(instrumental orchestral music)
- Hey there and welcome to Brain Stuff.
I'm Josh Clark and this is the Brain Stuff
where I explain to you how jet lag works.
So jet lag, also called desynchronosis,
is a collection of symptoms that
arise when we quickly travel across time zones
and it's the result of disrupting our circadian rhythms,
also known as our sleep/wake cycle.
We have our friends the chronobiologists,
people who study the effects of time on living systems,
to thank for our understanding
of just how jet lag works and just how bad it can be.
Jet lag all begins in the eye.
In your eye, you have specialized pigments
that are dedicated to sensing natural light
and when they do,
they send a signal to a tiny cluster
of about 20,000 neurons located in your hypothalamus
and this cluster is called the suprachiasmatic nucleus,
which is really fun to say.
Go ahead and say it yourself, I'll wait.
Yeah, see?
Now the suprachiasmatic nucleus
or SCN if you like to save time
and don't like to have fun saying things,
senses this natural light
and it sends out a signal to other parts of your body,
which are sleeping at the time
and that signal says, "Rise and shine.
"It's time to go ahead and get up and pee."
Then, as the day wears on and the sun starts to set
and the natural light that's picked
up by the pigment wanes a little bit.
Your suprachiasmatic nucleus says,
"Oh, it's starting to get time to slow down."
Once the sun sets, it releases a hormone called melatonin
and the melatonin puts you to sleep.
Then the whole thing starts over
again the next day when the sun comes up.
That's you sleep/wake cycle.
That's your circadian rhythm
and that's what gets messed up
when we travel from one time zone
to another time zone halfway around the world,
where the sun rising and setting
happens at a different timetable
than what your circadian rhythm is used to.
The effects overall are insane.
Now remember, the suprachiasmatic nucleus
is part of the hypothalmus
and the hypothalmus is a money gland in your brain.
It has its hands in all sorts of
different body system pots, right?
So, since your suprachiasmatic nucleus
is experiencing some weirdness,
your hypothalamus is as well, so when you have jet lag,
your body temperature will be messed up,
you will find yourself being ravenously hungry,
your urine production will increase or decrease,
depending on what your brain feels like doing at the time,
your blood pressure will rise,
stress hormones will flood your body,
your inflammatory response will be aggravated.
You will be messed up in profound ways
and our friends, the chronobiologists,
have informed us that the cumulative effects
of jet lag are actually worse than the acute symptoms.
We know this thanks to studies on poor mice and hamsters.
One study found that older mice
experience early death when they
are exposed to weekly jet lag,
which is terrible.
And another study, that involved hamsters,
found that these poor little hamsters
formed neurons at about half the rate
when they had jet lag than when they didn't.
The hamsters didn't ask for this.
So what do you do to get over stinky jet lag?
Well, there's a lot of tips and tricks out there,
some of which actually work.
One longstanding technique is that you,
before your trip, incrementally adjust
your sleep/wake cycle to match
what it will be when you get to your destination.
The thing is, this includes rising really, really early
or staying up really, really late before a big trip.
This technique obviously sucks though,
so how 'bout some other ones?
How 'bout melatonin?
Remember that hormone that your
suprachiasmatic nucleus helps release?
Well, it turns out you can find this in supplement form,
so you can take it to help yourself adjust
and it's just a pill that requires
no waking or staying up late,
which means it's obviously better than that first technique.
The thing is, is you don't wanna take these pills
or really any sleeping pill, on the plane.
While it may seem totally sensible
to sleep off jet lag going to or from your destination,
it's actually a really bad idea.
That's because on a plane,
blood clots can form in your legs,
if you just sit there in the seat for a long time
and remain immobile.
These blood clots can get loose
and travel up to your heart, your lungs,
your brain and kill you,
which is decidedly worse than jet lag.
Ultimately, while you're in the throes of terrible jet lag,
just remember, eventually your body should adjust to it,
as long as you're not an elderly mouse.
So how bad has your jet lag been?
We wanna hear all about it in the comments below.
While you're at it, go ahead and subscribe
and for even more awesomeness,
head to the great website How Stuff Works.