3:L10

Question 1

Difference in grey/white matter location in CNS and Peripheral

Answer 1

1. White (inner)- myelinated fibres that extend to other areas
2. Grey- cell body, nuclei
   SP:
3. These grey centralised (protection as cell bodies inside, + easily located)

Question 2

Difference between ventral and dorsal halves

Answer 2

dorsal half — sensory roots & ganglia

• ventral half — motor roots (auto and somatic to prephiery)

Question 3

5 Types of glia cells

Answer 3

Astrocyte
ologiodendrocytes
ependymal
olfactory ensheathing glia

Question 4

where do glia and neutrons service from

Answer 4

neuroectoderm

Question 5

where are o Oligodendrocytes, astrocytes and ependymal cells derived from compared to o Schwann cells and satellite cells

Answer 5

o Oligodendrocytes, astrocytes and ependymal cells from ventricular zone of neural tube
o Schwann cells and satellite cells from neural crest

Question 6

where are microglia derived from

Answer 6

derived from hematopoietic stem cells

Question 7

6 major stags in neural development

Answer 7

1. Neural precursor cells (NPCs) from ectoderm
2. NPCs Differentiation into NEURONS and GLIA
3. Migration to target site involving:
4. Axon extension
5. Synaptic connectivity (type, number and cellular location) (if non= rejected or non functional system)
6. Modification of neural connections

Question 8

Overall function for radial glial cells

Answer 8

• Act as a scaffold for migrating neurons and glial progenitors

Question 9

What do radial glial cells turn into

Answer 9

astrocytes + neurons

Question 10

Glial cell function in developmnent

Answer 10

o Guidance of neurogenesis, neuronal growth and migration
o Trophic influences (sustainance, molecules that maintain viablity)
o Synaptogenesis (formation of synapses)
o Myelination and formation of vasculature

Question 11

Glial cell function in adult life

Answer 11

o Blood Brain Barrier (BBB)
o Regulation of blood flow
o Maintenance of neural environment (ion/pH buffering, role at synapses, neurotransmitter recycling, metabolism, etc.)

Question 12

Glial cell function in injury

Answer 12

o Phagocytosis, proliferation and scarring, either -ve or +ve influence on plasticity and growth, immune mediation, etc.

Question 13

how can someone identify astrocytes

Answer 13

multiple branches
fuses to other astro, blood vessels, synapses
GFAP +ve filaments

Question 14

what is a syncytial network

Answer 14

• Fusing of astrocytes to form one system

Question 15

what do astrocytes do during innjury

Answer 15

• When injured they change morphology + secrete molecules (=activated)
If not bad injury go back to non activated state
If bad injury= stay activated> form glial scar to seal of injury site

Question 16

what is oligodendrocytes function

Answer 16

myeline ate

Question 17

describe microglial function

Answer 17

• Small cells, resting and activated states
• Activated in pathological states and trauma
• Motile antigen expressing cells – role in immune responses
• Able to secrete factors that can influence angiogenesis and astrocyte proliferation (complex interactions)

Question 18

what are olfactory ensheathing glia

Answer 18

• Persistent renewal of olfactory pathway throughout life

* Therefore OEGs may be able to support axonal growth and regeneration in adult brain

Question 19

what are schwann cells equiv to

Answer 19

oligo but in PNS

Question 20

function of schwann cells

Answer 20

• Myelination
• Phagocytic activity
• Trophic support
• Modulation of synaptic activity
• Presentation of antigens

Question 21

what are growth and trophic factors

Answer 21

Soluble/diffusible factors - polypeptides

Question 22

what is retro/anterograde transport of growth factors

Answer 22

• Retrograde (brain> periph) and anterograde transport (periphery > brain)
• Targets (need to find otherwise will die)

Question 23

what is paracrine/autocrine fucnctions for growth factors

Answer 23

• Paracrine (between cells) and autocrine (within cells) functions

Question 24

Describe link between retrograde + neuronal viability and phenotype

Answer 24

Target independency/dependency:
• If not connected yet and target removed= can survive and find new target
• If connected (dependent) and target removed= dies

Question 25

Name 3 examples of growth and trophic factors in the neurotrophic family

Answer 25

• Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3

Question 26

4 types of cues for axon extension

Answer 26

graded axon guidance cues
homophobic adhesion cues
axon-axon recognition cues
sub-cellular adhesion cues

Question 27

what are attraction and repulsive cues for growth cone

Answer 27

Attractive = leads to asymmetric synthesis of β-actin on side near to source of gradient > attractive turning of cone

Repulsive
activate axonal translation of actin-depolymerizing proteins RHOA and cofilin when uniformly applied in cell culture.

Question 28

example of attractive and repulsive cues

Answer 28

Attractive cues, e.g. netrin 1 & BDNF,

Repulsive cues, e.g. SEMA3A and SLIT2

Question 29

Describe attraction example in spinal cord

Answer 29

1. As neuron develop: dorsal molecules heads towards netrin (target dependent) which is being produced at ventral
2. TAG/NCAM (involved in this process) are then turned off and L1 at distal alters trajectory and neuron follows = development needs these intermediates to guide axon through terrain

Question 30

what growth factors increase and decrease with age

Answer 30

o Increased GFAP espression with age in certain areas of brain

• BDFN decreases with age (in hippocampus)