Methods (part 1) Flashcards
Why do we need to measure the behaviour of a whole organism
treatments and cures need to be tested on organism to check for therapeutic value and unwanted side effects
Clinical relevance of measuring behaviours
- fear (PTSD, phobias)
- anxiety (product of condition)
- attention (schizophrenia, ADHD)
- depression (bipolar disorder)
- locomotor activity (PD)
- locomotor coordination (Huntington’s Chorea)
- learning (autism spectrum disorder)
- memory (Alzhimer’s disease)
- sensory perception (pain sensitivity, chronic pain)
How can we measure fear
cued or contextual fear conditioning
How can we measure anxiety
elevated plus maze/light-dark maze
How can we measure attention
attentional set-shifting task
How can we measure depression
learned helplessness
How can we measure locomotor activity
activity box
How can we measure locomotor coordination
rotarod, skilled reaching, balance beam
How can we measure learning
morris water maze, radial arm maze, paired associate learning
How can we measure memory
memory: spontaneous alternation, novel object recognition
How can we measure sensory perception
Von Frey test, temperature sensitivity
What are the 3 validity criteria for animal models
- construct validity
- predictive validity
- face validity
Describe construct validity
similar cause of pathophysiology between the human condition and the animal model
Describe predictive validity
treatments that are effective in animal models are also effective in human patients, and vice versa
Describe face validity
the symptoms of the animal model mimic the symptoms of the human condition
Describe the simplified duel coding for behavioral tasks
- translational: train an animal to mimic a human test
- naturalistic: use a relevant intrinsic or innate skill or preference of the animal
Describe classical conditioning
- e.g. Pavlov’s dog
- stimulus triggers biological response is paired with a new stimulus that results in the same reaction
- cannot create new behaviour, but instead triggers involuntary biological responses
- conditioning can be undone through extinction
Clinical relevance of classical conditioning
- e.g. addiction
- contextual cues of drug taking/smoking/drinking
- can be positive/negative
- conditioned stimulus affect physiological response, so might compensate for “missing” conditioned stimulus
What is an unconditioned stimulus
intrinsic response (e.g. dog salivating)
Cued fear conditioning
- unlearned sound = shock (unconditioned stimulus) = freeze (jump/run)
- learned sound (conditioned stimulus) = freeze
Contextual fear conditioning
- dining room when sound and no shock = no freeze
- bedroom with sound and shock = freeze
- bedroom with sound and no shock = freeze
Parts of the brain involved in cued fear conditioning
amygdala
Parts of the brain involved in contextual fear conditioning
amygdala and hippocampus
Role of the hippocampus
- store and remember information
- ‘tags’ memories with information about where and when they occurred
- when ‘threat system’ is active, the hippocampus doesnt work as well and can forget to tag the memories with time and place information, meaning they sometimes get stores in the wrong place
- when we remember it can feel like it is happening again
Role of the amygdala
- threat system
- set off fight or flight response
- not good at discriminating between real dangers and percieved dangers
- can trigger FoF by just thinking about unpleasant memory or danger that has passed
Regulatory relationships between the mPFC, hippocampus and amygdala
- mPFC inhibits amygdala and stimulates hippocampus
- amygdala inhibits mPFC and hippocampus
- hippocampus inhibits amygdala and stimulates mPFC
Lateral hypothalamus in panic response
- increased HR
- increased BP
Dorsal vagal nerve in panic response
- bradycardia
- ulcer disease
Parabrachial nerve in panic response
- panting
- respiratory diseases
Basal forebrain in panic response
- arousal
- hypervigilance
- attention
Nucleus reticularis pontis caudalis in panic response
increased startle response
Central grey area in panic response
- freezing
- decreased social interaction
Paraventricular nerve in panic response
corticosteroid release
What is active place avoidance
- “sophisticated” version of fear conditioning
- tests accurate spatial learning and spatial strategies
- using negative reinforcer (shock)
- creates angry/anxious/ fearful mice
Describe active place avoidance
Measuring anxiety
- elevated plus maze / light-dark maze
- measure time spent in oven (aversive) vs closed (safe) arms
- no certain stimulation
- prefer dark environment
- more anxious they are, longer it would take to come into open arms
- uses natural animal behaviour
Measuring attention
- attentional set-shifting task
- rat/mouse pay attention to either odour of bowl, texture of digging medium, or texture of bowl covering
- correct strategy is switched frequently
- test attention to different types of sitmuli
- wisconsin card shifting task
Measuring depression
