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Periodically, Dr. Dickson lectures on neurodegenerative diseases and integrating research discoveries from the Neuropathology and Microscopy Lab and the Mayo Clinic Brain Bank in Florida.

2026

"Rainwater Prize Winners: Advancing Tau Research"

In this episode, Louise Serpell, Ph.D., D.Phil., is joined by Dr. Dickson as well as Melissa E. Murray, Ph.D., and Marc Aurel Busche, M.D., Ph.D. — all 2026 Rainwater Prize winners.

Rainwater Prize Winners: Advancing Tau Research

Chapter 1: Introduction to the Conversation

[Voice Over]: The Dementia Researcher podcast, talking careers, research conference highlights, and so much more.

Chapter 2: Introduction to the Rainwater Prize and Its Significance

Professor Louise Serpell, University of Sussex: Hello, and welcome to the Dementia Researcher Podcast. Today we're exploring the science behind the 2026 Rainwater Prize and the researchers whose work is shaping our understanding of tau related neurogenerative disease.

Hello, I'm Professor Louise Serpell from the University of Sussex, and I'm delighted to be hosting today's episode. The Rainwater Prize recognises major advances in tauopathy research. In this podcast, we'll be discussing the scientific questions and the impact of the work and what this means for the future of the field. So without further ado, I'd like to introduce the three 2026 Rainwater Prize Winners. Professor Dennis Dickson and Professor Melissa Murray have been recognised for outstanding innovation in neurodegenerative research. And Professor Marc Busche has been recognised as an innovative early career scientist. Thank you all for joining us and congratulations.

To start us off, could I ask each one of you to briefly introduce yourselves and describe your main research focus and where you work when you found out you'd won. Dennis, would you like to go first?

Dennis Dickson, M.D., Neuropathologist and Director of the Brain Bank for Neurodegenerative Disorders, Mayo Clinic, Jacksonville, FL: Okay, I'm a neuropathologist and I'm the director of the Brain Bank for Neurodegenerative Disorders at Mayo Clinic in Jacksonville. And this brain bank is the largest brain bank for neurodegenerative disorders in the world, especially when it comes to atypical telepathy such as progressive supranuclear palsy. I have an MD from the University of Iowa and I'm actually boarded in anatomic pathology and neuropathology.

Professor Serpell: Thank you very much. And where were you when you first found out that you'd got the prize?

Dr. Dickson I was on a zoom call with the Rainwater Foundation.

Professor Serpell: Perfect.

Dr. Dickson For a Tau Consortium meeting, and then Jeremy popped in and gave us the great - Surprise. (Dennis chuckles) - Surprise, surprise.

Professor Serpell: Exciting. Yeah. Melissa, would you like to go next?

Melissa Murray, Ph.D., Professor of Neuroscience, Mayo Clinic, Florida: I'd love to. Hi, I'm Melissa Murray. I'm a professor of neuroscience at Mayo Clinic in Florida. I received my Ph.D. from Mayo Clinic, which allowed me to do much more translational science. So I'm a translational neuropathologist and I have devoted the last 15 to 20 years to studying tau in many different forms.

And, I happened to very kindly be on a call with Dr. Dennis Dickson with the Rainwater team and we were meant to be talking about brain banking and upcoming Tau Consortium meeting and they just completely surprised us, like a surprise party. It was the most wonderfully endearing, I don't know, moment ever. And, so, as Jeremy gets on the call, he went to interrupt us, we thought to say hi, and then he began with, On behalf of the Board of Governors, we are delighted to share with you that the Rainwater Charitable Foundation and family, but it was just, it was, we were speechless. It caught us by the surprise.

Professor Serpell: Yeah, sounds amazing. Thank you. And Marc?

Marc Busche, Clinical Academic: Yeah, thank you Luis for having me. My name is Marc Busche. I'm a clinical academic, I split my time between the clinic and the lab. I care for patients with tauopathies and other neurodegenerative diseases and run a research effort that is focused on better understanding how these diseases affect the brain at the level of single synapses, cells, and circuits and how that leads to symptoms that we see at the bedside. And we hope that through this understanding we can develop more mechanism based treatments.

And a lot of the work that has been recognised by the prize was done with my team at the UK Dementia Research Institute at University College London. But I've also recently moved to Basel in Switzerland to lead the Mayo clinic and the old age psychiatry there at the University of Basel. I found out about the prize in a similar, slightly unexpected way. The Rainwater team scheduled a zoom call with me to talk about a technique we're using and then towards the end of the call they told me, which was a genuine surprise and really lovely news.

Professor Serpell: Fantastic. It sounds like they had a little bit of a plan associated with all of it.

Dr. Murray: Yeah, I think we had a lot of fun. It's so nice.

Professor Serpell: Yeah. So real personal touch, isn't it? That's brilliant.

Chapter 3: Understanding Tau: The Central Protein in Neurodegeneration

So before we explore individual projects, I want to set the scientific scene. The Rainwater prize focuses specifically on tau related neurodegeneration. And I'd like to start by asking all of you why you believe that tau is such a central and challenging protein in this field. So I might start with Melissa this time.

Dr. Murray: So Tau is an incredible protein. It's a protein that we require for normal functioning. It's what allows our electrical impulses to transmit throughout the brain for really fast communication faster than a computer. And so you have this protein that's critical and yet in many diseases it starts to change.

And we like to think of it as this protein that helps to keep the railroad track stabilised where tau is that nail. And as tau changes whether through altered structures on a protein level or earlier than at mutation carriers, the brain isn't able to cope. And so for us, the focus, or for me, the focus on tau pathology is kind of the why and the where. I really enjoy trying to understand why tau changes in particular areas of the brain and why that matters very much for primary tauopathies and Alzheimer's disease suffers.

Professor Serpell: That's so interesting. And to think about tau as a functional protein as well as a pathological one. And I might follow up with that a little bit more in a moment. So in regards to your work, Marc, what do you think is most interesting about tauopathy research?

Marc Busche: Yeah, I agree with Melissa. I think the key point is that tau is a normal neuronal protein that the brain needs throughout life. We actually have evidence that suggests that tau is essential for the normal pattern of brain activity. If tau is gone, this pattern becomes disrupted. And in tauopathy is the problem is not that tau is existent, but the problem is that tau changes, it comes chemically modified, it moves into the wrong compartments, it begins to self-assemble into toxic species eventually filaments. And once that happened, tau can disrupt a neuronal function. And it also seems to spread through network.

So clinically tau is interesting because it maps very closely onto symptoms and progression across multiple disorders. So it is a central therapeutic target, but it is difficult because you want to block the harmful forms without interfering with tau's normal function.

