恐怖記憶の制御基盤

Mechanisms of Fear Memory Processes

恐怖記憶は恐怖体験時の文脈と恐怖情動との条件付け記憶である。そこで，この文脈に再遭遇すると，恐怖記憶が想起され，恐怖反応が表出する。このような恐怖記憶は線虫からヒトに至るまで観察され，齧歯類を中心とした動物モデルを用いて，固定化，想起，再固定化，不安定化，消去といった記憶制御プロセス群のメカニズムが解明されてきた。本総説では，恐怖記憶制御プロセス群とそのメカニズムを紹介する。

Abstract

Fear memory is defined as the associative (fear-conditioned) memory between the context of a fear experience (conditioned stimulus) and fear itself (unconditioned stimulus). Re-exposure to the conditioned context retrieves the fear memory and triggers a fear response. Fear memories have been observed in both nematodes and humans, suggesting common neural mechanisms. Studies using rodents and other animal models have identified the mechanisms of fear memory processes, such as consolidation, retrieval, reconsolidation, destabilization, and extinction, at the molecular, cellular, circuit, and behavioral levels. This review introduces fear memory processes and their mechanisms.