Animal Models Flashcards
Why use animal models in neuroscience?
Knowledge/understanding about function of a gene and it’s encoded proteins or Isoforms
Learn how specific gene and protein interact
Signalling pathway and how this works
Formation and specification of cell types/tissues/organs
Functional animal studies: mutate/inactivate/over-express a gene-protein
Find interacting/binding partners of a gene/protein
Screen for enhancers/suppressors of disease/gene/protein - then epistasis tests = the effect of mutation dependent on genetic background.
Then manipulation of signalling pathway - targeted activation/inactivation of neural circuits = regulation/function of behaviours
Bakers Yeast
Saccharomyces cerevisiae
Very fast experiments
Regulation of cell cycle/cell division
Genes that regulate cell division in yeast are homologous = SAME structure genes in mice, flies, humans
Eukaryote = cells contain nucleus in organisms
Worms - Caenorhabditis elegant
Simple anatomy
950 somatic nuclei
302 neurons
Transparent
Small - 1mm long
250 offspring
Easy to cultivate
Eats bacteria
Life cycle - only 3 days
Zebra fish
Can do functional imaging of whole brain
Manipulate circuits and genetics
Transparent embryo = very fast growth seen = 72 hours
Mouse
Mus Musculus
90% gene similarity to humans
Has social behaviours
Genetic model organism = small brain
What studies are possible in live humans?
Cell culture
Non-invasive studies with written consent
Majority of animal studies NOT possible in humans
Drosophila melanogaster - fruit fly
Genome: 180 megabases
Only x4 chromosomes
13,600 genes
65% structural similarity to humans
Complex small brain and complex behaviour/learning/memory
In Vivo = entire organism
1912 - Thomas Hunt Morgan - phenotypes in mutated genomes
Short life cycle - 10-12 days including embryonic stage
Start with behaviour: to identify protein and gene
