Conference Paper

Spatial and Temporal Selectivity of Hippocampal CA3 and Its Contribution to Sequence Disambiguation

DOI: 10.1007/978-3-540-74695-9_6 Conference: Artificial Neural Networks - ICANN 2007, 17th International Conference, Porto, Portugal, September 9-13, 2007, Proceedings, Part II
Source: DBLP


Many episodes are acquired in the hippocampus. An episode is expressed by a sequence of elements that are perceived in an
event. Episodes are associated each other by events that contain information shared among the episodes. Sequences must be
recalled individually, even if the sequences are overlapped at some representations. Therefore, sequence disambiguation is
an essential function to dissociate overlapped sequences. In this study, we especially focus on the location-dependencies
of the STDP effects on synaptic summation and the expression of AMPA receptor. We firstly show that the hippocampal CA3 is
divided into two regions in which one region has spatial selectivity and the other has temporal selectivity. Moreover, we
confirm that the divided CA3 could generate a code for sequence disambiguation in computer simulations. Consequently, we suggest
that the CA3 can be divided into two regions characterized by their selectivity, and the divided CA3 contributes to sequence

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    ABSTRACT: It has been suggested that the cooperation between spatial and temporal selectivities of hippocampal CA3 contributes to sequence disambiguation, which is one of essential functions of the hippocampus. We demonstrate the validity of the suggestion by using sequences assumed from a modified T-maze in which rats perform a task. It should be noted here that CA3c, which is one of the CA3 subregions, generates context-like information that contributes to sequence disambiguation. Finally, we discuss the significance of the context-like information generated in CA3c from a structural and functional viewpoint and suggest that the feedforward and feedback of the context-like information play an essential role in the memory formation of the hippocampus by affecting spatial and temporal information processing in hippocampal dentate gyrus and CA1, respectively.
    No preview · Conference Paper · Nov 2008