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Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:06.76,0:00:09.24,Default,,0000,0000,0000,,Imagine the brain could reboot,
Dialogue: 0,0:00:09.24,0:00:14.41,Default,,0000,0000,0000,,updating its withered and damaged cells\Nwith new, improved units.
Dialogue: 0,0:00:14.41,0:00:16.66,Default,,0000,0000,0000,,That may sound like science fiction,
Dialogue: 0,0:00:16.66,0:00:20.94,Default,,0000,0000,0000,,but it's a potential reality\Nscientists are investigating right now.
Dialogue: 0,0:00:20.94,0:00:24.50,Default,,0000,0000,0000,,Will our brains one day \Nbe able to self-repair?
Dialogue: 0,0:00:24.50,0:00:28.32,Default,,0000,0000,0000,,It's well known that embryonic cells\Nin our young developing brains
Dialogue: 0,0:00:28.32,0:00:30.34,Default,,0000,0000,0000,,produce new neurons,
Dialogue: 0,0:00:30.34,0:00:33.78,Default,,0000,0000,0000,,the microscopic units \Nthat make up the brain's tissue.
Dialogue: 0,0:00:33.78,0:00:39.24,Default,,0000,0000,0000,,Those newly generated neurons migrate\Nto various parts of the developing brain,
Dialogue: 0,0:00:39.24,0:00:43.13,Default,,0000,0000,0000,,making it self-organize \Ninto different structures.
Dialogue: 0,0:00:43.13,0:00:44.44,Default,,0000,0000,0000,,But until recently,
Dialogue: 0,0:00:44.44,0:00:50.04,Default,,0000,0000,0000,,scientists thought cell production came to\Nan abrupt halt soon after this initial growth,
Dialogue: 0,0:00:50.04,0:00:52.79,Default,,0000,0000,0000,,leading them to conclude \Nthat neurological diseases,
Dialogue: 0,0:00:52.79,0:00:54.98,Default,,0000,0000,0000,,like Alzheimer's and Parkinson's,
Dialogue: 0,0:00:54.98,0:00:59.76,Default,,0000,0000,0000,,and damaging events, like strokes,\Nare irreversible.
Dialogue: 0,0:00:59.76,0:01:01.62,Default,,0000,0000,0000,,But a series of recent discoveries
Dialogue: 0,0:01:01.62,0:01:06.60,Default,,0000,0000,0000,,has revealed that adult brains \Nactually do continue to produce new cells
Dialogue: 0,0:01:06.60,0:01:09.46,Default,,0000,0000,0000,,in at least three specialized locations.
Dialogue: 0,0:01:09.46,0:01:12.42,Default,,0000,0000,0000,,This process, known as neurogenesis,
Dialogue: 0,0:01:12.42,0:01:16.08,Default,,0000,0000,0000,,involves dedicated brain cells,\Ncalled neural stem cells
Dialogue: 0,0:01:16.08,0:01:17.92,Default,,0000,0000,0000,,and progenitor cells,
Dialogue: 0,0:01:17.92,0:01:22.25,Default,,0000,0000,0000,,which manufacture new neurons\Nor replace the old ones.
Dialogue: 0,0:01:22.25,0:01:25.21,Default,,0000,0000,0000,,The three regions where neurogenesis\Nhas been discovered
Dialogue: 0,0:01:25.21,0:01:29.35,Default,,0000,0000,0000,,are the dentate gyrus,\Nassociated with learning and memory,
Dialogue: 0,0:01:29.35,0:01:33.94,Default,,0000,0000,0000,,the subventricular zone, which may\Nsupply neurons to the olfactory bulb
Dialogue: 0,0:01:33.94,0:01:36.86,Default,,0000,0000,0000,,for communication \Nbetween the nose and brain,
Dialogue: 0,0:01:36.86,0:01:40.17,Default,,0000,0000,0000,,and the striatum, \Nwhich helps manage movement.
Dialogue: 0,0:01:40.17,0:01:43.99,Default,,0000,0000,0000,,Scientists don't yet have a good grasp\Non exactly what role
Dialogue: 0,0:01:43.99,0:01:47.62,Default,,0000,0000,0000,,neurogenesis plays \Nin any of these regions,
Dialogue: 0,0:01:47.62,0:01:51.99,Default,,0000,0000,0000,,or why they have this ability \Nthat's absent from the rest of the brain,
Dialogue: 0,0:01:51.99,0:01:56.74,Default,,0000,0000,0000,,but the mere presence of a mechanism\Nto grown new neurons in the adult brain
Dialogue: 0,0:01:56.74,0:01:59.60,Default,,0000,0000,0000,,opens up an amazing possibility.
