Well good evening everybody and welcome, thank you for joining us. I'm Charlotte Zinclair and I'm an equine vet at B&W and I'm also a senior lecturer at the Royal Agricultural University. I'm delighted to welcome our guest speaker this evening, Dr Andrew Hemmings.
Andrew is Associate Professor in Equine Science at the Royal Agricultural University and he is also the Head of School of Equine Management and Science. Andrew has a PhD from Aberystwyth University and has a long-standing research interest in the equine brain and equine behavior. So this evening Andrew's presenting a lecture titled Training the Equine Brain, a headfirst approach to your horse's well-being and management. So if you would like to submit questions please do so through the Q&A and we'll have questions at the end but feel free to pop them in the Q&A during the presentation. Thank you very much, over to you Andrew.
Thank you very much Charlotte and thanks to CVS Equine for inviting me this evening and welcome everyone to my spare room and as Charlotte says my primary specialism is the brain and how that links to behaviour in the horse and I think it's fair to say I obviously work at an agricultural university. And if you look at the livestock species, sheep, pigs, cows, etc, very often we're more interested in what they can produce for us in terms of milk and meat and wool. And if we think of what's the primary production trait of interest in the horse, from my standpoint, it's the horse's behaviour.
Because we can have a horse that's got X excellent confirmation, looks amazing, but if the temperament of that horse is not trainable, then that animal might be dangerous and very, very ill-suited to what we need it for. So for me, the primary output trait of interest in the horse is behaviour. And if we're going to understand behaviour, we first need... to understand the brain.
So that's why my talk's entitled a head first approach. Okay folks, so this evening then our sort of aims and objectives for this talk. We're going to start with some brain basics, brain structure and function, then we're going to move on to my favorite brain signaling molecule or neurotransmitter or brain hormone. Call it what you will. But I want to introduce you to dopamine, which is probably the most crucial neurotransmitter where behavior is concerned.
And we're going to link that to learning and cognition and relate that to training and trainability. Then finally, we're going to finish with the linkage between what we put into the horse in terms of feed and how that. can determine the behavioural output in this species. And as Charlotte says, at the end of my talk, there'll be plenty of time for questions. So here we go, guys.
This is a comparison of the horse and the human brain. The horse brain is roughly half the mass of the human equivalent, but I'm sure you'll agree from this picture at least, the structural similarities between the horse and the human brain are quite considerable. There are some areas that do differ, and here I've highlighted an area of the brain called the prefrontal cortex, and this is part of a brain structure known as the cerebral cortex. which is this folded outer coating which covers the two hemispheres or halves of the forebrain.
And I've showed you here a region called the prefrontal cortex. And this is from this diagram you will see that the human prefrontal cortex is taking up a much larger proportion of the brain than the equine equivalent. So what does the prefrontal cortex do? We refer to it very much as an executive center.
And if you think what executives do... They make decisions and they dish out orders. And that's exactly what the prefrontal cortex does.
And because the horse has a smaller prefrontal cortex, that animal will be more a creature of its more basic desires, such as the desire to flee or to fight. And the prefrontal cortex of the human. Because it's quite big, it plays a role in suppressing some of these more primitive desires, such as to flee or to fight. So when my students are back on campus and they're very stressed out in an exam hall, for example, everything in their body is telling them, get up and run out of the exam hall. But because they got this enlarged prefrontal cortex.
that can override their more basal desires. But the horse is not able to do that to such an extent. And that's something I want to come back to a little bit later on, because it's something we need to bear in mind when we manage and train this species.
And for some poor humans who find themselves under repeated stress, let's say in combat zones, the prefrontal cortex can lose a degree of its functionality. And those poor individuals can find themselves less able to suppress primitive desires relating to aggression, for example. So take home message, the horse and the human brain are really similar in terms of their structure, but also their function.
But there are some key differences, such as this prefrontal cortex. But the group of brain structures that I really want to drill into this evening, folks, and we haven't got time to make this a comprehensive review, but if you look at the literature, the primary brain structures, which are really crucial to the governing of behavioral output, the primary brain structures belong to a collective grouping known as the stream. striatum, the striatum, and it's a collective of three brain structures, the caudatus, the putamen, and the nucleus accumbens.
And these three structures have received by far and away the most research attention down the years in terms of their importance in governing behavioral output. So the caudatus, this crescent-shaped structure here and the lobe-shaped structure here called the putamen, they're really crucial for the fine motor control in any animal. So for example, I'm maneuvering this laser pointer on the screen.
