Neunuebel, JoshuaMemory is an abstract concept referring to stored representations of previous
experience that may prove relevant to future behavior. Working memory refers to the
process by which those representations are put to use in a given context, with a
necessary temporal component. Spatial working memory (SWM), in particular, refers
to those working memory activities occurring within the context of spatial navigation
behaviors. The process requires representations of learned experiences, current
context, comparisons between the two, and rule-based decision making. Each of these
has been previously shown to depend on some combination of three critical structures;
the prefrontal cortex (PFC), the hippocampus (HC), and the midline thalamic nucleus
reuniens (Re). However, it had not yet been demonstrated when during the SWM
timeline the information flow across specific pathways linking the structures was
necessary to support accurate goal-directed navigation. The current experiments use
optogenetics to target pathway-specific activity during isolated portions of the SWM
timeline. The results, suggesting high-degrees of selectivity to contributions necessary
to SWM, are discussed within the context of how the brain supports the construction
and application of critical neuronal representations for: learned experiences, current
context, comparisons between the two, and rule-based decision making.University of Delaware, Department of Psychological and Brain SciencesM.S