Professor Serpell: Absolutely, yes. So, I mean, coming back to function just briefly, I think it's really interesting to think what tau is doing. Many of the other amyloidogenic or misfolding proteins, we don't know what they do, but we do know for tau, don't we? So Melissa, you mentioned the railroad tracks, the microtubules that are in the cells and the cytoskeletal association. So why do you think there is this toxic effect? Do you think it's a loss of function or maybe a gain of function or both?

Dr. Murray: So I think there might be a few different things that might be occurring. Some of the mutation carriers, so there is a gene called microtubule associated protein tau It's M-A-P-T, MAPT. It's the gene that encodes from the tau protein that we're all discussing. And mutation carriers where there's different parts of tau that is affected have various differences. Dennis Dickson, Dr. Dickson's gonna speak a little bit about different forms of tauopathies and it's striking to think where the position on tau has affected all of these different patterns of pathology.

But I like to think about tau as a signalling molecule. And so I think we're getting the clues of where the signals are in different parts of the brain that we don't wanna stop some of the signals. But I think what might be happening is it's hijacking some form that evolutionarily has protected us, but somehow in this disease state it might be starting something that's helpful and then the brain can't compensate.

Professor Serpell: Well, that's fascinating. And what about you, Marc, what do you think is happening with tau and its function and dysfunction?

Chapter 4: The Role of Tau in Neurodegenerative Diseases

Marc Busche: Yeah, so I think it's entirely possible that some of the changes we see are due to a loss of function, but at the same time we also know that tau, which is abundant in the axon, so in the long processes that connect the cell body with the synapses is redistributed into other compartments, for example, into the soma. And then it can have an impact on neuronal function, on also synaptic function in the dendrites. And I guess this is something we also speak about at a later time point. So I think it could be a bit of both.

Professor Serpell: Yes, thank you. So Dennis, back to the original question. What do you think is so special about a tauopathies? Why have you devoted your academic career to understanding these diseases?

Dr. Dickson Well, in part I would wanna echo what has already been said about tau in terms of its function, and it takes on abnormal forms. But that's kind of begging the question because we know that there are these abnormal forms, we can see them in the tissue. But what causes that? And I don't think we have a grasp of the major driving mechanisms for the abnormal forms of tau. Clearly, tau doesn't go abnormal or rogue if you will, until mid to late life.

The majority of people with tauopathies are in their 60s, 70s, or even older. So it's something that occurs with the time as a factor that contributes to these degenerative properties of tau protein. And I don't think... I think if we could understand what those driving forces are, then we could get it to root causes of the tauopathies.

Professor Serpell:Yes, and so I'm in really interested in whether there are clues from the traumatic brain injuries, 'cause that's I guess gives us a little bit of a sort of prompt as to something that causes tau to start misbehaving?

Dr. Dickson It's interesting that you should say that because Dr. Anne McKinney was an invited speaker just like half an hour ago in our neurology grand rounds. And she clearly makes a very strong case that repetitive head injury over a period of time leads to aggregation of tau protein, not only within neurons but also in glia. We don't actually think of tau as being necessarily a glial protein. So why would a protein that isn't even abundant in glia aggregate within glia?

Professor Serpell: Yeah, fascinating.

Dr. Murray: May I just add something briefly? One of the things Dennis said, that I think is particularly relevant and that I think is still our current mystery, is the timing. And what we witnessed with tau is almost a paradoxical ageing effect where we do see certain proteins increase with age and if we think of them as age associated, yet the individuals who experience the devastation of tauopathies the younger they are, they often have much greater pathology.

Whether we think about that in our primary tauopathy patients in comparison to late onset Alzheimer's disease or even younger forms of tauopathies, that there seems to be a much more aggressive course. So there could be something acting on it in younger life that enables it or isn't catching as opposed to some protective methods in later life.

And Dr. McKee was just here and one of the things she said that was really quite striking from the traumatic brain injury area is that they're seeing neuronal loss before some of the tau, such that tau is an important feature at least in that context. But there may be something that's killing our neurons that we could understand even prior to that, maybe tau in this instance in that experimental condition could be responding to the trauma. So it's fascinating to think on a disease level.

Chapter 5: Exploring the Pathology of Tau and Its Variants

Professor Serpell: Absolutely, I mean that makes me wonder about the sort of species of tau that's being involved. So when you are looking at the pathology, is it that you see a lot of filaments or can you detect smaller species of tau in the brain tissue?

Dr. Murray: So our brain bank as well as I think many other people in the field were really fortunate that Dr. Peter Davies was such a giving person. And so he would actually create tau antibodies that were derived from brain homogenous. So he would actually identify tau antibodies relevant to humans. And so we can see different proteoforms.

So if we think about that nail again, if the nail gets really rusty, we can see little changes on tau. We can see truncated forms and conformationally. But are we thinking filaments like cryo-EM filaments?

Professor Serpell: Yeah, I mean in the past we've done some electron microscopy looking at sections of human brain from Alzheimer's patients and we could actually see that the filaments themselves look like paired helical filaments. So we got enough resolution to be able to see those. But I'm guessing that you see a large aggregate of protein structure, but you don't necessarily know what sort of structure that is at the level that you're looking at. Is that right?

Dr. Murray: Yeah, I mean fortunately Dennis has recruited several EM specialists, electron microscopy specialists that do give us that little window. But yeah, when we're looking down at the microscope, even under at a hundred magnification you can see filamentous structures, but not that beautiful paired helical that you would see on the black and white images.

Professor Serpell: Yeah, not enough resolution. Yeah, absolutely. And I might turn to Marc at this point 'cause I know Marc, that you are very interested in the species of tau that are important in the observations that you've made. So did you want to say something about that, about what form of tau might be important?

Mr. Busche: I guess there are multiple forms of tau that might be important. What we have found is that it's not only the tangle that can impair the function of a neuron, but it's also the soluble species, oligomeric tau, which are probably not as well described and understood, but seem to have an effect on neurons and very specific effects on neurons as well.

Professor Serpell: Yeah, that's fascinating. I think we've also note that's been reported in other neurodegenerative diseases where the oligomeric species seems to be really important in terms of the disease. So I think we might advance a little bit onto the next part of the questions. So I really wanted to talk to you a bit more about the science of the award, and Dennis and Melissa, what is it specifically that you have benefited from the brain banking advances that you've made?

Dr. Dickson Yeah, so I think every brain has a story to tell, basically. And even though disorders are defined or described based on certain characteristic properties in terms of distribution of pathology and the morphology of the lesions, be they neuronal or glial, each case is different from every other case in terms of the absolute amount of pathology and the distribution.

