Introspection on insomnia

Vanessa De Mello explains the mechanisms that malfunction to cause this nocturnal nuisance.

Comic by Vanessa De Mello.

I write this lying awake at 2.38am, wondering why I can’t for the life of me sleep. To make the situation even worse, ‘Let it Go’ from Frozen is going over and over in my head. Do you ever suffer from this phenomenon? Do you find yourself constantly counting numbers, sheep, anything to shut down your mind, stop the annoyingly catchy songs from looping?

Insomnia: what is it?

Insomnia is my best friend; it even gives me a topic to write about when I can’t sleep. So what exactly is insomnia? Insomnia refers to the inability to fall asleep or stay asleep long enough to feel refreshed the next day. The most common symptoms (one of which I am facing now) are not being able to fall asleep and waking in the middle of the night and being unable to return to sleep. The following day brings feelings of fatigue and irritability. What causes insomnia? Stress, depression, schizophrenia, asthma, alcohol, drugs… For me right now it’s worrying that I won’t be able to fall asleep; a never ending vicious cycle.

How is our sleep controlled?

Sleep is thought to be regulated by two systems: a biological clock and something that acts like a ‘homeostat’ in the brain telling us when we’ve been awake for too long. So right now one of my two sleep inducing mechanisms has messed up; possibly from caffeine previously ingested.

Check your (biological) clock

Our biological clock regulates the periods when we feel tired and alert over 24 hours, creating daily rhythms in sleep and wakefulness known as circadian rhythms.

Our biological clock regulates the periods when we feel tired and alert over 24 hours, creating daily rhythms in sleep and wakefulness known as circadian rhythms. The clock isn’t composed of cogs and wheels but is instead made of nerve cells located in the brain; to be more precise, in the suprachiasmatic nucleu within the hypothalamus. The rhythm of sleepiness created by this internal clock dips and rises throughout the day, causing the strongest urge to sleep between 2.00–4.00am and 1.00–3.00pm. However, the circadian rhythm can vary between difference people, hence why you get morning larks and night owls. It is thought that the faster your clock is the more of a morning person you are, the slower it is the more of a night person you are.

The homeostat switch on the other hand works by regulating nerve cells in the brain that fire when you’re tired. Studies in the fruit fly have shown that if you remove this switch you end up creating insomniac flies. But it is still unknown how to activate the switch; which would come in handy for nights like this.

In a perfect world, both systems work together; your biological clock will tell you it’s the right time to sleep and your homeostat will have enough pressure built up to put you to sleep.

NOTE: SHORTLY AFTER WRITING THIS I FELL ASLEEP, FOLLOWED BY ANOTHER NIGHT OF INSOMNIA WITH 2 HOURS OF SLEEP.

About the Author

Vanessa De Mello Vanessa is a PhD student in the Musculoskeletal group at the University of Aberdeen, and works on the Hippo pathway in muscle stem cells. When out of the lab she likes to draw and sometimes sing.