Do Bugs Have Brains?

Do Bugs Have Brains?


Hey there Brainiacs! Welcome back to Neuro Transmissions. And hey there, Inés. Hi Alie! I have a question for you. Why do neuroscientists study the brain? Well, I think that there are a lot of reasons. They want to better understand how our senses
work and find treatments and cures for different diseases and disorders. But I think a lot of neuroscientists really
just want to understand what makes ou human brains unique. Our brain is pretty unique. But what about the brains of other animals? Oh sure, we study those too. Monkeys, rats, mice, birds, fish… …Bugs? You would ask that. See, in addition to being an amazing YouTuber,
Ines is an entomologist. She studies the mechanics of how flies…well,
fly! Yep! My research focuses on how three species of
fly fly, and whether they do so similarly or differently. So even though I study the brain and Inés
studies insects, you might be surprised to learn that there is plenty of overlap between
those two. Because bugs DO have brains. And in fact, lots of neuroscientists are studying
insect brains, because their brains are pretty cool! Now of course, I knew that already, I just
wanted to hear you say it. Insect brains are so cool. They’re way smaller than ours, and kinda
less complicated, containing about a million neurons or fewer. For context, remember that the human brain
has about 100 billion neurons. That’s a hundred thousand times as many. In fact, unlike human brains, which have to
be folded up to fit inside our skulls, insect brains are more of a sort of simple ladder
shape. They’re made up of six ganglia, or clusters
of neuronal cell bodies. The first pair, called the protocerebrum,
mostly controls vision, while the next pair, the deutocerebrum, processes information coming
from the antennae. Finally, the tritocerebrum controls the labrum,
or mouth parts, and helps process information coming from the other parts of the brain. It also connects the brain to the ventral
nerve cord. Basically an insect’s spinal cord, except
they don’t have a spine, because they have an exoskeleton. And the stomodaeal nervous system, which controls
the insect’s internal organs. Because even insects have to know when they’re
hungry or in danger. These six ganglia make up the brain, but there
are other ganglia throughout the insect body, controlling lots of different functions, like
movement and digestion. This is because in insects, the nervous system
is sort of…scattered around. So the control of behavior isn’t so centralized
like it is in humans. The brain can control some things, but lots
of things like eating, moving, and mating, are controlled by the other ganglia. And so an insect, unlike a human, can survive
for quite a long time without a head. For example, cockroaches can live for weeks
after decapitation. But aside from being kind of cool and kind
of freaky, that doesn’t sound very helpful for understanding how our brains work, does
it? Well, you might be surprised. Some insects are actually very important models
in neuroscience. And one insect in particular. The friendly, unassuming fruit fly, drosophila
melanogaster. Hey, I know those! I actually study them. Fruit flies are those very tiny, annoying
brown bugs you might find in your kitchen if you’ve left out your bananas for too
long. They’re very popular in research because
they’re easy to breed and raise in the lab and we’ve got lots of genetic tools to help
us manipulate their DNA. And, we share about 60% of the same genes. Fruit flies only have about 130,000 neurons. Which is…still a lot, but a lot less to
deal with than you’d find in a mammalian brain. Their brains are actually really unique. See, in human brains, we’ve got gray matter,
where most of the cell bodies hang out, and white matter, which are big tracks of axons
that send signals from brain region to brain region. And in our brains, the grey matter and white
matter are sort of grouped in different areas, and kind of wrap around each other. But in the fruit fly brain, all of the cell
bodies, the gray matter, is grouped on the outside of the brain. And all of those axons and dendrites fill
up the middle of the brain, sending signals back and forth. And unlike in humans, where scientists think
about half of the brain is made up of glia, fruit fly brains are only about 10% glia. And form a sort of sheet over the outside
of the brain. Scientists are working on creating a full
fruit fly connectome right now. That means they’re trying to map every single
cell and every single synapse in the fruit fly brain. Mapping the whole fruit fly brain will make
it easier for scientists to figure out how individual cells and circuits play roles in
different kinds of behaviors, which can help us understand at a smaller level how similar
cells and circuits might play a role in our own behavior. Lots of labs have been discovering really
fascinating things using fruit fly brains. In fact, the 2017 Nobel Prize in Physiology
or Medicine went to Drs. Jeffrey Hall, Michael Robash, and Michael Young for their study
of how genes affect circadian rhythms in fruit flies. They figured out how a couple of genes change
their expression over a 24 hour period. A sort of cellular clockwork that keeps animals
moving on a regular daily cycle. That’s so cool! And I’ve heard that scientists continue
to discover really interesting things studying fly brains, using all kinds of amazing techniques,
like optogenetics, which lets them turn different kinds of neurons on and off. By changing which cells are signaling when,
they can influence how the fly behaves under different conditions, which can tell us something
about how the circuits in the brain play different roles in behavior. So next time you start swatting those fruit
flies in your kitchen, think twice. You might be destroying someone’s PhD project. Oh no, we don’t want that! Inés, thank you so much for joining us today! Thank you so much for having me on! Head over to Inés’ channel Draw Curiosity,
where you can find all kinds of science videos to stimulate your curiosity. And now that we’ve talked about the insect
brain, you can check out our other collaboration video on her channel to tackle the next big
bug question: Do insects feel pain? Thanks for watching this episode of Neuro
Transmissions. Until our next transmission, I’m Alie Astrocyte. Over and out!

32 thoughts on “Do Bugs Have Brains?”

  1. It was so much fun to work on this collaboration together – thank you for having me on and talking bug brains with me! 🐞

  2. Brainiacs, if you have not subscribed to Draw Curiosity yet, do yourself a favor: https://www.youtube.com/channel/UCOs_jEnQF2ePJzjJTgRtunA

  3. This was really cool! It always blows my mind that fruit flys are such a good model for understanding our own brains.

  4. Excellent presentation. It gives me a whole new perspective on pesticides (which was one of my fields of research). Unfortunately you have burdened me with new questions that forces me to do some additional reading. Inés is a brilliant communicator and the two of you make a great pair. I enjoyed this video very much. Thank you.

  5. Drosophila? Tagging PZ Myers here! (Oh wait that's not how this website works.)

    Thanks for the buggy video I mean video on bugs!
    =8)-DX

  6. 👋🏾Hi Inés. Hi Alie! Great video! Very informative. I have 1 question and 1 observation:
    1) Nice visual pun at 3:10. 60% of genes/jeans 😄
    2) Have you seen the Pickle Rick Episode of Rick and Morty?

  7. Ganglia is a personal favourite word of mine, so any excuse to hear that again gets a thumbs up from me.
    Super interesting, it was great fun watching your two respective study fields come together. Well done, ladies!

  8. Today we make a connectome(?) of the fruit fly and tomorrow we will emulate a human. After all, computer science isn't scared of big numbers. 100.000 fold increase is easy enough to do in 10 years. Sounds like a way to superintelligence.

  9. i’m watching this because i just called a bug a “dumb ass.” then i wondered & here’s your glorious video

  10. welp time to trap several botflies in a container, rip off their wings as they turn into adult flies and burn them slowly in thinner or fire

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