But if that was taken to an extreme, it would just be a chaotic situation. But after looking at hundreds and even thousands of brains of PSP, we actually see very reproducible patterns of pathology and we see selective vulnerability, certain brain regions such as the subthalamic nucleus, the basal ganglia, the substantia nigra, the cerebellar dentate nucleus.

These areas are vulnerable, and these are areas that are not vulnerable in many other neurodegenerative disorders. So disorders that are associated with, for example, TDP-43 pathology, we usually don't see much pathology in the cerebellar dentate nucleus. We don't necessarily see pathology in the globus pallidus, for example. So there's the concept of selective vulnerability is crucial to understanding diseases and how they present clinically and pathologically.

What we don't understand, and maybe this is where molecular high profiling, you know, deep phenotyping will eventually give us answers, will explain why is the cerebellar dentate nucleus more vulnerable? Why is the globus pallidus more vulnerable? And so I think as a pathologist I can describe it, I can correlate my findings with the clinicians, but I can't get to the fundamental processes that lead to those changes. And that's where I need people like Marc and Melissa to come to the rescue.

Chapter 6: The Impact of Brain Banking on Neurodegenerative Research

Professor Serpell: At this point, I just wanted to ask you a bit more about PSP. So it's progressive supranuclear palsy and just you'd mentioned that the symptoms sort of correlate with the region that's affected. So I wondered if you wanted to say a bit more about that?

Dr. Dickson So there's variation in the distribution and density of the pathology, but certain areas are affected in virtually every case of PSP, the substantia nigra, globus pallidus, the dentate nucleus and the cerebellum and a certain brainstem nuclei. We don't know what makes those regions vulnerable, but they all are regions where we get accumulation of four repeat tau within neurons.

And I'd be remiss to say in contrast to a disorder like Alzheimer's disease with the overwhelming majority is purely neuronal. This disorder is a neuronal and glial tauopathy. And so I think you have to think a little bit outside the box in using the AD paradigm to try to understand PSP because AD is missing for the most part except for ageing related astroglial pathology. It's missing that glial component. So the PSP and corticobasal degeneration, other 4R tauopathies are really unique set of disorders that challenge us to understand how both neurons and glia can contribute to the disease process.

Professor Serpell: Yeah, okay. So that's really interesting. So in terms of the symptoms of PSP, do you understand more about how the symptoms are associated with those particular areas of the brain?

Dr. Dickson I think so. So for example, there are nuclei in the midbrain that control vertical gaze, eye movements and vertical gaze. And those areas are selectively damaged in PSP, the areas in the substantia nigra in the midbrain, substantia nigra are involved in the Parkinsonian features. Involvement of the basal ganglia could lead to more complex motor dysfunction as well. So there's a pretty good correlation between the anatomy and the clinical presentation.

So for example, most patients with PSP don't have cognitive problems. If they do, it's more of a mental slowing, but they don't have cortical abnormalities. But a subset of PSP patients have widespread diffuse pathology and it affects the cortex. Those are individuals that present with corticobasal syndrome or frontal lobe dementia or other types of complex neural behavioural syndromes, which we don't see in most patients with PSP, but it's these atypical PSP patients that have the more widespread involvement of higher order cortical areas.

Professor Serpell: Okay, so that actually makes me wonder about asking if it's alright to ask you, Melissa, about heterogeneity in neurodegenerative diseases and how you feel that your work has really informed us about heterogeneity, maybe overlap of different neurodegenerative diseases.

Dr. Murray: I'd love to, and so I was raised scientifically in a molecular neurobiology of disease programme, as well as clinically and neuropathology and neuroimaging. And so I had this best of both worlds. It might have taken me a little extra longer to learn because the disciplines would be so different, but it's so important in the context of neuropathology and behavioural neurology to understand these patterns that we're seeing enriched in different individuals that experienced the same disease. And I became particularly interested in heterogeneity across tauopathies within Alzheimer's disease. It was to help us to understand different subtypes that would explain why some had memory problems and some didn't.

And in the context of primary tauopathies where the primary function is a dysfunction of tau, I really became passionate about biomarkers. So biological markers would allow us to track disease progression in an individual. And my early work was neuroimaging and now fluid biomarkers. And it became so interesting to see something like hippocampal volume as a biomarker realising that it may not serve a subset about maybe 15% of Alzheimer's disease patients who don't have that relative hippocampal sparing involvement or hippocampal involvement.

And in contrast, as we've moved from neuroimaging into Tau PET, so MRI-to-Tau PET allows us to take picture of tau as it's deposited in vivo and into fluid biomarkers. We have these great tau markers that were not working in tauopathies, and I love mysteries. And so in the context of the Tau PET being raised scientifically and growing my work as a co-director in the brain bank, we are very fortunate because Larry, Dr. Larry Golbe and Dr. Dickson and got together from cure PSP a long time ago and realised we needed to serve our patients.

Chapter 7: Progressive Supranuclear Palsy: Symptoms and Pathology

And so we have this beautiful tauopathy brain bank where we can understand atypical forms because somebody will come in as a corticobasal syndrome, but be under the microscope PSP or Alzheimer's. And it's actually that tissue level understanding that helped us when we were looking at the Tau PET markers that worked in vivo on Alzheimer's.

We could see where they were not working and the tauopathies, and that gets back to what we were talking about earlier, it's the different forms of tau. And so you can find these ways to recognise it, but different forms of tau can be found in Alzheimer's and then individual types of tauopathies.

And this also became a difficulty with fluid biomarkers. We, once again, we had an ability to measure tau and biofluids, but when we looked at primary tauopathy and others across the world, we weren't seeing that change. The differences are really how tau is shaped in the context of Tau PET where there isn't a way for that locking key mechanism for it to label. But we think the fluid biomarkers that we have right now for those phosphorylated forms, we think it's actually because amyloid is somehow shocking the neuron and letting the tau get out.

That's not happening in our primary tauopathies. So there's many people across the globe trying to find a 4R, four repeat specific that lets us look at the specific kind of tau. And I have to say it being raised in a brain bank like this with such beautiful detailed work, I can ask these hopeful questions to see what we can do to make changes. And so yes, I have devoted a couple decades to heterogeneity and embracing it rather than hiding from it.

Professor Serpell: Absolutely, that sounds fantastic. I think that the, it seems really important at the moment to consider the confirmation of tau and where the surface level interactions could be. So we're talking earlier about all these antibodies, I think it was Peter Davis has made, and the idea of confirmational antibodies initially was quite confusing for people, I think. But now when we have all these structures for the different tauopathies, it seems really important that we might be able to recognise different areas of the tau that are exposed.

