1 00:00:09,000 --> 00:00:11,000 Complexity. 2 00:00:11,000 --> 00:00:15,000 Nothing quite embodies this word like the human brain. 3 00:00:15,000 --> 00:00:19,000 So for centuries we've studied the complexity of the human brain 4 00:00:19,000 --> 00:00:22,000 using the tools and technology of the day. 5 00:00:22,000 --> 00:00:26,000 If that's pen and paper from the age of da Vinci 6 00:00:26,000 --> 00:00:29,000 through advents in microscopy 7 00:00:29,000 --> 00:00:32,000 to be able to look more deeply into the brain 8 00:00:32,000 --> 00:00:36,000 to a lot of the new technologies that you've heard about today 9 00:00:36,000 --> 00:00:38,000 through imaging, magnetic resonance imaging, 10 00:00:38,000 --> 00:00:41,000 able to look at the details of the brain. 11 00:00:41,000 --> 00:00:44,000 Now one of the first things you notice when you look 12 00:00:44,000 --> 00:00:48,000 at a fresh human brain is the amount of vasculatur 13 00:00:48,000 --> 00:00:51,000 that's completely covering this. 14 00:00:51,000 --> 00:00:56,000 The brain is this metabolically voracious organ. 15 00:00:56,000 --> 00:01:01,000 Approximately a quarter of the oxygen in your blood, 16 00:01:01,000 --> 00:01:04,000 approximately a fifth of the glucose in your blood 17 00:01:04,000 --> 00:01:06,000 is being used by this organ. 18 00:01:06,000 --> 00:01:09,000 It's so metabolically active there's a waste stream 19 00:01:09,000 --> 00:01:13,000 which comes out into your cervical spinal fluid. 20 00:01:13,000 --> 00:01:17,000 You generate 0.5 liter of CSF every day. 21 00:01:17,000 --> 00:01:21,000 So, as you know, researchers have taken advantage 22 00:01:21,000 --> 00:01:25,000 of this massive amount of blood flow and metabolic activity 23 00:01:25,000 --> 00:01:29,000 to begin to map regions of the brain, to functionally annotate the brain 24 00:01:29,000 --> 00:01:31,000 in very meaningful ways. 25 00:01:31,000 --> 00:01:33,000 You'll hear a lot more about those kinds of studies, 26 00:01:33,000 --> 00:01:38,000 but basically taking advantage of the fact that there's active metabolism 27 00:01:38,000 --> 00:01:40,000 with certain tasks going on. 28 00:01:40,000 --> 00:01:42,000 You can put a living human in a machine 29 00:01:42,000 --> 00:01:44,000 and you can see various areas that are lighting up. 30 00:01:44,000 --> 00:01:48,000 For example, going around right now is the temporal cortex 31 00:01:48,000 --> 00:01:51,000 auditory processing going on there, you're listening to my words, 32 00:01:51,000 --> 00:01:53,000 you're processing what I'm saying. 33 00:01:53,000 --> 00:01:56,000 Moving to the front of this brain is your prefontal cortex, 34 00:01:56,000 --> 00:01:58,000 your executive decision-making, 35 00:01:58,000 --> 00:02:02,000 your higher-thinking areas of the brain. 36 00:02:02,000 --> 00:02:08,000 And so the thing that we're very much interested in 37 00:02:08,000 --> 00:02:10,000 from the perspective of the Allen Institute 38 00:02:10,000 --> 00:02:13,000 is to go deeper, to get down to the cellular level. 39 00:02:13,000 --> 00:02:17,000 So when you look at this slice, it doesn't really look like gray matter, does it? 40 00:02:17,000 --> 00:02:20,000 It's more tan matter, or beige matter. 41 00:02:20,000 --> 00:02:25,000 And scientists about, I guess around the late 1800's, 42 00:02:25,000 --> 00:02:28,000 discovered that they could stain tissue in various ways, 43 00:02:28,000 --> 00:02:33,000 and this sort of came along with various microscopy techniques. 44 00:02:33,000 --> 00:02:37,000 And so this is a stain, it's called Nissl, and it stains cell bodies, 45 00:02:37,000 --> 00:02:40,000 it stains the cell bodies purple. 