That requires fine motor tuning and it's the caudatus and putamen which are really crucial for that. And again, for unfortunate human beings who develop conditions such as Parkinson's disease, it's the caudatus and the putamen which begin to degenerate. And as these two brain structures degenerate, people become quite shaky and they lose their fine motor control. So the caudatus and the putamen and where they continue ventrally at the bottom here.
We have a third brain region called the nucleus accumbens and it's a small chunk of tissue which occurs in both the right and the left side of the forebrain and this is probably the most researched pleasure centre of the brain. So for example when we eat something that tastes really good, a highly palatable feed. It's the nucleus accumbens which attaches the positive reinforcement or the pleasure to that eating activity. OK, and so the nucleus accumbens, it's a pleasure center, but it also responds to stress. And in another talk and another day, I can tell you a little bit more about that.
So we have the caudatus, the putamen, the nucleus accumbens, all in the forebrain. Then two additional brain structures that I want us to. to consider this evening, guys, actually occur in the mid brain.
And they've got fairly horrible names. The substantia nigra. and the ventral tegmental area, which will be known later on in this talk just as the VTA. And I want you to think about these as neurotransmitter factories, and they produce a brain signaling molecule or neurotransmitter called dopamine, probably the most important neurotransmitter where behavioral outcomes output and the control of behavior is concerned. And that dopamine is produced.
It's transmitted along nerve fibers, which terminate in the striatum. So this nerve fiber bundle in red terminates in the nucleus accumbens. And so, for example, when we eat something that tastes nice, the ventral tegmental area activates.
It transmits dopamine, which then binds to docking molecules or receptors on the nucleus accumbens. And it's that interaction between dopamine and its receptor that brings about pleasure. Okay.
So brain structures that are really crucial to behavior, caudatus, putamen, nucleus accumbens, the neurotransmitter that I want you to be thinking about is dopamine. This is just a sort of a horizontal plane or a bird's eye view of the forebrain here, just so you can get a better indication of where the striatum sits. And what we're looking on here, this bit of grey matter here and here, that's actually the top of the chordatus that we can see in this diagram here. So that just gives you a better indication of where the striatal brain structures sit.
But now I want us to think a bit more along the lines of neurotransmitters and dopamine. And in horses, measuring dopamine in relation to behavior is actually quite a challenge because we don't have sophisticated brain scanning technologies. We don't want to do anything that's ethically questionable, such as.
invasive neuroscience. So for the last 10 years, I've been figuring out behavioral indicators of brain activity with specific reference to dopamine. So how can we measure dopamine to learn more about how it interacts and governs behavioral output in the species? How are we going to measure dopamine?
Well, It just so happens that we've got a really simple measure called spontaneous eye blink rate or SBR. So don't take my word for it, folks. Here's a little bit of evidence.
OK, if you give an animal such as a non-human primate chimpanzee, for example, a dopamine agonist, this is a type of drug which increases the availability of dopamine in the brain. called is the release of dopamine in the brain. And an example of a dopamine agonist would be cocaine.
Okay. And if you give an animal cocaine, it starts blinking rapidly. And if any of you, um, ever want to figure out whether you've got, got children and, uh, what have you, um, or, or naughty students that I might have, um, high blink rate is a really good indicator of.
dopamine, of cocaine abuse. Then on the other hand, if you give an animal a drug that blocks dopamine, an antagonist, blinks come down. So we're building up a bit of a picture here.
Then again, for humans with pathologies, psychopathologies, mental conditions such as schizophrenia, and schizophrenia is characterized by increased levels of dopamine in the brain. Patients with schizophrenia display elevated blink rate. Then on the other hand, for unfortunate patients who experience death of dopamine containing nerve cells and have lower levels of dopamine in the brain, then this is meant to read decreased.
Sorry, folks, that's a typo. So patients with Parkinson's disease show deep priest blink rate and a little bit of equine evidence as far as blink rate is concerned um One of the horse diseases which we could consider to some extent similar to human Parkinson's disease is Cushing's disease or PPID, pituitary pars intermediate dysfunction. And these horses experience death of dopamine containing nerve cells which start in the hypothalamus and transmit down to the pituitary.
