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Feng H, Qiao QC, Luo QF, Zhou JY, Lei F, Chen Y, Wen SY, Chen WH, Pang YJ, Hu ZA, Jiang YB, Zhang XY, Zhou TY, Zhang XY, Yang N, Zhang J, Hu R. Orexin Neurons to Sublaterodorsal Tegmental Nucleus Pathway Prevents Sleep Onset REM Sleep-Like Behavior by Relieving the REM Sleep Pressure. RESEARCH (WASHINGTON, D.C.) 2024; 7:0355. [PMID: 38694202 PMCID: PMC11062508 DOI: 10.34133/research.0355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/25/2024] [Indexed: 05/04/2024]
Abstract
Proper timing of vigilance states serves fundamental brain functions. Although disturbance of sleep onset rapid eye movement (SOREM) sleep is frequently reported after orexin deficiency, their causal relationship still remains elusive. Here, we further study a specific subgroup of orexin neurons with convergent projection to the REM sleep promoting sublaterodorsal tegmental nucleus (OXSLD neurons). Intriguingly, although OXSLD and other projection-labeled orexin neurons exhibit similar activity dynamics during REM sleep, only the activation level of OXSLD neurons exhibits a significant positive correlation with the post-inter-REM sleep interval duration, revealing an essential role for the orexin-sublaterodorsal tegmental nucleus (SLD) neural pathway in relieving REM sleep pressure. Monosynaptic tracing reveals that multiple inputs may help shape this REM sleep-related dynamics of OXSLD neurons. Genetic ablation further shows that the homeostatic architecture of sleep/wakefulness cycles, especially avoidance of SOREM sleep-like transition, is dependent on this activity. A positive correlation between the SOREM sleep occurrence probability and depression states of narcoleptic patients further demonstrates the possible significance of the orexin-SLD pathway on REM sleep homeostasis.
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Affiliation(s)
- Hui Feng
- Department of Neurobiology,
Army Medical University, 400038 Chongqing, P.R. China
- Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital,
Army Medical University, 400038 Chongqing, P.R. China
| | - Qi-Cheng Qiao
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Qi-Fa Luo
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Jun-Ying Zhou
- Sleep Medicine Center, West China Hospital,
Sichuan University, 610000 Chengdu, Sichuan, P.R. China
| | - Fei Lei
- Sleep Medicine Center, West China Hospital,
Sichuan University, 610000 Chengdu, Sichuan, P.R. China
| | - Yao Chen
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Si-Yi Wen
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Wen-Hao Chen
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Yu-Jie Pang
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Zhi-An Hu
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Yi-Bin Jiang
- Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital,
Army Medical University, 400038 Chongqing, P.R. China
| | - Xu-Yang Zhang
- Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital,
Army Medical University, 400038 Chongqing, P.R. China
| | - Teng-Yuan Zhou
- Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital,
Army Medical University, 400038 Chongqing, P.R. China
| | - Xin-Yan Zhang
- Sleep Medicine Center, West China Hospital,
Sichuan University, 610000 Chengdu, Sichuan, P.R. China
| | - Nian Yang
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Jun Zhang
- Department of Neurobiology,
Army Medical University, 400038 Chongqing, P.R. China
- Department of Physiology,
Army Medical University, 400038 Chongqing, P.R. China
| | - Rong Hu
- Department of Neurosurgery and Key Laboratory of Neurotrauma, Southwest Hospital,
Army Medical University, 400038 Chongqing, P.R. China
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Li S, Machida K, Burrows EL, Johnson KA. Quicker Exogenous Orienting and Slower Endogenous Orienting in Autistic People. J Autism Dev Disord 2024:10.1007/s10803-024-06311-8. [PMID: 38446266 DOI: 10.1007/s10803-024-06311-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2024] [Indexed: 03/07/2024]
Abstract
Research is equivocal on whether attention orienting is atypical in autism. This study investigated two types of attention orienting in autistic people and accounted for the potential confounders of alerting level, co-occurring symptoms of attention-deficit/hyperactivity disorder (ADHD) and anxiety, age, and sex. Twenty-seven autistic participants (14 males; 9-43 years) and 22 age- and sex-matched non-autistic participants (13 males; 9-42 years) completed the exogenous and endogenous Posner tasks. Response time and pupillometric data were recorded. Autistic participants were faster at orienting attention to valid cues in the exogenous task and slower at disengaging from invalid cues in the endogenous task compared to non-autistic participants. With increasing age, autistic participants showed faster exogenous and endogenous orienting, whereas non-autistic participants showed faster exogenous orienting but stable speed of endogenous orienting. Higher ADHD symptoms were associated with slower exogenous orienting in both groups, whereas higher anxiety symptoms were associated with faster exogenous orienting only in autistic participants. No group differences were noted for alerting levels, sex, or pupillary responses. This study provides new evidence of superior exogenous orienting and inefficient endogenous orienting in autistic people and suggests that age and co-occurring symptoms are important to consider when assessing attention orienting in autism.
