先天的恐怖誘発機構の解明および精神疾患との関連

2018 Fiscal Year Research-status Report

• Project/Area Number: 17K08133
• Research Institution: University of Tsukuba
• Principal Investigator: 曹 麗琴 筑波大学, 国際統合睡眠医科学研究機構, 助教 (60399475)
• Co-Investigator(Kenkyū-buntansha): クレウエ・ネベニウス ダニエラ 筑波大学, 国際統合睡眠医科学研究機構, 研究員 (60737667)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 先天的恐怖 / 恐怖感情 / 精神疾患

Outline of Annual Research Achievements

Fear is a basic emotion that enhances animal survival by triggering appropriate defensive responses (e.g. freeze, fight or flight) to perceived danger. However, irrational fears are linked to a variety of mental illnesses, such as phobia, anxiety, depression, PTSD etc. The molecular mechanism of fear is unclear. We performed a novel predator odor-based “innate fear” forward genetic screen using ethylnitrosourea (ENU)-mutagenized mice, and identified a recessive Fear2m/m mutant that exhibited “fearless” phenotype and a dominant Popcornm/+ mutant that exhibited stereotypic “fearful-like” phenotype in the presence of predator odor.
We identified and validated that the causative mutation responsible for “fearless” phenotype is a null mutation in Trpa1. We carried out a set of behavior tests, brain c-fos mapping, tissue-specific lesion, and AAV-Trpa1 virus injection to rescue fear behavior in Trpa1－/－ mice, and made novel findings that Trpa1 functions as a chemosensor for predator odor, and the trigeminal system besides olfactory plays important roles in predator odor-evoked innate fear behaviors. The results are published in Nature Communications 9, 2041 (2018). For the dominant Popcornm/+ mutant pedigree, we performed comprehensive behavior tests. The mutants exhibited “schizophrenia-like” phenotypes in these tests comparing with their wild-type littermates.

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

We have an excellent research team and received great help from outstanding collaborators.
We collaborated with Dr. Bruce Beutler at UT Southwestern Medical Center, and identified our recessive fearless Trpa1－/－ mutant mice using his ENU mutant mice generated for his immune screen. We collaborated with Drs. Ko Kobayakawa and Reiko Kobayakawa who are pioneers in the innate fear research, and with Dr. Takehashi Sakurai who is an outstanding neuroscientist.

Strategy for Future Research Activity

1.To perform comprehensive behavioral analysis of Popcornm/+ mutant mice and evaluate their “schizophrenia-like” phenotypes at different developmental stages.
2.To conduct whole brain c-fos mapping to examine where Popcorn may act in the brain
3.To elucidate the sleep architecture of Popcornm/+ mutant mice.

Causes of Carryover

Some reagents for the experiments will be purchased in FY2019

Research Products

• [Journal Article] Large-scale forward genetics screening identifies Trpa1 as a chemosensor for predator odor-evoked innate fear behaviors (2018)
  • Author(s): Wang, Y., Cao, L., Lee, C-Y., Matsuo, M., Wu, K., Asher, G., Saitoh, T., Klewe-Nebenius, D., Wang, L., Soya, S., Hasegawa, E., Cherasse, Y., Miyoshi,C., Irukayama, Y., Wang, Z., Sakurai, K., Funato, H., Sakurai, T., Yanagisawa, M., Nagase, H., Kobayakawa, R., Kobayakawa, K., Beutler, B., Liu, Q
  • Journal Title: Nature Communications Volume: 9 Pages: 2041
  • DOI: DOI: 10.1038/s41467-018-04324-3
  • Peer Reviewed / Open Access
• [Journal Article] Quantitative phosphoproteomic analysis of the molecular substrates of sleep need (2018)
  • Author(s): Z. Wang, J. Ma, C. Miyoshi, Y. Li, M Sato, Y. Ogawa, T. Lou, C. Ma, X. Gao, C. Lee, T. Fujiyama, X. Yang, S. Zhou, N. Hotta-Hirashima, D. Klewe-Nebenus, A. Ikkyu, M. Kakizaki, S. Kanno, L. Cao, S. Takahashi, J. Peng, Y. Yu, H. Funato, M. Yanagisawa, Q. Liu
  • Journal Title: Nature Volume: 558 Pages: 435-439
  • DOI: doi: 10.1038/s41586-018-0218-8
  • Peer Reviewed
• [Presentation] Large-scale forward genetics screening identifies Trpa1 as a chemosensor for predator odor-evoked innate fear behaviors (2019)
  • Author(s): Wang, Y., Cao, L., Lee, C-Y., Matsuo, M., Wu, K., Asher, G., Saitoh, T., Klewe-Nebenius, D., Wang, L., Soya, S., Hasegawa, E., Cherasse, Y., Miyoshi,C., Irukayama, Y., Wang, Z., Sakurai, K., Funato, H., Sakurai, T., Yanagisawa, M., Nagase, H., Kobayakawa, R., Kobayakawa, K., Beutler, B., Liu, Q
  • Organizer: Keystone Symposia, Mammalian Sensory System (C4)
  • Int'l Joint Research
• [Presentation] Psycho, a potential mouse model of schizophrenia (2018)
  • Author(s): Liqin Cao, Daniela Klewe-Nebenius, Greg Asher, Makito Sato, Chika Miyoshi, Hiromasa Funato, Masashi Yanagisawa, Qinghua Liu
  • Organizer: The 7th Annual IIIS International Symposium
  • Int'l Joint Research
• [Presentation] Large-scale forward genetics screening identifies Trpa1 as a chemosensor for predator odor-evoked innate fear behaviors (2018)
  • Author(s): Wang, Y., Cao, L., Lee, C-Y., Matsuo, M., Wu, K., Asher, G., Saitoh, T., Klewe-Nebenius, D., Wang, L., Soya, S., Hasegawa, E., Cherasse, Y., Miyoshi,C., Irukayama, Y., Wang, Z., Sakurai, K., Funato, H., Sakurai, T., Yanagisawa, M., Nagase, H., Kobayakawa, R., Kobayakawa, K., Beutler, B., Liu, Q
  • Organizer: The 7th Annual IIIS International Symposium
  • Int'l Joint Research