sleep centers on the emotional and social brain. REM is when dreaming occurs. And both, the REM brain waves and dreaming, act together to support emotional resilience and social cognition skills (i.e., being in tune with our own emotions, reading facial expressions and body language of others, and having empathy). It’s during REM sleep when the brain overcomes psychological and social challenges that take place during the day and restores the capability to have emotional resilience and social cognition skills. Problem solving and creativity are also enhanced during REM sleep.
During sleep the brain will literally be trying to clean itself, eliminating waste products that build up during the day. This work is done by the glymphatic system. This system primarily functions while we sleep and washes away waste products by pumping cerebrospinal fluid through the brain. During the deep sleep part of NREM sleep, there is a dramatic increase in the cleansing of the brain. Factors like circadian timing and depth of sleep play roles in turning the system on and off, and in how efficiently it works.
This cleansing process appears to also play a role in getting the immune system ready for a new day. Sleep can be thought of as a time when the immune system does a lot of talking, listening, and replenishing, so that it can be alert and ready for a new day. Just a few nights in a row of less sleep (or poor sleep) are sufficient to weaken the immune system and increase our vulnerability to germs.
What is Qualia Night? Why Did Neurohacker Collective Create It?
Some of the reasons that individuals have difficulty with relaxing at night and getting quality sleep have to do with (1) the stress system, (2) circadian issues and melatonin production, (3) the GABA braking system that supports relaxation, and (4) brain energy production (i.e., mitochondria and ATP). These and other processes either support or interfere with experiencing a relaxing evening and a good night’s sleep.
The brain will be doing a lot of work while we sleep. We’ve touched on several important jobs. Work the brain is doing during NREM sleep is important both after and before learning new things. During sleep is when daily practice gets transformed into mastery. REM sleep is when work occurs that translates into enhanced daytime emotional resilience and social skills. The brain will be cleansing itself while we sleep, which is needed for long-term brain health and immune system refreshment.
The work the brain does during sleep is needed to perform at our best mentally, physically, emotionally and socially every day. It is these daytime experiences that are the signature, and ultimately a goal of sound sleep. You might say Neurohacker Collective had our eyes on the prize when we formulated Qualia Night. Our goal was to support a relaxed evening, sound sleep, and how people felt and performed the next day.
Qualia Night was designed to support the many different pathways and molecules the brain relies on to (1) de-stress in the evening, (2) get a good night’s sleep, (3) do work during sleep, and (4) wake feeling alert and ready for the next day. It does this by combining 25 carefully selected ingredients—Rasayana rejuvenators, herbal adaptogens, restorative nootropic ingredients, superfoods, and cellular antioxidants.
We designed Qualia Night to be a complete solution for refreshing sleep, stress support, enhanced next day performance, and long-term brain health. The brain will be doing a lot of important jobs leading up to and during sleep. Neurohacker Collective believes that it makes as much sense to support the brain in the evening as it does during the day. When nighttime function and sleep are supported, more brain work can get done, which helps us get more out of each and every day.
