Toward a new theory of insect olfaction with Dr. Thomas M. Dykstra | Part 2 of 4

Hello and welcome back to Advancing Eco Agriculture's series. This one is going to be a little bit different because this is going to be done a little offline. So I'm going to be making this presentation as well as the next one done a little bit differently. The first one, for those of you who are there, this is actually a four part series. The first one has already been put up and this is now the second one. As you can see, the title of this is going to be Toward a New Theory of Insect Olfaction. During the first presentation we were just looking at the current theory of insect olfaction and I spent some time discussing the merits and the demerits of that theory. And so now it is time for us to move on to a little bit of what we believe is going on. My name is Tom Dykstra and in this series I'm going to be talking about insect olfaction. I have been studying in Self Action for many years now. This is something that has been a relatively big part of my career thus far. And I'm happy to be giving these series of four presentations which will culminate the fourth presentation, which I believe is going to be on August 30th. So I'm going to assume everyone, and I realize not everyone has. I'm going to assume that everyone has seen the first presentation. I don't plan on repeating a lot of it, so it's going to go quick. And for those of you who feel that you need to view the first one in order to make this a little bit clearer, please do so. But for those of you who have already seen it, I think it's time for us to begin. So Toward a New Theory of Insect Olfaction. We're obviously moving away from the current theory of insectile faction that I discussed during the first presentation. Okay, so there we go. And there I am, right there, my microscope. And I am AEA's scientific advisor. I have been that for just over a year right now. They've been tolerating me for that long. I'm with Dijkstra Laboratories, been doing that since 1997. So it's been about a quarter of a century and my contact information is down there. And we're now ready to get into the the gist of the presentation itself. First of all, olfaction and insects, how is it accomplished? It's a question that I asked during the first presentation. I'm going to start answering it now. A little bit more clear than the first time because last time I was more or less attacking the current theory. And now I'm going to be setting up how insects are actually smelling. For those of you who are not aware from the first presentation, it was in 2016 that we believe that we decipher the insect olfactory code. And these presentations are now helping us to understand how that deciphering occurs and how it all comes together, at least for the insect. I had briefly mentioned that the sensilla on the insect antenna. There are sensilla, of course, on the maxillary pulps, labial pulps, and other parts of the body where chemoreception occurs. But these on the antenna are certainly the key players when it comes to olfaction or the smelling of odorants. I mentioned during the last presentation that these scilla, and this is a cross section of the sensilla that you see off to the left, that there was a certain amount of time that the pheromone needed in order to reach the dendrite. It had to come from the outside, pass in through these tiny pores of the insect sensilla, then make its way through this watery matrix, make its way to the dendritic membrane. I mentioned the seven steps that are necessary in order for it to reach it in order to activate the receptor. And during that presentation, I made it very clear that there was no way that this could happen and that this wasn't just unlikely, it was actually impossible. So because it was impossible, the whole theory really has to be scrapped, because there was no way that I could get the odorant there in a timely manner. Now, I did know this probably about 2003 and 2004, when I became convinced that that something else was going on. But as far as what that was, that came certainly usually after that date, for the most part. All right, so the early conclusions that I drew is that the pheromone either binds with the receptor or it does not bind with the receptor. These are the only two choices that can happen with insect olfaction if binding occurs. I had mentioned that technology has not found a way to show this yet. If binding does occur, detection of the pheromone must occur through some alternate means. What is that alternate means? I mean, obviously it's going to have to be done without binding, and so now it's going to have to be detecting it from a distance, which complicates things, as you might imagine. So there are two main theories that are out there in regards to olfaction. One is the lock and key hypothesis of olfaction, and that is simply that pheromone for example, or any odorant locks itself into this blue receptor right there. And activation occurs with physical contact with the receptor. This lock and keypathesis has been well delineated. It's well understood in regards to neurotransmitters and many other biological processes, but it has not been successfully applied to insect olfaction. The other theory is the vibrational theory of odor. Many of you have probably heard of the vibrational theory of odor. I will not be talking about electron tunneling, I will not be talking about the card swipe model, But I'm going to be talking about essentially a theory of odor that is akin to the vibrational theory of odor. And we'll just call it that for simplicity. And that is if you have an odorant as designated by this white oval right now in that an insect's in scilla represented by this triangle, would be able to detect it from a distance. And if it was going