Adult neurogenesis Flashcards
Abnormal (1) has been proposed to be a contributing factor to the onset of schizophrenia
pruning
Lack of pruning in this brain region may be specifically implicated in the onset of schizophrenia
Prefrontal cortex
The prefrontal cortex is involved in (3)
Complex behaviour, personality, social behaviour
In rodents > primates, this brain area undergoes massive refinement during adolescence
Prefrontal cortex
What are 3 pieces of evidence that pruning could be implicated in the onset of schizophrenia?
- expression of many synaptic vesicle markers are depleted
- neuropil volume is decreased, but number of neurons in the same
- dendritic spines are decreased in number in PFC
If there are no good animal models of schizophrenia, how could you test the hypothesis that overpruning may contribute to the disease?
Get induced pluripotent stem cells and get them to be induced into microglia
What is happening here?
Phagocytic index on Y axis: in the schizophrenia induced microglia there is more engulfing happening, therefore evidence for overpruning
What are the two hallmark features of alzheimers disease?
tangles (tau protein) and plaques (amyloid beta protein)
Amyloid plaques have this role in AD
Synaptotoxic agent, cause a loss of synapses
In early stage AD, (1) are the primary synaptotoxic agents
soluble amyloid beta oligomers
GWAS studies have identified genes associated with (1) to be switched on early in AD
Complement immune pathway
Evidence that neurogenesis is not complete in adults comes from the fact that…
EGF is present in adult human and rodent CNS
Explain what is happening in this figure
Researchers trying to isolate EGF-reponsive cells in the adult CNS to prove that neurogenesis is happening - initially a lot of the cells die but some of them go on to produce clonal spheres.
In panel F, these cells express the neural marker nestin which is only expressed in developing cells – could be evidence for neural stem cells
It was found that neural cells following dissocation could be forming new neurons, but the authors wanted to check to make sure this wasn’t an artifact of their method. What did they do?
Label BrdU+ cells (dividing cells, evidence for neural stem cell pool)
Where are the two regions in the brain associated with adult neurogenesis?
Subgranular zone (dentate gyrus)
Subventricular zone
In pattern separation, it is thought that neurogenesis…
Is required to add additional details to existing memory
Another hypothesis about adult neurogenesis is that it allows…
Temporal proximity – associate unrelated events
Another event much later would not impact this as too much time has occurred
Describe how neurogenesis is thought to impact memory resolution (level of detail)
Mature neurons are capable of remembering original features of a memory, but are not capable of encoding novel details of the memory
