Monday, 30 April 2012

Jet lag

                Last Friday afternoon I was sitting in my favorite coffee shop in Vancouver, Canada. It was bright and sunny (shocking, I know, for all those familiar with rainy Vancouver), and I was WIDE AWAKE.
            Then I got on a plane.
            For nine hours.
            After a 6 hour delay.
            The plane was delayed again for an hour in a holding pattern over London Heathrow Airport.
            I finally arrived in London, England on Sunday night, tired, hungry and dying for a shower.
            By 2 am, I was WIDE AWAKE.
            4 hours and a giant snack later, and I was still WIDE AWAKE.
            By Monday afternoon I was ready for a mega-nap.
            Darn jet lag...
            I’ve now been in England for a week, and my sleep schedule is finally sorted out.
            Have you ever been jet lagged? Ever wonder why? The simple explanation is that it’s because you’ve just jumped forward or back a number of hours, and this screws up your sleep cycle. But there’s a lot of interesting information hidden in that little blurb.
            First of all, why do we jump forward or back? Do you know why London is eight hours ahead of Vancouver? (Hint: The answer is in astronomy, not in neuroscience.)
            Why we feel jet-lagged is a quirk of neuroscience. We all have a clock in our brains called the circadian clock. The clock is on a 24-hour cycle, just like a real clock. Every day the clock resets itself based on light.
            When it’s dark, the pineal gland in your brain releases a hormone called melotonin. Melotonin acts like a neurotransmitter. At night, melotonin levels are high, and you are sleepy. During the day, when it’s bright out, melotonin levels are low.
Melotonin levels change over the course of the day. Chart modified from www.ch.ic.ac.uk
            What happens if you suddenly jump forward eight hours, as I did last week? Your pineal gland can’t keep up with the sudden change. I landed in London at 7 pm (11 am Vancouver time). I’d managed a few hours sleep in the plane, and when I woke it was bright above the clouds. My brain thought it was morning. My melotonin levels were low. My pineal gland can’t read a clock, and didn’t know it was really 7:00 pm.
            Fast forward to 2 am that night (6 pm Vancouver time). My melotonin levels were still low, because my brain thought I was in Vancouver, where it was late afternoon. But it was actually the middle of the night. My melotonin levels should have been high. They weren’t. So instead of sleeping, I sat WIDE AWAKE in the kitchen of my cousin’s house reading a book and munching on toast and marmite. And cheesy crackers. An apple. I think there was a sandwich in there as well. Oh, also some brownies. I was hungry.
            The problem was that my body was in London, but my brain was still in Vancouver.
            It took a few days of normal, 24-hour cycling sunlight/darkness, for my brain to figure out that I wasn’t in Vancouver anymore.
            Now I’m well rested and happy. My melotonin levels are normal and I'm and loving my vacation!

Me...fast asleep

1 comment:

  1. Great post! I always wondered how Jet Lag manages to win every time. it's astronomy! :)

    ReplyDelete