Research Activities of Each Sub-Project [ Elucidation of sequential learning through physiological experiments ] Sub-project leader : Hayashi (1) Outline of the project When we move in the environment, our brain learns the time-series of both the landmark object information and the spatial information by association. In our brain, entorhinal hippocampus loop (EC/Hip loop) processes the information of both. In the loop the information flows from II layer of entorhinal cortex (EC) to the dentate gyrus (DG) of hippocampus via perforant path, and comes back to II layer of EC from hippocampus via V layer of EC. Spike-timing dependent plasticity (STDP) is a basic neural phenomenon for learning. In STDP, the synaptic plasticity is dependent on the timing between the spikes of the presynaptic cell and postsynaptic cell. Prof. Hayashi has proposed the model to process the time-series inputs using EC/Hip loop. While STDP function is important in the model, the function has not yet been clarified by physiological experiment. So, in this project, Dr. Ogata and Prof. Natsume are trying to clarify STDP function at the synapse in EC and Professor Ishizuka is studying the function at the synapse of DG of hippocampus. Prof. Hayashi will develop the DG model for associating the time-series object information with the spatial information. In the project, neurophysiological lab (Prof. Ishizuka and Prof. Natsume), and neurocomputational lab (Prof. Hayashi) are collaborating. (2) Members of the project Kiyohisa Natsume（Neural Information Processing, Professor）：To study the STDP function at the synapse in entorhinal cortex experimentally Hatsuo Hayashi（Neural Information Processing, Professor）：To propose the Brain-inspired model to process time-series inputs using STDP phenomena in EC/Hip Loop Satoru Ishizuka,（Higher Brain Functions, Associative Professor）To study the STDP function in dentate gyrus of hippocampus experimentally Genki Ogata（Postdoctoral fellow）：To study the STDP function at the synapse in entorhinal cortex experimentally (3) Graphs and Figures Page top ↑ Page top ↑ References [1] Jun Igarashi A Hatsuo Hayashi A Katsumi Tateno, Theta phase coding in a network model of the entorhinal cortex layer II with entorhinal-hippocampal loop connections, Cognitive Neurodynamics, 1, pp. 169-184, 2007. [2] Kiyohisa Natsume, Satoru Ishizuka, Genki Ogata, and Hatsuo Hayashi Spike-timing dependent plasticity in the entorhinal cortex layer II and the dentate gyrus, Abstracts of BrainIT2007, p. 31, 2007. [3] Genki Ogata, Kiyohisa Natsume, Satoru Ishizuka, and Hatsuo Hayashi, Spike-timing dependent plasticity at the synapse from layer V to layer II in the rat medial entorhinal cortex slices, Abstracts of BrainIT2007, p. 56, 2007. HOME | Back | Page top ↑