developmental biology in the adult brain

Question 1

why does post-natal development of the brain occur?

Answer 1

to form memories

Question 2

name the two regions where new neurones are generated in the adult brain

Answer 2

striatal subventricular zone (SVZ) and subgranular zone (SGZ)

Question 3

what are stem cells in SVZ?

Answer 3

a type of astrocytes

Question 4

what are protein markers for these SVZ astrocytes?

Answer 4

GAFP and Prominin-1

Question 5

what additional function do these SVZ astrocytes have?

Answer 5

wafting cilia that wash away toxins in the brain as we sleep

Question 6

where are SVZ astrocytes found?

Answer 6

in contact with the ventricle or directly below

Question 7

asymmetric division of SVZ astrocyte occurs to form:

Answer 7

one stem cell and one transient amplifying cell

Question 8

these SVZ transient amplifying cells divide to make:

Answer 8

neuroblasts and some oligodendrocytes

Question 9

proteins markers for SVZ neuroblasts are:

Answer 9

PSA-NCAM

Question 10

in rodent PSA-NCAM can be used to track SVZ neuroblasts to the:

Answer 10

olfactory bulb via the rostral migratory stream

Question 11

what do SVZ neuroblasts produce? and what disease are these depleted in?

Answer 11

striatal inter-neurones

these are depleted in Huntington’s

Question 12

what is Neurog2?

Answer 12

a pro-neural TF

Question 13

why is new neurone production repressed in all but two regions of the brain?

Answer 13

reduces the risk of cancer

Question 14

how many new neurones are made in a rat brain per day?

Answer 14

20,000 as smell and memory of these smells are very important

Question 15

how do adult NCS progeny differ from embryonic?

Answer 15

• delayed firing
• more excitable
• deeper layer

Question 16

what are NSC in the SGV?

Answer 16

a type of astrocyte/radial glia hybrid

Question 17

what are protein makers for SGV NSC?

Answer 17

GFAP, nestin and Sox2

Question 18

what neurones are formed from SGV NSC?

Answer 18

glutamatergic dendrite granule cells

Question 19

TF changes are induced by signalling. give three examples of this signalling

Answer 19

• Wnt
• neurotransmitters
• miRNA

Question 20

why does the hippocampus need new neurones from SGZ?

Answer 20

• spatial learning
• fear conditioning
• clearing memory traces
• navigation

Question 21

how might depression be linked to the hippocampus?

Answer 21

in depression the hippocampus is less able to make new memories/disrupt old ones, locking in old memories

Question 22

what factors affect neurogenesis?

Answer 22

exercise increases neurogenesis. stress and raised cortisol levels reduce neurogenesis in the hippocampus.

Question 23

highly active dentate granule cells activate interneurons. what is leaks from interneurons to inform nearby SGZ NSC everything is ok?

Answer 23

GABA

Question 24

what does the absence of GABA induce?

Answer 24

activation of SGZ NSC as this is an indication of diseased/damaged neurones

Question 25

does the number of NSC decrease with age?

Answer 25

yes

Question 26

how does the activity of NSC fair with age?

Answer 26

it decreases, NSC become quiescent

Question 27

what reduces NSC efficiency?

Answer 27

age and reduced exercise

Question 28

what is heterochronic parabiosis?

Answer 28

when a young and an old mouse blood circulation is linked

Question 29

what happens in heterochronic parabiosis?

Answer 29

increased number of NSC and neuroblasts in old brain.

something in young blood that rejuvenates old brain degeneracy.