WEBVTT 00:00:00.555 --> 00:00:02.288 I am a neuroscientist 00:00:02.288 --> 00:00:06.056 with a mixed background in physics and medicine. 00:00:06.056 --> 00:00:10.600 My lab at Swiss Federal Institute of Technology 00:00:10.600 --> 00:00:14.036 focuses on spinal cord injury, 00:00:14.036 --> 00:00:16.816 which affect more than 50,000 people 00:00:16.816 --> 00:00:19.612 around the world every year, 00:00:19.612 --> 00:00:22.987 with dramatic consequences for affected individuals, 00:00:22.987 --> 00:00:25.605 whose life literally shatters 00:00:25.605 --> 00:00:28.762 in a matter of a handful of seconds. NOTE Paragraph 00:00:28.762 --> 00:00:32.437 And for me, the man of steel, 00:00:32.437 --> 00:00:34.178 Christopher Reeve, 00:00:34.178 --> 00:00:36.114 had best raised the awareness 00:00:36.114 --> 00:00:38.922 on the distress of spinal cord injured people. 00:00:38.922 --> 00:00:42.122 And this is how I started my own personal journey 00:00:42.122 --> 00:00:43.838 in this field of research, 00:00:43.838 --> 00:00:46.874 working with the Christopher and Dana Reeve Foundation. NOTE Paragraph 00:00:46.874 --> 00:00:49.019 I still remember 00:00:49.019 --> 00:00:51.762 this decisive moment. 00:00:51.762 --> 00:00:53.730 It was just at the end of a regular day of work 00:00:53.730 --> 00:00:55.317 with the foundation. 00:00:55.317 --> 00:00:59.739 Chris addressed to us, the scientists and experts, 00:00:59.739 --> 00:01:03.362 "You have to be more pragmatic. 00:01:03.362 --> 00:01:05.791 When leaving your laboratory tomorrow, 00:01:05.791 --> 00:01:08.603 I want you to stop by the rehabilitation center 00:01:08.603 --> 00:01:10.428 to watch injured people 00:01:10.428 --> 00:01:12.283 fighting to take a step, 00:01:12.283 --> 00:01:15.031 struggling to maintain their [??]. 00:01:15.031 --> 00:01:16.723 And when you go home, 00:01:16.723 --> 00:01:18.778 think about what you are going to change in your research 00:01:18.778 --> 00:01:22.146 on the following day to make their lives better." NOTE Paragraph 00:01:22.146 --> 00:01:25.785 These words, they stuck with me. 00:01:25.785 --> 00:01:28.790 This was more than 10 years ago, 00:01:28.790 --> 00:01:31.499 but ever since, my laboratory has followed 00:01:31.499 --> 00:01:33.614 the pragmatic approach to recovery 00:01:33.614 --> 00:01:36.030 after spinal cord injury. 00:01:36.030 --> 00:01:38.157 And my first step in this direction 00:01:38.157 --> 00:01:41.199 was to develop a new model of spinal cord injury 00:01:41.199 --> 00:01:44.877 that would more closely mimic some of the key features of human injury 00:01:44.877 --> 00:01:48.251 while offering well-controlled experimental conditions. 00:01:48.251 --> 00:01:50.816 And for this purpose, we placed two [??] 00:01:50.816 --> 00:01:52.693 on opposite sides of the body. 00:01:52.693 --> 00:01:54.669 They completely interrupt the communication 00:01:54.669 --> 00:01:56.789 between the brain and the spinal cord, 00:01:56.789 --> 00:01:59.485 thus leaving to complete and permanent paralysis 00:01:59.485 --> 00:02:01.590 of the leg. 00:02:01.590 --> 00:02:05.418 But, as observed, after most injuries in humans, 00:02:05.418 --> 00:02:08.247 there is this intervening gap of intact neural tissue 00:02:08.247 --> 00:02:11.018 through which recovery can occur. 