Melatonin takes a main role of regulating circadian and it is linked to the light and dark cycle. When people under a light environment, the secretion of melatonin is less than people in dark environment. It shows that the brightness of environment, include artificial lights, will influence the secretion of melatonin. Although it does not directly affect the sleep quality or induction of sleep, it has a main side effect of drowsiness and maintain the order of sleep-wake cycle. Therefore, decreasing the secretion of melatonin can help people maintain arousal and less likely to sleep. The methods below may help reduce sleep.
Staying under a bright light environment can let people have higher alertness. Evening is the period that melatonin start having higher level secretion and the sun goes down and have dimmer light. According to research, bright light exposure will suppress the secretion of melatonin and delay the sleep wake cycle. According to the journal, working college students have an increase in alertness and decrease in sleepiness when exposure to the bright light environment during evening, 7p.m. to 9 p.m. Some similar studies show that there is a reduction in salivary melatonin among secondary school students compare to control group when under bright light at night. So if human were under bright light environment in a very long period, their sleepiness can be decreased and suppresses melatonin in a lower level. Human will less motivation to go to sleep.
Besides the method of suppress melatonin to reduce sleep, we can also activate the dopamine receptors and orexin receptors to boost our wakefulness and attention. These may help solve the problems of deficits in concentration, motivation, perception when lack of sleep.
Modafinil is a agent that is wake-promoting and it influenced neurotransmitter systems such as dopamine, GABA and orexin. It is originally made for curing daytime sleepiness and narcolepsy. To bring up the arousal effects of Modafinil, Dopamine receptors is essential. Under the mice experiment, the mice with 180 mg/kg dose of modafinil can maintain wakefulness for nine hours, reduce REM sleep for 98%. This compound is significantly to increase the wake time to the wild type mice.
It will block the dopamine receptor to cause the brain have higher dopamine rate. This medicine is considered as safe because the participants do not have amphetamine-like withdrawal when stop the drugs. However, it contains some side effects such as anxiety, depression, psychosis and dyskinesia. It is not an ideal drug that can maintain living quality when take it for long period not sleeping.
Orexin/ hypocretin neuron system is taking a main role in staying wakefulness and regulating sleep-wake cycle. the neuropeptides Orexin-A and Orexin-B with their receptors can be found in mammals. The activity of orexins is highest in the waking time and lowest during slow wave sleep. It is a connection with alertness and food seeking locomotor activity.
In a research of using orexin-A, the test subjects, monkeys, can maintain 30 to 36 hours awake and able to engage cognitive task. It is effective in reducing the cognitive deficits of loss of sleep. If we can maintain the high activity of orexins system or increase the dose of orexin of our brain, we may able to stay alertness for a long period with no side effects of low motivation or low concentration. Nevertheless, it is uncertain that can it be a kind of medicine that can widely used by public and it needs further research.