This video aims to provide a holistic approach towards explaining
Alzheimer's disease.
It will explain dementia.
And Alzheimer's disease,
provide details regarding the pathophysiology of Alzheimer's disease
highlight,
some genetic factors related to the disease,
describe symptoms,
diagnosis and treatment options.
Dementia is not technically a disease
but more of a way to describe a set of
symptoms, like poor memory and difficulty learning new information,
which can make it really hard to function independently.
Usually, dementia is caused by some sort of damage to
the cells in the brain,
which can be caused by a variety of diseases.
Alzheimer's disease is the most common cause of dementia.
Alzheimer's disease is considered to be a neurodegenerative disease,
meaning it causes the degeneration or loss of neurons in
the brain,
particularly in the cortex.
This as you might expect leads to the symptoms characteristic
of dementia,
although the cause of Alzheimer's disease are not completely understood
two,
major players that are often cited in his progression,
are plaques and Tangles ology of Alzheimer's disease
here.
We've got the cell membrane of a neuron in the
brain. In the membrane.
We have the smaller kuehl called amyloid,
precursor protein,
or a p p.
One of the protein is inside the South and the
other end is outside the cell.
This protein helps the neuron grow and repair itself after
an injury,
since a PP is a protein just like other proteins,
it gets used up over time and it gets broken
down and recycled.
Normally.
It gets broken down by Nan's.
I'm called Alpha secretase and Gamma secretase.
This broken of protein is soluble and everything goes
away under normal circumstances.
However,
if another enzyme beta secretase replaces Alpha secretase,
instead,
we encounter a problem.
Bator secretaries breaks down a pee pee from a different
location causing the broken peptide,
to be a non soluble molecule,
this non soluble unit of protein form,
a molecule called amyloid-beta.
The chemical composition of amyloid-beta causes it to be sticky
due to this reason they start to bond together just
outside the neurons and form.
What is called beta-amyloid plaques?
This plaque can potentially get between the neurons and
can interfere with Neurontin,
Iran signaling,
if the brain cannot signal and relay information,
then brain functions like memory in Inverness can be seriously
impaired.
These plaques can also trigger immune response and cause inflammation,
which can damage surrounding neurons,
the condition called amyloid angiopathy arises.
When beta-amyloid plaques deposit around blood vessels amyloid,
angiopathy weakens the walls of the blood vessels and increases
the risk of hemorrhage or rupture and blood loss,
another big part of Alzheimer.
Disease are Tangles.
These are found inside the cell,
similar to other cells in.
The body. Neurons are held together by their cytoskeleton,
which is partly made up of microtubules,
these track like structures act like passages for important nutrients
and molecules along the length of the cell,
a special protein called.
Tau protein,
makes sure that these passages do not break apart.
It is believed that the buildup of beta-amyloid plaques outside,
the neuron initiates Pathways inside the neuron,
that lead to the activation of kindness and enzyme that
transfers,
phosphate groups to the Tau protein,
the Tau protein then changes its shape causing it to
stop supporting the microtubules and clumps up with other towel
proteins and gets Tangled.
This leads to another characteristic finding of Alzheimer's disease called
neurofibrillary,
Tangles neurons with Tangles and non-functioning,
microtubules,
cannot signal Isabel.
And sometimes end up undergoing a pop ptosis or programmed
cell death as neurons died Visible Changes start to take
place in the brain.
The brain begins to shrink.
This is also known as a trophy,
the gyri,
Richard characteristic Ridges of the brain get narrower and
the Soul side which are Gru's between the gyri.
End up getting lighter,
the ventricles which are fluid filled cavities.
Also get larger with that.
Rafi.
Let's talk about genetics.
Why do some people exhibit more symptoms than others?
Alzheimer's disease can be split into two groups sporadic and
familial the term sporadic is Used to define the late
onset type of Alzheimer's disease,
where the exact cause is not very well-defined and is
probably a combination of genetic and environmental risk factors.
In addition,
with sporadic Alzheimer's,
the risk increases significantly with h genes can be thought
of as an instruction manual.
For protein.
There can be many versions of the same gene.
These are called alleles a proteins.
Functionality can be affected by where a specific Gene is
located within an.
Allele a gene that has been identified as possibly contributing
to an increased risk of Alzheimer's disease is the apoe4.
Gene. Apoe is the name of the protein that the specific
Gene is coding for.
While the E4 is the allele that the gene is
located on.
This Gene code for the April lipoprotein e which helps
break down the beta-amyloid.
However,
the E for allele seems to be less effective compared
to other alleles.
Meaning patients are more likely to develop beta-amyloid plaques.
The term.
Familial Alzheimer disease is used to describe cases where some
dorm and Gene was inherited that speeds up the progression
of the disease as a result.
Familial Alzheimer disease is referred to as early onset Alzheimer's
disease.
Mutations in the psen1 OR psen2 genes
are linked to early onset,
Alzheimer's disease,
these jeans and code for the preschool in one,
and presuming to protein subunit,
which make up the gamma secretase protein mutations.
Indie,
subunits can change the location where gamma secretase brakes to
a Lloyd.
Precursor protein,
producing different lengths of beta-amyloid molecules are better
at clumping and forming plaques symptoms of Alzheimer's disease,
worse,
as plaques and Tangles build up and cause damage to
the neurons symptoms,
are not detectable during the early stages as they progress
patients.
Might lose short term.
Memory loss of motor skills and language,
eventually,
long-term memory is affected and patients become disoriented and eventually
bedridden.
Doses of Alzheimer's disease is very tough.
The only made to provide evidence that a person has
Alzheimer's disease is by performing brain biopsy after autopsy
currently there is no cure for Alzheimer's disease,
some medications exist,
but they are aimed at slowing down the progression of
the disease. Every 4 seconds.
Someone is diagnosed with Alzheimer's disease,
being the most common cause of Dementia in effect,
40 million people worldwide.
Despite of being discovered more than a century ago.
It is still not very well interested.
Finding a cure is something that eludes researchers till this
day.