Prefrontal Cortex Links Non-overlapping Events in Memory

Marieke R. Gilmartin, Marquette University
Hiroyuki Miyawaki, University of Wisconsin - Milwaukee
Fred J. Helmstetter, University of Wisconsin - Milwaukee
Kamran Diba, University of Wisconsin - Milwaukee

Published Version. Journal of Neuroscience, Vol. 33, No. 26 (June 2013): 10910-10914. DOI. © Society for Neuroscience 2013. Used with permission.

Abstract

The medial prefrontal cortex (mPFC) plays an important role in memory. By maintaining a working memory buffer, neurons in prelimbic (PL) mPFC may selectively contribute to learning associations between stimuli that are separated in time, as in trace fear conditioning (TFC). Until now, evidence for this bridging role was largely descriptive. Here we used optogenetics to silence neurons in the PL mPFC of rats during learning in TFC. Memory formation was prevented when mPFC was silenced specifically during the interval separating the cue and shock. Our results provide support for a working memory function for these cells and indicate that associating two noncontiguous stimuli requires bridging activity in PL mPFC.