Main content
Health and medicine
Course: Health and medicine > Unit 9
Lesson 4: Memory- Information processing model: Sensory, working, and long term memory
- Encoding strategies
- Retrieval cues
- Retrieval: Free recall, cued recall, and recognition
- Memory reconstruction, source monitoring, and emotional memories
- Long term potentiation and synaptic plasticity
- Decay and interference
- Aging and cognitive abilities
- Alzheimer's disease and Korsakoff's syndrome
© 2023 Khan AcademyTerms of usePrivacy PolicyCookie Notice
Alzheimer's disease and Korsakoff's syndrome
Learn about how Alzheimer's Disease and Korsakoff's Syndrome affect memory.
. Created by Carole Yue.
. Created by Carole Yue.
Want to join the conversation?
- Are professional athletes, e.g. football players and boxers, more prone to suffer for Alzheimer's at a later age?(6 votes)
- As she says in the video the cause is unknown, but there is heavy evidence and correlation between contact sports and later development of Alzheimer's disease.(3 votes)
- Why were these 2 diseases talked about specifically? Are there any more dementia related diseases we should know for the MCAT? Or any more details about these two? Thanks.(2 votes)
- These are the two most important dementia related diseases and the two that the MCAT focuses on specifically, if at all. You should know the physiological changes that occur. For AD, (outside the cell) beta-amyloids (that are usually cut off of APP and recycled) aggregate into beta-amyloid plaques. Inside the cell, the Tau protein becomes hyperphosphorylated causing the proteins to become aggregated into insoluble neurofibrillary tangles. As a result, the brain as a whole shrinks, but esp. the temporofrontal and frontal cortexes and the hippocampus (also, the ventricles increase). For Korsakoff's, you mainly just need to know that it results from severe thiamine deficiencies. Hope this helps! Good luck on your MCAT! :)(13 votes)
- my grandmother has dimentia and we trying to help her but she lies sometimes and then my dad gets mad, what can we do to help get her short term memory back, without the use of a lot of medication.(2 votes)
- The first thing to do is to go see a Doctor. If medical advice is to be had, they are the first place to go.
Besides the first suggestion, probably the best thing they could do is exercise. Exercise has been show to reduce cognitive decline. Eating healthy always helps too. That means not consuming more calories than needed, and getting proper nutrition (daily value), Include the dark leafy greens. Blue Berries are good too. A little bit of something from each food group is a simple way to do this.
You might also consider dancing sessions, music, or positive social interaction. And go to a Doctor, if you haven't already.(8 votes)
- Hi,
So I'm trying to understand this in the simplest way so that way I can remember it. I'm not really good with this. What exactly is thiamine for? you mentioned that thiamine is used up in order for the carbohydrates to be used. So when a person lacks thiamine, does that mean that the brain is unable to use the glucose leading to damage to the brain?(1 vote)- Thiamine, or vitamin B1, is in the enzyme, TPP, that converts Pyruvic acid (from the break down of glucose in glycolysis) to Acetyl CoA so it can enter the Krebs cycle. If a person has been starving and not taken in adequate vitamin B1, this reaction can’t occur. People that are starving are frequently given carbohydrate rich food unfortunately. But without TPP, the pyruvic acid builds up, which in turn increases the amount of lactic acid. In the brain this causes Wernicke-Korsakoff syndrome which are a variety of signs of brain damage, such as nystagmus and it may lead to long term problems such as memory deficits, confusion etc. Yes, if the person is lacking thiamine and given sugar, the brain can be damaged. So, when treating people that may have not eaten well, such as alcoholics, people with anorexia nervosa, cancer etc.. it makes sense to give them thiamine. Beriberi is another term meaning Thiamine deficiency. http://emedicine.medscape.com/article/116930-overview(8 votes)
- Who first discovered Alzheimer's disease?(3 votes)
- AtWhen she says thiamine is responsible for converting carbohydrates into glucose to give the cells energy. is she referring to catabolism or anabolism? its confusing. I expect her to be referring to anabolism if we are going from a large carbohydrate to a glucose, but the cells get energy by breaking down glucose not making it. 2:23(2 votes)
- Yes, you are close. First let's check definitions. Anabolism means to build up. (think anabolic steroids build up muscles- and no, I am not encouraging their use.) Catabolism means to break down. (think 'cut'abolism). If she said that carbs have to be converted to glucose, then she is referring to catabolism the break down of carbohydrates to glucose molecules. Thiamine is in an enzyme required to break down pyruvate (often from glucose) in cellular respiration to ATP, CO2 and H2O. Carbohydrates, starches and sugars are made up of many sugars. Glucose is a single sugar molecule.