Yeah, so one thing that I then wanted to turn to Marc regarding was about that because a lot of structural biology has been done on fibres and filaments of tau, but your work has focused mainly on oligomeric species and the dysfunction that those cause. And I just wondered how you marry those two things together and what you think about the oligomeric species.

Marc Busche: Yeah, so we didn't start out to study oligomers. So the question that we wanted to address is asking a very simple question, how does a neurofibrillary tangle affect the electrical activity of a neuron? Because we know, I mean, I was always intrigued by the clinical observation in Alzheimer's disease, the tau is more closely related to symptoms than amyloid. So the question is why? What is tau doing to the brain?

And I knew that understanding this would have implications for other tauopathies. But we wanted to look at neurofibrillary tangles and neurons. So we used in mice a method called two-photon microscopy which allows us to visualise the pathology, the tangle in a neuron. And at the same time we could measure the firing of the neurons, the activity of the neurons. And we saw that the neurons associated with tangles were often much less active and sometimes even silent.

But then came a surprise as often with a control experiment, you know, the one experiment that you postpone for a long time until you have to do it for the paper in which we used mice that had elevated levels of soluble tau but no tangles. And we actually saw the same kind of functional phenotype of neuronal silencing. So we knew that tangles were neither sufficient or required for this phenotype and that the effect could depend on soluble tau, which to me to us was rather unexpected.

However, I mean there has been data that in mice suggesting that you can improve behaviour and function in mice without necessarily removing the tangles. And at the same time there was also growing clinical evidence, for example, from Bradley Hyman's group showing that soluble oligomeric tau species might be closer related to the rate of clinical progression in Alzheimer's disease than the actual tangles.

Chapter 8: Heterogeneity in Neurodegenerative Diseases

So that basically led us to, you know, think about soluble tau more, the problem, of course, in the brain is that everything is changing at once, so causality is hard. And then we had this idea that we could perhaps put a pathological tau derived from a human Alzheimer's brains into just a single neuron. So one cell, and then follow what happens to the physiology of the cell over time. We have only one neuron which is surrounded by many neurons that do not have it. And the logic was that if tau is truly a soluble tau, is truly driving the dysfunction of neurons, it should be able to do it at the level of a single neuron.

And I actually remember thinking that this might not work because it's a very difficult experiment, but we extracted soluble tau species from human brain and delivered them with a very tiny glass pipette into a single hippocampal neuron and measured the firing and saw that a very low concentration of this sortable tau was sufficient to change firing of the neurons.

And not only the neurons fired less, but we found that a very specific activity pattern of the neurons burst firing, which are rapid clusters of action potentials that are important for synaptic plasticity and memory were very specifically disturbed or disrupted by soluble tau. So that was basically how we got into soluble tau and were interested then, of course, also in the molecular mechanisms that underlie this dysfunction.

Professor Serpell: It's really fascinating and so interesting to find when you are looking at something and you get something you didn't expect and really to then be able to pursue that in an environment like the Dementia Research Institute really drill down into the minutia of the one single neuron. That sounds incredible.

I feel I want to ask a question that is perhaps controversial. So Sjors Scheres who's the person who did the structure of tau filaments from all the different tauopathies, mainly he's pioneered all of that, believes there's no such thing as oligomeric tau. And I wondered if you had a viewpoint on that, Marc.

Marc Busche: Yeah, look, I'm not a biochemist, I'm a clinician and a neurophysiologist, and basically, we work with the species that have been described and characterised who work very closely with Bradley Hyman on this. All I can say is when we take this species and put it into single neurons, we do see a very characteristic effect, namely this dysfunction in burst firing.

It's actually also something we see in mice that produce high levels of this soluble tau when we specifically use antibodies to block tau, the effect is gone. So ultimately, it's not a tangle that we introduce in these neurons, it's something that is soluble that can be introduced in the neuron. It's something that can be extracted from the human brain that has been characterised. So I think, I guess that's my response to this question.

Professor Serpell: It's absolutely fascinating and it sort of mirrored some of the work that has been done previously on amyloid beta where amyloid fibres and oligomeric species have been very controversial and there's been a sort of almost like a tangle, amongst the fields, trying to work out which species is the most important. But I think it's really essential that we remember that these things are dynamic. So we know that we've got filaments and we know we've got intermediate species and whether we can isolate one particular one that's responsible for disease. We have yet to find out.

Dr. Dickson: So we have the tool, the electron microscopy that we can pair with antibody-based labelling. And we know that there are non filamentous forms of tau in the tauopathies such as PSP and corticobasal. And in fact maybe the most prevalent form of tau is not a filamentous form of tau. And we can actually see this at the light microscopic level as well, or with fluorescent methods for amyloid. Amyloid stains only pick up a very small proportion of the tau pathology that we see. And in fact, much of it is probably not a filamentous form, but it's a some protoform of a filament. But I mean, I'm not a biochemist, but these don't seem to have filamentous structures.

Professor Serpell: I completely agree with you. I think we've certainly seen that too in ImmunoGold labelling of tissue.

Chapter 9: Therapeutics Targeting Tau Species

I guess this makes me turn towards the therapeutics that are really important in the field at the moment where people are talking about targeting amyloid beta and perhaps soluble forms of tau using immunotherapies and so on. So really trying to work out which of these species is going to be the most important one. I think all of you are really contributing to that and finding the way that that therapeutics can target a particular species. So I might ask you in turn about where you think the field is going in terms of therapeutics. And I'll start with you, Marc.

Marc Busche: So yeah, so first of all I think, I mean our work and other people's work reinforces that tau is a central target. It has clearly detrimental effects, but of, as you say, the key question is what tau species you actually want to target? And we have to be very precise about which tau species and where it is extracellular versus intracellular tau aggregated versus more specific soluble forms.

And I mean, based on our work, if very small amounts of certain intracellular soluble tile species can disrupt the firing patterns of neurons that are important for cognition, learning and memory, then therapies only aimed at tangles, or only aimed at extracellular tau may miss part of the mechanism. At the same time, as we discussed earlier, tau has some normal physiological role. So the goal is not to remove tau indiscriminately, but it's to target the pathological forms while preserving normal function.

Professor Serpell: Absolutely, yes.

Melissa, I thought you might comment on that too, maybe in terms of biomarkers

Dr. Murray: We think about the different species of tau a lot from a biomarker perspective and especially on the fluid biomarker level. And I think that there are going to be species that allows us to understand these early physiologic changes. I'd like us to get out of the thought of tau or even abnormal tau being bad because there could be tau changes that are actually helpful that signifies the brain's working hard to fight something.

