Title of Research:

Proposal of a new AOP for the neurotoxicity and developmental
neurotoxicity assessment of glutamate receptor binding agoniststhat cause learning and memory impairment.
Principal Investigator:
Yuko Sekino, PhD (Project Professor, Endowed Laboratory of Human Cell-Based Drug Discovery,
Graduate School of Pharmaceutical Sciences, The University of Tokyo) 7-3-1 Hongo, Bunkyo-ku,
Tokyo 113-0033, Japan(tel)+81-3-5841-4355, (e-mail) yukos@g.ecc.u-tokyo.ac.jp
Collaborators
Hiroyuki Yamazaki, PhD (Associate Professor, Faculty of Social Welfare, Gunma University ofHealth and Welfare) 191-1, Kawamagari-machi, Maebashi, Gunma, 371- 0852, Japan(tel) 027-253-0294 (e-mail) yamazaki@shoken-gakuen.ac.jp
Yonehiro Kanemura, MD, PhD (Director, Department of Biomedical Research and Innovation
Institute for Clinical Research, National Hospital Organization Osaka National Hospital) 2-1-14
Hoenzaka, Chuo-ku, Osaka 540-0006, Japan(tel)+ 81-6-6942-1331, (e-mail) kanemura.yonehiro.hk@mail.hosp.go.jp
Daiju Yamazaki, PhD (Section Chief, Division of Pharmacology, National Institute of HealthSciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa, 210-9501, JAPAN(tel)+81-44-270-6642, (e-mail) daiju-y@nihs.go.jp
Noriko Koganezawa, PhD (Associate Professor, Department of Pharmacology, Gunma
University Graduate School of Medicine) 3-39-22, Showa-machi, Maebashi, Gunma, 371- 8511,
Japan(tel) 027-220-8052, (e-mail) n-koganezawa@gunma-u.ac.jp
Summary of Research:
The purpose of this study is to propose an adverse outcom pathway (AOP) in which the molecular
initiating event (MIE) is the binding of a compound to the glutamate receptors, resulting in theadverse outcome (AO) defined as learning and memory impairment. First, we have established analgorithm for high content imaging to detect dendritic spines with drebrin immunoreactivity, and animage analysis method by machine learning. Then, morphological changes of dendritic spines
were quantitatively evaluated using frozen hippocampal nerve cells from rat embryos and neurons
derived from human iPS cells. We will validate the possibility as an alternative method fordevelopmental neurotoxicity/neurotoxicity testing, using known compounds with learning andmemory impairment.
Timeline:
March 1, 2020 –Topics:Presentation in LRI Research Report Meeting 2021 “Establishment of an in vitro test method forpredicting the neurotoxicity and developmental neurotoxicity of glutamate receptor-binding compounds
that cause learning and memory impairment.”

Publications:Shogo Mase, Izuo Tsutsui, Toshinari Mitsuoka, Noriko Koganezawa, Hiroyuki Yamazaki, Yuuichi
Kato, Hiroshi Kawabe, Tomoaki Shirao, Yuko Sekino, “Developmental neurotoxicity assessment ofglutamate receptor binding agonists that cause learning and memory impairment：analysis ofdrebrin immunoreactivity in rat hippocampal cultured neuron” The 48th Annual Meeting of theJapanese Society of Toxicology, Kobe (Web), July 2021
Shogo Mase, Toshinari Mitsuoka, Noriko Koganezawa, Hiroyuki Yamazaki, Yuuichi Kato, Izuo
Tsutsui, Tomoaki Shirao, Hiroshi Kawabe, Yuko Sekino “Upregulation of drebrin in dendritic spinesand neuronal death induced by a synthetic cannabinoid, CP55940, in cultured rat hippocampal
neurons” The 44th Annual Meeting of the Japan Neuroscience Society, Kobe (Web), July 2021.
Shogo Mase, Toshinari Mitsuoka, Noriko Koganezawa, Hiroyuki Yamazaki, Yuuichi Kato, Izuo
Tsutsui, Tomoaki Shirao, Hiroshi Kawabe, Yuko Sekino “Effects of a synthetic cannabinoid,
CP55940, on synaptogenesis of cultured hippocampal neurons: imaging analysis of drebrin
immunocytochemistry” The 64th Annual Meeting of the Japanese Society for Neurochemistry,
Nara (Web), September 2021