00:02:11.018 --> 00:02:13.482 But how to make it happen? NOTE Paragraph 00:02:13.482 --> 00:02:17.458 Well, the classical approach 00:02:17.458 --> 00:02:20.071 consists of applying intervention 00:02:20.071 --> 00:02:22.974 that would promote the growth of the severed fiber 00:02:22.974 --> 00:02:25.022 to the original target. 00:02:25.022 --> 00:02:28.295 And while this certainly remained the key for a cure, 00:02:28.295 --> 00:02:32.393 this seemed extraordinarily complicated to me. 00:02:32.393 --> 00:02:35.046 To reach clinical fruition rapidly, 00:02:35.046 --> 00:02:36.818 it was obvious: 00:02:36.818 --> 00:02:40.552 I had to think about the problem differently. NOTE Paragraph 00:02:40.552 --> 00:02:43.034 It turned out that more than 100 years of research 00:02:43.034 --> 00:02:45.210 on spinal cord physiology, 00:02:45.210 --> 00:02:47.703 starting with the Nobel Prize Sherrington, 00:02:47.703 --> 00:02:49.526 had shown that 00:02:49.526 --> 00:02:51.638 the spinal cord below most injuries 00:02:51.638 --> 00:02:54.862 contained all the necessary and sufficient neural networks 00:02:54.862 --> 00:02:57.273 to coordinate locomotion, 00:02:57.273 --> 00:03:00.071 but because input from the brain are interrupted, 00:03:00.071 --> 00:03:02.154 they are in a non-functional state, 00:03:02.154 --> 00:03:03.886 like kind of dormant. 00:03:03.886 --> 00:03:07.777 My idea: we awaken this network. NOTE Paragraph 00:03:07.777 --> 00:03:11.958 And at the time, I was a post-doctoral fellow in Los Angeles, 00:03:11.958 --> 00:03:14.584 after completing my Ph.D in France, 00:03:14.584 --> 00:03:16.478 where independent thinking 00:03:16.478 --> 00:03:19.415 is not necessarily promoted. 00:03:19.415 --> 00:03:21.491 (Laughter) 00:03:21.491 --> 00:03:24.903 I was afraid to talk to my new boss, 00:03:24.903 --> 00:03:27.512 but decided to muster up my courage. 00:03:27.512 --> 00:03:30.122 I knock at the door, my wonderful advisor, 00:03:30.122 --> 00:03:34.175 Reggie Edgerton, to share my new idea. NOTE Paragraph 00:03:34.175 --> 00:03:36.703 He listened to me carefully, 00:03:36.703 --> 00:03:39.412 and responded with a grin. 00:03:39.412 --> 00:03:42.487 "Why don't you try?" NOTE Paragraph 00:03:42.487 --> 00:03:43.950 And I promise to you, 00:03:43.950 --> 00:03:46.966 this was such an important moment in my career, 00:03:46.966 --> 00:03:49.293 when I realized that the great leader 00:03:49.293 --> 00:03:52.686 believed in young people and new ideas. NOTE Paragraph 00:03:52.686 --> 00:03:53.971 And this was the idea: 00:03:53.971 --> 00:03:56.499 I'm going to use a simplistic metaphor 00:03:56.499 --> 00:03:58.763 to explain you this complicated concept. 00:03:58.763 --> 00:04:04.192 Imagine that the locomotor system is a car. 00:04:04.192 --> 00:04:05.853 The engine is the spinal cord. 00:04:05.853 --> 00:04:09.157 The transmission is interrupted. The engine is turned off. 00:04:09.157 --> 00:04:11.902 How could we re-engage the engine? 00:04:11.902 --> 00:04:14.997 First, we have to provide the fuel; 00:04:14.997 --> 00:04:17.340 second, press the accelerator pedal; 00:04:17.340 --> 00:04:19.463 third, steer the car. 00:04:19.463 --> 00:04:21.349 It turned out that there are known neural pathways 00:04:21.349 --> 00:04:24.149 coming from the brain that play this very function 00:04:24.149 --> 00:04:25.823 during locomotion. 