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Affiliation(s)
- Shuting Li
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3052, Australia.
| | - Keitaro Machida
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Emma L Burrows
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Katherine A Johnson
- Melbourne School of Psychological Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
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Wiersielis K, Yasrebi A, Degroat TJ, Knox N, Rojas C, Feltri S, Roepke TA. Intermittent fasting disrupts hippocampal-dependent memory and norepinephrine content in aged male and female mice. Physiol Behav 2024; 275:114431. [PMID: 38072036 DOI: 10.1016/j.physbeh.2023.114431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 12/04/2023] [Accepted: 12/07/2023] [Indexed: 01/08/2024]
Abstract
Intermittent fasting (IMF) is associated with many health benefits in animals and humans. Yet, little is known if an IMF diet affects mood and cognitive processing. We have previously identified that IMF in diet-induced obese males increases norepinephrine and dopamine content in the hypothalamus and increases arcuate neuropeptide Y (NPY) gene expression more than in ad libitum control males. This suggests that IMF may improve cognition through activation of the hindbrain norepinephrine neuronal network and reverse the age-dependent decline in NPY expression. Less is known about the association between anxiety and IMF. Although, in humans, IMF during Ramadan may alleviate anxiety. Here, we address the impact of IMF on anxiety-like behavior using the open field test, hippocampal-dependent memory using the Y-maze and spatial object recognition, and hippocampal-independent memory using novel object recognition in middle-aged male and female (12 mo) and aged male and female (18 mo) mice. Using ELISA, we determined norepinephrine (NE) content in the dorsal hippocampus (DH) and prefrontal cortex (PFC). We also investigated gene expression in the arcuate nucleus (ARC), the lateral hypothalamus (LH), and the locus coeruleus (LC). In IMF-treated females at both ages, we observed an improvement in spatial navigation although an impairment in spatial object orientation. IMF-treated females (12 mo) had a reduction and IMF-treated males (12 mo) displayed an improvement in novel object recognition memory. IMF-treated females (18 mo) exhibited anxiolytic-like behavior and increased locomotion. In the DH, IMF-treated males (12 mo) had a greater amount of NE content and IMF-treated males (18 mo) had a reduction. In the ARC, IMF-treated males (12 mo) exhibited an increase in Agrp and Npy and a decrease in Adr1a. In the ARC, IMF-treated males (18 mo) exhibited an increase in Npy and a decrease in Adr1a; females had a trending decrease in Cart. In the LH at 12 months, IMF-treated males had a decrease in Npy5r, Adr1a, and Adr1b; both males and females had a reduction in Npy1r. In the LH, IMF-treated females (18 mo) had a decrease in Hcrt. In the LC at both ages, mice largely exhibited sex effects. Our findings indicate that IMF produces alterations in mood, cognition, DH NE content, and ARC, LH, and LC gene expression depending on sex and age.
