Neuroplasticity and Dementia Flashcards
Do our genes impact Dimentia, or syndromes in general?
Our genes do have an impact. There is a probability of developing certain diseases based on something pre-disposed, i.e from our parents.
BUT, genes only operate in the context of which they find themselves, i.e, your environment.
Environment/ how we interact with our environment influences the brain and has an impact on any brain injury that may occur.
Knowing this helps us to prevent harm.
What is Neuroplasticity and what are the ideas behind it?
Neurons themselves are highly malleable, details of them can change in a short space of time. They are not static/fixed structures.
- We were shown a neuron across a span of time, the physical structure of the dendrites changed. - This is dependent on our environment and the experiences we’ve engaged in.
Once we reach our teens/ adult years, our number of neurons is set.
However, there are some developments in new neurons (neurogenesis) in two regions of the adult brain.
These include the: Hippocampus, and Olfactory Reigon (associated with smell).
How do enriched environments help with our brain health?
- The quality of our brain can be diminished by a poor environment and aging.
- But also, a good environment can give rise to a better brain
This is evident when we have 2 people with the same brain injury but get different results. What’s different between these 2 people is their environments.
An enriched environment includes social, physical, nutritional, and occupational enhancements compared to a deprived environment.
- A study was done where rats learnt better than other rats. The ones who learnt better were raised differently and had larger forebrains.
Explain details of the adult neurogenesis in the Hippocampus. What’s the specific region? What role does this play? What environmental factors play into this neurogenesis?
Studies found that the ‘Denate Gyrus’ region inside the hippocampus produces new cells throughout life, even in old adults. - sometimes 9000 cells are born every day, not all will survive, but many form into mature neurons.
- animals in enriched environments have more sustained new neurons then when not.
- This area of the brain plays a role in learning and memory, and emotional behaviour.
Explain details of the adult neurogenesis in the Olfactory Region. What role does this play? What environmental factors play into this neurogenesis?
When our brain develops - beginning from our neural tube - Our brain cells originate from the lining of the brain ventricles/ it’s the walls of the tube that forms/generates new neurons.
These developing neurons repopulate in the smell area of the brain.
- The loss of sense of smell is an indicator of one or two future progressions to one or two degenerate conditions.
Neuroplasticity of the human hippocampus and Taxi driver study/ medical student study. Explain the study, and how this effected the brain.
TAXI:
Through analysing the brains of newly trained taxi drivers over 3-4 months, they found that the quality and volume of the hippocampus would change as a consequence.
- They found that the back end of the hippocampus shows a volumetric increase on both sides - more on the right side than on the left but that’s to be expected as the right side is more related to spacial info.
MED:
Similar experiment was done with med students.
They found an increase in volume in the hippocampus and a continual increase.
- Also n increase in volume in parts of the cortex towards the back of the brain - mostly parts of the parietal cortex ( non-continual though)
- Learning stuff made a difference to the volume of hippo and parts of cortex
Do enriched environments change the impact of brain injury? Rat study focusses on ATN leison….
The rat study looked at the different effects on the Anterior Thalamic Nuclei (ATN) which is also one of the regions that show injury in Korsokoffs syndrome.
- In rats, when looking at the CA1 (critical area for memory and learning) part of the Hippocampus in the context of damage to the ATN- there is a reduction in the number of spines in those neurons
i.e
- Damage to the ATN in rats led to fewer dendritic spines in the CA1 region of the hippocampus.
- This reduction could impair memory and learning, indicating a link between ATN damage and hippocampal function.
In thi study they compared different rats and found:
normal rats with normal environments had a good amount of spines on these neurons.
Rats with lesions had a little amount.
Enriched rats had a lot.
Animals with leisons AND enriched environments had almost the same as normal rats.
In another study this also translated to a learning-based activity. ‘Instead of number or dendrites’ they measured how well they could learn. Same results.
What is dementia?
It is a neurodegeneration syndrome(s), where the brain loses volume and function.
Alzheimer’s is the most common form of dementia.
How do your diagnose dimentia?
It’s not the easiest without actually scanning the brain. However, individuals tend to lose cognitive ability and they find it hard to live okay independently.
What does the Alzheimers brain look like?
In dementia, there’s much more going wrong than just memory loss. A lot of the cortex is decaying, affecting various brain functions. Memory loss is just one obvious symptom, but many other problems are occurring that are less visibly obvious.
What causes Alzheimers?
Degeneration is caused by unruly proteins that stop behaving normally.
- When lots aggregate together abnormally, they stop the nerve cell itself from working and can block communication between other cells
What are the proteins that cause neurodegeneration?
There are two types of misfolded protein aggregates/clusters/groups.
Amyloid-beta Plaques: Amyloid Proteins:
- these become aggravated and cause clumps outside the neuron, they tangle the other nerve terminals from other neurons - stopping them from doing their job
Tau Tangles: Tau Proteins:
- these form tangles inside the cell, clogging te inside and once all is clogged up it fails to function
What does the disease progression of Alzheimer’s look like? How can we detect early?
- The Amyloid Proteins kick off first before anything else.
- Then tau increases, begins to show abnormality
- And then brain structure begins to degenerate - mild cognition impairment stage
- Then memory starts to go
- Then dimentia
Early detection of this disease is important so that you can intervene
- there are drugs that break up Amyloid in early detection.
What relationship does education have with Brain reservation?
Longer education is shown to counter the association between amyloid plaques and cognitive decline in older adults.
-Education is shown to make huge differences to pre-disposing genes later in life
What is a favourable lifestyle that reduces the risk in dementia, and pre-disposed genes?
Moderate physical activity, good diet, low alcohol, low smoking. wtc etcccc
