中華心理學刊 民 104，57 卷，1 期，109-120
Chinese Journal of Psychology 2015, Vol.57, No.1, 109-120
Hsu-Ching Hung（Department of Psychology, National Chung Cheng University）；Ching-Ju Hsieh（Department of Psychology, National Chung Cheng University）；Jay-Shake Li（Department of Psychology, National Chung Cheng University）
The encoding process of episodic memory is considered by many researchers as a rapid formation of flexible associations, in which semantic elements are retrieved and reorganized in a unique temporal and spatial context. In animal studies, episodic-like memory is defined as the ability to remember what happened where and when. A previous study showed that rats with lesions of medial prefrontal cortex (mPFC) failed to form an episodic-like memory for a fear conditioning event, indicating that the mPFC might play a crucial role. However, details about how mPFC is involved in the encoding process remain unknown. In this study, we temporarily deactivated mPFC of rats at different time points during the memory encoding procedures, and observed how the episodic-like memory of a fear conditioning event was influenced. We found that mPFC deactivation in the preexposure phase didn't interfere with the formation of time-context paired associations, while manipulation before foot-shock impaired the episodic-like memory. Subsequent experiments excluded the alternative interpretations that temporary mPF C deactivation impaired the more basic Pavlovian fear conditioning. The results are consistent with the idea that episodic encoding is a reorganization of mnemonic elements, in which mPFC is involved.