We have our first drug discovery approach in the lab and we're actually very laser focused on a MAPT mutation and in an intronic region. Our friend Linde Lee Jacobs who allowed me to say her name in public, she has this devastating mutation that we wanna prevent from her experience and what her family has.

But I think the field, and especially the, so in the states, the FDA decided the ones that regulate our drugs, they just launched a framework for rare diseases. So I think that we're gonna see some leaps and bounds of understanding as people allow themselves to work on the rare diseases like these tauopathies. But I think they're gonna actually give us some of the clues to help us really accelerate. And so for us, we're tailoring our drug discovery to her mutation so that then we can expand out further into the genetic forms and then hopefully into sporadic.

Professor Serpell: So that's really interesting. So presumably an intronic mutation is actually affecting the type of tau that's formed rather than changing the confirmation or the structure of the protein.

Dr. Murray: Yeah, she that's the type of tau. They get more of this four repeat that we keep talking about. So tau is this really interesting, well, many proteins do this. But tau has certain places that as it gets transformed into the protein level, it can get cut in certain places. And if there's three repeats that we've been talking about are four repeats, we see that change in the brain in different brain regions and also even how they shape inside of the brain cells. Her specific mutation in many of them increased four repeat tau, and I think four repeat tau is quite helpful. Theirs just goes well past the physiologic balance. And so I think the more we can understand these balances.

Professor Serpell: Yeah.

Dr. Murray: And really keeping an open mind, especially with work like what Marc's doing and helping us to understand the different aspects and what that downstream might be.

Professor Serpell: Yes, Dennis, I'm guessing that your perspective on neuropathologic pathology is really informing us about how we might go on to work with therapeutics and where we might target them.

Dr. Dickson: I didn't think neuropathology had much to offer in terms of-

Dr. Murray: I would like to respectfully like to- (laughs)

Dr. Dickson: If neuropathology could get at fundamental disease processes, perhaps then down the line targeting those disease processes might be therapeutic. But we already know quite a bit about the pathology. A lot of it's insoluble aggregates, and I mean maybe there are aggregate busting drugs out there, but those don't seem to be the types of drugs that we're talking about here. But I think-

Dr. Murray: Can I give him a couple of examples how he's already helped change the world? - So absolutely, yes. I was at a conference in Europe, it was a wonderful conference, and I had met a new colleague and we were walking, and the individual essentially was letting me know there was no difference between progressive supranuclear palsy and cortical basal degeneration. I was still a bit newer in my training, and it's actually, I think that conversation that made sure that for any other next conversation I would have the answer ready and they couldn't understand the differences in the astrocyte.

And so I was able to follow up. But Marc said something earlier that Dennis helped change the face of this planet. So Dennis has looked at a lot of different tauopathies under the microscope, but what he saw was that where those tauopathies are forming these changes matters. And so corticobasal degeneration, Dennis, if you don't mind me saying, he recognised that yes, it's a neuron and an astrocyte that's affected, but in corticobasal degeneration, Marc was talking about earlier how tau moves and how it redistributes. The ends of their astrocytes are where tau is found whereas in PSP it's more on the proximal and the inside portion.

And so it's those careful observations under the microscope that allows our functional researchers and our therapeutic targeting to make these seminal observations by Lavon in my group looked at a treated and untreated cases and she's seeing these histologic changes that I think will really change the face of how we understand the beautiful intersection between neuropathology and therapeutics.

Chapter 10: Mentorship and Leadership in Research

Thank you so much for that. That was really helpful. It's nice when somebody talks about someone else and they don't have to talk.

So what I've realised is that I've been enjoying myself too much and that I should move on a little bit to research leadership and building impacts. And just maybe briefly talk about a little bit about your career. And I might start with Melissa, what you have enjoyed in terms of your work and how you have progressed in the field? Maybe what advice you would give to other people?

Dr. Murray: I'd be happy to. So I think one of the things that I was very fortunate was to have mentors that if I needed to stop by their office, I could ask those questions. I have attention problems, and I'll perseverate not be able to move off. Finding mentors, whether they are structured or unstructured is a game changer. People that you can go to for two minutes, maybe it's a question about how to navigate politics or how to ask for something. Those quick answers and questions allows for a game changing event.

I really kind of have more of a flat leadership in my lab where I encourage my trainees to teach me. They'll even make me little how to guides 'cause I don't understand a lot of the benchtop science. And so I think as a leader being open to make sure that it's okay to be trained by others, even after you're in a position of leadership and mostly listening to your team. I think that understanding their needs helps you to go forward so much more quickly.

Professor Serpell: Thank you. That was really helpful to our audience. Dennis, you've spent a long time working in your field and working with Melissa. How do you navigate mentorship and supporting other people in your career?

Dr. Dickson: Well, I think probably the most important thing is to provide an open environment and where people can take risks and even if they don't come up with a successful result, just the process of taking that risk and doing the experiments and then finding out it didn't work. We learn from the negative results as much as we do the positive. And so I think that that would be the one thing that I would emphasise in terms of the scientific method. If you always came up with the result that you intended, why even do the experiment in the first place?

Professor Serpell: Yeah.

Dr. Dickson: You already know the answer. So the major scientific advances are gonna be where you don't know the answer and then you get a result that is only partially what you thought it would be or completely against it. And then you have to redevice your experiments to try to answer which of the two is it. And so it's an iterative process. It's not a one and done. It takes time, it takes effort, perseverance to have a successful programme.

Professor Serpell: Absolutely, I've been thinking so much about how creative science is that and allowing that space to be creative is so important. And Marc, how have you benefited and how have you enjoyed mentorship and being a mentor and so on in your career?

Marc Busche: Yeah, I think it's in incredibly important to have mentors, to have collaborators but also the right environment for this kind of science. So I was very lucky. I mean, what Dennis described, I was very lucky that I, you know, was appointed one of the first groups in the UK Dementia Research Institute when it was brand new in 2018. And I genuinely felt that they appointed me because they believed in me as a scientist, as a researcher and wanted me to try ambitious things.

It was also very practical at that time when we needed a piece of equipment to test an idea we could ask for it. It arrived. It sounds very simple, but this speed changes everything because it means you can actually do a high risk experiment rather than just talk about it for a year or apply for funding, which takes forever. And I was encouraged to take, you know, to do difficult, risky experiments that in many ways could go wrong. And that was very important for me personally. And that's also what I try to give back now because I also remember I had advice when I started, you know, don't do too risky things.

