L7 Neural development and regeneration Flashcards
CNS
brain, brainstem, spinal cord, eye
CNS controls higher order thoughts, integrates and mounts co-ordinated responses to environmental signals
Neuron
Nerve cell
define information flow: dendrite (input), soma (integration), axon (action potential - output), synapse (connection)
Neural circuit
function of each neuron depends entirely on its connections i.e. neural circuitry, which can be depicted in different ways
neurodevelopmental disorders
see onenote
genetic disorder that affect the normal central nervous system
some genes are important in the proper generation of neurons, specific regions/neural types or neural circuits
depends on stage of neurogenesis and whether the gene function is confined to a particular part of the CNS
neurodevelopmental vs neurodegenerative
genetic disorder that affect the normal central nervous system
term indicates when the phenotype occurs during development or is only observed later in life
- gives us a hint to the function of the affected gene(s)
Proliferation, fate, migration, terminal differentiation
see onenote
Retina as neural development model
see onenote
Multipotency
see onenote
Cells can generate multiple types
fate specification: which fate genes tell these progenitors what neuron type to make?
Gene networks
see onenote slides
What combination in what sequence makes what neuron?
combine transgenes to watch gene expression with live imaging
cannot be examined in species where we have to rely on post-mortem analysis of fixed non-living tissue/cells
Lineage experiments
see onenote slides
Lineage describes gene networks in each progenitor over time - allows us to determine combination and sequence of genes
Lineage experiment: examine temporal sequence of gene expression in progenitors, does each progenitor only turn on 1 fate gene?
Anthonal 5 to make photoreceptor and ganglion cells
Visual homeobox genes 1 and 2 to make bipolar cells
Pancreas TF 1 a to make horizontal amacrine cells?
live imagine revealed more complex and very stereotypical gene interactions within progenitors refuting the one gene one fate theory
Gene loss of function
see onenote slides
Necessity of a gene (reverse genetics): mutant or morphant
Gene loss of function - Assessing cell death
Activated caspase 3 staining labels apoptopic cells, key converging factor that triggers DNA fragmentation
Terminal dUTP nick-end labelling (TUNEL) marks DNA breaks (fragmentation)
Combine transgenesis to mark all cells that activate the promoter with MO knockdown
see onenote
can visualise what happens to cells that turned on the promoter but unable to generate the resulting protein
Assess fate of wrongly located cells using neuron type markers
see onenote slides
transgenes or immunostaining with antibodies against proteins
Gene gain of function
see onenote slides
Sufficiency of a gene (reverse genetics): GAL4/UAS