to do it from a distance, it would have to be composed of some electromagnetic frequency, because there is really no clean way to do this without electromagnetics, since there is no contact. So this is activation without physical contact. We know that activation occurs. We know that the odorants are going to activate the receptors. This is, I think, well established. But how this occurs is not that clear. And now I'm going to introduce you to a new theory which is based upon the vibrational theory of odor. And so it's a good idea, in an order to acknowledge those who went before you, the vibrational theory of odor. Is this something that Tom Dijkstra came up with? Absolutely not. I think a lot of you know this already. GM Dyson was really the first one to put it in paper, and that was back in the 20s and 30s. And he had just a few publications, didn't go into, in a lot of depth out there, but he was really the first one to talk about this. And then it kind of died down for a few decades. Robert Wright, who was based up in Canada, really took off and did this. Started in the 1950s and worked through the 1980s, published a lot of it is to him that I attribute deterrent frequencies. He was the one who introduced that term. I will not be talking about deterrent frequencies during this presentation, but he really set up a fantastic foundation that we could test and understand how insects were smelling a little bit better. And then Philip Callahan came a little bit later. They were contemporaries with one another, but Phil Callahan was in Florida, Robert Wright was in Canada. And so there was not a whole lot of overlap. But Occasionally they would have run into one another. And Shell published in the 1960s and the 90s, and he was taking a look at it from a slightly different aspect as well. But these were the three individuals with which the whole theory kind of began and continues to do so. And my job was simply to build upon the foundation made by these, these three gentlemen. So this is. It should be similar. For those of you who've seen the first presentation, this is a cross section of the sensilla. And I've got pheromone, which is designated by these blue balls on the outside of the. Of the insect. And the cuticle is designated by these really thick black lines. I have some pores in them because we do know that these pores exist. There are some tiny pores that exist that are, think somewhere between 6nm to 65nm. So they're very tiny pores, but they're there. And then we have the sensillar lymph, which is a watery matrix. And then we have the receptors. Now, as I mentioned, activation occurs. We know that the pheromone can be detected by these receptors, as designated by a dimer receptor off to the left of the screen. So if we know that activation occurs, and yet I've shown that the physical contact is not occurring, we've got an issue. We've got several issues, as a matter of fact, and that is, how is the pheromone detected if it actually cannot make physical contact? And there are three different issues that need to be addressed and will be addressed very briefly during this presentation. The first one is the interface of the cuticle. So the pheromone, if it's not getting inside the actual sensilla itself, is sending a message. We believe it's a vibrational message, and it must make it through the cuticle in some fashion or another. It must collect that energy and it must pass it through. That's the first thing that we need to. To address. The second part is the insular lymph. This is a. It's a rather large area, watery matrix. It's in between the pheromone on the outside and the dimer receptor on the dendritic membrane on the inside. And we have to get through that as well. So that needs to be addressed as well. And then finally, we need to get to the receptor itself. And that is, how is the receptor actually activated? Assuming that the message gets through the first, which is the cuticle, gets through the second, which is the sensillar length, finally makes its way to the receptor, how would it actually activate it? And so I'll very briefly be discussing those and we'll discuss them in more depth in presentation number three. So the first one, what do we know? Erickson in 1975 found that the mean surface potential of honeybees varied throughout the daily flight period. What he found is that bees that were leaving the hive had a charge on the outside of their body between negative 14 millivolts to plus 8 millivolts, which if you average is running right around zero. So essentially this means that they're not charged when they are in, inside the hive, but the returning bees are. And they have anywhere between plus 13 millivolts to plus 59 millivolts. So the charge difference is huge. And you can see that there are no negative charges when the bees come back into the hive. It's all positive. And it's relatively high, too, at least compared to the negative 14 and the plus 8. So what this is, what is happening right now is that the bees are being charged through flight with the beating of the wings, with the friction of the air. And this charging of the body is something which is happening with the bees. We know through the, through biophysics that this is going to be happening with all insects. But we're just showing this as, as far as honeybees are concerned, is that so long as they are moving and flying, and this is how most insects smell, most of them are smelling in flight, is that they are charging the outside of their body and that there is a positive charge associated with it. This is. Let's see what we're showing here. This was a German researcher, Ulrich Wernke, who was taking a look also at honeybees as well. And he found that abnormal wing fluttering occurs in a group of bees in a Faraday cage. Faraday cage means