Don't be too ambitious, think about your tenure, do the safe experiments. But I think if I felt that a question was very important and I had the right environment, the right people around me, the mentors to allow me to move fast, basically, this crazy idea can turn into an experiment and sometimes, not always, it actually turns into discovery. That was really critical for me.

Professor Serpell: Absolutely. So I have one final question. Have you decided where your trophies are going to live? Melissa?

Dr. Murray: Yes, I really want it here. And it was funny 'cause I was thinking about that and I can't help it show y'all. My husband made me a trophy when I became a professor. - Oh wow. So it got like my little name on it, and so, And a brain. Yeah, received the trophy and he's a very famous scuba diver in Florida. And I was like, oh my gosh, you got a trophy? He made me one. It's so now to actually get a trophy. - That's fantastic. - I dunno, I might wear it on my necklace. I just walk with it everywhere. (chuckles)

Professor Serpell: I recently went to where one of the examiners said that you should have a pile of successes, that things that you are proud of. And I think that's fantastic that every time we do something we're quite proud of, we should get a trophy, I think that sounds fantastic. So what about you, Marc? Where are you going to put your trophy?

Marc Busche: It'll be probably in my office or in the office in the lab environment. It's a reminder of the team effort. It's a reminder of the patients, the families we're working for it. If it makes people think, you know, walk into the lab and think, okay, let's do something ambitious today, I think then it's the right place and it's a good reminder of that.

Professor Serpell: Absolutely. And Dennis?

Dr. Dickson: I would probably do as both of my colleagues have done and they would have it in a conspicuous place (chuckles) where people would have a hard time not seeing it.

Professor Serpell: (laughs) - Yes. (laughs) You absolutely deserve to do that. So thank you so much, all three of you, for sharing your work today and for your perspectives. We'd also like to thank the Rainwater Charitable Foundation for its work and its leadership in the field. I's obviously been an enormous benefit to many people. Really inspiring. And the links to the Rainwater prize and related resources will be included in the show notes. Thank you for listening. I'm Professor Professor Louise Serpell, and you've been listening to the Dementia Researcher Podcast. It's been lovely talking to you.

-Pleasure.

-Thank you.

[Voice Over]: The Dementia Researcher Podcast was brought to you by University College London with generous funding from the UK National Institute for Health Research, Alzheimer's Research UK, Alzheimer's Society, Alzheimer's Association, and Race Against Dementia. Please subscribe, leave us a review and register on our website for full access to all our great resources, dementiaresearcher.nihr.ac.uk.

2024

"Pathology of Parkinsonism"

View the Pathology of Parkinsonism presentation from Feb. 27, 2024.

2023

"Behavioral Neurology Lecture Series"

View the Behavioral Neurology Lecture Series presentation from Nov. 14, 2023.

"Behavioral Neurology Lecture Series"

View the Behavioral Neurology Lecture Series presentation from Sept. 19, 2023.

2019

"An Overview of Findings and Implications for Multiple System Atrophy in Brain Pathology"

In this video, Dr. Dickson presents the findings and implications of brain pathology research for multiple system atrophy. He stresses the importance of brain sample donations.

2016

"Mayo Clinic Minute: Go Inside the Brain Bank"

In this interview, Dr. Dickson goes inside the Mayo Clinic Brain Bank in Florida. He explains the significance of sample brain bank donations for research and the benefits for patient families.

"Neuropathology of Parkinsonism"

During a professional short course, Dr. Dickson shares research highlights related to the neuropathology of parkinsonism and similar conditions.

2015

"Mayo Clinic Receives Gift for Lewy Body Dementia Research"

In this video, Dr. Dickson describes Lewy body dementia and Mayo Clinic studies that this research award supports.

2013

"Update on the Eloise H. Troxel Memorial Brain Bank"

Dr. Dickson speaks at CurePSP's 2012 International Research Symposium.

Dennis Dickson, M.D., Neuropathologist and Director of the Brain Bank for Neurodegenerative Disorders, Mayo Clinic, Jacksonville, FL: All right so this is the number of brains we've received. You can see this, I, I just want to point out that this chart includes all the PSP and cortical basil brains and MSA brains that we have uh in in our brain bank. The great majority of these come through the Cure PSP uh Society for PSP. But there are other sources for the, especially the Parkinson brains in this from our, our Parkinson Center.

But just to give you an idea the number of brains are available, this is actually for 10 months and we were, have almost, 100 brains this year. We're averaging about 80 per year. We have 117 MSA brains and over a thousand PSP and cortical basil brains. And, I think I might have shown this in previous years, we were hovering around five or so brains per year until the PSP, cure PSP made MSA an initiative. And, even though brain banking wasn't part of that initiative by default people started sending us MSA brains. And, again, we're almost 20 MSA brains just for this year alone.

So, now, this is actually the number that we actually sent into us from the PSP Society. We're almost approaching almost a thousand brains. Slightly more men than women. It's almost all Caucasian but there is some ethnic diversity in our collection. The majority of the cases come with fixed and frozen tissue. There are several brains that have come with only fixed tissue. The majority, we generate paraffin blocks and we generate a report in about a month after we receive the material.

Just in terms of, of the, the diagnostic accuracy we reported this in, number of years ago, 5 years ago. And, the diagnostic accuracy rate was about 80%. But when I looked at the, the current data for 866 brains that had in their primary clinical diagnosis PSP or at least the clinician at some point considered PSP. The number that had PSP pathology was 93%. Which I think attests to the fact that PSP is a very fairly stereotypic disorder. And, that even practicing neurologists, that aren't specialists in movement disorders, can accurately make this diagnosis.

Now in contrast if we do the same exercise with respect to cortical basil degeneration. So, these are patients where they either thought it was cortical basil degeneration or they thought the possibility that it might be cortical basil and maybe it was actually something else. The number is quite different. Less than 50% of people that are thought to have cortical basil degeneration actually have cortical basil pathology. The most common finding in brains of, with cortical basil syndrome, is in fact PSP.

We also have cases where they had PSP pathology or cortical basil pathology where they did not, the clinician didn't suspect either PSP or cortical basil. Many of these were other types of atypical parkinsonian disorders and you, you see the the mix of these cases.

What the, this collection has contributed to, the PSP GWAS, which we heard a little bit about. We just point out that there are three non-tau genes: Syntaxin 6, PERK (involved in unfolded protein response) and myelin oligodendrocyte binding protein. And, we've actually looked at this as it relates to pathology in PSP brains and I'll present something very briefly on this.

