The Mysteries Of Memory, A New Blue Dot, And A Robotic Fly

IRA FLATOW: This is Science Friday. I’m Ira Flatow, coming to you today from the studios of 90.5 WESA in beautiful downtown Pittsburgh. Just how memories are formed, stored, retrieved in the brain, you know, it is still a mystery. The prevailing theory is that changes in the connections between neurons or synapses encode our experiences. But this week, researchers reported a surprising finding about memory in snails. What does that mean? Well, joining us to talk about it and other science news from the week is Amy Nordrum, who’s editor at IEEE Spectrum. She’s in our New York studios. Welcome back, Amy.

AMY NORDRUM: Thanks, Ira.

IRA FLATOW: So what’s going on with this memory story?

AMY NORDRUM: Yeah, this new research out of UCLA could upend some of the current existing theories on how memories are formed and stored in the brain. As you said, the common theory has been that the connections between neurons matter most. But this research suggests that maybe neurons themselves store, or at least have a role in storing memories once they’re formed in our brains.

This research was done with snails, marine snails. Researchers at UCLA were able to extract RNA from one set of snails that they had applied electrical shocks to, and show increased sensitivity in another group of snails that had not ever received those shocks. So it’s also a form of learning, but these researchers are saying that this suggests that RNA plays a more important role in forming memories than we previously thought.

IRA FLATOW: How did they know that the memories were moved around?

AMY NORDRUM: Well they actually were able to then test sensitivity in the snails that received the RNA that had never been shocked before. And they use this organ called the siphon that can push out and pump in water to and from the snail’s body. And after the snails received shocks, they exhibited a longer response time, and being sensitive to basically a poke of that organ. So they would extract it into their body. And then there was a longer time that it took for them to recover. And then the snails that they injected the RNA into that had never been shocked before showed a very similar response.

IRA FLATOW: Of course, this sort of upsets an apple cart, as you mentioned, about how we think how memories are formed. So this must be quite controversial. And people are looking to redo it, right?

AMY NORDRUM: Absolutely. It would need to be replicated to say anything really meaningful. And of course, this is in snails, not anywhere near humans yet. The researcher, David Glanzman, told me it took him months to even convince his own lab to do this work. So it’s definitely outside of the box thinking.

IRA FLATOW: All right, let’s go on to the next one. There’s a new version of the pale blue dot picture looking back on our planet from far away. Tell us how that came about.

AMY NORDRUM: That’s right. NASA released a new image this week, and it’s connected to the InSight Lander that is headed for Mars– will arrive there in November. But alongside InSight are two tiny satellites that are flying along. For the mission these are cubesats. I know you’ve talked about cubesats on the show before.

These two cubesats are going deeper into space than ever before. Usually cubesats are relegated to a low Earth orbit area. They’re used for all kinds of satellite imagery up there. But these two cubesats are venturing deep into space. You know, part of the challenge of going to Mars is getting all the data back from there. And these cubesats are playing an important role, hopefully, in being able to send, through specially-designed antennas, data all the way back from Mars once they arrive there.

IRA FLATOW: So it’s not just that this is a great new picture of the pale blue dot, but it’s also significant about the cubesats unfolding properly, their antenna.

AMY NORDRUM: Yeah. The whole way we got that photo is one of the cubesats taking a photo of itself to show that its antenna had unfolded properly, which happily, it has.

IRA FLATOW: That’s great. So you have an antenna the size of a breadbox sending data back from near Mars. Isn’t that something? Tiny little–

AMY NORDRUM: It’s pretty remarkable. And the advantage is this is a much cheaper way than sending much bigger satellites and antennas deep into space like that.

IRA FLATOW: Let’s move on to a story about chemical warfare, and caterpillars, and plants.

AMY NORDRUM: It’s a crazy world down there. You have plants– when a herbivore like a caterpillar starts to attack, plants can emit these compounds that are sort of a defense against the herbivore. But it seems, through some new research, that caterpillars may have found a way to use these plant defenses to their own advantage. Because some new research suggests that relationship is more complicated.

Not only are the compounds meant to deter the herbivores from eating further, but the herbivores themselves are kind of protected by the compounds because other predators like wasps do not like to approach a caterpillar that has the smell of these compounds on it. So it actually keeps the caterpillar safe from its own predators, even though the whole point is to defend from the caterpillar in the first place.

IRA FLATOW: So they’re sort of making the chemicals that would deter the caterpillars themselves?

AMY NORDRUM: Absolutely. Yeah, so the plan is emitting these compounds, these chemicals that are very aromatic in this case, this one that was studied. And then the caterpillar starts to smell like that. But then the wasps don’t really like it either. So I don’t know if that’s really working to the plant’s full advantage there.

IRA FLATOW: Another story– next week is one of the world’s largest robotics conference, and you’ve got your eye on that, right?

AMY NORDRUM: Absolutely. Some announcements have started to come out. We’ll hear a lot more next week. But there are some fun prototypes and interesting experiments that are going to be on show there in Brisbane next week. One of them is a tiny robot called RoboFly. This is robot about the size of a fly. It even has its own wings. And it can barely take off.

One of the things that is innovative about this particular robot is the way that it’s powered. When you try to scale a robot down that small, it’s very hard to get a reliable power source onboard. So the researchers here at the University of Washington attached a PV cell, and then shined a laser onto it. So the PV cell is able to harvest enough energy from that laser to do a small lift off. The only problem is as soon as it goes outside the range of the laser beam, it falls back to the ground.

IRA FLATOW: Details, details.

AMY NORDRUM: It’s only a prototype.

IRA FLATOW: So what are some of the big questions at the conference?

AMY NORDRUM: Yeah. Things like power, certainly mobility. And then also practical tasks. There’s a research group out of Georgia Tech that’s built a robot that they’re trying to design to dress humans. You can imagine a lot of people need help getting dressed in the morning and undressed at night. And this robot, hopefully, could help with that someday. But right now, the most it can really do is put a sleeve on someone’s arm. And it takes about 10 seconds to do that. It’s a very delicate process to work with humans, and it could be very valuable, but we’re kind of inching close to that.

IRA FLATOW: Let’s now go to the most important story of the week– researchers looking into the optimal age for puppy cuteness.

AMY NORDRUM: That’s right. Researchers at Arizona State University did what must have been one of the most fun experiments ever as a college student to participate in. They’re interested in this question of how the animal-human relationship evolves. And one thing they know is that most of the dogs on the planet are not pets. They, in fact, live on the street. They’re sort of part wild. But they still depend on humans a lot– it’s street dogs in big cities.

And so they wanted to know how is this relationship forming. They took a bunch of images, asked some students to categorize them according to cuteness on a scale from 1 to 100 of different puppies. And they found that the age at which the puppies appealed most to humans was about eight weeks. This is interesting because that’s also the age at which dogs are weaned from their mother, typically. And so if you’re a street dog, and you’re weaned from your mother at eight weeks old, you’re still not big and strong enough maybe to find food on your own, it could be a real advantage to have your maximal cuteness at that particular age so that a human would take you in, or at least throw some food out for you.

IRA FLATOW: Hope all these young puppies are listening to us. Thank you, Amy. Amy Nordrum is editor at the IEEE Spectrum in New York. Thanks for joining us this week.

AMY NORDRUM: Thanks, Ira.

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