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Affiliation(s)
- Kimberly Wiersielis
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States.
| | - Ali Yasrebi
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Thomas J Degroat
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Endocrinology and Animal Biosciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Nadja Knox
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Endocrinology and Animal Biosciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Catherine Rojas
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States
| | - Samantha Feltri
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States
| | - Troy A Roepke
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Joint Graduate Program in Toxicology, Rutgers, The State University of New Jersey, Piscataway, NJ, United States; Endocrinology and Animal Biosciences Graduate Program, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, Piscataway, NJ, United States; Institute for Food Nutrition and Health (Rutgers Center for Lipid Research, Center for Human Nutrition, Exercise and Metabolism Center, and Center for Nutrition Microbiome and Health), Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, United States
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Xiang X, Chen Y, Li KX, Fang J, Bickler PE, Guan Z, Zhou W. Neuroanatomical Basis for the Orexinergic Modulation of Anesthesia Arousal and Pain Control. Front Cell Neurosci 2022; 16:891631. [PMID: 35558876 PMCID: PMC9090436 DOI: 10.3389/fncel.2022.891631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/04/2022] [Indexed: 12/02/2022] Open
Abstract
Hypothalamic orexin (hypocretin) neurons play crucial roles in arousal control. Their involvement in anesthesia and analgesia remains to be better understood. In order to enhance our view on the neuroanatomy, we systematically mapped the projections of orexin neurons with confocal microscope and light sheet microscope. We specifically expressed optogenetic opsins tagged with fluorescence markers in orexin neurons through adeno-associated viral infection in the mouse brain. The imaging results revealed fine details and novel features of the orexin projections throughout the brain, particularly related to the nuclei regulating arousal and pain. We then optogenetically activated orexin neurons in the lateral hypothalamus to study the effects on anesthesia-related behaviors. cFos staining showed that optogenetic stimulation can activate orexin neurons in the ChR2-mCherry group, but not the control mCherry group (62.86 ± 3.923% vs. 7.9 ± 2.072%; P < 0.0001). In behavior assays, optogenetic stimulation in the ChR2-mCherry group consistently elicited robust arousal from light isoflurane anesthesia (9.429 ± 3.804 s vs. 238.2 ± 17.42 s; P < 0.0001), shortened the emergence time after deep isoflurane anesthesia (109.5 ± 13.59 s vs. 213.8 ± 21.77 s; P = 0.0023), and increased the paw withdrawal latency in a hotplate test (11.45 ± 1.185 s vs. 8.767 ± 0.7775; P = 0.0317). The structural details of orexin fibers established the neuroanatomic basis for studying the role of orexin in anesthesia and analgesia.
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Affiliation(s)
- Xuaner Xiang
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States
| | - Yuzhang Chen
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States
| | - Ke-Xin Li
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Jianqiao Fang
- Key Laboratory of Acupuncture and Neurology of Zhejiang Province, The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Philip E. Bickler
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States
| | - Zhonghui Guan
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States
| | - Wei Zhou
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Wei Zhou,
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Van Egroo M, Koshmanova E, Vandewalle G, Jacobs HI. Importance of the locus coeruleus-norepinephrine system in sleep-wake regulation: implications for aging and Alzheimer’s disease. Sleep Med Rev 2022; 62:101592. [PMID: 35124476 PMCID: PMC9064973 DOI: 10.1016/j.smrv.2022.101592] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/24/2021] [Accepted: 01/12/2022] [Indexed: 12/13/2022]
Abstract
Five decades ago, seminal studies positioned the brainstem locus coeruleus (LC) norepinephrine (NE) system as a key substrate for the regulation of wakefulness and sleep, and this picture has recently been elaborated thanks to methodological advances in the precise investigation and experimental modulation of LC structure and functions. This review presents and discusses findings that support the major role of the LC-NE system at different levels of sleep-wake organization, ranging from its involvement in the overall architecture of the sleep-wake cycle to its associations with sleep microstructure, while accounting for the intricate neuroanatomy surrounding the LC. Given the particular position held by the LC-NE system by being at the intersection of sleep-wake dysregulation and initial pathophysiological processes of Alzheimer's disease (AD), we conclude by examining emerging opportunities to investigate LC-NE mediated relationships between sleep-wake alteration and AD in human aging. We further propose several research perspectives that could support the LC-NE system as a promising target for the identification of at-risk individuals in the preclinical stages of AD, and for the development of novel preventive interventions.
