title: Optimal design for hetero-associative memory: hippocampal CA1 phase response curve and spike-timing-dependent plasticity.
abstract: Recently reported experimental findings suggest that the hippocampal CA1 network stores spatio-temporal spike patterns and retrieves temporally reversed and spread-out patterns. In this paper, we explore the idea that the properties of the neural interactions and the synaptic plasticity rule in the CA1 network enable it to function as a hetero-associative memory recalling such reversed and spread-out spike patterns. In line with Lengyel's speculation (Lengyel et al., 2005), we firstly derive optimally designed spike-timing-dependent plasticity (STDP) rules that are matched to neural interactions formalized in terms of phase response curves (PRCs) for performing the hetero-associative memory function. By maximizing object functions formulated in terms of mutual information for evaluating memory retrieval performance, we search for STDP window functions that are optimal for retrieval of normal and doubly spread-out patterns under the constraint that the PRCs are those of CA1 pyramidal neurons. The system, which can retrieve normal and doubly spread-out patterns, can also retrieve reversed patterns with the same quality. Finally, we demonstrate that purposely designed STDP window functions qualitatively conform to typical ones found in CA1 pyramidal neurons.
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Kanagawa, Japan ; Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Miyata
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ota
authors.forename: Toru
authors.initials: T
authors.lastname: Aonishi
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology