Adult Neurogenesis & NSC Flashcards
(36 cards)
Define NSCs
diverse population of NSC with different cellular and molecular properites with different ways of divison and differentiation
constantly dividing
How did they discovery NSC ?
In adult mice brain by in vitro dissociated culture iwth high mitogen conc
How does neurosphere assay demonstrate stem cell properites (Reynolds and Weiss 1992)
Neurosphere can differentiate into 3 neural cell types- neruon, oligodendrocyte and astrocyte
Define Transit amplifying cell
an undifferentiated cell that lies between a stem cell (SC) and a differentiated cell.
Limitation of neurosphere assay
only restrospecitve assay, neurospheres are very hetrogenous and mostly differentiated so neurosphere contains few stem cells by the time you can investigate them.
Where are NSC found in rodents brian?
Subventricular zone (SVZ)- Produce olfactory neruons for olfactory bulb.
Sungranualr zone (SGZ)
What do NSC in SVZ produce?
Subventricular zone (SVZ)- Produce olfactory neruons for olfactory bulb. Then migration of neural precursors
What do SGZ NSCs produce
produce neruons for hippocampus locally
Define quiescence
a state of reversible cell cycle arret (G0)
They have lower transcription and protein synthesis and diffferent glucose and lipid metabolism
What does quiescence protect?
Protects cells from accumilation of mutations and proliferative exhaustion
How do adult NSC differ from NSC in embryo?
Adult NSC divde less and Moslty quiscencent
How do adult NSC resemble embyo NSCs?
-Adult NSCs share morphology
(radial process) and molecular
features (glial markers) with embryo NSC
- They produce a similar cell lineage
comprising rapidly dividing
intermediate progenitors and neurons
that differentiate protractedly
What factors regulate quiescence and acivity of adult NSCs - 5 things
1.excersise - promotes SC proliferation and survival/memory
2.epileptic seizures increase cell proliferation in both SGZ and SVZ
3.Stroke induces stem/progenitor proliferation and migration of adult born neruon to infarct sites
4.stress/depression- causes reduction in cell proliferation
5.Ageing- reduces stem cells in both adult SGZ and SVZ
Epilepsy effect
Increase hippocampal neurogenesis in adut humans
Stimuli reulate neruogensis ate which time points
1.Stem cells
2.Progenitors
3.Adult-born neurons
What is the NSC niche?
Enviroment that supports growth and maintence of NSC, inclu microglia, endothelial, astrocytes, local interneruon, cortical axons
what do NSC niche release
activating and quiscence inducing signals.
Which niche factors do astrocytes release
VEGF
Wnt-3
IL-6
FGF-2
TSP-1
Which niche factors do microglial cells release
IL-1beta
IL-6
TNF-alpha
Which niche factors fo endothelial cells release?
VEGF, BDNF, BMP, IGF-1, CCL-11
What reulated NSC Quiscence and controls adult hippocampal neruogensis + study name?
Bao et al, 2017
Long-range GABAergic inputs
What fucntions fo adult born neurons have on circuitry
They can be hyperexcitable to generate plastiicty in pre-exsisting ciruits.
Spatial memory in hippocampus
Suppression of stress
Who disputes neurogenesis in the adult hippocampus?
Sorrells et al, 2018 found no evidence of adult hippocampal neruogensis with Ki6,DCX, PSA-NCAM markers
Moreno-Jimenez et al, 2019 found no evidence of this -they did not use Ki67 marker.
different methods used-post mortem
Describe neurogenesis levels post birth
best examined in hippocampus
neurogenesis peaks in juveniles and rapidly declines right after
neurogenesis decline slows down at sexual maturity and stabilsies at lower level until end of life