OK, we found in a 2014 study that horses with PPID or Cushing's showed significantly lower blink rate. So blink rate seems to be a reasonable indicator of dopamine functioning in this species, in the horse. But following on from that, it could well be, OK, and Charlotte might shoot me down here, but it could well be that a bee. behavioural indicator of dopamine in the future may well become part of a series of tests that we apply to horses that we suspect have Cushing's disease to complement some of the endocrine indicators that we more commonly use and we know that things like ACTH are subject to both day-based diurnal but also seasonal fluctuation, could well be that a behavioral indicator such as blink rate may well be an additional diagnostic tool in the veterinarian's arsenal. Then on the other hand, dopamine links quite closely to temperament, and generally speaking if we elevate levels of dopamine massively in the brain, it increases anxiety, we bring the levels of dopamine down, then people become more docile.
And in this study here that we conducted back in 2016, we took a group of 100 horses and measured several temperament variables, and we found that there was a nice positive correlation between anxiety and blink rate. and a negative correlation between docility and blink rate. Basically meaning that horses which blink faster in this study had higher levels of anxiety and lower levels of docility. And what we've got here then guys is potentially a use of blink rate to help us assess temperament. Now obviously we've all shelled out for a for an expensive five-stage vetting and it could well be in the future that an indicator such as this might contribute to a six-stage vetting which featured a measurable numerical or quantitative measure of temperament which i put to you could be blink rate so blink rate has a range of diagnostic and indicative potential, I believe, in this species.
But more recently, we've been using BlinkRate to assess the linkage between dopamine and learning. Dopamine does an awful lot, folks. It's a pleasure neurotransmitter, but it's also really crucial. to the processes that underlie learning of a new task. So we wanted to try and test that a little bit more in the horse and learn more accurately what is the relationship between dopamine, blink rate and learning ability in this species.
And we chose a cognitive test or call it an intelligence test. if you want. And we borrowed this from the rodent neurosciences.
And this intelligence test or cognitive test is called the five choice serial reaction time tasks. Now, behaviorists like to like to like to sound very scientific. So we attach these horrible long words to things.
But this is a rodent based task and I think a good way to describe this. Have any of you played a game called Whack a Mole, either on your phones or at the Village Fate? What you've got is a series of holes in front of you and your mole pops up and the aim of the game is for you to take a hammer and hit the mole on the head. Okay, that's the Whack a Mole game and this task is very similar to that.
Now... Imagine that you're trying to predict which hole the mole is going to emerge from. And let's say you hit a hole too early.
That's an example of an impulsive behavior, an impulsive behavior when you go too soon. On the other hand, if the mole emerges, you hit it on the head, then keep hitting that hole. That's a more repetitive behaviour referred to as compulsive. So we have impulsive, which is going too early, and compulsive, which is being too repetitive. And this task essentially tests that.
And this is how it does it. OK, so a screen lights up. The rodent is then required to select the correct screen.
And if it selects the correct screen, a food reward then arrives in the feed trough or the feed magazine. OK, and we set about measuring impulsive and compulsive behaviours in the horse. And we adapted the five choice task to the equine scenario.
So this is basically the. three choice serial reaction time task and this was our prototype device. We took three screens then rather than have the feed trough at the back of the stable we presented it under the device okay and we messed around initially with touch screens um but we found very quickly that horses tend to slobber on touch screens.
and they stop working quite quickly, I'm afraid. So we came up with something a little bit different and we published this back in 2017 in the Journal of Neuroscience Methods and we collaborated with the neuroscience department over at Cambridge. And what you see here is the first fully automated intelligence testing or cognitive testing device for the horse.
And so we've got our three screens that you see here. And rather than have those as touch screens, we had a infrared beam. And as the horse's nose selects the screen, it breaks the beam. OK, so we can then program the computer to record that choice. So there we go, guys.
Here I present to you the iPLOD. OK, so this is our cognitive testing device. And on this, we can run the serial reaction time task.
So in a second, on the right hand of your screens, you will see one of the screens on the device. It will light up and the horse, if it selects the. the correct screen will receive a food reward.
So let's just run that through. Okay so the horse got that correct but just ask yourselves folks it then went back to the previously lit screen. So is that an example of impulsive or an example of a compulsive behavior? So ask yourself that question.
And the answer to that is obviously that was an example of a compulsive behavior. So we looked at the relationship between blink rate and performance in the three choice task. And again, we used a cohort of 100 horses.
And we split that cohort into three groups. Animals which blinked 15 or less times per minute. OK, just get my pointer up again.
Animals which blinked between 15 and 21 blinks per minute. So we've got a low and a medium. And then we've got the really high blinkers that blinked more than 21 blinks per minute.
