Source Paper
Consolidation of Extinction Learning Involves Transfer from NMDA-Independent to NMDA-Dependent Memory
Edwin Santini, Robert U. Muller, Gregory J. Quirk
Journal of Neuroscience • 2001
Conditioned Freezing Extinction
Objective: Examine extinction of conditioned freezing responses to a tone paired with foot shock, and assess NMDA receptor involvement in short-term and long-term extinction memory consolidation
Gather these items before starting the experiment. Check off items as you prepare.
Equipment2
Materials1
Not specified • Not specified • Not specified • Not specified
2 items available from ConductScience
Estimated: $7,190.00
As an Amazon Associate, we earn from qualifying purchases. Product links help support this free resource.
Protocol Steps
Conditioned fear acquisition
Rats were conditioned with a tone paired with foot shock to establish conditioned freezing response
Note: Baseline conditioning phase before extinction testing
View evidence from paper
“Extinction of conditioned fear to a tone paired with foot shock”
Extinction session with CPP administration
Rats underwent extinction training in the presence of systemic CPP at 10 mg/kg dose
Note: CPP is NMDA receptor antagonist; rats extinguished normally during this session
View evidence from paper
“Rats extinguished normally during a 90 min session in the presence of systemic CPP (10 mg/kg)”
24-hour extinction recall test
Test extinction memory 24 hours after the extinction session with CPP
Note: Rats were unable to recall extinction learning at this timepoint
View evidence from paper
“were unable to recall extinction learning 24 hr later”
48-hour extinction recall test
Test extinction memory 48 hours after the extinction session with CPP
Note: Extinction learned in presence of CPP was recalled normally at 48 hours, suggesting delayed consolidation
View evidence from paper
“extinction learned in the presence of CPP was recalled normally when tested 48 hr after training”
CPP injection on rest day
CPP was injected on the rest day between training and 48-hour test in control experiments
Note: This prevented 48 hr recall of extinction learned under CPP, demonstrating NMDA involvement in delayed consolidation
View evidence from paper
“CPP injected on the rest day between training and test prevented 48 hr recall of extinction learned under CPP”
Control experiments for state-dependent learning
Control experiments were conducted to verify that CPP effects on memory consolidation were not caused by state-dependent learning or reduced expression of freezing under CPP
Note: Necessary controls to isolate consolidation effects from other confounding factors
View evidence from paper
“Control experiments showed that the effect of CPP on memory consolidation was not caused by state-dependent learning or reduced expression of freezing under CPP”