Fear extinction is a process in which a learned fear response is reduced or eliminated through repeated exposure to the fear-inducing stimulus in the absence of any adverse consequences. Fear extinction specifically refers to the reduction of conditioned fear responses, such as freezing behavior, in rats that have been previously conditioned to associate a neutral stimulus (conditioned stimulus, CS) with an aversive outcome (unconditioned stimulus, US). NMDA receptor antagonists can facilitate fear extinction by affecting different stages of the fear extinction memory process:
1. **Initiation**: An NMDA antagonist impairs the initiation of fear extinction memory when administered before or shortly after the extinction session. This means that it interferes with the beginning of the process where the fear response starts to diminish.
2. **Consolidation**: An NMDA antagonist also disrupts the consolidation of fear extinction memory. This stage involves the stabilization of the reduced fear response over time. When an NMDA antagonist is given during this phase, it hinders the solidification of the reduced fear memory.
Mandatory FDA Disclaimer: Not intended to diagnose, treat, cure or prevent any disease.
Mandatory FDA Disclaimer: Not intended to diagnose, treat, cure or prevent any disease.