Dialogue: 0,0:01:59.60,0:02:04.66,Default,,0000,0000,0000,,Could we harness that mechanism\Nto get the brain to heal its scars
Dialogue: 0,0:02:04.66,0:02:07.88,Default,,0000,0000,0000,,similar to how new skin\Ngrows to patch up a wound,
Dialogue: 0,0:02:07.88,0:02:11.89,Default,,0000,0000,0000,,or a broken bone \Nstitches itself back together?
Dialogue: 0,0:02:11.89,0:02:13.78,Default,,0000,0000,0000,,So here's where we stand.
Dialogue: 0,0:02:13.78,0:02:18.05,Default,,0000,0000,0000,,Certain proteins and other small molecules\Nthat mimick those proteins
Dialogue: 0,0:02:18.05,0:02:20.14,Default,,0000,0000,0000,,can be administered to the brain
Dialogue: 0,0:02:20.14,0:02:22.93,Default,,0000,0000,0000,,to make neural stem cells \Nand progenitor cells
Dialogue: 0,0:02:22.93,0:02:26.60,Default,,0000,0000,0000,,produce more neurons \Nin those three locations.
Dialogue: 0,0:02:26.60,0:02:28.74,Default,,0000,0000,0000,,This technique still needs improvement
Dialogue: 0,0:02:28.74,0:02:31.16,Default,,0000,0000,0000,,so that the cells \Nreproduce more efficiently
Dialogue: 0,0:02:31.16,0:02:33.08,Default,,0000,0000,0000,,and more cells survive.
Dialogue: 0,0:02:33.08,0:02:36.42,Default,,0000,0000,0000,,But research shows that progenitor cells\Nfrom these areas
Dialogue: 0,0:02:36.42,0:02:40.02,Default,,0000,0000,0000,,can actually migrate to places where\Ninjury has occurred
Dialogue: 0,0:02:40.02,0:02:43.20,Default,,0000,0000,0000,,and give rise to new neurons there.
Dialogue: 0,0:02:43.20,0:02:45.31,Default,,0000,0000,0000,,And another promising possible approach
Dialogue: 0,0:02:45.31,0:02:48.31,Default,,0000,0000,0000,,is to transplant healthy \Nhuman neural stem cells,
Dialogue: 0,0:02:48.31,0:02:51.84,Default,,0000,0000,0000,,which are cultured in a laboratory,\Nto injured tissue,
Dialogue: 0,0:02:51.84,0:02:53.76,Default,,0000,0000,0000,,like we can do with skin.
Dialogue: 0,0:02:53.76,0:02:55.67,Default,,0000,0000,0000,,Scientists are currently experimenting
Dialogue: 0,0:02:55.67,0:03:00.82,Default,,0000,0000,0000,,to determine whether transplanted\Ndonor cells can divide, differentiate
Dialogue: 0,0:03:00.82,0:03:06.15,Default,,0000,0000,0000,,and successfully give rise \Nto new neurons in a damaged brain.
Dialogue: 0,0:03:06.15,0:03:07.34,Default,,0000,0000,0000,,They've also discovered
Dialogue: 0,0:03:07.34,0:03:10.40,Default,,0000,0000,0000,,that we might be able to teach\Nother kinds of brain cells,
Dialogue: 0,0:03:10.40,0:03:13.74,Default,,0000,0000,0000,,such as astrocytes\Nor oligodendrocytes
Dialogue: 0,0:03:13.74,0:03:18.65,Default,,0000,0000,0000,,to behave like neural stem cells\Nand start generating neurons, too.
Dialogue: 0,0:03:18.65,0:03:22.99,Default,,0000,0000,0000,,So, a couple of decades from now\Nwill our brains be able to self-repair?
Dialogue: 0,0:03:22.99,0:03:24.72,Default,,0000,0000,0000,,We can't say for sure,
Dialogue: 0,0:03:24.72,0:03:29.07,Default,,0000,0000,0000,,but that has become one of the major \Ngoals of regenerative medicine.
Dialogue: 0,0:03:29.07,0:03:31.85,Default,,0000,0000,0000,,The human brain has 100 billion neurons
Dialogue: 0,0:03:31.85,0:03:37.76,Default,,0000,0000,0000,,and we're still figuring out the wiring\Nbehind this huge biological motherboard.
Dialogue: 0,0:03:37.76,0:03:44.48,Default,,0000,0000,0000,,But everyday, research on neurogenesis\Nbrings us closer to that reboot switch.