hippocampal dependent neurogenesis: techniques and behaviours Flashcards
why investigate neurogenesis? relevance - 2
inc ageing population
inc neurological disease, disorders that affect memory function
what is adult neurogenesis
generation of new neurons in adult brain that contribute to normal brain function
what does adult hippocampal neurogenesis affect
brain structure and plasticity
as this contributes to normal brain function and spatial memory
where does adult hippocampal neurogenesis occur - 2
SVZ of lateral ventricles
dentate gyrus (DG) of hippocampus
what affects adult hippocampal neurogenesis
age - declines with age
exercise
environmental enrichment
dietary manipulation
5 stages of hippocampal neurogenesis
radial glia-like cell (type 1)
neuronal progenitor (type 2)
neuroblast (type 3)
immature neuron
mature neuron
3 markers of radial glia-like cell (type 1)
GFAP
Nestin
Sox2
3 markers of neuronal progenitor (type 2)
Nestin
Sox2
BLBP
3 markers of immature neurons
Calretinin
DCX
NeuN
3 markers of mature neurons
Calbindin
Prox1
NeuN
what is BrdU or bromodeoxyuridine
thymidine analogue that incorporates into DNA of dividing cells - S phase of cell cycle
used for borth dating and monitoring cell proliferation, labels new born cells
can be administered orally or through injection
how are neurogenic markers and antigens of interest detected
immunohistochemistry IHC
what is immunohistochemistry or IHC
process of detecting presence of proteins and antigens on tissue sections with the use of antibodies
antibody-antigen interactions are visualised chromogenically or flourescently
reveals location of proteins in whole tissue context
chromogenically means what
with coloured enzyme substrate
what is DAB-OHC
Diaminobenzidine Immunohistochemistry
staining technique
DAB used as chromogen, produces coloured precipitate when reacted with an enzyme
brown/black precipitate
what is flourescent-IHC
flourescent labelled antibodies used to detetct specific antigens in tissue samples
what is contextual fear conditioning
learned fear memory, survival response
this requires inputs from hippocampus and CA3
where rodents learn to associate a neutral context with an aversive stimulus - e.g. foot shock
display fear response e.g. freezing behaviour
what is spontaneous location recognition task (SLR)
pattern separation memory (degeneration dependent)
sensitive to changes in hippocampal neuroplasticity
SLR manipulates similarity of spatially landmarked locations during sample phase when memory is encoded and pattern separation processes are active
what is location discrimination (touchscreen task)
operant box task, same concept as SLR hand task
rodents discriminate between 2 white squares on screen
distance between squares can be varied
this uses hippocampus and neurogenesis
3 behavioural tasks that test anxiety
open field test
elevated plus maze
elevated zero maze
