2023-11-19 by Khushi Goel

[Transcript] IndiaAsksWhy | Why Do People Get Paralysed?

0:06 Both: Hi, everyone! Utsuka: I’m Utsuka Jigyasa: I’m Jigyasa

U: You are listening to IndiaAsksWhy Season 3 supported by IndiaBioscience Extension Grant.

J: At IndiaAsksWhy, we love to chase our curious science questions!

U: This season, listeners from across schools are joining us on our curiosity-chasing endeavor. So let's get started. Shall we?

0:32 U: We humans, or most animals have something special that the plants don't have. We can move from one place to the other. But can you imagine what would happen if one was to lose their ability to move? This is what one of our curious listeners from DPS Secunderabad wondered about. Human paralysis. Join Utsuka and Jigyasa as they chat with Myra and Kanishka about the different reasons for paralysis. They also spoke to Dr Sheeba Vasu, a brain scientist who specializes in movements. She explains how she uses flies to study movements in the lab. They also spoke to Dr Vasu about her motivations and inspirations for making such an interesting career choice.

1:32 Kanishka: The other day, we were learning the differences between plants and animals.

1:37 Myra: Oh, what was the most striking difference to you?

1:41 K: The fact that we animals can move and plants can't.

1:47 M: In general? Yes, there's such a fundamental difference. I can't imagine a life where I won't be able to move anymore.

1:54 K: Totally. But you know, there are conditions when this can happen.

1:59 M: What do you mean, conditions where one can't move?

2:02 K: Yes, it's called paralysis. The body is paralyzed, which means you can't move anymore.

2:09 M: This sounds devastating. I feel sorry for anyone who has to go through this.

2:15 U: Definitely, it is a devastating condition. But have you wondered why some people get paralyzed?

2:27 J: This is such a vast question. There are multiple reasons for paralysis.

2:32 K: Let's discuss everything.

2:35 M: What exactly is paralysis?

2:38 J: I'm glad you asked. Paralysis is the inability to move the muscles of the body. Meaning even if you want to move your hand or leg, you aren't able to, this condition is called paralysis.

2:56 M: Meaning I want to move it and in my brain, I have the will to move it. But when I try to move, it doesn't work.

3:03 J: Exactly. That's a great way to put it together. Now, can you tell me which of the two organ systems are involved in this process of moving your hands and legs?

3:16 K: Yes, Jigyasa. I can try! Since there is thinking involved- there is the brain- which means the nervous system.

3:24 M: And since there is movement involved, there is the muscle- which means the muscular or skeletal system.

3:31 J: Perfect answer from both of you, the nervous system and the muscular system. Now, paralysis can happen due to something going wrong in either of the systems. And there are a plethora of reasons for this to happen. Can you take a few guesses on what these reasons could be?

3:53 K&M: Yes Yes!

3:54 K: accidents, brain cancers?
M: Brain diseases like Parkinson's? K: Maybe some weird foods can cause paralysis to happen suddenly out of the blue.

4:05 J: Oh, wow. Great reasons. You both are such critical thinkers, Kanishka and Myra. So let's hear our scientist on call, Doctor Sheeba Vasu. She also gave us a very nice analogy between the reasons for paralysis and fever.

4:25 Dr Sheeba Vasu: So first thing I wanted to say is that paralysis itself is for multiple reasons. It's true that, at the final readout, you may have a fever but fever happens for various very, very, very different reasons. In the same way it is with paralysis because that's what a lack of movement in the overt sense, right? Muscular movement is what is lost.

4:48 J: So as Dr. Vasu said, paralysis can happen when muscular movement is lost. And you both pointed out that muscle movements need the nervous system.

5:00 K: What are the different reasons that could stop the nervous system from working, Jigyasa?

5:06 J: Very good question! If let's say an accident or cancer affects the spinal cord or brain- one may lose the ability to send messages to their muscles. Or in case of a stroke in the brain, which usually comes all of a sudden, due to many existing complications. This can stop a part of the brain from functioning for a period of time and that also leads to paralysis.

5:37 K: Interesting..so many reasons could affect something so important!

5:43
M: Jigyasa, you told us different reasons that could stop the nervous system from working. Now tell us what could stop the muscle from working?

5:53 J: Yes! If the muscles get heavily injured in an accident, then even though the brain is sending messages to the muscle, it wont work. And there could be several ways accidents could occur, you know!