46 00:02:40,000 --> 00:02:43,000 And so you can see a lot more structure and texture 47 00:02:43,000 --> 00:02:45,000 when you look at something like this. 48 00:02:45,000 --> 00:02:49,000 You can see the outer layers of the brain and the neocortex, 49 00:02:49,000 --> 00:02:54,000 there's a six-layer structure, arguably what makes us most uniquely human. 50 00:02:54,000 --> 00:02:58,000 As you've heard before about there's on average in a human, 51 00:02:58,000 --> 00:03:03,000 there's about 86 billion neurons, and those 86 billion neurons 52 00:03:03,000 --> 00:03:05,000 you can see are not evenly distributed, 53 00:03:05,000 --> 00:03:09,000 they're very focused and specific structures. 54 00:03:09,000 --> 00:03:11,000 And each of them has their own sort of function 55 00:03:11,000 --> 00:03:15,000 both on an anatomic level and at a cellular level. 56 00:03:15,000 --> 00:03:19,000 So if we zoom in on these cells, what you can see is large cells 57 00:03:19,000 --> 00:03:23,000 and small support cells that are glias and astrocytes 58 00:03:23,000 --> 00:03:27,000 and these cells are as we know connected in a variety of different ways. 59 00:03:27,000 --> 00:03:31,000 And we like to think about, although there's 86 billion cells, 60 00:03:31,000 --> 00:03:36,000 each cell might be considered a snowflake, they're actually able to be binned 61 00:03:36,000 --> 00:03:39,000 into a large number of cell types or classes. 62 00:03:39,000 --> 00:03:43,000 What flavor of activity that particular cell class has 63 00:03:43,000 --> 00:03:49,000 is driven by the underlying genes that are turned on in that cell, 64 00:03:49,000 --> 00:03:53,000 those drive protein expression which guide the function of those cells, 65 00:03:53,000 --> 00:03:56,000 who they're connected to, what their morphology is, 66 00:03:56,000 --> 00:04:00,000 and we're very much interested in understanding these cell classes. 67 00:04:00,000 --> 00:04:02,000 So how do we do that? 68 00:04:02,000 --> 00:04:05,000 Well, we look inside the cell at the nucleus, 69 00:04:05,000 --> 00:04:07,000 (and it will get to the nucleus) 70 00:04:07,000 --> 00:04:10,000 and so inside we've got 23 pairs of chromosomes, 71 00:04:10,000 --> 00:04:12,000 we've got a pair from mom, a pair from dad, 72 00:04:12,000 --> 00:04:17,000 on those chromosomes about 25000 genes and we're very much again interested in 73 00:04:17,000 --> 00:04:22,000 understanding which of these 25000 genes are turned on 74 00:04:22,000 --> 00:04:24,000 at what levels they're turned on. 75 00:04:24,000 --> 00:04:28,000 Those are going to, of course, drive the underlying biochemistry of the cells 76 00:04:28,000 --> 00:04:33,000 they're turned on in and again every cell in our bodies more or less has these 77 00:04:33,000 --> 00:04:35,000 and we want to understand better 78 00:04:35,000 --> 00:04:41,000 what the driving biochemistry driven by our genome is. 79 00:04:41,000 --> 00:04:44,000 So how do we do that? 80 00:04:47,000 --> 00:04:51,000 We're going to deconstruct a brain in several easy steps. 81 00:04:51,000 --> 00:04:54,000 So we start at a medical examiner's office. 82 00:04:54,000 --> 00:04:56,000 This is a place where the dead are brought in 83 00:04:56,000 --> 00:04:58,000 and obviously it's useful 84 00:04:58,000 --> 00:05:03,000 for the kind of work we do, [it] is not non-invasive, 85 00:05:03,000 --> 00:05:08,000 we actually need to obtain fresh brain tissue 86 00:05:08,000 --> 00:05:13,000 and we need to obtain it within 24 hours because the tissues start to degrade. 87 00:05:13,000 --> 00:05:15,000 We also wanted for our projects to have normal tissue 88 00:05:15,000 --> 00:05:18,000 as much normal as we could possibly get. 89 00:05:18,000 --> 00:05:24,000 So over the course of a two- or three-year collection time window 90 00:05:24,000 --> 00:05:30,000 we collected 6 very high-quality brains, 5 of them were male, one was female. 