Figure 7.

A synaptic model proposed for extinction of memory. Extinction training activates Rac1 in a BDNF-dependent manner in the vmPFC. Active Rac1 induces synaptic actin polymerization via activating Pak1-cofilin signal pathway. Meanwhile, extinction training also results in Arc mRNA transcription. Arc mRNA is then translocated at dendritic spines through actin polymerization-dependent machinery. Within the dendritic spines, Arc proteins are rapidly translated and then form a complex with dynamin (Dyn) to facilitate GABA_AR endocytosis, thereby leading to LTP induction and CPA extinction.