6:08 K: So it turns out there are really an unlimited number of causes of paralysis! M: Dr Vasu said, it is like a fever. There is usually not one reason for fever, but many. Because fever is not a disease itself, it is the outcome of a disease.

6:29 J: Yes! You are very correct. Paralysis is the outcome of something that went wrong either in the nervous system or the muscular system Or… M: Or what Jigyasa? K: Is there a third system involved?

6:45 J: Yes! Or, it could be the junction of these two systems! Called the neuromuscular junction.

K: This sounds interesting. The word junction reminds me of a railway station!

6:58 J: Haha! That's actually a good analogy, Kanishka! The neuromuscular junction is the place where there is a connection between two modes of transport. For example, let's say you want to get a parcel from another city. Then the parcel first crosses the big distance by train to enter your city, and then to get closer to your house, it comes by a truck. So there is a junction where the train and the truck meet. Same way there is a junction where the Neurons and the Muscles in your body meet for you to make movements.

7:42 M: So if something goes wrong at the meeting point of the train and the truck, the parcel will never reach me. J: Exactly!

7:50 M: Same way in our body. If something goes wrong at the neuromuscular junction, the signal to move will never reach the muscle, leading to paralysis.

8:00 K: I have so many more questions about paralysis, how it's diagnosed,how it is studied..so many! J: Then let's talk to Dr. Sheeba Vasu!

8:11 J: And now it's time to ask a scientist.

8:16 K: How is paralysis diagnosed?

8:20 S: By movement, by deficiencies in movement sense. So you have to stimulate, right? Stimulate an individual or a patient and the normal response should be movement and that does not happen. Now again, movement, we often think of movement as walking. But even just for me to blink, it's movement because…muscles! For my food to get digested, there is movement because there's peristalsis in your intestine, may not be movement of walking. So diagnosis would be, there should be a normal case. Under normal situation. a control person should be able to move that particular part of the body or organ while this individual or animal model is unable to do so.

9:05 M: The next question I have is what are the mental effects of paralysis?

9:10 S: The paralysis has occurred because certain brain regions have become defective. Whatever lack of nutrition, lack of blood supply, injury, degeneration due to various reasons, infection, right? All of these reasons can lead to a breakdown of cells or ill health of cells in certain regions in the brain, which are important for motor function. Now, we think that these regions are very important for motor function. It doesn't mean that these don't have any role to play with our emotional or cognitive abilities. We can't rule that out, correct.

9:47 M: Is there any way to prevent paralysis?

9:50 S: Yeah. Again, like I said, paralysis is the end result like fever. Is there a way to prevent fever? I don't think there's one answer to that because paralysis can occur for various reasons. And if we are able to somehow keep an individual healthy or an animal healthy, then you reduce the chances of paralysis. That's all.

10:13 U: From the discussion so far, we've realized how complex paralysis is. So we were wondering how you actually study this phenomenon in your lab. We know that you work with fruit flies, right? So how do you do the research?

10:29 S: OK. So I must again clarify here. It turns out that we studied the condition which also is associated with paralysis. One of those early collaborations was the work that Anushka did. Now, it turns out that in humans, as I told you, as you guys were discussing, there is a gradual progression where motor functions are gone in people who suffer from that condition. We needed to model that in the fly. We chose what is known as the neuro-muscle junction. So not neuron-neuron connection, but neuron-muscle connection in the fly, neuromuscular junction. This synaptic region becomes big and expanded. Here is a place where a neuron is missing meeting a muscle. Neurons and muscles are needed for movement. So we chose a motor neuron meeting a muscle wala circuit to do our studies. How do you do that? You can do it. So another thing to remind you is we work with Drosophila melanogaster. So the fruit fly which you can commonly see in your homes if you have a fruit. That's very right. You'll see them buzzing around. So what Anushka did… In our studies we focused on the larva most of the time. So the larva, have you seen? No, you probably haven't actually, next time you see a rotting fruit, take a closer look at if flies have laid eggs on it in a few days, you know, you will see this little or almost translucent, creamish white, little wriggly worms inside these cut inside these rotting fruits. So we grow them of course in the app and in a glass dish, you can filet them out. You have these larvae in these dishes and with a very in dissection equipment, you can cut them out in such a way that you can fill them out like this and their gut and everything is gone and only their body wall is left. So, imagine a tube like this. And then you just cut it out. So now all you gotta do is do this and you have like a flat filet and the muscles are, you know, flattened out and it's, as I said, a very, very stereotypical organization. So larva after lava after larva, you can dissect out and they have the exact same muscle band number 1234 and you know, motor neuron, ABCD and how it's supposed to innervate. So you can go exactly to the same region in sample after sample after sample and you have a very stereotypic preparation. So under the microscope, you are seeing this neuron to muscle junction.