they were excluding many of the external electromagnetic frequencies. And the fluttering is associated with auto electrification. How do we know this? You can see the large lines on the left side of the screen. And this is the abnormal wing fluttering that is occurring. As soon as the cage is supplied with atmospheric ions, which is that large arrow at the top, that abnormal wing fluttering ceases instantaneously. And they can go back and forth and they can play this game again and remove it. And the wing fluttering begins again. And then they can introduce the ions and the wing fluttering will stop. And so this, this auto electrification effect can actually occur inside the hive as well, and not just when it's in flight, but you can see the importance of this process and the importance of ions Especially on the outside of insects in general. We also know from 1984 that the fixed negative charges are going to be present on the inner cuticle of the sensillae. The inner cuticle is different from the outer cuticle. I was just talking about the outer cuticle, and I was talking about these positive charges. But on the inner cuticle, Kyle found that there were negative charges, fixed negative charges present on the inner cuticle. Well, this is interesting, because if we have fixed negative charges on the inside of the cuticle and we have positive charges on the outside, we have now created a differential, an electrical potential, a differential between the outside and the inside. Positive on the outside, negative on the inside. And this is important because we have now created what is known as a dielectric. A dielectric just means two electrical charges, and that's where the dye comes from. So there's two electrical charges are opposing one another. They're positive versus negative. And these, these can be maintained as long as you have a dielectric substance in between them, which in this case is going to be the cuticle. And it actually is the wax as well. The wax is actually helping out because it has electric properties. So because we know this is happening right now, we now have a dielectric situation. And so because of this, it's good to take a look to see what do I mean by a dielectric. And it's directly opposed to a conductive material. Many conductive materials are made of metal, and many antennas are also made of metal. Everyone, I think, is familiar with the metal antennas that people put up on their houses, or at least they used to. I'm sure. Not sure that's done so much anymore. But I know there are a lot of ham radio operators. I know a few myself, and they're still using metal antennas. But it's conductive material where positive and negative charges are allowed to pass through it because it's conductive. This is different than a dielectric material. A dielectric material does not allow charges to pass between them, which means they can maintain a charge differential on opposite sides of the dielectric material. So here you can see that there's a largely positive charge on one side of this imaginary dielectric material and largely negative charges on the opposite, opposite side of the dielectric material. Well, this has repercussions for us because dielectric and conductive are two different forms of antennae. And one dielectric that I think everyone is familiar with is polystyrene. Polystyrene has Been known to be a very good dielectric, and obviously it protects your hand from the hot coffee, if that's what it's for. But they also knew about dielectric antennas back in the 40s, and they often use, at times they were using polystyrene as a, as a, as a type of dielectric antenna. So I just want you all to be aware that there, there is a little bit more out there besides just a metal antenna. And a dielectric antenna has been known since the 40s, so it's been around for a long time. And they are useful. They have certain properties associated with them. And it's these that I need to focus ever so briefly on during this presentation. So this is a good dielectric antenna. After you drink the coffee, you can turn it upside down and it will actually be a better antenna because it should be sloped towards the top. Especially if it can come to a point, it will form an even better antenna. But this cup could be used as a dielectric antenna, although a crude one. So the properties of a dielectric antenna, there's only two. As long as these two conditions are met, you can have a potential dielectric antenna. One, it needs to be composed of a dielectric material. So that's one of those dumb moments. But to the dielectric material must have an effective dielectric constant. Well, what's an effective dielectric constant? It shouldn't be too high and it shouldn't be too low. So the waxy layer on the outside of the insect has a dielectric constant between 2.5 and 3. We've known this since at least 1967, probably earlier. This just happens to be when it was first reported. And it's similar to the dielectric constant of polystyrene, which is 2.55, which is an excellent dielectric, and as I mentioned, can be used for picking up electromagnetic frequencies. So these two conditions are the only things that need to be met in order to have an existing dielectric antenna. However, it does get more complicated because it's not just about having an upside down coffee cup. So you can have a dielectric rod antenna, which would be off the left, but you can make it better. And you can make it better by tapering it to a point, as I alluded to a couple slides ago. You can also make it even better if you take the diameter of this dielectric rod, which is now tapered, and make it thinner at the bottom. That will actually make It a better, more efficient antenna. And you can also lengthen this same antenna and this will actually make it even better. What