So these are potentially the ones with loads of dopamine flowing through their midbrain. And we ran those three groups through the test. And we found that the high blinkers performed significantly more compulsive behaviors than the medium and the low equivalents. And we took this to the British Neuroscience Association annual conference. And I haven't got the data here, guys, but we found exactly the same thing with impulsive responses as well.
The high blinkers, those that blink more than 21 times a minute, they committed significantly more impulsive behaviors. So here we've got this really simple measurement that we can all do on our horses called spontaneous blink rate. It could potentially be a measure of. Cushing's temperament. And now it's even showing some promise as a measurement of cognition and learning with this particular test.
So in terms of where I would like to take the talk now for the last 10 minutes or so, we're going to stick with the same brain structures, the ventral tegmental area and the nucleus accumbens. But we're now going to explore how these brain structures react to feeding. And when we give a horse a palatable food, something that tastes good, we see the release and liberation of a different type of neurotransmitter in the brain. known collectively as the opioids.
And you may be familiar with some of the opioids, for example, the endorphins. And when we eat chocolate or when the horse eats palatable course mix, for example, the brain is flooded with endorphins, which bind to specific receptors or blocking molecules on the ventral tegmental area, causing it to activate and produce our old friend dopamine, which then binds to its docking molecules or dopamine receptors on the nucleus accumbens, causing that brain structure to activate. And the upshot of nucleus accumbens activity from a behavioral perspective, on one hand, it results in a hyperactive horse. This is one of the reasons why foods that taste good can lead to hyperactivity in our animals.
But also really crucial to my research, one of the other things that we see when the nucleus accumbens activates in certain animals. So on one hand, hyperactivity, but also stereotypic behavior and the most commonly recorded. Feed-induced stereotypic behavior is crib-biting.
And crib-biting is certainly where some of my research has been focused for the last two or three years. But interestingly, if you then inject a horse with an antagonist, remember antagonist's block thing. If you inject a horse with a drug that is an antagonist. where opioids are concerned, so an opioid antagonist and an example of an opioid antagonist, if you want to Google this, folks, it's called naloxone, naloxone. And this is a life-saving drug for humans who've taken morphine overdoses or heroin overdoses.
Naloxone can save the lives of these individuals. but if you give it to a crib biting horse it blocks these receptors and that crib biting is stopped. It's abolished.
Okay. This led us to think to ourselves, let's have a closer look at what's going on in the brains of these crib biters. And we counted opioid receptors.
Okay. And we looked at these in the nucleus accumbens and the ventral tegmental area of crib biters and also control horses. And we didn't just find a small difference, we found over double the number of opioid receptors in the ventral tegmental area, and very nearly that sort of a difference in the nuclear succumbance. This means in the crib biter, the VTA and the nuclear succumbance are going to be hypersensitive.
And here you see a crib biting horse being fed. a small quantity of palatable food. So there's a horse eating its handful of course mix. Imagine what's going on in that horse's brain. The opioids are liberating, okay, the opioids such as the endorphins are being released, they're binding to their receptors on the ventral tegmental area, VTA produces dopamine and crib biting.
is the result. And here we go, folks. For me, it's almost time to abandon some of the more often used approaches to suppressing or reducing crib biting in the horse.
Very often, and I've done this before as a horse owner, I'll reach for the crib strap, okay, and tighten up this crib strap. For me, that's not... the way forward. The very best way to bring crib biting down is to feed that animal less highly palatable concentrate rations and feed that horse instead a good source of high quality forage. Very much the best way to bring down on one hand crib biting but on the other hand hyperactivity in a majority of animals.
And also, if you're ever assessing a horse for purchase at a horse sale, for example, and you're trying to assess whether or not that animal in front of you is a crib biter, the very best way to reveal that is to give it a polo or a small quantity of feed, and that horse will beat its way. to the nearest crib biting surface. Okay, so take home messages to end on then folks. Blink rate, this easy to apply non-invasive tool, can tell us a good deal about temperament traits such as anxiety and docility.
Okay, it can also tell us about the cognitive function of that animal and what we found is blinks in excess of 21 blinks per minute will lead to higher levels of both impulsivity and compulsivity and from a training standpoint an impulsive horse is probably the one that's going to react inappropriately to the rider's commands the other hand But compulsive horse, we have found these animals are more prone to repetitive behaviors, such as crib biting, and might be slightly less flexible when being trained and unable to unlearn and improve during their training regime. So in the future, I really think that blinks could become a decent measurement of certain aspects of cognitive function. And if we want to use dietary manipulation to bring down stereotypic behavior, but also hyperactive behavior, feed the horse in the way that it's been evolved for the last 55 million years, and that is to survive on primarily forage.
