GO TOP

Field

Integrative Life Sciences :
Brain and Nervous System

Research

JAPANESE
Associate Professor OHARA Shinya
Campus Katahira campus
Laboratory Systems Neuroscience
Tel +81-22-217-5052
E-mail shinya.ohara.d3＠tohoku.ac.jp

To elucidate the function and organization of the complicated central nervous system, we have been developing novel methods using viral vectors. By using viral vectors and in vitro electrophysiological techniques, we are examining the complex wiring of the hippocampal/parahippocampal region in rodents. Our final goal is to reveal the function of the newly identified circuits, and understand the mechanism of memory formation.

Career
2004 B.S., Department of Biology, Faculty of Science, Tohoku University
2006 M.S., Graduate School of Life Sciences, Tohoku University
2009 Ph.D., Graduate School of Life Sciences, Tohoku University
2009-2009 Specially Appointed Research Associate, Graduate School of Life Sciences, Tohoku University (GCOE)
2009-2017 Research Associate, Graduate School of Life Sciences, Tohoku University
2017-2018 Researcher, Norwegian University of Science and Technology
2018-present Research associate, Graduate School of Life Sciences, Tohoku University
Selected Publications
Papers
  •  Ohara S.*, Rannap M.*, Tsutsui KI., Draguhn A., Egorov AV., Witter MP., (2023). Hippocampal-medial entorhinal circuit is differently organized along the dorsoventral axis in rodents. Cell Rep, https://doi.org/10.1016/j.celrep.2023.112001.
  • Ohara S.*, Yoshino R.*, Kimura K., Kawamura T., Tanabe S., Zheng A., Nakamura S., Inoue KI., Takada M., Tsutsui KI., Witter MP., (2021) Laminar Organization of the Entorhinal Cortex in Macaque Monkeys Based on Cell-Type-Specific Markers and Connectivity. Front Neural Circuits, 15:790116.
  • Ohara S., Blankvoort S., Nair RR., Nigro MJ., Nilssen ES., Kentros C., Witter MP., (2021) Local projections of layer Vb-to-Va are more prominent in lateral than in medial entorhinal cortex. Elife, 10:e67262.
  • Ohara S., Gianatti M.,  Itou K, Berndtsson C.H., Doan T.P., Kitanishi T., Mizuseki K., Iijima T., Tsutsui KI., Witter MP.,(2019).Entorhinal Layer II Calbindin-Expressing Neurons Originate Widespread Telencephalic and Intrinsic Projections. Front Syst Neurosci, 13(54).
  • Ohara S.*, Onodera M.*, Simonsen ØW., Yoshino R., Hioki H., Iijima T., Tsutsui KI., Witter MP.,(2018). Intrinsic Projections of Layer Vb Neurons to Layers Va, III, and II in the Lateral and Medial Entorhinal Cortex of the Rat. Cell Rep,  24(1) 107-116.
  • Ohara S.*, Sota Y.*, Sato S., Tsutsui KI., Iijima T., (2017). Increased transgene expression level of rabies virus vector for transsynaptic tracing. PLoS One, 12(7).
  • Witter, MP., Doan, TP., Jacobsen, B., Nilssen, ES., Ohara, S., (2017). Architecture of the Entorhinal Cortex A Review of Entorhinal Anatomy in Rodents with Some Comparative Notes. Front Syst Neurosci, 11(46)
  • Ohara S., Sato S., Oyama K., Tsutsui KI., Iijima T., (2013). Rabies virus vector transgene expression level and cytotoxicity improvement induced by deletion of glycoprotein gene. PLoS One, 8(11).
  • Ohara S., Sato S., Tsutsui KI., Witter M., Iijima T., (2013). Organization of multisynaptic inputs to the dorsal and ventral dentate gyrus: Retrograde trans-synaptic tracing with rabies virus vector in the rat. PLoS One, 8(11).
  • Oyama K.*, Ohara S.*, Sato S., Karube F., Fujiyama F., Isomura Y., Mushiake H., Iijima T., Tsutsui K., (2013). Long-lasting single-neuron labeling by in vivo electroporation without microscopic guidance. J Neurosci Methods, 218(2):139-47.
  • Ohara S., Inoue K., Witter M., Iijima T., (2009). Untangling neural networks with dual retrograde transsynaptic viral infection. Front Neurosci, 3 (3), 344-349.
  • Ohara S., Inoue K., Yamada M., Yamawaki T., Koganezawa N., Tsutsui KI., Witter M., Iijima T. (2009). Dual transneuronal tracing in the rat entorhinal- hippocampal circuit by intracerebral injection of recombinant rabies virus vectors. Front Neuroanat, 3:1.
Publications
  1. Ohara S., Iijima T., (2012). Optical monitoring of neural activity using molecular probe. Jikken igaku special edition, 30 (2), 175-180.
Activities in Academic Societies

Japan Neuroscience Society
Society for Neuroscience
Teaching

Introductory Science Experiments (General Education), Laboratory of Developmental Biology (undergraduate), etc.

Recent Activities

  The entorhinal cortex, in particular neurons in layer V, are the main recipient of hippocampal projections, and originate the main output to the neocortex. This hippocampal output circuit via layer V is considered to play an important role in transferring transiently stored information in the hippocampus to downstream neocortical networks for long-term memory formation. Recently, this circuit has been shown to comprise a hippocampal output recipient layer Vb and a cortical projecting layer Va. To delineate the organization of this hippocampal output circuit, we examined the connection from layer Vb-to-Va with the use of in vitro electrophysiology in transgenic mice specific for layer Vb. To our surprise, we found that the local circuits of layer Vb neurons differ between the functionally distinct medial (MEC) and lateral (LEC) subdivisions: connections from layer Vb-to-Va neurons are stronger in dorsal LEC compared with dorsal MEC. Although further in vivo experiments are needed, our findings imply a potential difference in how LEC and MEC mediate long-term memory formation (Ohara et al., eLife, 2021). This study was conducted in Kavli Institute for Systems Neurosciene, NTNU, together with Prof. Menno Witter, Prof. Clifford Kentros, and their colleagues.

Research