10: Brain Damage and Neuroplasticity Flashcards
Parkinson’s disease…
A motor disorder in middle- and old-aged people.
Common symptoms (3)…
Tremor when inactive (but not sleep), rigidity in muscles, face becomes mask-like.
Lewy bodies…
Lumps of protein found in surviving dopamine neurons of the substantia nigra in autopsy patients.
Roughly how many gene mutations have been linked to Parkinson’s?
10
All found related gene mutations are responsible for interfering with the function of…
Mitochondria, the cell structures which produce the cell’s energy.
Deep brain stimulation…
A treatment method. Electrical stimulation is applied to the subthalamic nucleus, which is connected to the basal ganglia.
What are the differences between Parkinson’s and Huntington’s disease? (3)
Huntington’s is rarer, has a genetic basis, and is highly correlated with dementia.
Huntingtin…
The single dominant gene responsible for the 50% likelihood that you will develop Huntington’s,
When do the first symptoms of Huntington’s appear?
Middle-age, around 40 years.
Multiple Sclerosis (MS)…
- Autoimmune disorder.
- Attacks myelin of axons in CNS which causes degeneration of said axons. Hardened (hence name ‘sclerosis’) areas of scar tissue develop in CNS.
Experimental autoimmune encephalomyelitis…
Animal model of multiple sclerosis involving injecting them with myelin.
Common symptoms of MS (3)…
Ataxia (loss of motor coordination), visual disturbances, and numbness.
3 genetic implications for MS…
- Higher concordance in MZ twins (25%: weak)
- 3 x higher in females.
- Higher incidence in caucasians.
3 environmental implications for MS…
- Higher incidence in colder climates.
- Positive relationship between susceptibility rates and living in a high-incidence region.
- Higher incidence for smokers.
What is the most common cause of dementia?
Alzheimer’s disease.
3 early symptoms of Alzheimer’s disease…
- Selective memory loss
- Attention deficits
- Personality changes
What are the two defining characteristics of Alzheimer’s disease?
- Neurofibrillary tangles - tangles of protein in neural cytoplasm.
- Amyloid plaques - scar tissue of degenerating neurons and the protein, amyloid.
3 areas where neurofibrillary tangles and amyloid plaques are prevalent…
- Entorhinal cortex
- Amygdala
- Hippocampus
These are all involved in memory.
What are the chances of onset if a family member has Alzheimer’s?
50%!
Why is it difficult to find a cure for Alzheimer’s?
Because it is uncertain as to what the primary symptom is; amyloid plaques or neurofibrillary tangles.
What is the main support for the amyloid hypothesis?
That the associated genetic mutations for early onset have an effect on amyloid synthesis.
What important chemical did initial treatments for Alzheimer’s focus on?
Acetylcholine, as decline in the levels of this are one of the first symptoms.
Immunotherapeutic approach…
Treatment for Alzheimer’s which involves amyloid vaccines to reduce generation of plaques.
Currently has serious side-effects so too dangerous.
Kindling model of epilepsy….
- A type of animal model.
- The gradual building and intensification of seizures triggered by regular electrical stimulations to the brain (particularly the amygdala).
- Convulsions also become somatically generalised.
Interictal behaviour…
Behaviour that occurs between seizures in epileptic patients.
What is a major disadvantage of transgenic mouse models of Alzheimer’s?
A majority of the models do not demonstrate neurofibrillary tangles, a major symptom.
But triple transgenic mouse models do exhibit these.
What is MPTP?
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine!
- MPTP is a substance that produces cell loss in substantia nigra.
What has the MPTP model of parkinson’s disease discovered?
- Deprenyl. Monoamine agonist that blocks MPTP’s effects.
- Useful discovery for treatment, but not aetiology.
What is a widely used method to measure controlled neural degeneration?
Cutting the axons of neurons.
Anterograde degeneration…
- Type of neural degeneration.
- Degeneration of the distal segment.
- Distal is the segment between cut and synaptic terminals, the part FURTHEST AWAY from cell body.
- Effects occur soon after.
Retrograde degeneration…
- Type of neural degeneration.
- Degeneration of the proximal segment.
- Proximal is the segment between cut and cell body - NEARBY.
- Effects occur a while after.
Concerning regeneration, how do olfactory ensheathing cells differ from Schwann cells?
- They aid continual growth of axons projecting from regenerated PNS neurons into the CNS.
How does transplantation of foetal tissue work?
- It can develop and integrate into host brain, which would get rid of offending symptoms.
- But has side effects months later.
How does transplantation of stem cells work?
When injected, the stem cells can develop into replacing neurons or myelin.
What does the term ‘multipotent’ for stem cells mean?
That they can develop into many types of mature cells.