00:04:25.823 --> 00:04:27.939 My idea: replace this missing input 00:04:27.939 --> 00:04:29.602 to provide the spinal cord 00:04:29.602 --> 00:04:31.244 with the kind of intervention 00:04:31.244 --> 00:04:35.619 that the brain would deliver naturally in order to walk. NOTE Paragraph 00:04:35.619 --> 00:04:40.105 For this, I leveraged 20 years of past research in neuroscience, 00:04:40.105 --> 00:04:42.746 first to replace the missing fuel 00:04:42.746 --> 00:04:45.023 with pharmacological agents 00:04:45.023 --> 00:04:48.370 that prepare the neural and in the spinal cord to fire, 00:04:48.370 --> 00:04:52.425 and second, to mim the accelerator pedal 00:04:52.425 --> 00:04:54.352 with electrical stimulation. 00:04:54.352 --> 00:04:56.321 So here imagine an electrode 00:04:56.321 --> 00:04:58.665 implanted on the back of the spinal cord 00:04:58.665 --> 00:05:00.897 to deliver painless stimulation. 00:05:00.897 --> 00:05:03.360 It took many years, but eventually we developed 00:05:03.360 --> 00:05:06.193 an electrochemical neuroprosthesis 00:05:06.193 --> 00:05:08.176 that transformed the neural network 00:05:08.176 --> 00:05:12.827 in the spinal cord from dormant to highly functional state. 00:05:12.827 --> 00:05:19.214 Immediately, the paralyzed rat can stand. 00:05:19.214 --> 00:05:21.526 As soon as the treadmill starts moving, 00:05:21.526 --> 00:05:25.471 the animals show coordinated movement of the leg, 00:05:25.471 --> 00:05:27.448 but without the brain. 00:05:27.448 --> 00:05:29.454 Here what I call "the spinal brain" 00:05:29.454 --> 00:05:32.191 cognitively processes sensory information 00:05:32.191 --> 00:05:34.333 arising from the moving leg 00:05:34.333 --> 00:05:38.227 and takes decisions as to how to activate the muscle 00:05:38.227 --> 00:05:41.386 in order to stand, to walk, to run, 00:05:41.386 --> 00:05:43.498 and even here, while sprinting, 00:05:43.498 --> 00:05:45.795 instantly stand 00:05:45.795 --> 00:05:48.458 if the treadmill stops moving. NOTE Paragraph 00:05:48.458 --> 00:05:49.857 This was amazing. 00:05:49.857 --> 00:05:53.121 I was completed fascinated by this locomotion 00:05:53.121 --> 00:05:55.601 without the brain, 00:05:55.601 --> 00:05:59.256 but at the same time so frustrated. 00:05:59.256 --> 00:06:01.695 This locomotion was completely involuntary. 00:06:01.695 --> 00:06:04.952 The animal had virtually no control over the legs. 00:06:04.952 --> 00:06:09.257 Clearly, the steering system was missing. 00:06:09.257 --> 00:06:11.133 And it then became obvious from me 00:06:11.133 --> 00:06:12.729 that we had to move away 00:06:12.729 --> 00:06:15.561 from the classical rehabilitation paradigm, 00:06:15.561 --> 00:06:17.529 stepping on a treadmill, 00:06:17.529 --> 00:06:20.289 and develop conditions that would encourage 00:06:20.289 --> 00:06:25.721 the brain to begin a voluntary control over the leg. NOTE Paragraph 00:06:25.721 --> 00:06:29.006 With this in mind, we developed a completely new 00:06:29.006 --> 00:06:32.089 robotic system to support the rat 00:06:32.089 --> 00:06:35.097 in any direction of space. 