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How studying fruit flies and zebrafish might unlock secrets of the human brain

July 23, 2014 at 6:26 PM EDT
The fruit fly has a very long and distinguished career in science. At a facility considered a Nirvana for scientists, researchers pursue greater understanding of biomedical processes, using test subjects like dragonflies and zebrafish. Science correspondent Miles O’Brien reports on how the Janelia Farm Research Campus supports groundbreaking basic research.

GWEN IFILL: Next: trying to better understand what’s happening in the brain of a fruit fly, a dragonfly, or a zebra fish, all part of a larger puzzle to learn more about how our own brains work.

NewsHour science correspondent Miles O’Brien has the first in our three-part series on the science of the brain.

MILES O’BRIEN: Oh, to be a fly on the wall at the Basic Research Facility scientist consider nirvana. You might see a Nobel Prize in the making or you might be subjected to this, the fruit fly version of a scary movie, the rapidly growing shadow of a predator homing in for the kill.

GWYNETH CARD, Howard Hughes Medical Institute-Janelia Farm Research Campus: My lab is really interested in how flies make decisions.

MILES O’BRIEN: Neuroscientist Gwyneth Card runs a laboratory at the Howard Hughes Medical Institute-Janelia Farm Research Campus near Washington, D.C. She films fruit flies at 6,000 frames per second to better see what they do and eventually she hopes understand how their brains issue commands and their bodies turn that into lifesaving action.

GWYNETH CARD: One of the interesting things we have discovered is that if you show a fly one of these scary movies, they actually don’t do one particular thing knee-jerk reflex. They actually do a whole sequence of behaviors that’s quite flexible and quite varied.

MILES O’BRIEN: This is why we can’t swat a fly.

GWYNETH CARD: This is exactly why it’s really hard to swat a fly.

MILES O’BRIEN: This is the kind of question that bugs a neuroscientist in another lab here, Gerry Rubin. He has spent his entire career studying fruit flies, also known as Drosophila.

GERRY RUBIN, Executive Director: Fruit flies have a very distinguished and long career in biomedical research, mainly because they breed like flies.

MILES O’BRIEN: But the bugs are more than rapidly prolific. They can do a lot of very interesting things and, compared to humans, are much easier neuroscience test subjects.

GERRY RUBIN: These are very complicated calculations done by a very small biological computational device. If — we feel, if we could understand how those actually work, then we would know something important about how every brain works, including our own brains.

MILES O’BRIEN: Rubin not only runs a lab here, but the overall facility as well.

In fact, it’s his baby. He hatched the idea in 2002, the doors opened in 2006, and right now it houses 350 scientists working in 42 labs and on five collaborative teams. It is a well-oiled machine, to be sure, robotic efficiency. They feed, breed, bar code and house more than a million insects here, hoping they might hold answers to some of the most challenging problems in basic biomedical research.

It is funded by the Howard Hughes Medical Institute, for the record, also a NewsHour underwriter. HHMI plans to spend $50 million to $100 million a year for at least 20 years here, giving the best and the brightest scientists what amounts to a blank check to do their work as they see fit.

GERRY RUBIN: So, we could bring together an unusual group of people, protect them from the real world, put them in a place where they just had to focus on their science, encourage them to work together, encourage them to work on challenging problems, and give them the freedom to do it, and see what happened.

MILES O’BRIEN: Rubin modeled Janelia after a workplace on his resume, the legendary Bell Laboratories founded by AT&T and Western Electric in 1925. It attracted the best scientists from virtually every discipline, encouraged them to collaborate and gave them the freedom and funding to conduct basic research, even if there was no obvious profit-making application evident.

Over the years, Bell researchers made big strides in the realm of basic science. They discovered cosmic background radiation, and thus the Big Bang theory, but they also invented some game-changers in the marketplace, including the transistor, the laser and the charged couple device. The lab garnered seven Nobel Prizes in all.

But in recent years, corporate funding of fundamental science with long-term goals has all but vanished, and federal funding for basic science has dropped precipitously.

GERRY RUBIN: I think there’s a broad recognition that there is a way the federal government chooses projects to fund, the way it supports them is — tends to cut out the most creative work.

