[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:06.61,0:00:08.16,Default,,0000,0000,0000,,Every four seconds,
Dialogue: 0,0:00:08.16,0:00:09.70,Default,,0000,0000,0000,,someone is diagnosed with
Dialogue: 0,0:00:09.70,0:00:11.58,Default,,0000,0000,0000,,Alzheimer's disease.
Dialogue: 0,0:00:11.58,0:00:13.75,Default,,0000,0000,0000,,It's the most common cause of dementia,
Dialogue: 0,0:00:13.75,0:00:16.61,Default,,0000,0000,0000,,affecting over 40 million people worldwide,
Dialogue: 0,0:00:16.61,0:00:19.13,Default,,0000,0000,0000,,and yet finding a cure is something that still
Dialogue: 0,0:00:19.13,0:00:21.62,Default,,0000,0000,0000,,eludes researchers today.
Dialogue: 0,0:00:21.62,0:00:24.89,Default,,0000,0000,0000,,Dr. Alois Alzheimer, a German psychiatrist,
Dialogue: 0,0:00:24.89,0:00:27.94,Default,,0000,0000,0000,,first described the symptoms in 1901
Dialogue: 0,0:00:27.94,0:00:30.40,Default,,0000,0000,0000,,when he noticed that a particular hospital patient
Dialogue: 0,0:00:30.40,0:00:32.31,Default,,0000,0000,0000,,had some peculiar problems,
Dialogue: 0,0:00:32.31,0:00:34.12,Default,,0000,0000,0000,,including difficulty sleeping,
Dialogue: 0,0:00:34.12,0:00:37.48,Default,,0000,0000,0000,,disturbed memory, drastic mood changes,
Dialogue: 0,0:00:37.48,0:00:39.65,Default,,0000,0000,0000,,and increasing confusion.
Dialogue: 0,0:00:39.65,0:00:41.53,Default,,0000,0000,0000,,When the patient passed away,
Dialogue: 0,0:00:41.53,0:00:43.74,Default,,0000,0000,0000,,Alzheimer was able to do an autopsy
Dialogue: 0,0:00:43.74,0:00:45.78,Default,,0000,0000,0000,,and test his idea that perhaps
Dialogue: 0,0:00:45.78,0:00:48.20,Default,,0000,0000,0000,,her symptoms were caused by irregularities
Dialogue: 0,0:00:48.20,0:00:50.16,Default,,0000,0000,0000,,in the brain's structure.
Dialogue: 0,0:00:50.16,0:00:52.11,Default,,0000,0000,0000,,What he found beneath the microscope
Dialogue: 0,0:00:52.11,0:00:54.59,Default,,0000,0000,0000,,were visible differences in brain tissue
Dialogue: 0,0:00:54.59,0:00:56.78,Default,,0000,0000,0000,,in the form of misfolded proteins
Dialogue: 0,0:00:56.78,0:00:58.12,Default,,0000,0000,0000,,called plaques,
Dialogue: 0,0:00:58.12,0:01:00.55,Default,,0000,0000,0000,,and neurofibrillary tangles.
Dialogue: 0,0:01:00.55,0:01:02.93,Default,,0000,0000,0000,,Those plaques and tangles work together
Dialogue: 0,0:01:02.93,0:01:05.34,Default,,0000,0000,0000,,to break down the brain's structure.
Dialogue: 0,0:01:05.34,0:01:07.14,Default,,0000,0000,0000,,Plaques arise when another protein
Dialogue: 0,0:01:07.14,0:01:09.78,Default,,0000,0000,0000,,in the fatty membrane surrounding nerve cells
Dialogue: 0,0:01:09.78,0:01:12.48,Default,,0000,0000,0000,,gets sliced up by a particular enzyme,
Dialogue: 0,0:01:12.48,0:01:15.06,Default,,0000,0000,0000,,resulting in beta-amyloid proteins,
Dialogue: 0,0:01:15.06,0:01:16.86,Default,,0000,0000,0000,,which are sticky and have a tendency
Dialogue: 0,0:01:16.86,0:01:18.45,Default,,0000,0000,0000,,to clump together.
