The brain-specific microRNA miR-128b regulates the formation of fear-extinction memory

Fear-extinction learning increases the expression of the brain-specific microRNA miR-128b. The authors find that this increase in miR-128b expression disrupts the stability of plasticity-related target genes and directly regulates fear-extinction memory. Increased miR-128b activity could facilitate the transition from retrieval of the original fear memory to the formation of a new fear-extinction memory. MicroRNAs are small non-coding RNAs that mediate post-transcriptional gene silencing. Fear-extinction learning in C57/Bl6J mice led to increased expression of the brain-specific microRNA miR-128b, which disrupted stability of several plasticity-related target genes and regulated formation of fear-extinction memory. Increased miR-128b activity may therefore facilitate the transition from retrieval of the original fear memory toward the formation of a new fear-extinction memory.