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Zhang D, Liu J, Zhu T, Zhou C. Identifying c-fos Expression as a Strategy to Investigate the Actions of General Anesthetics on the Central Nervous System. Curr Neuropharmacol 2021; 20:55-71. [PMID: 34503426 PMCID: PMC9199548 DOI: 10.2174/1570159x19666210909150200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 09/05/2021] [Accepted: 09/09/2021] [Indexed: 02/08/2023] Open
Abstract
Although general anesthetics have been used in the clinic for more than 170 years, the ways in which they induce amnesia, unconsciousness, analgesia, and immobility remain elusive. Modulations of various neural nuclei and circuits are involved in the actions of general anesthetics. The expression of the immediate-early gene c-fos and its nuclear product, c-fos protein, can be induced by neuronal depolarization; therefore, c-fos staining is commonly used to identify the activated neurons during sleep and/or wakefulness, as well as in various physiological conditions in the central nervous system. Identifying c-fos expression is also a direct and convenient method to explore the effects of general anesthetics on the activity of neural nuclei and circuits. Using c-fos staining, general anesthetics have been found to interact with sleep- and wakefulness-promoting systems throughout the brain, which may explain their ability to induce unconsciousness and emergence from general anesthesia. This review summarizes the actions of general anesthetics on neural nuclei and circuits based on a c-fos expression.
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Affiliation(s)
- Donghang Zhang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041. China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041. China
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041. China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041. China
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Frazer MA, Cabrera Y, Guthrie RS, Poe GR. Shining a Light on the Mechanisms of Sleep for Memory Consolidation. CURRENT SLEEP MEDICINE REPORTS 2021. [DOI: 10.1007/s40675-021-00204-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract
Purpose of review
This paper reviews all optogenetic studies that directly test various sleep states, traits, and circuit-level activity profiles for the consolidation of different learning tasks.
Recent findings
Inhibiting or exciting neurons involved either in the production of sleep states or in the encoding and consolidation of memories reveals sleep states and traits that are essential for memory. REM sleep, NREM sleep, and the N2 transition to REM (characterized by sleep spindles) are integral to memory consolidation. Neural activity during sharp-wave ripples, slow oscillations, theta waves, and spindles are the mediators of this process.
Summary
These studies lend strong support to the hypothesis that sleep is essential to the consolidation of memories from the hippocampus and the consolidation of motor learning which does not necessarily involve the hippocampus. Future research can further probe the types of memory dependent on sleep-related traits and on the neurotransmitters and neuromodulators required.
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Yeung MK, Lee TL, Han YMY, Chan AS. Prefrontal activation and pupil dilation during n-back task performance: A combined fNIRS and pupillometry study. Neuropsychologia 2021; 159:107954. [PMID: 34252415 DOI: 10.1016/j.neuropsychologia.2021.107954] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 05/29/2021] [Accepted: 07/06/2021] [Indexed: 12/30/2022]
Abstract
The n-back task is one of the most commonly used working memory (WM) paradigms in cognitive neuroscience. Converging evidence suggests activation in the lateral prefrontal cortex (PFC) and pupil dilation [a proxy for locus coeruleus (LC) activation] during this task. However, it remains unclear whether the lateral PFC and the LC are functionally associated during n-back task performance. This study's aim was to examine the relationship between changes in lateral PFC activity and the pupil diameter and to evaluate the effect of WM load on such relationship during the n-back task. Thirty-nine healthy young adults (10 males, 29 females) underwent a number n-back paradigm with 0- and 3-back conditions. Their prefrontal hemodynamics and changes in pupil size during task performance were simultaneously measured using a 16-channel functional near-infrared spectroscopy (fNIRS) device and a wearable eye tracker. Young adults exhibited significant activation in the bilateral lateral PFC and significant increases in pupil size when the WM load was high (i.e., 3-back) but not low (i.e., 0-back) compared with the resting period. Interestingly, significant positive correlations were found between changes in lateral PFC activity and pupil size during the 0-back task only. These correlations tended to be stronger during the 0-back than the 3-back condition. Thus, the functional relationship between the lateral PFC and the LC may vary at different load levels during the n-back task. Our findings have important implications for neuropsychiatric research and support concurrent fNIRS and pupillometric measurements for a better understanding of the mechanisms underlying WM processing.
