That Neuroscience Guy - Neuroscience Bites - Taste

Episode Date: May 4, 2022

Everyone has that one favourite food that always tastes better than anything else. But what goes into our perception of taste? In today's Neuroscience Bite, we discuss the neuroscience of our sense of taste.

Hi, my name is Olof Kregolsen, and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to another Neuroscience Bite. I was with my lab in Vancouver this past weekend at a conference, and I love going to Vancouver. There is just so much good food there. There's restaurants literally from every country in the world, or at least it seems that way. And one night we went out for this Lebanese meal, and it was literally the best meal I've had in the past two years, I'd say. And as I was sitting there enjoying this wonderful Lebanese food, I started thinking a bit about the neuroscience of taste. I don't really know a lot about taste. You know, I remember studying it in grad school,

but when you do a PhD, you kind of focus in on a couple of things and you don't learn about everything there is to learn. So I did a lot of reading over the weekend and I found it quite fascinating. As you're probably aware, there's basically five primary tastes, sweet, sour, bitter, salty, and savory, with savory sometimes called umami because it was discovered in 1910 by a Japanese researcher. And basically the way taste works is at the tongue level, you have a bunch of sensory receptors. Now those receptors are sensitive to these five tastes. So when that taste is encountered, neurons fire. That information is transferred from the tongue to the medulla oblongata by a series of neurons. This is a structure in the midbrain and specifically in the

brainstem that's basically a form of a relay station. And from there, the information is transferred to the thalamus. We've talked about the thalamus in the past. The thalamus is definitely a relay station. It's where pretty much everything coming into the brain goes through the thalamus. And then finally, another series of neurons convey the sensory information to the gustatory cortex, which is in the insula. Now, I'm not going to talk too much about the neurons that connect

the tongue to the medulla oblongata, because they're essentially, they're just carrying information. When a receptor on the tongue fires, that neuron fires. And same from the neurons going from the medulla oblongata to the thalamus. This is just relaying information. And again, from the thalamus to the gustatory cortex, relaying the information that's coming in. But in the gustatory cortex, the way that works is there's basically five primary receptive areas and one for each of the tastes that we mentioned earlier in this little bite. So if you eat something sweet, for instance, then neurons fire on the tongue because it's detecting that. That information is relayed through the midbrain

to the gustatory cortex, and that's where your conscious awareness of the taste occurs. Now, obviously, tastes are a little bit more complex than just the five primary tastes. You can have combinations of these things firing at any given time. And of course, there's actually neurons in between the primary receptive areas in the gustatory cortex, and those neurons might be sensitive to multiple tastes or even all the tastes. So your perception of taste when you're eating is neurons firing in the gustatory cortex that are triggered by neurons firing on the tongue. And as you go through life, you learn and experience these different flavors. Now there's a bit more to it than that, but I'm

going to save part two for next week when I'll talk about the role of smell and the neuroscience of smell in another neuroscience bite. Don't forget our website's up, thatneuroscienceguy.com. There's links to Patreon where you can support us, to merch, and obviously the podcast itself, our YouTube channel, and some other stuff like my own blog. And remember, follow me on Twitter, at thatneuroscienceguy. There you can DM me directly if you've got ideas for a show. One listener reached out to us last week and was really curious about the neuroscience behind migraines. So we're actually going to do an episode on that in the very near future.

So if you've got an idea for an episode or something you're curious about, please reach out to me and let me know. My name is Olive Craig Olson, and I'm that Neuroscience guy. I'll see you on Sunday for another podcast.