You are sitting in your first-period class, eight hours of school ahead of you. Nevertheless, you make it through the day and return home, only to be immediately bombarded with homework. After such a long and grueling day, you are looking forward to a blissful, nine hours of sleep. But, once you head to bed, you find yourself lying awake, your exhaustion wholly and utterly missing.. Looking for something to blame? Hypocretin is the answer.
Hypocretin, in short, is the leading cause of insomnia and narcolepsy. It is the reason you struggle to stay awake during the day and fall asleep during the night. Hypocretin also is thought to affect ADHD and various other mental issues, such as depression. It is essentially a molecule found in your brain, that when regulated, helps you maintain a regular sleep schedule. Although the discovery of hypocretin, or orexins, is fairly old, new research has further assisted scientists in determining the true science behind sleep.
Though mostly associated with harmful conditions, hypocretin was actually meant to be a beneficial particle. As mentioned before, when appropriately regulated, it promotes healthy sleep patterns. If a person is stuck in a sleep deficit, it leads to narcolepsy, a disorder that makes people feel very drowsy during the day. Eventually,, insomnia (the inability to fall asleep at night) ensues. The amount of hypocretin in an individual depends on the hypocretin gene, which controls how much of the molecule is made. Through research, scientists have determined that low levels of hypocretin are due to an autoimmune reaction. Autoimmune reactions are diseases which cause the body’s immune system to attack perfectly healthy cells. In the case of hypocretin, the autoimmune reaction attacks hypocretin proteins, resulting in a decreased concentration of the substance. Receptors, or parts of the cell that receive the hypocretin, also play a large part in the regulation of the molecule. Scientists have found that controlling these receptors can be essential in preventing the development of such sleep-related neurological conditions. Mutations, or permanent changes, are also common in the receptors. In one study, a heritable form of narcolepsy was caused by a mutation in one of the receptor genes responsible for hypocretin.
Although gene expression (mRNA directs ribosomes to create proteins) mainly produces hypocretin, there are other small molecules that play their part in this elaborate system. Specifically, we have microRNAs. MicroRNAs function as little helpers to regulate proteins. They work almost like worker bees in a bee colony, helping to make sure they have enough honey. They go around and make sure hypocretin is at its homeostatic amount (correct amount). MicroRNA can also be blamed for narcolepsy to a certain extent. If mutated, the microRNA found in the brain can end up making you feel more tired during the day due to its inability to amplify the hypocretin being produced.
Although we can blame hypocretin for conditions related to sleep, there are other important regulators of sleep. One of these is the circadian rhythm. In theory, the circadian rhythm, or cycle, is the physical, mental, and behavioral changes the body experiences in 24 hours or a day. The cycle is affected by levels of light and dark, and is controlled by the brain. Our bodies have a natural circadian clock that lets us know when we need to sleep, and if the body does not receive the appropriate amount of light, the cycle is pushed back. Experiments have shown that if you are exposed to light earlier in the day, you get tired faster in the evening, but if you experience light towards the evening, sleep becomes hard to find.
Although hypocretin and other sleep molecules do play a major role in sleep-related conditions, you can still control your own sleep, especially by maintaining a proper sleep schedule. Keeping a healthy circadian clock makes it easier to fall asleep at night, and maybe the next time you head to bed after a long day at school, you can get those nine hours.
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