Introduction to neurodegenerative diseases

Question 1

When was the reference to the first human brain

Answer 1

egyptian papyrus in 17th century BC

Question 2

The cerebrum/ cerebral cortex structure

Answer 2

2 hemispheres
- includes subcortical structures

subcortical structures:
- hippocampus
- basal ganglia
- olfactory bulb

Question 3

The cerebrum is only found in mammals. What is its function?

Answer 3

high order thinking
memory
problem solving
feeling
movement control

Question 4

What is the function of the hippocampus?

Answer 4

limbic system
short term/ long term memory
spatial memory

Question 5

What is the function of the basal ganglia?

Answer 5

neurons run through this structure
functions:
- processing centre
- interconnected with cerebrum, thalamus and brainstem

Question 6

What is the function of the olfactory bulb

Answer 6

processing smells

Question 7

What is the cerebral cortex

Answer 7

outer layer of grey matter of the cerebrum

Question 8

What is the difference between grey and white matter?

Answer 8

grey matter = neuronal bodies and other neurological cells
white matter = exons (myelin sheath gives it the white apparence)

Question 9

What is the function of the frontal lobe (largest lobe)

Answer 9

voluntary movement
conscience (good vs bad)
memories

Question 10

What is the function of the parietal lobe (located behind the frontal lobe)

Answer 10

integrates sensory information
language processing

Question 11

What is the functions of the occipital lobe (located caudally of parietal lobe)

Answer 11

visual processing

Question 12

What is the function of the temporal lobe (inferior to parietal lobe)

Answer 12

sensory input into meaning
long term memory

Question 13

What is the function of the cerebellum (located posterior and inferior to cerebrum)

Answer 13

coordination and balance
precision
timing
receives sensory information from spinal cord and other parts of brain

Question 14

What is the function of the brain stem (connectas to the spinal cord, located inferiorly to cerebrum)

Answer 14

controls autonomic functions functions (breathing, digestion, heart rate, blood pressure)

Question 15

What do each half of the cerebrum control

Answer 15

left = language area and controls movement on right side
right = movement on left side

Question 16

The brain has billions of neurons which use about 20% of oxygen and ‘fuel’. What is used as fuel for neurons?

Answer 16

sugars and ketone bodies

Question 17

What is the cause of intracerebral hemorrhage?

Answer 17

hypertension (high BP)
- blood vessels in brain cannot withstand high BP and therefore burst

Question 18

What is Anencephaly and what is the cause?

Answer 18

no cerebrum formed
- occurs when neural tube does not close properly along its length when fetus is developing

Question 19

What are common neurodegenerative diseases

Answer 19

alzheimer’s
parkinson’s
huntington’s
multiple sclerosis
amyotrophic lateral sclerosis (motor neuron disease)
- CNS and PNS affected

Question 20

Alzheimer’s, Parkinson’s and Huntington’s disease are polyglutamine diseases. What does this mean?

Answer 20

different proteins involved in each but the same genetic defect
- CAG trinucleotide expansion causes polyglutamine (polyQ) tract
essentially the misfolding of proteins
- not clear if aggregates cause the disease or is a consequence of the disease

Question 21

General features of neurodegenerative diseases

Answer 21

spontaneous cause (most cases) or familial (rare)
develop throughout life
- therefore manifests later in life
accumulation of aggregates of protein (intracellular or extracellular) can occur in brain or spinal cord

Question 22

Amyloidosis is a general feature of many neurodegenerative diseases. What is amyloidosis?

Answer 22

1. misfolded proteins cannot completely undergo proteolysis
2. therefore hydrophobic sections (beta sheets in proteins) aggregate
3. stabilised GAGs and serum amyloid P to form oligomers
4. oligomers aggregate further to form amyloid fibrils

Question 23

Neurodegenerative diseases may lead to dementia. What are the symptoms of dementia?

Answer 23

memory impairment
cognitive defects:
- language
- problem solving
- judgement
- calculation
- attention
- perception

Question 24

What are the common diagnostic brain technologies

Answer 24

computerised tomography (CT scan)
magnetic resonance imaging (MRI scan)
Positron emission tomography (PET scan)

Question 25

How does a CT scan work?

Answer 25

X ray beams are absorbed differently by different tissues and structures
x ray beams and detectors are placed around the head to produce a 3D scan

Question 26

How does and MRI scan work?

Answer 26

places tissues in a magnetic field causing protons to resonate differently and emit different radio waves
- does not expose body to radiation like Ct or x-ray

Question 27

How does a PET scan work?

Answer 27

based on the use of injected isotopes
- e.g radiolabeled glucose consumption indicates neuronal metabolism

blood oxygen levels
- e.g. radioisotopes of oxygen can indicate brain activity

Question 28

What can a PET scan detect

Answer 28

brain tumours, strokes, neuronal damage diseases which cause dementia, changes in brain metabolism

easily detectable by PET before structural changes visible in CT and MRI scans

Question 29

What is the difference between CT, MRI and PET

Answer 29

CT and MRI = detect structural changes
PET = detect changes in metabolism