And I know it's quite a while since I got on a horse, but I used to event quite a lot. And I found the majority of my horses would event quite happily off grass on a forage diet. So I think that's potentially something that we should seriously think about.
in all the horses that we manage. So I'm at my 35 minute point here, guys. So at this stage in the proceedings, I'd be delighted to open the floor to any questions.
Thank you, Andrew. That was a great presentation. Really interesting.
I hope everyone else enjoyed it as much as I did. So I just turn my video on there. Yeah, thanks.
Super. Thank you very much indeed. So I do have a question from the audience, which was how did you select the three different groups of blink rates? So you had the less than 15 blinks per minute, the 15 to 21 blinks per minute, and then the above 21. blinks per minute so how what was the rationale behind that selection? Basically we we looked at human studies but also what was considered normal in that a very small number of equine studies which is had assessed blink rate and we took a hundred horses and I should have should have said earlier but we then grouped that population into 30 animals which then went on to do the task so 10 low blinkers 10 medium blinkers then then 10 fast blinkers so so that the cognitive test was actually performed on 30 horses out of an initial cohort of 100 of which you selected the extremes and then the middle group oh thank you for clarifying absolutely and if i tell you what charlotte um that the poor phd student who had to count blinks on three occasions for 30 minutes in 100 horses.
It was quite a task. Well I have seen some students up at the Cotswold Wildlife Park sort of sitting for eight hours at a time monitoring the giraffe feeding behaviour, so they're very dedicated these students aren't they to their research. So there's a question that was following on from the same person, how do you pull apart the different drivers of blink rates.
So is there a difference between disease and behaviour driven factors? I imagine that it's very difficult to pull apart. That's probably sort of... It's a brilliant question, Charlotte.
It's a very good question. And it's one of the fallibilities of blink rate as a measure. And principally, we were looking for a cheap and easy to apply measurement tool.
But obviously, that is then open to... certain vagaries such as dust levels, stabling conditions, and for example, to count blink rate accurately, or baseline blink rate accurately, that has to be conducted at least an hour either side of feeding, because we know that feeding elevates dopamine and could artificially elevate blink rate. So we do have to be quite careful about the way we we count blinks and also if you ever sit and watch a horse blinking for 30 minutes you get the full blinks the full occlusion of the eyeball by the eyelids but also you will see a number of twitches and half blinks and we're just beginning to try counting those as well to see if they are important and And as we use this as a stress measurement tool in future studies, I do believe that the half blinks and the twitches could be quite important. So that's something that we're trying to do. But the only way of doing that accurately and properly now is to figure out an automatic blink rate counting tool.
So my current PhD student is working on a... a computer algorithm that will take blink rate video and do the counting for us. So that's kind of like the next stage in the game.
Yes. And I was wondering whether you had correlated heart rate and blink rate at all, elevation in heart rate and changes in blink rate. We have. Well, not so much.
I'm sure we have correlated them. But what we have done in the past is look at blink rate. heart rate and salivary cortisol and and we found that um the heart rate measurements and the salivary cortisol measurements far more variable and yield significantly less robust data compared to the spontaneous blink rate which which always surprises me but but if you think that you're likely to get heart rate fluctuations in response to so many different things general levels of arousal and and the same goes for cortisol but for some reason the blink rate seems to throw up far more robust and less variable data sets compared to the other conventional indicators of stress which which I think is quite encouraging but then again surprising that such a simple measure could potentially be quite useful. So I've got a few more questions just come in thank you Andrew so if you were to measure a horse's blink rate do you do it for you do it for 30 minutes and which eye do you select to do it or do you have to do both?
We generally this is quite arbitrary but we generally select the the left eye and To get the best, most robust data, we do it in triplicate on three occasions for 30 minutes on each occasion. The Cushing study was just 10 minutes on three occasions, but the more recent work would be in triplicate for 30 minutes on each occasion. And another question, when trying to increase the diet back to their natural diet of fibre, Would you just feed chaffs and fibre based mashes along with hay, haylage and grasses? Or should you add balancers? Also, thank you for a very interesting talk.
Lots of people have been commenting. Thanks for a great talk. So, yeah, that's again, you know, it's beyond my remit a little bit.