00:06:35.097 --> 00:06:37.113 Imagine, this is really cool. 00:06:37.113 --> 00:06:41.114 So imagine the little 200 gram rat 00:06:41.114 --> 00:06:44.707 attached at the extremity of this 200 kilo robot, 00:06:44.707 --> 00:06:47.217 but the rat does not feel the robot. 00:06:47.217 --> 00:06:49.289 The robot is transparent, 00:06:49.289 --> 00:06:51.467 just how you would hold a young child 00:06:51.467 --> 00:06:54.187 during the first insecure steps. NOTE Paragraph 00:06:54.187 --> 00:06:57.569 Let me summarize: the rat received 00:06:57.569 --> 00:07:00.083 a paralyzing lesion of the spinal cord. 00:07:00.083 --> 00:07:02.666 The electrochemical neuroprostheses enable 00:07:02.666 --> 00:07:06.858 highly functional state of the spinal locomotor networks. 00:07:06.858 --> 00:07:10.593 The robot provides the safe environment 00:07:10.593 --> 00:07:12.587 to allow the rat to attempt anything 00:07:12.587 --> 00:07:15.361 to engage the paralyzed legs. 00:07:15.361 --> 00:07:17.663 And for motivation, we used what I think 00:07:17.663 --> 00:07:21.928 is the more powerful pharmacology of Switzerland: 00:07:21.928 --> 00:07:24.188 fine Swiss chocolate. NOTE Paragraph 00:07:24.188 --> 00:07:27.312 (Laughter) NOTE Paragraph 00:07:27.312 --> 00:07:31.673 Actually, the first results were very, very, 00:07:31.673 --> 00:07:33.758 very disappointing. 00:07:33.758 --> 00:07:37.610 Here is my best physical therapist 00:07:44.841 --> 00:07:47.569 completely failing to encourage the rat 00:07:47.569 --> 00:07:49.569 to take a single step, 00:07:49.569 --> 00:07:52.553 whereas the same rat, five minutes earlier, 00:07:52.553 --> 00:07:54.890 walked beautifully on the treadmill. 00:07:54.890 --> 00:07:56.925 We were so frustrated. NOTE Paragraph 00:07:56.925 --> 00:07:59.653 But you know, one of the most essential qualities 00:07:59.653 --> 00:08:02.209 of a scientist is perseverance. 00:08:02.209 --> 00:08:05.853 We insisted. We refined our paradigm, 00:08:05.853 --> 00:08:08.024 and after several months of training, 00:08:08.024 --> 00:08:11.799 the otherwise paralyzed rat could stand, 00:08:11.799 --> 00:08:13.708 and whenever she decided, 00:08:13.708 --> 00:08:15.943 initiated full weight-bearing locomotion 00:08:15.943 --> 00:08:19.256 to sprint towards the rewards. 00:08:19.256 --> 00:08:22.475 This is the first recovery ever observed 00:08:22.475 --> 00:08:24.432 of voluntary leg movement 00:08:24.432 --> 00:08:27.027 after an experimental lesion of the spinal cord 00:08:27.027 --> 00:08:30.412 leading to complete and permanent paralysis. NOTE Paragraph 00:08:30.412 --> 00:08:32.209 In fact -- NOTE Paragraph 00:08:32.209 --> 00:08:34.361 (Applause) NOTE Paragraph 00:08:34.361 --> 00:08:38.556 Thank you. NOTE Paragraph 00:08:38.556 --> 00:08:41.402 In fact, not only the rat could initiate 00:08:41.402 --> 00:08:44.141 and sustain locomotion on the ground, 00:08:44.141 --> 00:08:46.545 they could even adjust leg movement, 00:08:46.545 --> 00:08:48.932 for example, to resist gravity 00:08:48.932 --> 00:08:52.172 in order to climb a staircase. 00:08:52.172 --> 00:08:53.877 I can promise you this was 00:08:53.877 --> 00:08:56.476 such an emotional moment in my laboratory. 00:08:56.476 --> 00:08:59.142 It took us 10 years of hard work 00:08:59.142 --> 00:09:01.732 to reach this goal. NOTE Paragraph 00:09:01.732 --> 00:09:04.437 But the remaining question was, how? 00:09:04.437 --> 00:09:06.391 I mean, how is it possible? 