13:05 U: So we'll switch gears a little bit to talk about how your day in life as a scientist studying with Drosophila, studying neuroscience in Drosophila looks like.

13:16 S: Right now it's a lot of non-science that I'm doing. So I will not talk about that. But I think the perks of being a scientist is that first of all, you're constantly engaging with people asking something new each day. That is really the perk for, at least for me, having not actually doing experiments right now. But I must also tell you that while being a scientist, an active scientist at the bench, it's not always excitement. New things, new discoveries come after several, sometimes days, weeks and months of just keeping at doing things, you know, just a lot of perseverance.

13:59 J: That's interesting. But we wonder if science can lack excitement sometimes, then what inspired you to choose this career path or did you always know that you wanted to be a scientist?

14:15 S: In school, I had very nice science teachers, especially in high school where you know, think science little bit more like a future. So I think high school science teachers might have played a big role. And I think my dad also played a big role in the sense that he was one of those people who was constantly telling you to be aware of your surroundings, you know, pointing out plants and animals and insects all the time. Keeping us aware of our natural surroundings, I think, is very, very important. That's why I think it's not just that everybody doesn't need to be a scientist, but it's important for everyone to have a scientific temper no matter what you do in life. I think that is a very important thing. But again, luckily for me the microbiology teacher who…The department was very young in Mount Carmel College. Dr. Ishwar, I don't even know if she's a doctor, but it doesn't matter because she was such an energetic enterprising woman. She inspired all of us to do something, you know, more than what an average bachelor's degree would do. She would organize seminars, she would take us to so many institutions in Bangalore. She also arranged for a field trip to go to Pune and we visited a lot of scientific institutions in Pune. Because she's originally from Nashik and Pune. So she knew a lot of people there. She contacted IISc professors to come give talks on campus. All this was not a normal thing that all happened, you know. So one had to take this extra effort and I certainly enjoyed every one of those interactions. And I think I already felt like I would like to be a scientist. I probably was saying or doing things within that direction of being a curious person. Maybe I don't know. Yeah, or being excited really about doing experiments. I think that's the basic ingredient of being a scientist or just being somebody with a scientific temper.

16:16 J: So what did we learn today?

16:18 U: Paralysis is a devastating condition that can be caused because of several reasons. Anything that affects the nervous system or muscular system could possibly play a role in paralysis. We also learned that the junction between these systems can be affected, leading to paralysis. Dr Sheeba Vasu drew the perfect analogy between fever and paralysis. Paralysis is not the disease itself, it is an outcome of a disease.

16:55 J: Exactly. And we learned about the ways Dr Sheeba Vasu studies these conditions using flies in her lab! Her journey from a young observer to a scientist inspired us to look around and be curious, have a scientific temper and ask many more questions!

17:16 J: But listeners, what we know about paralysis and its reasons might change as we get more evidence over time.

17:26 U: Who knows, one of our listeners might study the reasons behind paralysis in the future to find out something that we never knew before!

17:34 U: So that’s it for today. If you enjoyed listening to our episodes, make sure to visit our website, www.indiaaskswhy.org, for more content. You’ll find illustrations, transcripts, blogs, and scientist profiles for all our episodes!

17:52 J: We’re sure we must have sparked your curiosity. You can submit all your questions on our website and get a chance to be featured in one of our episodes.

U: Follow us on Instagram and Twitter for more updates. Link in Show Notes.

J: IndiaAsksWhy is funded by IndiaBioscience Extension Grant.

U: Shweata N. Hegde and Ruchi Manglunia are the hosts of the podcast

J: Indulekha MS audio-edited the episode, and Khushi Goel transcribed it.

U: Also, thanks to all our team members for enabling Utsuka and Jigyasa to chase their curiosity!

J: Special thanks to Myra and Kanishka for joining us, and a big shout to Delhi Public School, Secunderabad teachers for making this possible.

U: Finally, thanks to Dr.Sheeba Vasu for answering all the curious questions we posed!

J: Don’t forget to like and rate our podcast, keep the new content coming to you! Until then, stay tuned and stay curious!