this does in effect is it increases the directivity or gain of an antenna. And this has been known as reported, you know, since 1952. So all of this is old information. Some of you may be familiar with it, some of you, this may be the first time that you've heard of something like this before. And so if we go back to the insect, we see we've got a close up a scanning electron micrograph of an insect antenna. There are a number of dielectric, I was going to say dielectric antenna, but I was sensilla on the outside of this posing as dielectric antenna. And so you can see that they are relatively thicker at the base and they get thinner as you get near the tip. We also can see it even happens with the coelaconica, the ones that look like little circles down there. They are also pointed at the tip as well. We have a cross section of the scilla off to the right. And you can see that there are two things and I do want to point out those two important things and that is the cuticle and the wax layer. The cuticle of the insect is relatively thick. However, when it comes to the sensilae, they are not that thick. As a matter of fact, they're quite thin. In addition to being thin, they're perfectly. They have a diameter which is almost perfect all the way up. So the cuticle on an insect varies a little bit based upon different parts of the body. But the cuticle on the insects and scilla does not vary that much. And as you can see, it is very thin. We still got it with the pores that I mentioned before, we stuck those in. So you can be clear that we're talking about the cuticle. And then we have the wax layer too. The wax layer is also generally a little on the thick side when it's covering the the insect largely for water loss. But this wax layer extends over the sensilla and you will also notice that it's very thin. Just like the cuticle is thin, the wax layer becomes very thin. And in addition to being thin, it's of a uniform thickness all the way up the sensilla. And that is what I wanted to point out to you here. So properties of a dielectric antenna. We need only two, but I'd kind of like to know what do I need for a good one? Because certainly there have to be some other properties. A third property they need to be long and thin or tapered or rounded at the tip. And sometimes we do find these roundings going on. We see them in the lepidopter antenna, the clubbed antennae and some of others. So this is the property as known by the dielectric rods and is associated with the dielectric antenna. Four, in order to have a good dielectric antenna, it needs to be covered by a good thermoelectric, such as wax, which it is. A fifth characteristic is the directivity. This is for you antenna people out there, and I, and I know some of you are going to be listening to this because I've talked to some already. The directivity is proportional to the tube length characteristic of dielectric rod, something we've known since the 40s. And so this is another characteristic which is also satisfied by the insects and scilla. If the wall is thin, it can achieve a single lobe radiation pattern, which makes it better because it more directivity, more gain, essentially making it a better antenna, which means it can localize where a message is coming from. And seven, the antenna and the thermoelectric need to be of a fixed consistency. They are not a fixed consistency. The antenna will not work well. And yet we do have that with all of the insects in silla. So not only do we have a dielectric antenna, but we satisfied five additional requirements for a good dielectric antenna, which means we're getting very, very close to showing the, the superiority of the system on the insect. What can we do better? How about a perfect one? Is it possible to make a perfect antenna? Some would say no. I would probably agree with them. But it has been reported that you can make a perfect antenna, a lossless antenna, and this can be done with a dielectric material, a dielectric antenna. In order to make a perfect antenna, many researchers have found and published that you need to make tiny perforations in order to create a lossless antenna. So if they started poking holes in a dielectric antenna, they could make it actually lossless. And this has to do with mathematics and physics. And it actually makes the, the thickness of the cuticle mathematically or physically zero, when actuality it's not. So it's an interesting phenomenon. And yet, even though it is interesting, we also have that too. The insect sensilla, not all of them, but many of the insects in silla have tiny perforations or pores. As I mentioned, they're usually running on the small side, 6nm. They can go all the way up to 65nm, but it's still tiny. And these tiny perforations exist on a lot of the antenna that are out there. So not only have we satisfied the conditions of a dielectric antenna and a good one, but. But we've even satisfied it as a perfect one. We're now faced with the reality that the insect has dielectric antenna, that they exist in a. They're very good, and that they might even be perfect. That is the truth that we're faced with right now. This doesn't say that the insect is actually using it as a dielectric antenna. It's just saying that all the conditions have been met for a dielectric antenna. And so that's all I needed to discuss right now in regards to that. I just wanted to show you. I draw. I tried to draw this to scale to the best of my ability, just to give you an idea of how thick the pores are. And they cover. The pores cover between 1 to 1.52% at most of the surface of an insect sensilla. So they are scattered. So most of the sensilla is composed of just cuticle. And there are. There are some holes, these pores, very tiny, but they're spread out and you can see that they're not