title: Serotonin neurons in the dorsal raphe nucleus encode reward signals.
abstract: The dorsal raphe nucleus (DRN) is involved in organizing reward-related behaviours; however, it remains unclear how genetically defined neurons in the DRN of a freely behaving animal respond to various natural rewards. Here we addressed this question using fibre photometry and single-unit recording from serotonin (5-HT) neurons and GABA neurons in the DRN of behaving mice. Rewards including sucrose, food, sex and social interaction rapidly activate 5-HT neurons, but aversive stimuli including quinine and footshock do not. Both expected and unexpected rewards activate 5-HT neurons. After mice learn to wait for sucrose delivery, most 5-HT neurons fire tonically during waiting and then phasically on reward acquisition. Finally, GABA neurons are activated by aversive stimuli but inhibited when mice seek rewards. Thus, DRN 5-HT neurons positively encode a wide range of reward signals during anticipatory and consummatory phases of reward responses. Moreover, GABA neurons play a complementary role in reward processing.
authors.affiliation: Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.|National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.|National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Weixin
authors.initials: W
authors.lastname: Zhong
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.|School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Daqing
authors.initials: D
authors.lastname: Wang
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Qiru
authors.initials: Q
authors.lastname: Feng
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.|PTN Graduate Program, School of Life Sciences, Peking University, Beijing 100081, China.
authors.forename: Jingfeng
authors.initials: J
authors.lastname: Zhou
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Chunying
authors.initials: C
authors.lastname: Jia
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Hu
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Zeng
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.|Wuhan National Laboratory for Optoelectronics-Huazhong, Britton Chance Center for Biomedical Photonics, University of Science and Technology, Wuhan 430074, China.
authors.forename: Qingchun
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Wuhan National Laboratory for Optoelectronics-Huazhong, Britton Chance Center for Biomedical Photonics, University of Science and Technology, Wuhan 430074, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Fu
authors.affiliation: Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China.|National Institute of Biological Sciences, Zhongguancun Life Science Park 7 Science Park Road, Beijing 102206, China.|School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Minmin
authors.identifier: http://orcid.org/0000-0003-3535-6624
authors.initials: M
authors.lastname: Luo
mesh_terms: D000818:Animals; D065847:Dorsal Raphe Nucleus / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D008297:Male; D051379:Mice / Q000502:physiology / Q000523:psychology*; D009474:Neurons / Q000502:physiology*; D012201:Reward; D012701:Serotonin / Q000378:metabolism*
chemical_list: D012701:Serotonin
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