Adult Hippocampal Neurogenesis Flashcards
Define adult neurogenesis (postnatal)
process in which neurons are generated from neural stem cells in the adult. This process differs from prenatal development.
what can NSCs form
oligodendrocytes
astrocytes
neurons
where is adult neurogenesis limited to
subventricular zone (SVZ) in the lateral ventricle
subgranular zone (SGZ) of the dentate gyrus
steps of NP proliferation
NPs proliferate and migrate from the granule cell layer
NPs differentiate
NPs receive inputs from the entorhinal cortex
project to CA3
what is NeuN
neuronal marker
what is CAG GFP
retrovirus labelling
Type 1 cells
quiescent radial NSCs GFAP+ SOX2+ coexist with type 2 cells
Type 2 cells
actively proliferating, GFAP- Sox2+ nonradial (rounded) that generate both astrocytes and neuroblasts
neuroblasts
migrate into the granule cell layer and mature into neurons
what is sox2
TF essential for maintaining self renewal
how to measure neurogenesis
carbon dating 14C
adult neurogenesis in rodents
70% of bulbar neurons are replaced during a 6 week period
adult neurogenesis in humans
700 new neurons in the hippocampus everyday
non neurogenic region NSCs (SC)
transplant in DG/SVZ - neurons
transplant in SC - no neurons
neurogenic region DG/SVZ NSCs
transplant in DG/SVZ - neurons
transplant in SC - no neurons
NP microenvironment
astrocytes (push NPs to become neurons)
endothelial cells
blood vessels (highly vascularised/blood vessels converge)
what is laminin required for
cell adhesion
role of neonatal astrocytes
form the largest neuronal culture
which growth factors are required for NSC proliferation
FGF-2
CCG
EGF
what is BrdU
NSC marker
what signalling is required for control of neurogenesis regulation
wnt signalling
where is wnt expressed
granule cell layer
wnt expression causes more neuronal and neuroblast expression via DAPI and DCX markers respectively
what occurs in DN wnt signalling
drop in newborn neurons
role of adult neurogenesis in learning and memory
-increases spatial memory capacity (MWM)
-reduce interference between memories (pattern separation)
-add information about time to new memories
-disturb established context (too much neurogenesis)
what is pattern separation
ability to distinguish between certain memories
what can too much neurogenesis cause
infantile amnesia
depression and adult hippocampal neurogenesis
treatment can promote adult hippocampal neurogenesis
antidepressant Prozac (SSRI)
neurodegenerative disorders
AD/PD
mood and cognition
how does AD affect neurogenesis
AHN affected
neuronal loss
amyloid deposition
inflammation
factors which increase neurogenesis
learning
sexual intercourse
exercise
running
factors which decrease neurogenesis
chronic stress
chronic sleep deprivation
ageing causes pattern separation
ageing assay
Villeda et al., 2011
young-young (isochronic) young-old (heterochronic) old-old (isochronic)
fuse mice circulatory system, attach for 3 months then detach
inject plasma - old mice plasma in young mice cause decreased neurogenesis
factors in diet
food texture
food content
meal frequency
calorie restriction
dietary factors which increase neurogenesis
calorie restriction (intermittant fasting then feeding)
omega 3 fatty acids
flavonoids
coffee
dietary factors which decrease neurogenesis
soft diet (texture)
caffeine
ethanol