To break down pyruvate, TPP is required, a thiamine containing enzyme. If this enzyme is not available then ketone acids accumulate which change the body pH and may damage the brain. This maybe more than you want but here is a link to the Krebs Cycle. https://en.wikibooks.org/wiki/Structural_Biochemistry/Krebs_Cycle_(Citric_Acid_cycle)(2 votes)
- I didn't get the planning part. Could someone explain what she meant by planning?(1 vote)
- I can't see this video... I press it and I get the aging and cognitive decay video.(0 votes)
- Are you sure? Did you try to reload the page multiple times and it still didn't work? How about trying to go to google and type KhanAcademy. Click on KhanAcademy and go to this video. Does it still not work?(1 vote)
Video transcript
Although everybody forgets,
excessive forgetting can be a sign of a
more serious problem. Dementia is the
term for a decline in memory and other
cognitive functions that gets to the point of
interfering with daily life. Dementia results
from excessive damage to brain tissue, which can
be from multiple strokes or other causes. The most common form of dementia
is Alzheimer's disease, or AD. Now, the exact cause
of AD is still unknown, but we do know that
in people with AD, their neurons die off over time. As people with AD lose
their neurons and synapses, their cerebral cortex
shrinks in size. The earliest symptoms of AD
are memory loss, specifically the inability to encode or
retrieve recent memories. Subsequent problems
include difficulty with attention, planning,
semantic memory, and abstract thinking. As the disease progresses, more
severe language difficulties may appear, as well as
greater memory loss, such as the inability to
recognize close family and friends. As the disease continues
to progress, people with AD may experience emotional
instability and loss of control over their bodily functions. While there are many theories
as to the exact cause of the disease, a definitive
answer is still unknown, and the disease is terminal. We do know that people
with AD experience a buildup of proteins called
amyloid plaques in the brain, but how or why those
plaques start to build up and exactly what role they
play in the disease is still uncertain. Another neurological
disorder affecting memory is Korsakoff's
syndrome, which is caused by a lack of vitamin
B1, or thiamine, in the brain. This disorder is strongly
linked to severe malnutrition, eating disorders, or
especially alcoholism, because these groups
often don't ingest or are unable to process all the
nutrients their bodies need, including thiamine. Thiamine is important
because it's responsible for
converting carbohydrates into the glucose your
cells need for energy, and it's especially important
for the normal functioning of your neurons. At first, a person developing
Korsakoff's syndrome might have damage to
certain parts of the brain, resulting in poor balance,
abnormal eye movements, mild confusion,
and/or memory loss. At this stage, it's
actually called Wernicke's
encephalopathy, which is the precursor to
Korsakoff's syndrome. If Wernicke's encephalopathy
is diagnosed in time, then it's possible to
reverse the damage, or at least prevent more of it. If untreated,
however, the disease will progress into full-blown
Korsakoff's syndrome. The main symptom of Korsakoff's
syndrome is severe memory loss, and this symptom is often
accompanied by confabulation, which is when the
patient makes up stories, sometimes to fill in the
gaps in his or her memory. Unlike AD, Korsakoff's syndrome
is not necessarily progressive. If diagnosed and treated,
people can get better. People are often treated
with thiamine injections or other medication,
and they have to stay on a healthy diet
and abstain from alcohol. And some people may also
need to re-learn some things. The effectiveness
of this treatment really depends on how early
the disease is diagnosed and how well the patient follows
the treatment guidelines.