About the Authors

Yoshinori Aoki

Affiliations Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan, Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan

Kaori Yoshida

Affiliations Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan, Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan

Daisuke Nishizawa

Affiliation Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

Shinya Kasai

Affiliation Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

Tatsuya Ichinohe

Affiliation Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan

Kazutaka Ikeda

ikeda-kz@igakuken.or.jp

Affiliation Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

Ken-ichi Fukuda

Affiliation Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan

Competing Interests

Kazutaka Ikeda is a PLOS ONE Editorial Board member. This does not alter the authors' adherence to PLOS ONE Editorial policies and criteria.

Author Contributions

Conceived and designed the experiments: YA KI KF. Performed the experiments: YA KY DN SK. Analyzed the data: YA DN. Contributed reagents/materials/analysis tools: KY TI KI KF. Wrote the paper: YA DN KI KF.