MILES O’BRIEN: To pursue a greater understanding of neuroscience, Janelia scientists and engineers work in close collaboration to build new tools of discovery.

Developmental biologist and neuroscientist Philipp Keller showed me his amazing light sheet microscope.

PHILIPP KELLER, Group Leader, Janelia: So, this is a setup that is designed to basically minimally interfere with the normal development, the normal function of the biological sample.

MILES O’BRIEN: Living samples are bathed in laser light and recorded by two fast digital cameras to generate three-dimensional movies of biological processes. This is a Drosophila embryo from three hours after fertilization until it hatches 24 hours later.

PHILIPP KELLER: Every single little blob in this movie is one cell. We have tens of thousands of cells at this point in development. You can in fact now see these rapid movements. These are muscle contractions, so…

MILES O’BRIEN: This is one embryo from two angles, right?


MILES O’BRIEN: There’s something fishy in Keller’s lab as well, zebra fish, here waiting for their closeup, an extreme closeup. Keller’s groundbreaking movie shows a zebra fish larva brain in action. Each of these blips is a single neuron lighting up.

MILES O’BRIEN: Whoa. What happened there just now in that big flash?  It’s like a thunderstorm.

PHILIPP KELLER: We don’t quite know what the zebra fish was thinking at that point, but these types of experiments are aimed at trying to find out what exactly it is that….

MILES O’BRIEN: He was thinking about something good or something really bad, right? It was one or the other, right?

PHILIPP KELLER: We tried our best to make sure that he does not have to think about something bad.


MILES O’BRIEN: Nicely done. True professional.

ANTHONY LEONARDO, Group Leader, Janelia: True professional.

MILES O’BRIEN: Neuroscientist Anthony Leonardo uses that collaborative approach as he studies another insect, the dragonfly.

He captures them capturing fruit flies, rolling at 1,000 frames per second. He is focused on what 28 muscles controlled by four neurons each do in the span of 14 wing strokes.

ANTHONY LEONARDO: So, none of it is learned. It gets better with practice, but they understand how to do it from the start. They…

MILES O’BRIEN: What’s amazing is he starts with his back to the fruit fly.



ANTHONY LEONARDO: And this is a really significant thing, right?

MILES O’BRIEN: Leonardo is focused on how our brains coordinate complex behaviors in split-second real time, like catching a ball.

To get a better look at the problem, he and a Janelia engineer have outfitted some dragonflies with 60-milligram backpacks. They capture and transmit signals from 10 neurons linked to four muscles.

ANTHONY LEONARDO: What we’re trying to do is measure essentially all the relevant knobs it’s controlling to steer its body when it flies. So, then, by looking at all those things together, we can slowly build up a model of how the nervous system has solved this problem.

MILES O’BRIEN: Leonardo says the tiny backpack is an example of how Janelia collaborations can streamline scientific research.

But there’s a big catch. There’s no such thing as tenure here. Even though long-term funding is not a worry, the scientists themselves work on five-year contracts, and can be asked to leave if they don’t measure up. And, as we spoke, Anthony Leonardo’s contract was up for renewal.

ANTHONY LEONARDO: So, the way this was put to me when I was interviewing here that resonated a lot with me, though we don’t say it anymore, is the ethos of the place was, we will bet these massive resources on you, on your ideas, and you bet your career in exchange. And that was the gamble.

MILES O’BRIEN: Whether they’re studying dragonflies, fruit flies, or zebra fish, researchers here are keeping long-term basic research afloat at a time when it finds very few safe harbors.

GWYNETH CARD: It can be a tough sell because, of course, not every avenue of research works out. You don’t know exactly where it’s going and you don’t know exactly what you’re going to learn. That is the beauty of it. We don’t know what the truth is, or we wouldn’t need to pursue it. So, sometimes, it turns out as you expect. Sometimes, it doesn’t.

MILES O’BRIEN: There are no guarantees the research at Janelia will pay off with new Nobel-class discoveries. But that’s precisely the idea. The sure thing need not apply.

GWEN IFILL: Tomorrow, Judy explores new findings on genetics and schizophrenia.