Kenji Yamaguchi: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Yoshitomo Maeda: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Takeshi Sawada: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Yusuke Iino: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Mio Tajiri: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Ryosuke Nakazato: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Shin Ishii: International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Haruo Kasai: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Sho Yagishita: Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, Faculty of Medicine Bldg, The University of Tokyo, 1 #NC207, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. yagishita-tky@umin.ac.jp.
Reward reinforces the association between a preceding sensorimotor event and its outcome. Reinforcement learning (RL) theory and recent brain slice studies explain the delayed reward action such that synaptic activities triggered by sensorimotor events leave a synaptic eligibility trace for 1 s. The trace produces a sensitive period for reward-related dopamine to induce synaptic plasticity in the nucleus accumbens (NAc). However, the contribution of the synaptic eligibility trace to behaviour remains unclear. Here we examined a reward-sensitive period to brief pure tones with an accurate measurement of an effective timing of water reward in head-fixed Pavlovian conditioning, which depended on the plasticity-related signaling in the NAc. We found that the reward-sensitive period was within 1 s after the pure tone presentation and optogenetically-induced presynaptic activities at the NAc, showing that the short reward-sensitive period was in conformity with the synaptic eligibility trace in the NAc. These findings support the application of the synaptic eligibility trace to construct biologically plausible RL models.
References
Brain Res. 1985 Dec 16;359(1-2):113-9
[PMID: 4075139]