that dense. It just gives everyone who's listening to the presentation a little bit better idea of how many pores there are in a particular scilla. This one happens to be a Sensilla basiconica from Bombyx mori, which is the silk moth. And for those of you who are interested, you can go ahead and. Because I'm going to skip this very quickly, but I just wanted you to see that the idea of this being a dielectric antenna was started by Grant Back in 1948, the first one to talk about this, and it ends with 2002 papers where they were talking about perforating dielectric resonator antennas. And so if you would. Wanted to take a look at. If you wanted to pursue this a little bit further, you can take a look at some of these sources and you'll be able to read a little bit more about this. Okay. All right. So I've talked about the existence of this being a dielectric antenna. So we've now got a way to collect energy, which is a great start, but it's not. It's not everything. We've still got, you know, two and three to get through. So I've got the sinseller lymph and this at first Glance seems to be a problem because we are told that this is a watery matrix. And I can tell you right now, I mean, if you want to transmit energy through, especially infrared energy through water, you're, you're going to be in trouble because it's not very good, it's not a very conductive substance. It doesn't transmit all frequencies very well. Some frequencies it does transmit, others it doesn't do well. And so water is not really going to cut it as far as a good material to transmit any potential frequencies. But do we have that? Is there anybody who thinks that we have pure water in the sensilla lymph? I don't think we do because we understand that this is a live animal and animals are not dealing with. We just don't have distilled water in different parts of our body. The sinsillar lymph is not pure distilled water. It's complex. It is a salt based structure. There are lots of salts that are based in it. And these salts are important. Why? Because as soon as you introduce salt into water, for example, even if it's pure water, distilled water, what changes? The conductivity changes. The conductivity changes drastically. You can increase the conductivity, you know, 2, 3, 4 orders of magnitude over what it was before if it was just pure water. And the lymph is salt based. So we've now got an interesting situation here where we've now got the potential for a conductive fluid. So this is based upon many of the regular salts, predominantly sodium and potassium, but there's also some other potential salts that are in there and they have charges associated with them. For those of you who are familiar with chemistry, you understand the ionic bonds are separated and NaCl, or table salt is split up into Nac, sodium and then Cl, which is a chloride atom. So the sodium has a plus one charge, the chloride atom has a negative one charge and they break apart in water. And so you've now got these active charges moving around this watery matrix. It's a salt based matrix. And so because of this we now have salt, which means we now have a conductive substance. And we're now getting a little bit closer to understanding how insects might be smelling now. So I've also mentioned to you in the last presentation that the pheromone binding proteins are charged as well and that most of them are negatively charged. We've run through, I think over 150 of them and about 81% of them were negatively charged. Some of them were positively charged. We did have a few that were neutral. But you can see that there are some additional charges inside the sensilian F. It's just not about the salt is that these proteins seem to be contributing charge to the matrix. And this does seem to be important. So I want to mention it right now because I'm going to talk about this a little bit more in the presentation. So here's our situation right now. We've got this medium right now and this medium is composed of a high concentration of these binding proteins. We've got a salt matrix in the sensillar lymph. Then we have these binding proteins which are also charged too. And so we've now got a potential situation right now where we might be able to start transmitting electromagnetic frequencies across this lymph. But is that the whole story? Do we know for sure that this salt solution is important? And I would contend that we do. So if you take a look at decapod crustaceans and this would include lobsters, includes the blue crabs. Deca means 10. These just 10, 10 legged crustaceans, they're found in a marine environment. I think we all know that. So they're in the ocean and you can take a lobster and remove it from its saltwater environment and place it into fresh water and you can essentially flush, flush its environment with, with fresh water and it will cause them to become anosmic for about one hour, maybe 45 minutes. So during this time you've essentially cleaned out the decapod crustaceans sensory abilities for its ability to smell for about 45 minutes to an hour simply by flushing it with fresh water. This is interesting to know. And then it's restored and after about 45 minutes to an hour it's restored. And then usually further studies can be done. Many researchers will then do further studies on these decapod crustaceans, especially spiny lobster. And so that is a fact. We also know some of you may be saying well what about chelinectes? And I would say yes, what about chelinectes? Good point. So callinectes is the blue crab. It is found in a marine environment but it also migrates up the Chesapeake Bay and other other areas. It migrates up into a freshwater environment in order to breed. So what's the story with this? Because now we've got a crab, the blue crab, a decapod crustacean and it's in