91 00:05:30,000 --> 00:05:35,000 That's only because males tend to die untimely deaths 92 00:05:35,000 --> 00:05:39,000 more frequently than females, and then to add to that, 93 00:05:39,000 --> 00:05:42,000 females are much more likely to give consent 94 00:05:42,000 --> 00:05:45,000 for us to take the brain than vice versa. 95 00:05:45,000 --> 00:05:49,000 We have to figure that one out. 96 00:05:49,000 --> 00:05:52,000 We've heard people say, “He wasn't using it anyway!” 97 00:05:52,000 --> 00:05:55,000 (Laughter) 98 00:05:56,000 --> 00:06:00,000 So, once the brain comes in we have to move very, very quickly. 99 00:06:00,000 --> 00:06:06,000 So first we capture a magnetic resonance image. 100 00:06:06,000 --> 00:06:08,000 This, of course, will look very familiar to you, 101 00:06:08,000 --> 00:06:11,000 but this is going to be the structure in which we hang all of this information, 102 00:06:11,000 --> 00:06:15,000 it's also a common coordinate framework by which the many, many researchers 103 00:06:15,000 --> 00:06:17,000 who do imaging studies can map 104 00:06:17,000 --> 00:06:20,000 into our ultimate database, an Atlas framework. 105 00:06:20,000 --> 00:06:22,000 We also collect diffusion tensor images 106 00:06:22,000 --> 00:06:25,000 so we get some of the wiring from these brains. 107 00:06:25,000 --> 00:06:29,000 And then the brain is removed from the skull. It's slabbed and frozen, 108 00:06:29,000 --> 00:06:32,000 frozen solid, and then it's shipped to Seattle 109 00:06:32,000 --> 00:06:34,000 where we have the Allen Institute for Brain Science. 110 00:06:34,000 --> 00:06:36,000 We have great technicians who've worked out 111 00:06:36,000 --> 00:06:39,000 a lot of great techniques for further processing. 112 00:06:39,000 --> 00:06:45,000 So first, we take a very thin section, this is 25µm thin section, 113 00:06:45,000 --> 00:06:48,000 which is about a baby's hair width. 114 00:06:48,000 --> 00:06:52,000 That's transferred to a microscope slide and then that is stained 115 00:06:52,000 --> 00:06:55,000 with one of those histological stains that I talked about before. 116 00:06:55,000 --> 00:06:58,000 And this is going to give us more contrast as our team of anatomists 117 00:06:58,000 --> 00:07:02,000 start to make assignments of anatomy. 118 00:07:05,000 --> 00:07:06,000 So we digitize these images, 119 00:07:06,000 --> 00:07:11,000 everything goes from being wet lab to being dry lab. 120 00:07:11,000 --> 00:07:15,000 And then combined with anatomy that we get from the MR, 121 00:07:15,000 --> 00:07:17,000 we further fragment the brain. 122 00:07:17,000 --> 00:07:24,000 This is to get it into a smaller framework for which we can do this. 123 00:07:24,000 --> 00:07:27,000 So here's a technician who's doing additional cutting. 124 00:07:27,000 --> 00:07:30,000 This is again a 25µm thin section. 125 00:07:30,000 --> 00:07:32,000 You'll see da Vinci's tools, the paintbrush, 126 00:07:32,000 --> 00:07:34,000 being use here to smooth this out. 127 00:07:34,000 --> 00:07:37,000 This is fresh frozen brain tissue. 128 00:07:39,000 --> 00:07:42,000 And it can be very carefully melted to a microscope slide. 129 00:07:42,000 --> 00:07:44,000 You'll note that there's a barcode on the slide. 130 00:07:44,000 --> 00:07:46,000 We process 1000's and 1000's of samples, 131 00:07:46,000 --> 00:07:50,000 we track all of it in a backend information management system. 132 00:07:50,000 --> 00:07:53,000 Those are stained. 133 00:07:53,000 --> 00:07:57,000 And then we get more detailed anatomic information. 