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Affiliation(s)
- Michael K Yeung
- Department of Rehabilitation Sciences, the Hong Kong Polytechnic University, SAR, Hong Kong, China
| | - Tsz L Lee
- Neuropsychology Laboratory, Department of Psychology, the Chinese University of Hong Kong, SAR, Hong Kong, China
| | - Yvonne M Y Han
- Department of Rehabilitation Sciences, the Hong Kong Polytechnic University, SAR, Hong Kong, China
| | - Agnes S Chan
- Neuropsychology Laboratory, Department of Psychology, the Chinese University of Hong Kong, SAR, Hong Kong, China; Research Center for Neuropsychological Well-being, the Chinese University of Hong Kong, SAR, Hong Kong, China.
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Luppi AI, Spindler LRB, Menon DK, Stamatakis EA. The Inert Brain: Explaining Neural Inertia as Post-anaesthetic Sleep Inertia. Front Neurosci 2021; 15:643871. [PMID: 33737863 PMCID: PMC7960927 DOI: 10.3389/fnins.2021.643871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 02/05/2021] [Indexed: 12/13/2022] Open
Abstract
"Neural inertia" is the brain's tendency to resist changes in its arousal state: it is manifested as emergence from anaesthesia occurring at lower drug doses than those required for anaesthetic induction, a phenomenon observed across very different species, from invertebrates to mammals. However, the brain is also subject to another form of inertia, familiar to most people: sleep inertia, the feeling of grogginess, confusion and impaired performance that typically follows awakening. Here, we propose a novel account of neural inertia, as the result of sleep inertia taking place after the artificial sleep induced by anaesthetics. We argue that the orexinergic and noradrenergic systems may be key mechanisms for the control of these transition states, with the orexinergic system exerting a stabilising effect through the noradrenergic system. This effect may be reflected at the macroscale in terms of altered functional anticorrelations between default mode and executive control networks of the human brain. The hypothesised link between neural inertia and sleep inertia could explain why different anaesthetic drugs induce different levels of neural inertia, and why elderly individuals and narcoleptic patients are more susceptible to neural inertia. This novel hypothesis also enables us to generate several empirically testable predictions at both the behavioural and neural levels, with potential implications for clinical practice.
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Affiliation(s)
- Andrea I. Luppi
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Lennart R. B. Spindler
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - David K. Menon
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Emmanuel A. Stamatakis
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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10
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Luppi AI, Spindler LRB, Menon DK, Stamatakis EA. The Inert Brain: Explaining Neural Inertia as Post-anaesthetic Sleep Inertia. Front Neurosci 2021; 15:643871. [PMID: 33737863 DOI: 10.3389/fnins.2021.64387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 02/05/2021] [Indexed: 05/20/2023] Open
Abstract
"Neural inertia" is the brain's tendency to resist changes in its arousal state: it is manifested as emergence from anaesthesia occurring at lower drug doses than those required for anaesthetic induction, a phenomenon observed across very different species, from invertebrates to mammals. However, the brain is also subject to another form of inertia, familiar to most people: sleep inertia, the feeling of grogginess, confusion and impaired performance that typically follows awakening. Here, we propose a novel account of neural inertia, as the result of sleep inertia taking place after the artificial sleep induced by anaesthetics. We argue that the orexinergic and noradrenergic systems may be key mechanisms for the control of these transition states, with the orexinergic system exerting a stabilising effect through the noradrenergic system. This effect may be reflected at the macroscale in terms of altered functional anticorrelations between default mode and executive control networks of the human brain. The hypothesised link between neural inertia and sleep inertia could explain why different anaesthetic drugs induce different levels of neural inertia, and why elderly individuals and narcoleptic patients are more susceptible to neural inertia. This novel hypothesis also enables us to generate several empirically testable predictions at both the behavioural and neural levels, with potential implications for clinical practice.