a saltwater environment and that goes to a freshwater environment. Then it goes back to a salt. What's the deal with that? And that's an excellent question. So blue crabs survive in both freshwater and marine environments. They need to, because as I mentioned they will often. The mass migrations at the Chesapeake Bay at the base of it is there's a lot of fresh water there and they have the ability to move salt solutions into and out of their sensitlae depending on their environment. So they are able to create an ionic micro environment with their esthetasks which are the olfactory receptors, the kind of akin to the olfactory receptors that we find on insects. So this salt solution is moved up into the the olfactory receptors as they move into a freshwater environment and then as they go back to the ocean the salt is remove. So this brings up some, some good questions and that is what is the deal with these pores arthropods which include decapod crustaceans and insects, what's the deal with their sinicillae and what's the deal with their pores? Well, what do we know about them? Well, terrestrial insects, as I've kind of alluded to during this presentation, terrestrial insects, do they have pores or do they not have pores? And they're Cincelli and for the most part they, they do, they do have pores in their olfactory sensile as you would expect them to. Now what about the crustaceans in a marine environment? So a salt based environment, what about them? Do they have pores in their olfactory sensit? Yes, they do. And the reason why they do is because the marine environment, a salt based solution is going to slip through the pores and you're going to be able to maintain a salt based solution inside their sensory structures. So they don't really need to exclude it. It's not really an issue. What about aquatic insects? Aquatic insects, as I think most of us are aware, are exclusively found in freshwater environments. They are not found in the ocean. You do not find them in, generally speaking, marine environments are a few exceptions, but they're not important to mention. Now and these aquatic freshwater insects, what's the deal with their sensility? They have no pores in their olfactory sensility. And this should make sense as you're listening to me right now, because if they did, fresh water would be able to get in and it would make them probably anosmic, which means they wouldn't be able to smell again. And so they need to exclude fresh water from getting inside. They need to maintain obviously a salt environment inside it and then they need to exclude the fresh water so that they can still Smell while they're under the water. And these aquatic insects include mayflies, dragonflies, stoneflies, insects of that sort. But what about these same aquatic insects when they become adults? Because they leave the water and now they're flying around. Mayflies fly around as adults, Stone flies fly around as adults. Dragonflies, damselflies, they're flying around adults. What happens to their sensillae as terrestrial adults? They regain the pores again, as you would expect them to. So once again they have the pores just as the other terrestrial insects do. But the same insect in its aquatic stage didn't have them. And the same species, once it comes out of the water, now has pores in its olfactory sensile. So it's certainly not a species thing because they can do that within species. Well, this is really interesting because we've now got some evidence right now that salt based solutions are important for smelling. And so this applies not just to insects, but it even applies to other arthropods as well, as I'm kind of alluding to as I'm bringing in some, some further evidence. So we've now got the second situation kind of covered right now I'm going to be covering a little bit more in just a second, in a few more slides. But I wanted to focus a little bit more on these receptors, the dimer receptors or these membrane bound receptors, because eventually the message has to get to them and they have to respond in some fashion or another. What's the deal with them? Well, they are membrane bound, generally speaking. Most of the olfactory receptors and the gustatory receptors are seven transmembrane receptors, which means they happen to pass through the membrane seven times. A lot of these receptors have that, that seven transmembrane characteristic to them. There are some fives and sixes as well. But there are some other proteins which may only go through the membrane twice. These are in invertebrates. These are the CD36 proteins which only go through twice. They have a correlate in insects and they are associated with the olfactory receptors. These are the SNMPs. The SNMPs are the sensory neuron membrane proteins and they are similar to the CD36 proteins and vertebrates where they only pass through the membrane twice. And so but even though whether they pass through seven times or whether they pass through two times, they're still bound in the receptor itself. So anytime they would be absorbing energy, they're going to be doing so in the context of being in a membrane. And so any energy transfer to is usually going to be if it's close by to some other receptor. So I just need you to be aware. And there are a lot of these receptors just on E. Coli, one of the smallest cells that's out there, you're going to have maybe 60,000 membrane proteins, and that is a very, very small cell. So you can imagine that a much larger cell is going to have much more than 60,000 membrane proteins. So the take home message is there's a lot of them. There's a lot of them. So in order to test these receptors, it's difficult to test them when they're inside the sensilla. And so we have been able to decipher them and determine what their amino acid. Structure is. Lucky.