Source Paper
The Role of Ventromedial Prefrontal Cortex in the Recovery of Extinguished Fear
Gregory J. Quirk, Gregory K. Russo, Jill L. Barron, Kelimer Lebron
Journal of Neuroscience • 2000
Conditioned Freezing Measurement
Objective: Measure conditioned freezing responses and bar-pressing suppression as indicators of fear acquisition and extinction, and assess recovery of fear responses after extinction
This is a Conditioned Freezing Measurement protocol using rat as the model organism. The procedure involves 4 procedural steps, 2 equipment items, 1 materials. Extracted from a 2000 paper published in Journal of Neuroscience.
Model and subjects
rat • Not specified • unknown • Not specified • Not specified
Study window
Estimated timing pending
Core workflow
Surgical lesion creation • Day 1 - Fear acquisition • Day 1 - Extinction training
Primary readouts
- Conditioned freezing responses (percentage of time spent freezing)
- Bar-pressing suppression (reduction in bar-pressing behavior during tone presentation)
- Recovery of fear responses on Day 2 (percentage of acquired freezing recovered)
Key equipment and reagents
Use this page as an execution guide, then fall back to the source paper whenever you need exact exclusions, dosing details, or assay-specific caveats.
Confirm first
- Verify the animal model, intervention setup, and collection timepoints against the source paper.
- Check that every direct vendor link matches the exact specification your lab plans to run.
Use the page like this
- Work through the protocol steps in order and use the inline vendor chips only when you need to source or verify an item.
- Jump to Experimental Context for readouts, data shape, and analysis flow before planning downstream analysis.
Protocol Steps
Start here. The step list is optimized for running the experiment, with direct vendor links available inline when you need to source a cited item.
Surgical lesion creation
Electrolytic vmPFC lesions were made before training in experimental group. Sham lesions were performed on control group.
Note: Some lesions spared the caudal infralimbic (IL) nucleus as a control condition
View evidence from paper
“electrolytic vmPFC lesions made before training on the acquisition, extinction, and recovery of conditioned fear responses”
Day 1 - Fear acquisition
Rats were trained with tone-footshock pairings to acquire conditioned fear responses
Note: vmPFC lesions had no effect on acquisition
View evidence from paper
“On Day 1 vmPFC lesions had no effect on acquisition or extinction of conditioned freezing and suppression of bar pressing”
Day 1 - Extinction training
Tone was presented repeatedly in the absence of shock to extinguish conditioned fear responses
Note: Extinction involves new learning accompanied by inhibition of conditioned responding rather than erasure of tone-shock association
View evidence from paper
“extinction of conditioned freezing and suppression of bar pressing. On Day 1 vmPFC lesions had no effect on acquisition or extinction”
Day 2 - Recovery testing
Measurement of recovery of conditioned fear responses after a long delay following extinction training
Note: Sham rats recovered only 27% of acquired freezing, while vmPFC-lesioned rats recovered 86%
View evidence from paper
“On Day 2 sham rats recovered only 27% of their acquired freezing, whereas vmPFC-lesioned rats recovered 86%”