So, in all the cases where we receive the brain we do immunohistochemistry for TAU. We use the Phospho-tau antibody we have from Peter Dave. He's a very sensitive antibody cp13 and it detects the neuronal the astrocytic and [inaudible] lesions. We don't use silver stainings, it's cumbersome and less specific.

And, we, we know the pathology. The distribution affects predominately the basal ganglia, subthalamic nucleus, [inaudible]. But, also other areas of the brain. And, what we've been doing on each case is to score the neuronal lesions, the thread lesions the [inaudible] lesions and the astrocytic lesions in about, almost 20 different brain regions.

This (graph) actually is plotting cortical basil versus PSP, so you can you see the comparison. I just point out in terms of astrocytic lesions in PSP the, the striatum caudate in particular, is, an area that's very severely affected in the majority of the cases. And, that'll, that'll become relevant subsequently.

What are working with our statisticians, we wanted to analyze the genome, genomic information on these brains but we needed a way to reduce the data. So, there, there aren't enough case. We have eight, four variables in 18 different brain regions. We need to figure out a way to reduce that to a manageable number.

And, we generated what I referred to as latent trait variables. This is a, we took the semi-quantitative scores on the lesion types for 18 different brain regions on 850 PSP cases to generate latent variables. And, a latent variable is a single variable that reflects the severity and distribution of the pathology in that given case as it relates to the average severity and distribution pathology in the entire subset of 840 cases.

This is used in psychological testing all the time. So, for example, IQ based on Wechsler Adult Intelligence Scale is a, you generate a single IQ score for, based on your score on a number of different subtests. And, this is the same concept that's used here. Uses this graded response model in item response theory.

What we were able to do, just as with IQ you can have subtests, you can have a performance IQ and a verbal IQ that takes into account how well you score on a subset of verbally oriented tests or performance tests. So, we can do, we can look at a subtype of, so we have an overall latent variable and then a lesion specific variable.

The overall takes into account all type, all four types of lesions in all brain regions and all brains. And the lesion-specific, you just look at say the astrocytic marker in all the brain regions for that case with respect to the rest of the cases. And, this is a plot that shows you. This is striatum and we're looking at overall latent variable with respect to the oligodendroglia marker, the neuronal marker, the astrocytic marker and the threads. And, this is the, the score. So, none, mild, moderate, severe.

And, what you see in these graphs is that, in general, the more severe the pathology in, with respect to any one of these parameters, the higher the overall latent trait variable. Now, of course, this is not to say that there wouldn't be a, an individual that would have low score here, high here, intermediate here, whatever. So, each dot represents one out of 846 cases. But, I just point out that there is some internal validity to this scheme, in that the cases that, if you look at striatum. The overwhelming majority of cases have severe astrocytic pathology in the striatum. And, that the, if it actually maps quite well to what we know the pathology is. So, I think there's some internal validity in this latent trait measure.

And, then we took the genetic variance. In this exercise we just looked at tau and MOBP to see how those genetic variants map onto the trait. And these both, both of these genetic markers were correlated with the overall latent trait variable. Which would suggest that these genetic variants are somehow influencing the severity of the tau pathology in the brain.

So, maybe that's not so, not so surprising when it comes to the tau gene but it certainly has never been shown that that would be the case for the myelin oligodendrocyte binding protein. The interesting thing is if you start to look at the lesion subtypes none of these, neither of these markers are, are significantly correlated with neuronal lesions. On the other hand, glial lesions show the, the strongest correlation. And myelin oligodendrocyte binding protein is an oligodendroglia marker and coil bodies are oligodendroglia. And, most of the threads actually in PSP are probably oligodendroglia derived. And, both of these are either significant or trending which suggest that perhaps that MOBP is influencing risk for oligodendroglia Tau pathology.

So, this is a brief summary of that. They, these trait, the latent trait variable, which is based on a score of the tau pathology in multiple brain regions in PSP, correlates with the genetic variants. Interestingly enough, the glial variables are, were associated with tau but not neuronal. And, the measures of oligodendroglia such as the coil bodies and threads tended to be associated with the myelin oligodendrocyte binding protein.

So, what we know about the myelin oligodendrocyte binding protein. It's a gene that's expressed in oligodendroglia and it's involved in compaction of the myelin in central nervous system myelin. So, the fact that the we found the genetic associations with the genetic variance in myelin oligodendrocyte binding protein in with respect to lesions that we associate with oligodendroglia, the coil bodies and threads, would, would suggest that perhaps those genetic variants are actually influencing oligodendroglia pathology in PSP.

I think the other thing that that this initial analysis suggested, that the genetic variants that differentiate PSP from non-PSP controls, many of those are acting through glial - tau - not necessarily neuronal markers. And, at least with, as how PSP compares to normal controls, it, this might suggest that glial tau is, is a very fundamental difference in PSP compared to controls. That the genetic makeup of PSP patients favors them having glial tauopathy.

Now, one of the things that we're doing, and actually Naomi's done some preliminary work on this already, is we've confined our analysis just to PSP and we've tried to look at how these genetic variants vary within the universe of PSP cases, not comparing them to normal. And, we've actually then used the entire genome, all the genome variants not just the top hits from the the Cure PSP GWAS Report. And, in fact, we have identified several genes that are genome-wide significant, that actually correlate with the latent traits for PSP, when you just analyze within PSP.

And, the two genes that are highest on that list, one of them is genome-wide significance, one's bordering. Neither of them were implicated in the, in the Cure PSP GWAS. So, these are genetic risk factors that presumably tell us something about the heterogeneity of PSP, rather than risk for PSP. The ones that are, that are, that are telling us something about risk for PSP, we're, we're suggesting might be related to oligodendroglia or maybe astrocytic vulnerability.

But, these are different genes and what we're currently doing is the PSP GWAS was based on around four or 500 cases. We're currently in the process of genotyping those variants in a confirmatory autopsy cohort that has the same pathologic latent trait variables to see if we can validate it. And, I don't want to present it here because it is very preliminary, we haven't validated it yet. But, that's the future direction with this.

And, then, just in terms of the work I mentioned. Beth [inaudible], she's very important for our brain bank coordinator. She spends many hours a day on the phone talking to family members and making arrangements for the brain donation. People in the lab, people helping with database management, and particularly, this latent trait was the work of our statisticians in Jacksonville. And, the statistical genetics, Naomi has certainly helped with this. But, Nilufer Taner, who's recently been awarded a cure PSP Grant, and her postdoc [inaudible] have have also helped with the genetic analyses.

So I'll take some questions if you have any.

Question: How do you, how do you reconcile the hypothesis? Reconcile your observations on glia as a primary site of pathology with the hypothesis that the flow of pathology through the nervous system seems to be through synaptic pathways between neurons?

Dr. Dickson: That latter statement was an assumption, right? That it's through trans-synaptic spread? I think that hasn't been shown. One of the, one of the issues that Michelle raised was the possibility that it was through extracellular spread independent of synaptic, from synap to synap. It certainly hasn't been shown. I mean astrocytes don't form synapses? And, in some of these brain areas the major pathology is in astrocytes, it's not in neurons. And, how that astrocytic pathology, which is a local cell, doesn't project to other regions of the brain. How in an astrocyte then leads to spread say from the striatum to you know some other part of the brain, in the thalamus for example. Or...

I think it's, I think it's early days to assume that what's been shown in transwell experiments in cultured cells, where you can show it crossing a synapse and being taken up, which is very elegant work. But, I think it's early to assume that, that will, that, that it'll work. In fact, in terms of the, this whole scheme that there is cell-to-cell spread of the pathology, a lot of that it hinges on the work by [inaudible] Braak and his colleagues. Both with respect to staging of tau pathology and Alzheimer's disease and staging of synuclein pathology in Parkinson's disease.

And, there are, there's an assumption that the disease in both disorders has a [inaudible] and then it spreads from that [inaudible]. But, in fact, there are a number of studies that don't fit with Braak staging scheme, both with respect to the Alzheimer tau and with respect to the synuclein in Parkinson's disease.

Question: Well, I was referring specifically to the paper from pen from just this week, that showed an injection of alpha synuclein into the striatum of mice. It propagated alpha synuclein pathology through the synaptically-connected pathways.

Dr. Dickson: I think they don't know that it's synaptic because I believe that, in fact there's even cerebellum and the direct connections between the striatum and the cerebellum, there's not an obvious connection there. So, I, think it's, I think another interpretation of the data is that, that these are disorders where certain cells, certain neurons or cell types even including glia, have an intrinsic vulnerability to the disease process and that certain environments in the brain favor that more, more so than others.

And, that there's individual variability in terms of, is this going to be more of a forebrain pathology? Is this going to be more of a hindbrain? Which particular nucleus is going to be affected earliest and most severely? And, it may have nothing to do with spread but have something to do with the concept of selective vulnerability and whatever is the under overlying process or the underlying process that leads to the disease.

So, depending upon the individual, if they have more vulnerability in cortical areas than say cerebellum, then as the disease progresses you'll see increase of pathology in the cortex lagging behind the pathology in the cerebellum, but, it's, the whole disease is progressing. And, you'll conclude that it spread from the cortex to the cerebellum. When, in fact, it might have been - there's differential vulnerability of one area versus another - and then as the disease progresses maybe not equally at the same pace in all the different regions, but even assuming the same pace, it would give the appearance of spread when in fact it isn't actually a spread.

Question: I have lots of things. I don't know, I mean I, I would say that experimentally at least, there is good evidence that you get spread. I don't want to say it's through synapses necessarily, but spread. As for Braak staging, it's true that there are some people who say they can't, I mean there are cases that don't fit the description here. But, talking, even I mean when I talk to some of these people who criticize it and ask them what percentage of cases does it apply to? The figure is normally something like 80%. Which, if true, I would say is pretty good considering how relatively crude all this stuff is.

But, there is a problem with it and the problem is that there's a hidden assumption in it. Which, is that, if somebody dies. let's say in stage one or two of Braak tau pathology, the assumption is had this person lived, at age 80 or so, this person would have been at stage six and would have had Alzheimer's disease. And, we don't know whether that's true, that may not be true. So, that's I would say the problem.

The more general question I have is, in terms of tau and glial cells. Because I think that's, I mean there's no evidence that I know of, that in a normal brain there is tau and glial cells.

Dr. Dickson: That's not true. Oligos have a very rich microtubule network and oligos have tau. Astrocytes. I think it's more controversial when it comes to astrocytes.

Question: If you try in situ hybridization, which we did a long time ago, on a normal human brain. Not in culture cells, normal human brain. You don't see it in white matter at all.

Dr. Dickson: There are issues of sensitivity of the...

Question: I know, so the levels that you find, if they are there, must be very low.

Dr. Dickson: They must be low, I agree.

Question: These aggregations are heavily concentration dependent, right? And, so, for something to be predominantly a glial tauopathy. When 90, or more than 90% of the soluble ties in neurons, is a bit of a problem. Unless, it's overexpressed. Maybe it's overexpressed. I think it's an interesting question. It's the same for alpha synuclein MSA. Right. The same issue. The other...

Dr. Dickson: The bulk of the abnormal synuclein in MSA is clearly an oligodendroglia.

Question: Yeah, I know. But, again, if you look in a normal brain you don't see alpha synuclein much. No. You see it easily in neurons but not in glial cells. So, and the other thing is that whenever you have tau pathology in glial cells, as far as I know, you have a four-repeat tauopathy.

Dr. Dickson: And, that is presumably why the glial tauopathies are four-repeat tauopothies: PSP, cortical basil, [inaudible] disease. There's, there's some. But, actually, in, the in the astrocytic tau in Pick's, when you use isoform specific much of that is four-repeat tau even in Pick's. I don't know about the little Pick bodies but the more ramified tau positive astrocytes and Pick's, especially in the genetically determined forms of Pick's disease. It's four-repeat tau and glia.

And, there is in fact tau in astrocytes in aging. It's been well described in elderly individuals or so...

Question: Is that three or four repeat?

Dr. Dickson: It's four-repeat.

Question: Yeah, so whenever you have it in glial cells it's four-repeat. Sweet.

Question: Of course one of the clinical conundrums is why diseases like CBD are so highly asymmetrical or one side of the body is horribly affected the other side's relatively normal. Does that, how does this spread hypothesis fit in and is it does it really start with a [inaudible] that spreads given the [inaudible] symmetry of the disease?

Dr. Dickson: Yeah, maybe that's a good, good argument against it spreading. Because the asymmetry that you see in the early stage of the disease is asymmetrical as the disease progresses. It, if it started there, then maybe that's maxed out and it would go to the other side and then it would catch up but I don't think it ever catches up. I think if you look at brain imaging, disorders that are asymmetrical are always asymmetrical. It, maybe, given, you know the limits of quantification when you get really severe brain atrophy it becomes more difficultly detected, but it's, it's asymmetrical from the beginning.

2011

"Lewy Body Dementia: Autopsy"

Dr. Dickson discusses Lewy body dementia research based on autopsy results with Tanis J. Ferman, Ph.D., a Mayo Clinic colleague.