These Fighting Fruit Flies Are Superheroes of Brain Science | Deep Look

These Fighting Fruit Flies Are Superheroes of Brain Science | Deep Look


This episode is supported by the Great Courses Plus. Go to TheGreatCoursesPlus.com/Deep to learn
more. These fruit flies are throwing down. They’re like fruit fly gladiators. They lunge. Flip each other over. Roll around. And even toss each other, sumo-wrestler style. Normally, fruit flies don’t get this worked
up over a drop of apple juice. But these guys have had their genes manipulated,
something scientists have been doing to fruit flies for more than a century. Yep, these little insects that we only notice
when they get into our kitchen are unsung heroes of science. In 1910, biologist Thomas Hunt Morgan noticed
a rare white-eyed fly among his normal red-eyed ones. The discovery led to our fundamental understanding
of how genes get passed on from generation to generation. Since then, fruit flies have been key to figuring
out how human diseases work. That’s because, when it comes down to it,
fruit flies are more like us than you might think. They have about the same number of genes: 20,000 or so. In fact, 75 percent of the genes that make
humans sick are found, in a very similar form, in fruit flies. They’re a simpler version of us, a kind
of genetic mirror that scientists have used to learn about cancer, Parkinson’s, Alzheimer’s. And the fighter fruit flies? They’re helping researchers learn about
conditions that tap into our emotional states, like depression or addiction. Neuroscientist Eric Hoopfer – who studies
fruit flies in David Anderson’s lab at Caltech – flashes them with a red light. He has altered these research flies to be
sensitive to this light. It activates a cluster of neurons in the flies’
brains. And they fight. But change the intensity of the light, and
they do something very different. See how they’re vibrating just one wing? That’s fruit fly flirting. The researchers were surprised to see that
the same neurons controlled such different behaviors. What do fighting and “flirting” have in
common? In both, flies are pretty hot and bothered. These neurons control something like emotional
arousal. Pinpointing these circuits in their brain
could help us figure out where trouble starts in the human brain… and maybe one day, lead
to better treatments for mental illness. So the next time you see one of these guys
on your leftover piece of banana, you might want to think twice about swatting it. A little thanks might be in order instead. Thanks to the Great Courses Plus for sponsoring
this episode. The Great Courses Plus is a digital learning service providing a range of topics from educators. Start your one-month trial by clicking the
link below or going to TheGreatCoursesPlus.com/Deep. Hey guys. It’s Lauren. These flies seem to be having fun. If you’re curious about the amorous habits
of other animals, check out our video on newts. Every year they travel back to the pond where
they were born to get some underwater lovin’. And watch how garden snail babies are made. It involves a tiny spear called a “love
dart.” Thanks for watching.