Fear Conditioning

1
Fear Conditioning

• Michael Davis
• Ponca Symposium
• Presentation (notes from)

2
Conditioning

• Stimulus e.g. food
• Response e.g. salivation
• Conditioned Stimulus (CS)
• Bell rung always just before the food
• i.e. paired with unconditioned stimulus
• US
• Conditioned Response (CR)
• Unpaired with US (bell without food)
• Salivation
• Same as UR

3
Fear Conditioning

• Unconditioned Stimulus (US) shock
• Unconditioned Response (UR) freezing
• CS
• Light or sound (cannot cause UR alone)
• i.e. paired with US
• CR
• Unpaired with US (sound without shock)
• Freezing
• Same as UR

4
Fear Conditioning- another example

• US sudden loud noise
• UR startle
• CS Fear Stimulus shock or predator
• Pairing fear stimulus with US produces a greater
  startle response
• Following training
• US alone produces
• ..enhanced fear startle

5
Extinction of Fear Conditioning

• Extinction is NOT an erasure of original fear
  memory
• Extinction Actively inhibits memory
• Extinction is Context specific
• Extinction of Fear may be disrupted by stress

6
Fear Conditioning Neurocircuitry
Startle
Ear
Visual Pathway
CRN
Perirhinal Ctx
PnC
Spinal Cord
7
Extinction Actively Inhibits Fear Memory