Neurological Disorders Flashcards
What is one of the most defining features of Alzheimer’s disease?
Senile plaques
What are senile plaques?
Dense, roughly spherical, extracellular deposits that contain a protein called beta-amyloid.
Where in the brain are the senile plaques found?
Throughout the grey matter of the cerebral cortex and hippocampus. (can also appear in striatum, basal ganglia, and thalamus)
What are glial plaques usually surrounded by?
clumps of degenerating axons and glial cell activity, indicating that their presence is toxic to brain cells.
What accompanies senile plaques?
Neurofibrillary tangles (NFTs)
Where are neurofibrillary tangles found?
cytoplasm of neurons
What do neurofibrillary tangles resemble?
Tiny bundles of knotted string (technically called paired helical filaments)
What are neurofibrillary tangles made from?
A protein called tau
What does tau form an important part of?
The cell’s inner framework.
What enzyme was found to be reduced by up to 90 per cent in the cerebral cortex and hippocampus of Alzheimer’s brains?
Choline Acetyltransferase (CAT)
What is CAT involved in?
the synthesis of acetylcholine.
The only drugs which have shown benefits in the treatment of Alzheimer’s disease (and only in early stages) do what?
Increase levels of acetylcholine in the brain.
What are drugs that increase levels of acetylcholine in the brain?
Cholinesterase inhibitors such as Tacrine and Donepezil
How do cholinesterase inhibitors work?
these drugs work by inhibiting the enzyme acetylcholinesterase, which acts to break down acetylcholine after it has been released into the synapse. Inhibition of this enzyme leads to increased levels of acetylcholine in the synapse.
What is the amyloid cascade theory?
The theory proposes that the deposition of amyloid causes a chain reaction of events that leads to senile plaques, neurodegeneration and ultimately dementia.
The amyloid is a fragment of a much larger 695 amino acid protein, referred to as?
Beta-amyloid precursor protein (B-APP)
The B-APP has a short life, when it has served its purpose in the cell, it is removed from the membrane by being cut into smaller components by a class of enzymes called?
Secretases.
Developmental disorders and acquired disorders are?
Neurological disorders
What is acquired brain injury?
All types of brain injury that occur after birth
What is the definition of acquired brain injury?
Injury to the brain that results in deterioration of cognitive, physical or behavioural functioning
What are external causes of acquired brain injury?
Traumatic brain injury, poisoning, inhalation of organic solvents, diabetic coma, alcohol, drugs, infections and diseases.
What are internal causes of acquired brain injury?
Strokes, tumours, epilepsy, hypoxia/anoxia.
What are secondary effects of traumatic brain injury?
Haemorrhage or harm atoms, intracranial pressure, oedema or brain swelling, post-traumatic epilepsy.
What is frontal-temporal dementia?
A type of dementia that is associated with massive loss of nerve cells in the brain. and bundles of tau protein, although there is little evidence of amyloid deposition.