But what what I would say is that on one hand, there's this so many. really good fibre-based soakable feeds out there these days and I hate to mention particular suppliers but things like Fast Fibre by Allen and Page for example is a really good source of high quality fibre which is really low in starch but I really don't think it hurts to feed a balancer particularly the ones that contain live yeast and we've had really good results. from a behavioral standpoint on on certain balances such as the pink powders, for example, which which contain live yeast. And we've we've noted that behavioral profiles in quite hyperactive, aggressive animals have improved quite significantly on a high fiber diet with a balancer featuring yeast.
So I would actually think that that sort of a. a supplement would be really quite useful. Yes it's about adapting the balancer because to me the balancer has to have the critical protein in the essential amino acids the vitamins and the minerals but then it's what else you can add into that Andrew I guess to influence these factors without being especially palatable and stimulating that. That is the problem.
There are two things which govern hyperactivity from a feeding-based perspective. Firstly, the palatability, but then also the starch content, because obviously starch is degraded to glucose, very easily absorbed across the duodenal wall. And once starch crosses the blood-brain barrier, it affects...
a different group of brain systems that we didn't have time to review tonight. And one in particular, if you wanted to do any additional reading is called the hippocampus. The hippocampus and glucose tends to bring about the release of another neurotransmitter called serotonin from the hippocampus.
So if you elevate glucose, you elevate serotonin and serotonin is one of the best known happy hormones, which is more often associated with MDMA or ecstasy. And we know how that affects humans. And it seems to have a similar effect in other species, including the horse.
And that brings me nicely onto a question, which is, so am I right in understanding that increased dopamine levels are associated with anxiety. So it's not the happy hormone as previously described. Ah, that's again, yeah, well, well spotted.
It depends where that dopamine is being transmitted. OK, so dopamine from the ventral tegmental area. into the nucleus accumbens is almost always associated with pleasure. Now the nucleus accumbens is actually formed from two sub-regions, an outer shell and an inner core.
And the binding of dopamine to the outer shell is always associated with pleasure. The binding of dopamine to the inner core of the nucleus accumbens, then also the dorsal striatum, the caudatus in particular, is very much associated with hyperactivity and if dopamine elevates to a greater extent anxiety and when you talk about humans who've been using too much cocaine they they push the dopamine levels way over the required for pleasure and it in instead descend into the realms of paranoia and anxiety so it's a subtle balance with dopamine depends upon which sub-region of the nucleus accumbens it's being transmitted into. Thank you Andrew.
I've got another comment, really interesting, thank you. I have a horse that crib bites and also shows other anxiety related behaviours. Have you identified other behaviours linked to elevated dopamine and blink rates?
That's a good question. Now have we? I tell you what, we had a group of horses on a tyrosine supplement once, which tyrosine is a precursor of dopamine. Dopamine is actually synthesized from tyrosine.
And horses on the high dose of tyrosine also showed elevated incidence of aggression. So in that small subgroup on those horses with the... high levels of tyrosine supplementation, we did see some high levels of aggression. And some of the old biotin formulas, like the initial Farrier's formula, for example, at one point had very high levels of tyrosine.
And anecdotally, I heard from some owners that that did result in some behavioral abnormalities. That's not been measured scientifically, however. Yeah, and that came up in, we won't mention it, but another feed.
supplement recently uh well last year with several clients there was an alteration in a in a karma um i think with tyrosine in it so interesting just to um i just have one last comment here which is um are humans very similar have they found have similar responses in humans being found with regard to blink blink rate and dopamine that's that's where a lot of the receipt research yeah particularly um the research into Parkinson's disease and I believe blink rate is one of the diagnostic indicators with Parkinson's disease and so that definitely came primarily from the human neurosciences and the small body of research which have been done on non-human primates given dopamine agonists and antagonists and I mean very often in the horse we're learning from some of the more invasive neuroscience which has been done on other species which is you know less ethically palatable for for some people but but but it's actually helped us in our equine endeavors quite a lot and for me because we're gunning towards uh non-invasive measures of welfare status i i do believe that that what we're doing here um it's useful to learn from the human neurosciences in particular. Yeah it's fascinating how this transferable research and well that leaves me to thank the audience for their wonderful questions and of course to thank Andrew for a super presentation and for answering those questions and I think it would be great to have a part two of this and we'd be very interested in learning more from you because that was fantastic and it's great to have this sort of knowledge sharing. collaboration with the Royal Agricultural University so thank you very much indeed everybody and we'll hopefully reconvene again thank you very much continue thank you Charlotte thank you good evening everybody all night if you wanted me to thanks everyone goodbye