Optogenetic suppression of thalamic nucleus reuniens during spatial working memory
Date
2016
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
Spatial working memory (SWM), the temporary storage and manipulation of spatially relevant information in order to guide goal-directed behavior, has been demonstrated to depend on functional interactions between the medial prefrontal cortex (mPFC) and hippocampus (HPC). Recent demonstrations have shown that the nucleus reuniens (RE), part of the ventral midline thalamus reciprocally connected to both the HPC and mPFC, plays an essential role in coordinating interactions within the HPC-mPFC circuit during SWM. However, the precise circuitry that facilitates this coordination and the role of RE in distinct aspects of SWM has yet to be determined. Therefore, we investigated the functional involvement of RE in SWM by optogenetically silencing RE in rats performing the SWM-dependent delayed non-match to position (DNMP) task. Silencing RE during each experimental condition: sample phase, choice phase, delay period, and entire trial, showed impaired choice accuracy on all four conditions. These findings implicate RE in all aspects of SWM and set the stage for future experiments to investigate the possibility of pathway-specific roles of RE afferents during distinct stages of the SWM-decision making process.