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Affiliation(s)
- Andrea I Luppi
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Lennart R B Spindler
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - David K Menon
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Emmanuel A Stamatakis
- Division of Anaesthesia, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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Circadian differences in emergence from volatile anaesthesia in mice: involvement of the locus coeruleus noradrenergic system. Br J Anaesth 2020; 125:548-559. [PMID: 32807382 DOI: 10.1016/j.bja.2020.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/23/2020] [Accepted: 07/16/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Circadian differences in the induction, maintenance, or emergence from volatile anaesthesia have not been well studied. METHODS The minimal alveolar concentration (MAC) for preventing movement in response to a painful stimulus, MAC for loss of righting reflex (MACLORR), and MAC for recovery of righting reflex (MACRORR) in C57BL/6J male mice with isoflurane or sevoflurane exposure were measured during either the light or dark phase. Time to onset of loss of righting reflex (TimeLORR) and recovery of righting reflex (TimeRORR) upon exposure to 1 MAC of isoflurane or sevoflurane were determined. EEG was also monitored in the light and dark phase under isoflurane or sevoflurane exposure. The noradrenergic toxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) was used to deplete noradrenergic neurones in the locus coeruleus to explore the impact of norepinephrine on these measurements. RESULTS MACLORR, TimeLORR, and MAC did not show light- or dark-phase-dependent variations for either isoflurane or sevoflurane exposure. However, MACRORR was higher and TimeRORR was shorter in the dark phase than in the light phase for both isoflurane and sevoflurane exposure. The EEG delta wave power was higher but theta wave power was lower in the light phase than that in the dark phase during the rest state and emergence of anaesthesia. These light- and dark-phase-dependent changes in emergence were abolished in DSP-4-treated mice. CONCLUSION Our data show that circadian differences exist during emergence but not during induction or maintenance of sevoflurane or isoflurane anaesthesia. The locus coeruleus noradrenergic system may contribute to these differences.
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Hoyer D, Allen A, Jacobson LH. Hypnotics with novel modes of action. Br J Clin Pharmacol 2020; 86:244-249. [PMID: 31756268 PMCID: PMC7015741 DOI: 10.1111/bcp.14180] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 10/25/2019] [Accepted: 11/01/2019] [Indexed: 12/19/2022] Open
Abstract
Insomnia and, more generally, lack of sleep are on the rise. Traditionally treated by classical hypnotics, such as benzodiazepines and Z drugs, which both act on the GABAA receptor, and other modalities, including nondrug therapies, such as cognitive behavioural therapy, there is a range of new hypnotics which are being developed or have recently received market approval. Suvorexant and the like target the orexin/hypocretin system: they should have less side effects in terms of drug-drug interactions with e.g. alcohol, less memory impairment and dependence potential compared to classical hypnotics.
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Affiliation(s)
- Daniel Hoyer
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health SciencesThe University of MelbourneParkvilleVictoriaAustralia
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleAustralia
- Department of Molecular MedicineThe Scripps Research InstituteLa JollaCAUSA
| | - Andrew Allen
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health SciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Laura H. Jacobson
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health SciencesThe University of MelbourneParkvilleVictoriaAustralia
- The Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneParkvilleAustralia
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13
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The Locus Coeruleus Modulates Intravenous General Anesthesia of Zebrafish via a Cooperative Mechanism. Cell Rep 2019; 24:3146-3155.e3. [PMID: 30231998 DOI: 10.1016/j.celrep.2018.08.046] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/17/2018] [Accepted: 08/16/2018] [Indexed: 01/03/2023] Open
Abstract
How general anesthesia causes loss of consciousness has been a mystery for decades. It is generally thought that arousal-related brain nuclei, including the locus coeruleus (LC), are involved. Here, by monitoring locomotion behaviors and neural activities, we developed a larval zebrafish model for studying general anesthesia induced by propofol and etomidate, two commonly used intravenous anesthetics. Local lesion of LC neurons via two-photon laser-based ablation or genetic depletion of norepinephrine (NE; a neuromodulator released by LC neurons) via CRISPR/Cas9-based mutation of dopamine-β-hydroxylase (dbh) accelerates induction into and retards emergence from general anesthesia. Mechanistically, in vivo whole-cell recording revealed that both anesthetics suppress LC neurons' activity through a cooperative mechanism, inhibiting presynaptic excitatory inputs and inducing GABAA receptor-mediated hyperpolarization of these neurons. Thus, our study indicates that the LC-NE system plays a modulatory role in both induction of and emergence from intravenous general anesthesia.