Dialogue: 0,0:01:18.45,0:01:20.40,Default,,0000,0000,0000,,That clumping is what forms the things
Dialogue: 0,0:01:20.40,0:01:22.53,Default,,0000,0000,0000,,we know as plaques.
Dialogue: 0,0:01:22.53,0:01:24.32,Default,,0000,0000,0000,,These clumps block signaling
Dialogue: 0,0:01:24.32,0:01:25.83,Default,,0000,0000,0000,,and, therefore, communication
Dialogue: 0,0:01:25.83,0:01:28.16,Default,,0000,0000,0000,,between cells, and also seem to trigger
Dialogue: 0,0:01:28.16,0:01:30.70,Default,,0000,0000,0000,,immune reactions that cause the destruction
Dialogue: 0,0:01:30.70,0:01:32.83,Default,,0000,0000,0000,,of disabled nerve cells.
Dialogue: 0,0:01:32.83,0:01:35.61,Default,,0000,0000,0000,,In Alzheimer's disease, neurofibrillary tangles
Dialogue: 0,0:01:35.61,0:01:38.70,Default,,0000,0000,0000,,are built from a protein known as tau.
Dialogue: 0,0:01:38.70,0:01:41.59,Default,,0000,0000,0000,,The brain's nerve cells contain a network of tubes
Dialogue: 0,0:01:41.59,0:01:43.61,Default,,0000,0000,0000,,that act like a highway for food molecules
Dialogue: 0,0:01:43.61,0:01:45.18,Default,,0000,0000,0000,,among other things.
Dialogue: 0,0:01:45.18,0:01:47.72,Default,,0000,0000,0000,,Usually, the tau protein ensures that these tubes
Dialogue: 0,0:01:47.72,0:01:49.98,Default,,0000,0000,0000,,are straight, allowing molecules
Dialogue: 0,0:01:49.98,0:01:51.89,Default,,0000,0000,0000,,to pass through freely.
Dialogue: 0,0:01:51.89,0:01:53.60,Default,,0000,0000,0000,,But in Alzheimer's disease,
Dialogue: 0,0:01:53.60,0:01:57.06,Default,,0000,0000,0000,,the protein collapses into twisted strands or tangles,
Dialogue: 0,0:01:57.06,0:01:58.90,Default,,0000,0000,0000,,making the tubes disintegrate,
Dialogue: 0,0:01:58.90,0:02:01.40,Default,,0000,0000,0000,,obstructing nutrients from reaching the nerve cell
Dialogue: 0,0:02:01.40,0:02:04.03,Default,,0000,0000,0000,,and leading to cell death.
Dialogue: 0,0:02:04.03,0:02:06.36,Default,,0000,0000,0000,,The destructive pairing of plaques and tangles
Dialogue: 0,0:02:06.36,0:02:08.70,Default,,0000,0000,0000,,starts in a region called the hippocampus,
Dialogue: 0,0:02:08.70,0:02:11.12,Default,,0000,0000,0000,,which is responsible for forming memories.
Dialogue: 0,0:02:11.12,0:02:12.83,Default,,0000,0000,0000,,That's why short-term memory loss
Dialogue: 0,0:02:12.83,0:02:15.53,Default,,0000,0000,0000,,is usually the first symptom of Alzheimer's.
Dialogue: 0,0:02:15.53,0:02:17.42,Default,,0000,0000,0000,,The proteins then progressively invade
Dialogue: 0,0:02:17.42,0:02:19.03,Default,,0000,0000,0000,,other parts of the brain,
Dialogue: 0,0:02:19.03,0:02:20.86,Default,,0000,0000,0000,,creating unique changes that signal
Dialogue: 0,0:02:20.86,0:02:23.28,Default,,0000,0000,0000,,various stages of the disease.
