title: Basal Forebrain Cholinergic Neurons Primarily Contribute to Inhibition of Electroencephalogram Delta Activity, Rather Than Inducing Behavioral Wakefulness in Mice.
abstract: The basal forebrain (BF) cholinergic neurons have long been thought to be involved in behavioral wakefulness and cortical activation. However, owing to the heterogeneity of BF neurons and poor selectivity of traditional methods, the precise role of BF cholinergic neurons in regulating the sleep-wake cycle remains unclear. We investigated the effects of cell-selective manipulation of BF cholinergic neurons on the sleep-wake behavior and electroencephalogram (EEG) power spectrum using the pharmacogenetic technique, the 'designer receptors exclusively activated by designer drugs (DREADD)' approach, and ChAT-IRES-Cre mice. Our results showed that activation of BF cholinergic neurons expressing hM3Dq receptors significantly and lastingly decreased the EEG delta power spectrum, produced low-delta non-rapid eye movement sleep, and slightly increased wakefulness in both light and dark phases, whereas inhibition of BF cholinergic neurons expressing hM4Di receptors significantly increased EEG delta power spectrum and slightly decreased wakefulness. Next, the projections of BF cholinergic neurons were traced by humanized Renilla green fluorescent protein (hrGFP). Abundant and highly dense hrGFP-positive fibers were observed in the secondary motor cortex and cingulate cortex, and sparse hrGFP-positive fibers were observed in the ventrolateral preoptic nucleus, a known sleep-related structure. Finally, we found that activation of BF cholinergic neurons significantly increased c-Fos expression in the secondary motor cortex and cingulate cortex, but decreased c-Fos expression in the ventrolateral preoptic nucleus. Taken together, these findings reveal that the primary function of BF cholinergic neurons is to inhibit EEG delta activity through the activation of cerebral cortex, rather than to induce behavioral wakefulness.
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.
authors.forename: Dou
authors.initials: D
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.|The Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Tian-Xiao
authors.initials: TX
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.|The Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.|The Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Yan-Jia
authors.initials: YJ
authors.lastname: Luo
authors.affiliation: International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yoan
authors.identifier: 0000-0002-6139-8193
authors.initials: Y
authors.lastname: Cherasse
authors.affiliation: International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Michael
authors.initials: M
authors.lastname: Lazarus
authors.affiliation: Institute of Neuroscience, Shanghai Institute of Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Zi-Long
authors.initials: ZL
authors.lastname: Qiu
authors.affiliation: Department of Neurology, Division of Sleep Medicine, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.|The Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Qu
authors.affiliation: State Key Laboratory of Medical Neurobiology, Department of Pharmacology and Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Fudan University, Shanghai, China.|The Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Zhi-Li
authors.initials: ZL
authors.lastname: Huang
mesh_terms: D000818:Animals; D066187:Basal Forebrain / Q000166:cytology / Q000502:physiology*; D002540:Cerebral Cortex / Q000166:cytology; D059329:Cholinergic Neurons / Q000166:cytology / Q000502:physiology*; D003700:Delta Rhythm; D004569:Electroencephalography; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology; D012890:Sleep; D012894:Sleep Stages; D014851:Wakefulness