Source Paper
Consolidation of Fear Extinction Requires Protein Synthesis in the Medial Prefrontal Cortex
Edwin Santini, Hong Ge, Keqin Ren, Sandra Peña de Ortiz, Gregory J. Quirk
Journal of Neuroscience • 2004
Fear Extinction Learning
Objective: To determine whether protein synthesis in the medial prefrontal cortex is required for consolidation of fear extinction memory in rats
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Equipment2
Materials1
Not specified • Not applicable • Not mentioned • Not mentioned
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Protocol Steps
Fear conditioning
Rats undergo initial fear conditioning to establish conditioned fear response
Note: Baseline procedure to establish conditioned fear before extinction training
View evidence from paper
“Extinction of conditioned fear is thought to form a long-term memory of safety”
Anisomycin administration
Rats receive intraventricular or microinfusion infusions of anisomycin protein synthesis inhibitor
Note: Anisomycin administered either intraventricularly or microinfused into specific brain regions (mPFC or insular cortex)
View evidence from paper
“rats infused intraventricularly with the protein synthesis inhibitor anisomycin extinguished normally within a session but were unable to recall extinction the following day”
Extinction training session
Rats undergo extinction training with repeated exposure to conditioned stimulus without unconditioned stimulus
Note: Anisomycin-treated rats showed normal extinction within the training session
View evidence from paper
“rats infused intraventricularly with the protein synthesis inhibitor anisomycin extinguished normally within a session”
Extinction recall test
Test of extinction memory recall the day following extinction training
Note: Anisomycin-treated rats were unable to recall extinction the following day
View evidence from paper
“were unable to recall extinction the following day”
Re-learning of extinction
Rats undergo re-learning of extinction to assess savings in learning rate
Note: Anisomycin-treated rats showed no savings in rate of re-learning, consistent with amnesia for extinction training
View evidence from paper
“Anisomycin-treated rats showed no savings in the rate of re-learning of extinction, consistent with amnesia for extinction training”
c-Fos immunohistochemistry
Assessment of c-Fos levels in medial prefrontal cortex and insular cortex following extinction training
Note: Extinction training increased c-Fos levels in mPFC but not in insular cortex
View evidence from paper
“extinction training increased c-Fos levels in the mPFC but not in the insular cortex, consistent with extinction-induced gene expression in the mPFC”