00:09:06.391 --> 00:09:08.021 And here, what we found 00:09:08.021 --> 00:09:11.252 was completely unexpected. 00:09:11.252 --> 00:09:15.103 This novel training paradigm 00:09:15.103 --> 00:09:19.127 encouraged the brain to create new connections, 00:09:19.127 --> 00:09:21.754 some relay circuits 00:09:21.754 --> 00:09:25.002 that relay information from the brain 00:09:25.002 --> 00:09:28.372 past the injury and restore cortical control 00:09:28.372 --> 00:09:31.674 over the locomotor networks below the injury. 00:09:31.674 --> 00:09:34.719 And here, you can see one such example, 00:09:34.719 --> 00:09:38.039 where we label the fibers coming from the brain in red. 00:09:38.039 --> 00:09:41.210 This blue neuron is connected with the locomotor center, 00:09:41.210 --> 00:09:43.419 and what this constellation 00:09:43.419 --> 00:09:45.970 of synaptive contacts means 00:09:45.970 --> 00:09:50.057 is that the brain is reconnected with locomotor center 00:09:50.057 --> 00:09:53.922 with only one relay neuron. 00:09:53.922 --> 00:09:55.898 But the remodeling was not restricted 00:09:55.898 --> 00:09:57.051 to the lesion area. 00:09:57.051 --> 00:09:59.875 It occurred throughout the central nervous system, 00:09:59.875 --> 00:10:02.611 including in the brain stem, 00:10:02.611 --> 00:10:05.731 where we observed up to 300 percent increase 00:10:05.731 --> 00:10:09.459 in the density of fibers coming from the brain. 00:10:09.459 --> 00:10:13.074 We did not aim to repair the spinal cord, 00:10:13.074 --> 00:10:15.722 yet we were able to promote 00:10:15.722 --> 00:10:17.786 one of the more extensive remodeling 00:10:17.786 --> 00:10:20.178 of external projection ever observed 00:10:20.178 --> 00:10:22.410 in the central nervous system of adult mammal 00:10:22.410 --> 00:10:25.008 after an injury. NOTE Paragraph 00:10:25.008 --> 00:10:30.001 And, you know, there is a very important message 00:10:30.001 --> 00:10:34.604 hidden behind this discovery. 00:10:34.604 --> 00:10:37.811 They are the result of a young team 00:10:37.811 --> 00:10:40.249 of very talented people: 00:10:40.249 --> 00:10:44.785 physical therapist, neurobiologist, neurosurgeon, 00:10:44.785 --> 00:10:47.183 engineers of all kinds. 00:10:47.183 --> 00:10:48.943 We have achieved together 00:10:48.943 --> 00:10:52.201 what would have been impossible by single individuals. 00:10:52.201 --> 00:10:55.284 This is truly a trans-disciplinary team. 00:10:55.284 --> 00:10:57.472 They are work so close to each other 00:10:57.472 --> 00:11:00.833 that there is almost like a transfer of DNA. 00:11:00.833 --> 00:11:02.579 We are creating the next generation 00:11:02.579 --> 00:11:04.635 of MDs and engineers, 00:11:04.635 --> 00:11:07.171 get a bit of translating discoveries all the way 00:11:07.171 --> 00:11:09.782 from bench to bedside. 00:11:09.782 --> 00:11:11.820 And me? 00:11:11.820 --> 00:11:16.427 I am only the maestro who orchestrated this beautiful symphony. NOTE Paragraph 00:11:16.427 --> 00:11:22.523 Now, I am sure you are all wondering, aren't you, 00:11:22.523 --> 00:11:27.259 will this help injured people? 