ELM 2 Cells of NS

Question 1

whats the nissl stain?

Answer 1

allowed cell body to be seen. old.

Question 2

whats the golgi stain?

Answer 2

silver stain - to visualise cell processes - axons and dendrites.
allowed him to pick individual cells in detail, golgi believed neurites were fused together to form a network.

Question 3

what did cajal do w/ the golgi stain?

Answer 3

his drawings + stain laid foundation for concept of the neuron.
came up w/ principle of dynamic polarisation + principle of connectional specificity.

Question 4

what kind of structure is the brain?

Answer 4

hierarchical.

Question 5

what are 4 imaging techniques?

Answer 5

electron microscope, immunoflourescence, confocal microscopy, brain bow.

Question 6

whats the res of an electron microscope compared to light?
describe the electron microscope?
-ve?

Answer 6

0.1nm to 0.1 microm.
examine cell ultrastructure, confirmed existence of synapses.
-ve cells have to be dead.

Question 7

whats immunoflourescence?
describe the process?
-ve?

Answer 7

prepare selective antibody tagged w/ flourescent label.
add to tissue, allow to bind, wash off any free antibody, image distribution of flourescence.
limited by range of antibodies.

Question 8

whats confocal microscopy?
what can it do?
-ve?

Answer 8

lasers, high sensitivity cameras, imaging software.
3d pics of cells, examine live cells, physiology.
modest res - 0.1 microm.

Question 9

what’s the brain bow technique?
what does it allow us to do?

Answer 9

gentically modifying an animal so its cells produce a random combo of up to 4 fluorescent dyes, so end up being a colour.
trace neuronal paths.

Question 10

what can damage to glial cells cause?

Answer 10

after injuries, they proliferate, this can inhibit regen of damaged axons.
in pns, they promote regrowth of neurons.

Question 11

why does NS have glia?

Answer 11

has no internal connective tissue, so supporting cells are all glia.

Question 12

what are the 6 types of glial cells?

Answer 12

ependymal, oligodendrocytes, schwann cells, astrocytes, microglia, satellite cells.

Question 13

what are glial cells involved in?

Answer 13

signalling, brain diseases, support neurons.

Question 14

Describe astrocytes + their roles?

Answer 14

star shaped, fill space between neurons.
regulate comp of extracellular fluid.
direct proliferation = differentiation of neural stem cells.

Question 15

What do oligodendrocytes/ schwann cells do?

Answer 15

myelinate axons.
Oli - CNS, many axons.
Schwann - PNS, single axon.

Question 16

What do microglia/ependymal cells do?

Answer 16

Microglia - brain scavengers, can migrate - phagocytic/immune func.
ependymal - lines ventricles + direct cell migration during development of brain, produce CSF + reserve of cells for regen.

Question 17

when does HD develop?

Answer 17

between the ages of 30 and 50 years.

Question 18

What are some early symptoms of Huntington’s disease?

Answer 18

Early symptoms may include changes in personality, mood swings, irritability, and difficulties with cognition such as concentration problems.

Question 19

What are the characteristic motor symptoms of Huntington’s disease?

Answer 19

The characteristic motor symptoms include involuntary jerky movements known as chorea, as well as rigidity and writhing motions.

Question 20

how does Huntington’s disease affect cognitive function?

Answer 20

Huntington’s disease leads to progressive cognitive decline, ultimately resulting in dementia in the later stages of the disease.

Question 21

What is the average life expectancy after diagnosis of Huntington’s disease?

Answer 21

s around 20 years.

Question 22

What is the genetic basis of Huntington’s disease?

Answer 22

Huntington’s disease is caused by a mutation in the huntingtin gene (HTT), resulting in an abnormal polyglutamine (polyQ) tract in the huntingtin protein.

Question 23

How does the number of CAG repeats in the huntingtin gene influence the disease?

Answer 23

The number of CAG repeats determines the age of onset and severity of Huntington’s disease, with longer repeats associated with earlier onset and more severe symptoms.

Question 24

What role does the huntingtin protein play in cells?

Answer 24

The huntingtin protein is involved in various cellular functions, including neuronal development and intracellular transport.

Question 25

What happens to the mutant huntingtin protein in Huntington’s disease?

Answer 25

he mutant huntingtin protein is not properly broken down and accumulates within neurons, forming aggregates known as inclusion bodies

Question 26

How does neuroinflammation contribute to the progression of Huntington’s disease?