Dialogue: 0,0:02:23.28,0:02:24.52,Default,,0000,0000,0000,,At the front of the brain,
Dialogue: 0,0:02:24.52,0:02:28.05,Default,,0000,0000,0000,,the proteins destroy the ability to process logical thoughts.
Dialogue: 0,0:02:28.05,0:02:31.22,Default,,0000,0000,0000,,Next, they shift to the region that controls emotions,
Dialogue: 0,0:02:31.22,0:02:33.56,Default,,0000,0000,0000,,resulting in erratic mood changes.
Dialogue: 0,0:02:33.56,0:02:34.78,Default,,0000,0000,0000,,At the top of the brain,
Dialogue: 0,0:02:34.78,0:02:37.14,Default,,0000,0000,0000,,they cause paranoia and hallucinations,
Dialogue: 0,0:02:37.14,0:02:39.20,Default,,0000,0000,0000,,and once they reach the brain's rear,
Dialogue: 0,0:02:39.20,0:02:41.20,Default,,0000,0000,0000,,the plaques and tangles work together
Dialogue: 0,0:02:41.20,0:02:43.62,Default,,0000,0000,0000,,to erase the mind's deepest memories.
Dialogue: 0,0:02:43.62,0:02:45.24,Default,,0000,0000,0000,,Eventually the control centers governing
Dialogue: 0,0:02:45.24,0:02:48.03,Default,,0000,0000,0000,,heart rate and breathing are overpowered as well
Dialogue: 0,0:02:48.03,0:02:49.83,Default,,0000,0000,0000,,resulting in death.
Dialogue: 0,0:02:49.83,0:02:51.86,Default,,0000,0000,0000,,The immensely destructive nature of this disease
Dialogue: 0,0:02:51.86,0:02:54.86,Default,,0000,0000,0000,,has inspired many researchers to look for a cure
Dialogue: 0,0:02:54.86,0:02:58.62,Default,,0000,0000,0000,,but currently they're focused on slowing its progression.
Dialogue: 0,0:02:58.62,0:03:00.00,Default,,0000,0000,0000,,One temporary treatment
Dialogue: 0,0:03:00.00,0:03:02.63,Default,,0000,0000,0000,,helps reduce the break down of acetylcholine,
Dialogue: 0,0:03:02.63,0:03:05.28,Default,,0000,0000,0000,,an important chemical messenger in the brain
Dialogue: 0,0:03:05.28,0:03:07.80,Default,,0000,0000,0000,,which is decreased in Alzheimer's patients
Dialogue: 0,0:03:07.80,0:03:10.86,Default,,0000,0000,0000,,due to the death of the nerve cells that make it.
Dialogue: 0,0:03:10.86,0:03:13.18,Default,,0000,0000,0000,,Another possible solution is a vaccine
Dialogue: 0,0:03:13.18,0:03:15.64,Default,,0000,0000,0000,,that trains the body's immune system to attack
Dialogue: 0,0:03:15.64,0:03:19.23,Default,,0000,0000,0000,,beta-amyloid plaques before they can form clumps.
Dialogue: 0,0:03:19.23,0:03:22.03,Default,,0000,0000,0000,,But we still need to find an actual cure.
Dialogue: 0,0:03:22.03,0:03:23.78,Default,,0000,0000,0000,,Alzheimer's disease was discovered
Dialogue: 0,0:03:23.78,0:03:25.45,Default,,0000,0000,0000,,more than a century ago,
Dialogue: 0,0:03:25.45,0:03:28.11,Default,,0000,0000,0000,,and yet still it is not well understood.
Dialogue: 0,0:03:28.11,0:03:29.78,Default,,0000,0000,0000,,Perhaps one day we'll grasp
Dialogue: 0,0:03:29.78,0:03:32.70,Default,,0000,0000,0000,,the exact mechanisms at work behind this threat
Dialogue: 0,0:03:32.70,0:03:34.91,Default,,0000,0000,0000,,and a solution will be unearthed.