134 00:07:57,000 --> 00:08:08,000 That information is ... (playing here) ... this is a laser capture microscope, 135 00:08:08,000 --> 00:08:12,000 the lab technician is actually describing an area on that slide. 136 00:08:12,000 --> 00:08:15,000 And a laser, you see the blue light cutting around there, 137 00:08:15,000 --> 00:08:17,000 very James Bond like. 138 00:08:17,000 --> 00:08:20,000 Cutting out part of that, and underneath there, 139 00:08:20,000 --> 00:08:23,000 you can see the blue light again, from the microscope in real-time, 140 00:08:23,000 --> 00:08:28,000 it's collecting in a microscope tube that tissue. 141 00:08:28,000 --> 00:08:30,000 We extract RNA, 142 00:08:30,000 --> 00:08:35,000 RNA is the product of the genes that are being turned on, 143 00:08:35,000 --> 00:08:38,000 and we label it, we put a fluorescent tag on it. 144 00:08:38,000 --> 00:08:39,000 Now what you are looking at here 145 00:08:39,000 --> 00:08:43,000 is a constellation of the entire human genome 146 00:08:43,000 --> 00:08:45,000 spread out over a glass slide. 147 00:08:45,000 --> 00:08:48,000 Those little bits are representing the 25000 genes. 148 00:08:48,000 --> 00:08:52,000 There's about 60000 of these spots and that fluorescently labeled RNA 149 00:08:52,000 --> 00:08:56,000 is put onto this microscope slide and then we read out quantitatively 150 00:08:56,000 --> 00:09:00,000 what genes are turned on at what levels. 151 00:09:00,000 --> 00:09:04,000 So we do this over and over and over again for brains that we've collected; 152 00:09:04,000 --> 00:09:07,000 as I mentioned we've collected 6 brains in total. 153 00:09:07,000 --> 00:09:10,000 We collect samples from about 1000 structures in every brain 154 00:09:10,000 --> 00:09:14,000 that we've looked at, so it's a massive amount of data. 155 00:09:14,000 --> 00:09:18,000 And we pull all of this together, back into a common framework, 156 00:09:18,000 --> 00:09:22,000 that is a free and open resource for scientists around the world to use. 157 00:09:22,000 --> 00:09:24,000 So at the Allen Institute for Brain Science, 158 00:09:24,000 --> 00:09:28,000 we've been generating these kinds of data resources for almost a decade. 159 00:09:28,000 --> 00:09:32,000 They're free to use for anybody, they're online tools, 160 00:09:32,000 --> 00:09:38,000 just for example today a given workday, there'll be about 1000 unique visitors 161 00:09:38,000 --> 00:09:43,000 that come in from labs around the world to come use our resources and data. 162 00:09:43,000 --> 00:09:47,000 They get access to tools like this, which allows them to see 163 00:09:47,000 --> 00:09:50,000 all of that anatomy and the structure that we created before 164 00:09:50,000 --> 00:09:55,000 and to start mapping in then the things that they're particularly interested in. 165 00:09:55,000 --> 00:09:57,000 So in this case you're looking at the structure 166 00:09:57,000 --> 00:09:59,000 and they're going to look at these color balls 167 00:09:59,000 --> 00:10:02,000 are representing a particular gene they're interested in 168 00:10:02,000 --> 00:10:05,000 that's either being turned up or down 169 00:10:05,000 --> 00:10:11,000 in those various areas depending upon the heat color that's specified there. 170 00:10:11,000 --> 00:10:14,000 So what are people doing when they come in and using these resources? 171 00:10:14,000 --> 00:10:17,000 Well, one of the things that you might hear lots about 172 00:10:17,000 --> 00:10:19,000 is human genetic studies. 173 00:10:19,000 --> 00:10:23,000 Obviously if you're very interested in understanding disease 174 00:10:23,000 --> 00:10:25,000 there's a genetic underpinning to many of them. 175 00:10:25,000 --> 00:10:28,000 So you'd like more information, you do a large-scale study 176 00:10:28,000 --> 00:10:31,000 and you get out of those studies collections of genes 177 00:10:31,000 --> 00:10:34,000 and one of the first things you're going to want to know is more information. 