Answer 26

Neuroinflammation, involving activation of astrocytes and microglia, exacerbates neuronal damage and contributes to the progression of Huntington’s disease.

Question 27

What age group is primarily affected by Alzheimer’s disease?

Answer 27

Alzheimer’s disease tends to affect people aged 65 and older.

Question 28

What are some early symptoms of Alzheimer’s disease?

Answer 28

progressive cognitive decline, with memory problems being a classic early symptom. Individuals may also experience difficulties with language processing, behaviour, and performing daily tasks.

Question 29

What are the two types of protein deposits found in the brains of individuals with Alzheimer’s disease?

Answer 29

The two types of protein deposits are amyloid plaques and neurofibrillary tangles.

Question 30

What is the main protein involved in the formation of amyloid plaques?

Answer 30

Amyloid beta is the main protein involved in the formation of amyloid plaques.

Question 31

How are neurofibrillary tangles formed in Alzheimer’s disease?

Answer 31

Neurofibrillary tangles are formed when the tau protein becomes heavily phosphorylated and clumps together within neurons.

Question 32

What is the role of astrocytes and glial cells in Alzheimer’s disease?

Answer 32

Astrocytes and glial cells become activated and contribute to neuroinflammatory processes in Alzheimer’s disease.

Question 33

What is the correlation between glial cell activation and disease progression in Alzheimer’s disease?

Answer 33

There is a correlation between the number of activated glial cells and disease progression in Alzheimer’s disease.

Question 34

What is the role of astrocytes in Alzheimer’s disease pathology?

Answer 34

Astrocytes attach themselves to amyloid plaques, but their role in either removing the plaques or contributing to their buildup is still unclear.

Question 35

How might activated astrocytes contribute to neuronal death in Alzheimer’s disease?

Answer 35

Activated astrocytes may lose some of their ability to support neurons and become neurotoxic, potentially contributing to neuronal death in Alzheimer’s disease.

Question 36

What are some of the key factors contributing to the progression of Alzheimer’s disease?

Answer 36

Factors contributing to the progression of Alzheimer’s disease include protein accumulation, neuroinflammation, and disruption of normal cellular processes.

Question 37

whats a neuron vs nerves?

Answer 37

neuron = cell, nerves = bundle of axons that arise from neurons.

Question 38

Describe structure of neurons?

Answer 38

cell body - w/ cytosol + organelles..
dendrites.
axons.
cell membrane.
can’t divide.
highly polarised.

Question 39

What are the physiological manifestations of neuronal polarity?

Answer 39

axons propagate information and contain synaptic vesicles, while dendrites receive information and contain rough endoplasmic reticulum (ER), ribosomes, and Golgi apparatus.

Question 40

What are some differences between axons and dendrites?

Answer 40

Axons are long, untapered, and myelinated, while dendrites are short, tapered, and non-myelinated. Dendrites also contain dendritic spines.

Question 41

What organelles are present in the cytosol of neurons?

Answer 41

Peroxisomes, mitochondria, ribosomes, and vacuolar apparatus are present in the cytosol of neurons.

Question 42

Where does division occur between the axon and the cell body?

Answer 42

Division occurs at the axon hillock, where synaptic vesicles, mitochondria, and smooth ER are located.

Question 43

What molecular differences contribute to neuronal polarity?

Answer 43

Neurons exhibit differences in protein composition between dendrites

Question 44

what is the role of the neuronal cytoskeleton?

Answer 44

The neuronal cytoskeleton provides structural support, transports cargo to and from neurites, and tethers components at the membrane surface.

Question 45

What are the main components of the neuronal cytoskeleton?

Answer 45

The neuronal cytoskeleton consists of microtubules (for structural support and transport), neurofilaments (for mechanical strength), and microfilaments (for mediating shape changes).

Question 46

What are the functional classifications of neurons based on impulse direction?

Answer 46

Sensory neurons originate from sensory receptors and transmit signals to the central nervous system (CNS), motor neurons conduct signals from the CNS to effectors, and interneurons facilitate communication between neurons in the CNS.

Question 47

Why is repair of neuronal damage more difficult in the central nervous system (CNS) compared to the peripheral nervous system (PNS)?

Answer 47

In the CNS, repair is rare because glial cells colonize the damaged area and block regrowth of axons. In contrast, Schwann cells in the PNS promote the regrowth of axons.