L18 - Cognition Flashcards
How are mouse brains different to humans?
No sulci and gyri BUT there is a homologue of every human gene in mouse genome hence they are a good proxy
Is there just one mutation for ASD? List a few
NO - rare cases there are penetrant mutation (if you have this mutation then you are likely to develop ASD), most cases have is you need x number of mutations before you develop ASD
Neuroligin, neurexins, SHANK
As ASD Is behaviourally defined, what are the two core symptoms of ASD?
Social communication deficits and repetitive behaviour
*Associated symptoms: aggression, attention, anxiety
Is it possible to model ASD symptoms with mice? e.g. Language impairment
Mice do communicate in social contexts using ultrasonic communication (it is at a freq 10x higher than human hearing, 10 syllables per sec)
Children with ASD don’t develop language but those that develop?
Abnormal prosody
Do ASD mice use short and simple or long and complex sounds?
Short and simple
T/F - The mating and pheromone stage sounds are the same
F- Different
How do we test repetitive behaviour and attention in ASD mice?
Place mice in a room where they have to run and touch an image on one of the three screens (one image is correct and the other two are wrong) - if they touch the correct one then they get a reward
What if we could match non-random sequences with behaviour? Then this would make sense as it’s a language. So we need to playback the sounds to see which ones elicit specific behaviours
What if we could match non-random sequences with behaviour? Then this would make sense as it’s a language. So we need to playback the sounds to see which ones elicit specific behaviours
VISUAL DISCRIMINATION TASK
Study assessed whether mice would be able to learn one image over the other. The mutant mice took slightly longer to learn
The mice learnt it in 10 days
When there was reversal - making the alternate image the correct one, the mutant mice took MUCH longer time to learn
VISUAL DISCRIMINATION TASK
Study assessed whether mice would be able to learn one image over the other. The mutant mice took slightly longer to learn
The mice learnt it in 10 days
When there was reversal - making the alternate image the correct one, the mutant mice took MUCH longer time to learn
ASD mice perform differently on continuous performance test:
- lower hit rate (not hitting stimulus aka getting to the computer screen on time)
- less alarm rate is lower (don’t make as much mistakes)
- Same rate discriminating signal to noise (able to choose positive image and not the distractors - but only when its for 2 secs)
- high conservative rate
ASD mice perform differently on continuous performance test:
- lower hit rate (not hitting stimulus aka getting to the computer screen on time)
- less alarm rate is lower (don’t make as much mistakes)
- Same rate discriminating signal to noise (able to choose positive image and not the distractors - but only when its for 2 secs)
- high conservative rate
Genetic mutations in the __ signalling system, decreasing amount of it increase/decrease likelihood of anxiety
5-HT, increase
Low 5-HT expression increases vulnerability to adverse experiences but also?
Enhances susceptibility to beneficial experiences
How did mice studies show that 5HTT polymorphism is a vulnerability mutation?
5HTT KO mice don’t go into open areas BUT 5HTT KO enriched environment mice do
*Mice can be vulnerable to anxiety but also vulnerable to enriching environment
Stress, diet, behaviour, toxins and other factors activate chemical switches that regulate gene expression - these factors can affect how chromosomes are wound around histones
Stress, diet, behaviour, toxins and other factors activate chemical switches that regulate gene expression - these factors can affect how chromosomes are wound around histones
