Lecture 20: Neurogenesis 1 Flashcards
What happens when C cells (transient amplifying cells) are exposed to epidermal growth factor?
revert back to B cells (radial glia-like cell)
What happens when intermediate progenitor cells (IPCs) are exposed to Mash1?
become O cells (oligodendrocytes)
What is Mash1?
proneural protein belonging to the neurogenin family, promotes cell fate commitment
What is nestin?
acronym for neuroectodermal stem cell marker, type VI intermediate filament protein
expressed in RLG cells
What is vimentin?
type III intermediate filament protein expressed on mesenchymal cells
What is GFAP?
glia fibrillary acidic protein expressed on glia (most astrocytes)
What is DCX?
doublecortin, microtubule-associated protein, expressed by neural precursor cells and immature neurons
What is NeuN?
neuronal nuclear antigen (also called Fox- 3) marker for mature neurons
What is calretinin / calbindin?
calcium binding protein used as a marker of mature neurons
How are interneurons formed?
quiescent radial glia-like cell -> transient amplifying cell -> neuroblast -> migrating neuroblast and immature neuron -> interneurons
How are neurons formed?
radial glia-like cell -> progenitor cells -> neuroblast -> immature neuron -> neuron
What is Sox 2?
transcription factor playing key roles in mammalian development
What is MCM2?
minichromosome maintenance complex component 2, marker of progenitor cells and neuroblasts
What is neurogenesis?
the process by which new neurons are formed in the brain
When does neurogenesis occur?
not only occurs during brain development in utero and early postnatal period but also in adulthood
Where does neurogenesis occur in adulthood?
in the subventricular zone and dentate gyrus of the hippocampus
What are new neurons derived from?
radial glia-like cells located in specialised niches within the brain
In the dentate gyrus of the hippocampus what types of cells express nestin?
quiescent radial glia-like cells
What type of cells in the dentate gyrus express calretinin?
mature neurons
What type of cells in the dentate gyrus express calretinin?
mature neurons
What is the median turnover rate of neurons within a renewing subpopulation?
1.75% per year during adulthood which corresponds to approximately 700 new neurons per day in each hippocampus (same in men and women)
What is the role of Klf9?
functions as a negative regulator of dendritic
spines of hippocampal neurons in vitro and in vivo -> therefore overexpression of Klf9 would reduce the number of dendritic spines
What did overexpression of Klf9 result in?
eliminated a subset of dendritic spines of mature dentate gyrus cells (DGCs) and decreases their activity
enhanced integration of adult-born DGCs
activated neural stem cells without affecting
olfactory bulb neurogenesis
What did restoration of Klf9 expression to physiological levels result in?
restored dendritic spines and reverted levels of neurogenesis to steady state
What does elimination of spines in mature DGCs result in?
increased survival of adult-born DGCs
What does enhanced integration of adult-born DGCs result in?
re-organises adult-born DGC local afferent connectivity and promotes global remapping in the DG
What did rejuvenation of the DG by enhancing integration of adult-born DGCs result in?
enhanced memory precision
