Midterm 1 Flashcards
(24 cards)
Ways to assess habitual behavior:
Reinforcer devaluation:
- making reward lose its value (e.g. give it unlimited amount of food and see if behavior keeps happening)
Contingency degradation
- making reward unrelated to preceding action (e.g. random reward)
Lesioning the infralimbic cortex will results in what type of behavior?
- goal-directed, model-based
knock-in vs knock-out mice
Knock-in: adding gene to existing DNA
Knock-out: putting LoxP sites around gene you want out so Cre will remove it
Differ from BAC transgenic mice because:
- use of normal mammalian recombination
- gene editing at very specific locations on genome
TH-cre mouse
TH: tyronise hydroxylase
- precursor enzyme of dopamine
- will viral mediated gene expressed only in dopamine neurons
What does DIO mean in a virus name?
Double Inverted Open reading frame
- CRE DEPENDENT
ChR2
- channelrhodopsin 2
- excitatory light-gated ion channel
eYFP
- fluorescent protein
- for histological purposes (cell microscopy)
- control mice will likely receive a Cre-dependent virus that only has eYFP gene
Kamin blocking effect
- animal will not associate cue presented with previously learned cue
TMS
- non invasive method of temporarily changing neural activity
- can be excitatory or inhibitory
Say you overtrain a mouse to press lever to get yummy food. You then give them food-poisoning sensation and lesion their dorsolateral striatum. What would the mouse’s expected behavior be? What does it suggest about the dorsolateral striatum in rodents?
- the lesion would cause the mouse to stop pressing the lever (goal-oriented behavior) while a non-lesioned mouse would keep pressing it as a habitual behavior
- suggests dorsolateral striatum drives habitual (model-free) behavior -> if you break it, you see goal-oriented
Imagine you train a mouse go to a specific place for reward after hearing a tone. After some time, you establish that it is has become a habitual behavior by giving unlimited reward anywhere and seeing that the mouse still goes to the same place to get the reward. What behavior would be observed after lesions to the infralimbic area cause?
- mouse would stop the habitual behavior and start getting nearby reward immediately
- suggests infralimbic pathway drives habitual, model-free behavior
In an experiment, you minimally train a rat to backflip to get a yummy piece of cheese. Then, devalue the cheese by food poison the rat and lesion a part of its brain. Instead of stopping the conditioned action like any normal rat would, it keeps backfliping to get the cheese only to realize it doesn’t like the cheese afterwards. What area have you just lesioned?
- prelimbic pathway
- suggests it promotes goal-oriented behavior
What condition needs to be broken to drive extinction learning in an animal that did partial learning?
The sufficiency condition
- since animal has already experienced cue without reward, it needs enough cue -> no reward instances to infer that the cue isn’t sufficient anymore
DAT-Cre mouse
DAT: dopamine transporter
- viral mediated gene will be expressed in dop neurons
IRES
- gene promoter for Cre gene
- permits separate translation of Cre and DAT genes
GRAB-DA
- dopamine sensor
- does not change activity
- dop binds to sensor which then lights up
df/F
- dif in fluorescence divided by average fluorescence
- negative means less activity compared to baseline
- positive = more activity compared to baseline
dLight
- modified light-emiting dop receptor
- absorbs and reflects certain wavelength if right wavelength shone on it
- brighter when dop bound to it
Lesion studies are used to test
Necessity
- if behavior doesn’t happen after lesion to specific area, you can conclude this are is necessary for behavior to happen
Stimulation experiments are used to test
Suficiency
- if stimulated area produced specific behavior, we can conclude that area is enough (suficient) to produce behavior
- but there might also be another area causing the same behavior
DIO in a virus name?
Double Inverted Opening frame
- Cre-dependent
meaning of alpha in incremental learning
Importance given to recent events (RPEs) to determine expected value of thing
what does dop release represent during cue?
represents how well cue predicts reward
what does dop release mean during reward?
represents how unpredicted reward was