00:11:27.259 --> 00:11:30.655 Me too, every day. 00:11:30.655 --> 00:11:34.269 The truth is that we don't know enough yet. 00:11:34.269 --> 00:11:38.893 This is certainly not a cure for spinal cord injury, 00:11:38.893 --> 00:11:41.103 but I begin to believe that this may lead 00:11:41.103 --> 00:11:43.640 to an intervention to improve recovery 00:11:43.640 --> 00:11:46.965 and people's quality of life. NOTE Paragraph 00:11:46.965 --> 00:11:49.346 I would like you all 00:11:49.346 --> 00:11:53.045 to take a moment and dream with me. 00:11:53.045 --> 00:11:58.931 Imagine a person just suffered spinal cord injury. 00:11:58.931 --> 00:12:02.070 After a few weeks of recovery, 00:12:02.070 --> 00:12:04.522 we will implant a programmable [??] 00:12:04.522 --> 00:12:07.449 to deliver a personalized pharmacological cocktail 00:12:07.449 --> 00:12:09.966 directly into the spinal cord. 00:12:09.966 --> 00:12:13.046 At the same time, we will implant an electrode array, 00:12:13.046 --> 00:12:15.338 a sort of second skin 00:12:15.338 --> 00:12:18.958 covering the area of the spinal cord controlling leg movement, 00:12:18.958 --> 00:12:22.193 and this array is attached to an electrical pulse generator 00:12:22.193 --> 00:12:24.193 that delivers stimulations that are tailored 00:12:24.193 --> 00:12:26.841 to the person's needs. 00:12:26.841 --> 00:12:31.730 This defines a personalized electrochemical neuroprosthesis 00:12:31.730 --> 00:12:33.835 that will enable locomotion 00:12:33.835 --> 00:12:38.529 during training with a newly designed supporting system. 00:12:38.529 --> 00:12:41.674 And my hope is that after several months of training, 00:12:41.674 --> 00:12:44.143 there may be enough remodeling of residual connection 00:12:44.143 --> 00:12:47.613 to allow locomotion without the robot, 00:12:47.613 --> 00:12:51.298 maybe even without pharmacology or stimulation. 00:12:51.298 --> 00:12:53.817 My hope here is to be able to create 00:12:53.817 --> 00:12:56.297 the personalized condition 00:12:56.297 --> 00:12:58.960 to boost the plasticity of the brain 00:12:58.960 --> 00:13:00.706 and the spinal cord. 00:13:00.706 --> 00:13:02.906 And this is a radically new concept 00:13:02.906 --> 00:13:06.292 that may apply to other neurological disorders. 00:13:06.292 --> 00:13:10.737 What I termed "personalized neuroprosthetics," 00:13:10.737 --> 00:13:13.823 where by sensing and stimulating neural interfaces, 00:13:13.823 --> 00:13:17.722 I implanted throughout the nervous system, 00:13:17.722 --> 00:13:20.893 in the brain, in the spinal cord, 00:13:20.893 --> 00:13:23.572 even in peripheral nerves, 00:13:23.572 --> 00:13:26.924 based on patient-specific impairments. 00:13:26.924 --> 00:13:31.532 But not to replace the lost function, no: 00:13:31.532 --> 00:13:34.647 to help the brain help itself. NOTE Paragraph 00:13:34.647 --> 00:13:37.502 And I hope this enticed your imagination, 00:13:37.502 --> 00:13:39.321 because I can promise to you 00:13:39.321 --> 00:13:42.535 this is not a matter of whether this revolution will occur, 00:13:42.535 --> 00:13:44.294 but when. 00:13:44.294 --> 00:13:46.543 And remember, we are only as great 00:13:46.543 --> 00:13:50.062 as our imagination, as big as our dream. NOTE Paragraph 00:13:50.062 --> 00:13:51.934 Thank you. NOTE Paragraph 00:13:51.934 --> 00:13:55.934 (Applause)