178 00:10:34,000 --> 00:10:41,000 Is there something I can learn about the location of these genes 179 00:10:41,000 --> 00:10:44,000 that gives me additional clues as to their function, 180 00:10:44,000 --> 00:10:49,000 ways in which I might intervene in the disease process. 181 00:10:49,000 --> 00:10:52,000 They're also very interested in understanding human genetic diversity. 182 00:10:52,000 --> 00:10:59,000 Now we've already looked at 6 brains but as we know, every human is very unique. 183 00:10:59,000 --> 00:11:01,000 We celebrate our differences; 184 00:11:01,000 --> 00:11:05,000 this is a snapshot of the great workforce at the Allen Institute for Brain Science 185 00:11:05,000 --> 00:11:09,000 who does all the great work that I'm talking about today. 186 00:11:09,000 --> 00:11:15,000 But remarkably when we look at this level at the underlying data, 187 00:11:15,000 --> 00:11:20,000 and this is a lot of data from 2 completely unrelated individuals, 188 00:11:20,000 --> 00:11:24,000 there's a very high degree of correlation, correspondence. 189 00:11:24,000 --> 00:11:26,000 So this is looking at 1000's of different measurements 190 00:11:26,000 --> 00:11:30,000 of gene expression across many, many different areas of the brain; 191 00:11:30,000 --> 00:11:32,000 and there's a very high degree of correspondence. 192 00:11:32,000 --> 00:11:33,000 This was very reassuring to us. 193 00:11:33,000 --> 00:11:36,000 First because when you generate data on this scale 194 00:11:36,000 --> 00:11:38,000 you want to make sure that it's high quality, 195 00:11:38,000 --> 00:11:41,000 so reproducibility is obviously important, 196 00:11:41,000 --> 00:11:43,000 but it was also important because we feel that it's given us 197 00:11:43,000 --> 00:11:46,000 a great snapshot into the human brain. 198 00:11:46,000 --> 00:11:50,000 And the people using the data, even with our low n, have confidence 199 00:11:50,000 --> 00:11:53,000 that what they're seeing has some relevance. 200 00:11:53,000 --> 00:11:58,000 Now, not everything is correlated here, you can see some outliers, 201 00:11:58,000 --> 00:12:00,000 and, of course, those outliers are going to be interesting 202 00:12:00,000 --> 00:12:03,000 related to human differences. 203 00:12:03,000 --> 00:12:04,000 We did study a couple of years ago 204 00:12:04,000 --> 00:12:09,000 in which we tried to understand a little better about those differences 205 00:12:09,000 --> 00:12:12,000 and looked at multiple individuals and different gene products 206 00:12:12,000 --> 00:12:15,000 and what we find as a tendency and as a rule 207 00:12:15,000 --> 00:12:19,000 is that those differences tend to be in very specific cell populations 208 00:12:19,000 --> 00:12:23,000 or cell types, cell classes, as I mentioned before. 209 00:12:23,000 --> 00:12:27,000 So, this is an example of 2 different genes that are turned on 210 00:12:27,000 --> 00:12:29,000 in very specific layers of the neocortex 211 00:12:29,000 --> 00:12:32,000 only in one individual and not found in another. 212 00:12:32,000 --> 00:12:36,000 Now we have no idea if that's due to environmental changes, 213 00:12:36,000 --> 00:12:39,000 environmental influences or if it's just genetics, 214 00:12:39,000 --> 00:12:43,000 but we did do a study in which we looked at the mouse several years ago 215 00:12:43,000 --> 00:12:48,000 and we were looking at genes that encode for, in this case a DRD2, 216 00:12:48,000 --> 00:12:52,000 the gene listed on the top is a dopamine receptor. 