Biologists have shown that a functioning circadian system is critical to hamsters' ability to remember what they have learned. Without it, in fact, they can't remember anything.
Hamsters whose circadian system was disabled consistently failed to remember their environment, unlike hamsters with normally functioning circadian systems.
Until now, it has never been shown that the circadian system is crucial to learning and memory. The change in learning retention appears to hinge on the amount of a neurochemical called GABA, which the circadian clock uses to control the daily cycle of sleep and wakefulness.
This is another great example of the crucial role sleep and your circadian clock play in your overall health and the quality of your life.
The Stanford University study cited in this article is groundbreaking in that it demonstrates that your circadian system – or internal body clock -- must be in optimal condition in order for you to learn new information and remember it.
One of the worst things you can do to disrupt your body clock is to engage in regular night shift work. I realize many may not have a choice in selection of their job but it is vital to understand when you regularly shift your sleep patterns because of a job like police, fire or ER work, then you are simply sacrificing your longevity as if you engage in this shifted sleep period for many years you can easily knock ten or more years off your lifespan.
A Good Night’s Sleep Can Keep Your Memory Intact
In brief, your circadian clock controls your daily cycle of sleep and wakefulness by alternately inhibiting and exciting different parts of your brain through regulation of the release of certain neurotransmitters. The part of your brain known as the hippocampus must be excited in order for the things you learn to be organized in such a way that you’ll remember them later.
If your internal clock isn’t functioning properly, it causes the release of too much GABA, the brain inhibiting neurotransmitter. According to the results of the Stanford study, an excess of GABA inhibits the brain in a way that leads to short term memory problems and the inability to retain new information.
Honoring Your Biological Rhythms
Your circadian rhythm has evolved over many years to align your physiology with your environment. Your body clock assumes that like your ancestors, you sleep at night and stay awake during daylight hours.
If you confuse the situation by staying up very late, or depriving yourself of enough hours of sleep, or eating meals at odd hours (times at which your internal clock expects you to be sleeping), you send conflicting signals to your body. In response, your body will produce ‘sleep chemicals’ during times when you need to be awake and alert, and ‘awake chemicals’ when you need rest.
Based on the implications of this study, it’s easy to see the relationship between a compromised circadian system, unhealthy sleep patterns, and memory problems – especially in an aging population.
High-Quality Sleep Tunes Your Body Clock
Regardless of your age, the best way to keep your circadian clock functioning properly is to make sure you’re getting the necessary amount of high quality sleep, during those hours when your body expects to be sleeping. The right amount for you is based on your individual sleep requirements and not on a one-size-fits-all prescribed number of hours.
A good night’s sleep is an essential requirement for being healthy, regardless of your age. You can do everything else right – eat nutritious meals, exercise, manage stress – but if you aren’t getting high-quality sleep, you simply won’t be healthy.
Your individual circadian rhythm regulates activity throughout your body, from your brain, to your lungs and heart, to your liver, to your skeletal muscles. Your internal clock keeps all your organs and systems running smoothly.
Your Body Clock and Your Weight
A disrupted body clock can wreak havoc on many areas of your health, including your weight.
Lack of sleep has been shown to affect levels of two hormones linked with appetite and eating behavior. When you are sleep deprived, your body decreases production of leptin, the hormone that tells your brain there is no need for more food. At the same time it increases levels of ghrelin, a hormone that triggers hunger.
Your Body Clock and Cancer
Overnight shift work is a probable carcinogen because it disrupts your biological clock. This disruption may influence cancer progression through changes in hormones like melatonin, which your brain makes during sleep, and which is known to suppress tumor development.
Melatonin is an antioxidant that helps to suppress harmful free radicals in your body and slows the production of estrogen, which can activate cancer. When your circadian rhythm is disrupted, your body may produce less melatonin and therefore may have less ability to fight cancer.
More About Sleep and Your Brain
In addition to the problem with memory reported in the Stanford study, lack of sleep can also harm your brain due to elevated levels of corticosterone, the stress hormone associated with road rage.
When your body is under stress, it releases hormones that increase your heart rate and blood pressure. Your muscles get tense, your digestive processes stop, and certain brain centers are triggered, which alter your brain chemistry.
Left unchecked, this stress response can eventually lead to a variety of health problems including: