Emotional Learning and the Amygdala Flashcards
What is the CS in fear cond?
tone or light
What is the US in fear cond?
footshock
What are some fear responses?
Freezing(defensive behavior)
Autonomic arousal
reflex potentiation
stress hormones
What are some behavioral measures in FC?
Freezing, conditioned suppression of bar pressing, fear-potentiated startle
What are some autonomic measures in FC?
Blood pressure and HR
How do they measure autonomic measures in FC?
surgically input devices into the rat
What two areas deal with FC?
Basal Lateral amygdala
Central amygdala
What is the thalamocortical pathway?
The pathway from the neocortex to the amygdala, more processed information pathway
What is the thalamoamygdalar pathway?
the pathway from the MGN to the amygdala, more ‘raw’ information pathway
What happens if there is no MGN?
no CR is created, pathways are destroyed
What happens if the MGN -> primary auditory is destroyed?
CR okay
What happens if the MGN -> amygdala is destroyed?
CR okay
Where is the site of critical plasticity?
The amygdala
What is the major output region of the amygdala?
Central Amygdala
How do they measure neuronal activity during fear conditioning?
Implanted tiny electrodes into the brain region of interest
What neurons become more responsive to CS during the acquisition of CR?
Neurons in the LA
What do pretraining lesions on the LA do?
prevent the aquisiition of CR
What is a partial lesion?
When the researcher misses lesioning the whole LA and the animal still shows signs of deficit
What is Muceimol?
It is a temporary lesion that is a GABAa antagonist
What happens when Muceimol is injected before training?
prevents acquisition of CR
cannot learn so it cannot recall
What happens when Muceimol is injected before testing?
Prevents expression of CR
has learned but it cannot express it
What happens when Muceimol is injected before testing?
Prevents expression of CR
has learned, but it cannot express it
What are trigger neurons?
Early, transient changes in the CS-related responses of dorsal LA
What are storage neurons?
LAter, persistent changes in CS-related firing of ventral dorsal LA
What happens in LA with the extinction of the CR?
The storage neurons remain, but the trigger neurons are extinguished.
What does extinction in the LA tell us about extinction?
It is not erasing the memory but depressing the learning
overlaying new learning on the old
What role does NMDA play in LA?
it is important for induction but not maintenance
What is BDP-12?
it is an AMPAkine; AMPA Facilitator
drugs bind to AMPA receptor and has no effect of its own but when Glut binds it makes the ion channel open longer
What does the infusion of BDP-12 before training?
It speeds up acquisition of the learning
What does the infusion of BDP-12 into the BLA before training do?
Speeds up training
What does the infusion of AMPA blocker into the BLA before training do?
Prevents expression of CR
What do plasticity blocks do?
Prevent exocytosis of AMPA
What happens when you block synaptic incorporation of AMPA?
impairs memory formation