217 00:12:52,000 --> 00:12:58,000 Tyrosine hydroxylase (TH) is a gene involved in dopamine biosynthesis 218 00:12:58,000 --> 00:13:03,000 and those 2 gene products are very different in the cell types 219 00:13:03,000 --> 00:13:06,000 in these individual mouse brains. 220 00:13:06,000 --> 00:13:11,000 So, over on the left is “C57 black 6” which is a commonly used mouse strain, 221 00:13:11,000 --> 00:13:15,000 and then spread at the other end is a wild type strain. 222 00:13:15,000 --> 00:13:19,000 And so the further you go the more genetically unrelated you are. 223 00:13:19,000 --> 00:13:23,000 And when we looked in total across, sort of evolution if you will, 224 00:13:23,000 --> 00:13:25,000 across genetic relatedness, 225 00:13:25,000 --> 00:13:28,000 the further you were genetically unrelated, 226 00:13:28,000 --> 00:13:30,000 the more of these very specific cell types, 227 00:13:30,000 --> 00:13:34,000 specific changes, you could see. 228 00:13:34,000 --> 00:13:36,000 So at the Allen Institute for the next decade 229 00:13:36,000 --> 00:13:38,000 we're embarking on a pretty ambitious program 230 00:13:38,000 --> 00:13:43,000 to start to understand the cell types, understand the cell differences 231 00:13:43,000 --> 00:13:46,000 and how they ultimately relate to the functional properties of the brain. 232 00:13:46,000 --> 00:13:50,000 This is, I think, critical information for the entire field, 233 00:13:50,000 --> 00:13:54,000 to start linking up all of these fundamental parts 234 00:13:54,000 --> 00:13:57,000 which are the cells, to how they're connected, 235 00:13:57,000 --> 00:14:00,000 the underlying molecules that drive those connections, 236 00:14:00,000 --> 00:14:04,000 the underlying molecules that drive the physiological properties, 237 00:14:04,000 --> 00:14:06,000 the electric chemical properties 238 00:14:06,000 --> 00:14:09,000 and then ultimately the functional properties of those cells. 239 00:14:09,000 --> 00:14:14,000 So we're doing this in 3 different areas of research. 240 00:14:14,000 --> 00:14:17,000 First, we're focusing on the mouse, the mouse visual system, 241 00:14:17,000 --> 00:14:21,000 to look at, in real-time, in the living animal, 242 00:14:21,000 --> 00:14:25,000 the functions of a variety of different cells. 243 00:14:25,000 --> 00:14:28,000 We're linking these in this concept in the middle of cell types, 244 00:14:28,000 --> 00:14:33,000 trying to really understand the underlying molecules 245 00:14:33,000 --> 00:14:37,000 in all the properties as they relate to those functions 246 00:14:37,000 --> 00:14:40,000 and then we're looking at the human. 247 00:14:40,000 --> 00:14:44,000 In the human we're doing this both in the middle and cell types 248 00:14:44,000 --> 00:14:46,000 using the tissue driven work that I talked about before 249 00:14:46,000 --> 00:14:51,000 but also we're doing it in vitro using stem cell technology. 250 00:14:51,000 --> 00:14:55,000 We're learning how to make very specific cell types within the dish 251 00:14:55,000 --> 00:14:58,000 and then being able to test those functional properties 252 00:14:58,000 --> 00:15:04,000 and go back and forth between what we learn in the mouse to the human. 253 00:15:04,000 --> 00:15:08,000 So, with that I will finish and just say that it's an exciting time 254 00:15:08,000 --> 00:15:11,000 to be in biology and an exciting time to be in neuroscience. 255 00:15:11,000 --> 00:15:15,000 I think the technology of the day has come well beyond the pen and paper 256 00:15:15,000 --> 00:15:20,000 and it's really time for a renaissance in our understanding of this complex organ. 257 00:15:20,000 --> 00:15:21,000 Thanks. 258 00:15:21,000 --> 00:15:27,000 (Applause)