title: Exposure to extinction-associated contextual tone during slow-wave sleep and wakefulness differentially modulates fear expression.
abstract: Recent research has used context cues (odor or auditory cues) to target memories during sleep and has demonstrated that they can enhance declarative and procedural memories. However, the effects of external cues re-presented during sleep on emotional memory are still not fully understood. In the present study, we conducted a Pavlovian fear conditioning/extinction paradigm and examined the effects of re-exposure to extinction memory associated contextual tones during slow-wave sleep (SWS) and wakefulness on fear expression. The participants underwent fear conditioning on the first day, during which colored squares served as the conditioned stimulus (CS) and a mild shock served as the unconditioned stimulus (US). The next day, they underwent extinction, during which the CSs were presented without the US but accompanied by a contextual tone (pink noise). Immediately after extinction, the participants were required to take a nap or remain awake and randomly assigned to six groups. Four of the groups were separately exposed to the associated tone (i.e. SWS-Tone group and Wake-Tone group) or an irrelevant tone (control tone, CtrT) (i.e. SWS-CtrT group and Wake-CtrT group), while the other two groups were not (i.e. SWS-No Tone group and Wake-No Tone group). Subsequently, the conditioned responses to the CSs were tested to evaluate the fear expression. All of the participants included in the final analysis showed successful levels of fear conditioning and extinction. During the recall test, the fear responses were significantly higher in the SWS-Tone group than that in the SWS-No Tone group or the SWS-CtrT group, while the Wake-Tone group exhibited more attenuated fear responses than either the Wake-No Tone group or Wake-CtrT group. Otherwise, re-exposure to auditory tones during SWS did not affect sleep profiles. These results suggest that distinct conditions during which re-exposure to an extinction memory associated contextual cue contributes to differential effects on fear expression.
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Si-Zhi
authors.initials: SZ
authors.lastname: Ai
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Liu
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Jia
authors.initials: J
authors.lastname: He
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Yan-Xue
authors.initials: YX
authors.lastname: Xue
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Bao
authors.affiliation: Department of Pulmonary Medicine, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Han
authors.affiliation: Sleep Medicine Center, Translational Neuroscience Center, Mental Health Center, West China Hospital of Sichuan University, Chengdu 610041, China.
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Tang
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China; Sixth Hospital/Institute of Mental Health and Key Laboratory of Mental Health, Peking University, Beijing 100191, China; Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Lu
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, China. Electronic address: shijie@bjmu.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Shi
mesh_terms: D000328:Adult; D003214:Conditioning, Classical / Q000502:physiology; D003463:Cues; D005108:Extinction, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
keywords: Auditory tone; Extinction; Fear memory; Skin conductance response; Slow-wave sleep