An extensive literature suggests a role for the hippocampus in episodic memory, particularly in the re-construction of those memories;a growing literature is now suggesting a role for the hippocampus in planning and imagination, particularly in the construction of future potential episodes, a process termed ``episodic future thinking''. These two processes have obvious similarities (they both entail construction of episodic representations) and obvious differences (memory is trying to reconstruct a real past, imagination is trying to hypothesize a potential future). However, it is not known what the hippocampus contributes to these phenomena, nor how the information processing in the hippocampus differs between them. We have preliminary data that the hippocampus provides information about the past (episodic memory) and the future (episodic future thinking) at different times on a serial foraging task. New mathematical techniques now allow decoding of represented variables from neural ensembles at very fast timescales, enabling the observation of those transient, covert processes. The goal of this proposal is to use these new techniques to track the changes in hippocampal representation at cognitive (10 ms) timescales. Combining newly available multi-structure recording techniques, newly developed tasks, newly improved neural ensemble analysis techniques, and computational modeling, we will examine the relationship between the representations of past events and future possibilities in hippocampus to determine the mechanism by which the hippocampus computes these representations.

Public Health Relevance

Episodic memory entails a process in which past events in one's experience are re-constructed from memories;episodic future thinking entails a process in which future potential events are constructed for use in deliberation. The hippocampus plays roles in both of these processes, but how these computations are similar or different remain unknown. The goal of this proposal is to directly compare information processing in the hippocampus during memory and planning processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
High Priority, Short Term Project Award (R56)
Project #
2R56MH080318-06
Application #
8837127
Study Section
Special Emphasis Panel (ZRG1-IFCN-T (02))
Program Officer
Osborn, Bettina D
Project Start
2007-04-01
Project End
2016-05-31
Budget Start
2014-06-01
Budget End
2015-05-31
Support Year
6
Fiscal Year
2014
Total Cost
$373,362
Indirect Cost
$123,362
Name
University of Minnesota Twin Cities
Department
Neurosciences
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Lisman, John; Buzsáki, György; Eichenbaum, Howard et al. (2017) Viewpoints: how the hippocampus contributes to memory, navigation and cognition. Nat Neurosci 20:1434-1447
Papale, Andrew E; Zielinski, Mark C; Frank, Loren M et al. (2016) Interplay between Hippocampal Sharp-Wave-Ripple Events and Vicarious Trial and Error Behaviors in Decision Making. Neuron 92:975-982
Amemiya, Seiichiro; Redish, A David (2016) Manipulating Decisiveness in Decision Making: Effects of Clonidine on Hippocampal Search Strategies. J Neurosci 36:814-27
Redish, A David (2016) Vicarious trial and error. Nat Rev Neurosci 17:147-59
Wikenheiser, Andrew M; Redish, A David (2015) Hippocampal theta sequences reflect current goals. Nat Neurosci 18:289-94
Regier, Paul S; Amemiya, Seiichiro; Redish, A David (2015) Hippocampus and subregions of the dorsal striatum respond differently to a behavioral strategy change on a spatial navigation task. J Neurophysiol 114:1399-416
Hills, Thomas T; Todd, Peter M; Lazer, David et al. (2015) Exploration versus exploitation in space, mind, and society. Trends Cogn Sci 19:46-54
Wikenheiser, Andrew M; Redish, A David (2015) Decoding the cognitive map: ensemble hippocampal sequences and decision making. Curr Opin Neurobiol 32:8-15
Powell, Nathaniel J; Redish, A David (2014) Complex neural codes in rat prelimbic cortex are stable across days on a spatial decision task. Front Behav Neurosci 8:120
Takahashi, Muneyoshi; Nishida, Hiroshi; Redish, A David et al. (2014) Theta phase shift in spike timing and modulation of gamma oscillation: a dynamic code for spatial alternation during fixation in rat hippocampal area CA1. J Neurophysiol 111:1601-14

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