That Neuroscience Guy - Neuroscience Bites: Jet Lag

Episode Date: April 14, 2022

Long flights over time zones can cause serious jet lag; general mind and body fatigue. In today's episode of That Neuroscience Guy, we discuss the neuroscience behind why we get jet lagged. 

Hi, my name is Olof Kergolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to another Neuroscience Bite. I won't lie, I'm tired. I'm in Toronto, Canada, and I just took the red-eye flight from Vancouver, and I'm jet-lagged. And I was sitting on the up-train heading into downtown Toronto, and I started thinking to myself, well, I know a bit of the neuroscience around jet-lag, but what else is there? Well, the biggest one that most people probably could guess is what

are called circadian rhythms. Our body has a natural master clock. It's in a place called the suprachiasmatic nucleus or the SCN. It's just a small collection of about 20 to 30,000 neurons. But these neurons, their job is to basically keep track of time. And the SCN is sensitive to things like light, which is why those of us that have to work graveyard shifts or fly overnight struggle sometimes. And what the SCN is doing is it's creating these circadian rhythms. It's releasing hormones and other things into the bloodstream that help you be awake when you're supposed to be awake and help you fall asleep when you're supposed to fall asleep. A lot of us that travel a lot know all about melatonin, and some of you probably do.

Well, melatonin is one of the things that's released as a part of your circadian rhythm, and the body typically tries to release it as it gets dark and you're heading towards bedtime, and that's to help promote a good healthy night's sleep. So what does jet lag do? Well, probably the biggest thing that it does is it disrupts your circadian rhythm. When you're supposed to be awake, you're actually trying to sleep. And when you're supposed to be asleep, you're actually awake. And your body can adapt pretty quickly. Some of us do it better than others.

But it's just your body trying to adjust that master clock because the master clock is still wired to your home time zone. But that's not all. Circadian rhythms aren't the only thing that gets disrupted. For instance, there's been a really cool recent fMRI study, if you remember, functional magnetic resonance imaging, looking at people that were jet lagged. They put them in the scanner basically right after they got off a very long flight. And what they found was other mid brain structures, such as the basal gang structures, such as the basal ganglia

and the thalamus, there was a lot greater reduction in activity compared to healthy controls. And these are the midbrain structures that kind of help run things like the SCN. They're sort of the executive control or the government of the circadian rhythm clock. So these regions are reduced as well, which means that the clock is having a harder time, which means the clock is having a harder time trying to adjust. And finally, another thing that's been found is that there's increased connectivity between different brain regions. This is a bit of a tough one to tackle, but basically when brain regions are working to solve problems, you want them to work

together, but not too much. If they work together too much, that actually disrupts proper normal function, which is why you might feel a little bit off when you're jet lagged. And that's a typical finding in people that are jet lagged. There is increased connectivity between brain regions as the brain's clock and other brain regions are trying to sort themselves out. In terms of the neuroscience of jet lags and getting over them, there's not much you can do. It's the usual tips. Exercise, eat healthy, and try to get a good night's sleep.

My name is Olaf Kregolsen, and I'm That Neuroscience Guy. Please don't forget to check out the website, thatneuroscienceguy.com. There's links to our blog, to our merch, to Patreon, where you can support us, and of course, to our merch, to Patreon, where you can support us. And of course the podcast itself. And I'll see you on Sunday with another episode of That Neuroscience Guy. Thanks again for listening.