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14
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Mulvey B, Bhatti DL, Gyawali S, Lake AM, Kriaucionis S, Ford CP, Bruchas MR, Heintz N, Dougherty JD. Molecular and Functional Sex Differences of Noradrenergic Neurons in the Mouse Locus Coeruleus. Cell Rep 2019; 23:2225-2235. [PMID: 29791834 DOI: 10.1016/j.celrep.2018.04.054] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 02/23/2018] [Accepted: 04/13/2018] [Indexed: 01/01/2023] Open
Abstract
Preclinical work has long focused on male animals, though biological sex clearly influences risk for certain diseases, including many psychiatric disorders. Such disorders are often treated by drugs targeting the CNS norepinephrine system. Despite roles for noradrenergic neurons in behavior and neuropsychiatric disease models, their molecular characterization has lagged. We profiled mouse noradrenergic neurons in vivo, defining over 3,000 high-confidence transcripts expressed therein, including druggable receptors. We uncovered remarkable sex differences in gene expression, including elevated expression of the EP3 receptor in females-which we leverage to illustrate the behavioral and pharmacologic relevance of these findings-and of Slc6a15 and Lin28b, both major depressive disorder (MDD)-associated genes. Broadly, we present a means of transcriptionally profiling locus coeruleus under baseline and experimental conditions. Our findings underscore the need for preclinical work to include both sexes and suggest that sex differences in noradrenergic neurons may underlie behavioral differences relevant to disease.
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Affiliation(s)
- Bernard Mulvey
- Department of Genetics and Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | - Dionnet L Bhatti
- Department of Anesthesiology and Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Sandeep Gyawali
- Laboratory of Molecular Biology, Rockefeller University, and Howard Hughes Medical Institute, New York, NY, USA
| | - Allison M Lake
- Department of Genetics and Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Christopher P Ford
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael R Bruchas
- Department of Anesthesiology and Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Rockefeller University, and Howard Hughes Medical Institute, New York, NY, USA
| | - Joseph D Dougherty
- Department of Genetics and Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA.
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15
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Kaur S, Saper CB. Neural Circuitry Underlying Waking Up to Hypercapnia. Front Neurosci 2019; 13:401. [PMID: 31080401 PMCID: PMC6497806 DOI: 10.3389/fnins.2019.00401] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/08/2019] [Indexed: 12/13/2022] Open
Abstract
Obstructive sleep apnea is a sleep and breathing disorder, in which, patients suffer from cycles of atonia of airway dilator muscles during sleep, resulting in airway collapse, followed by brief arousals that help re-establish the airway patency. These repetitive arousals which can occur hundreds of times during the course of a night are the cause of the sleep-disruption, which in turn causes cognitive impairment as well as cardiovascular and metabolic morbidities. To prevent this potential outcome, it is important to target preventing the arousal from sleep while preserving or augmenting the increase in respiratory drive that reinitiates breathing, but will require understanding of the neural circuits that regulate the cortical and respiratory responses to apnea. The parabrachial nucleus (PB) is located in rostral pons. It receives chemosensory information from medullary nuclei that sense increase in CO2 (hypercapnia), decrease in O2 (hypoxia) and mechanosensory inputs from airway negative pressure during apneas. The PB area also exerts powerful control over cortical arousal and respiration, and therefore, is an excellent candidate for mediating the EEG arousal and restoration of the airway during sleep apneas. Using various genetic tools, we dissected the neuronal sub-types responsible for relaying the stimulus for cortical arousal to forebrain arousal circuits. The present review will focus on the circuitries that regulate waking-up from sleep in response to hypercapnia.
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Affiliation(s)
- Satvinder Kaur
- Department of Neurology, Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Clifford B Saper
- Department of Neurology, Program in Neuroscience, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
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16
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Tye KM. Neural Circuit Motifs in Valence Processing. Neuron 2018; 100:436-452. [PMID: 30359607 PMCID: PMC6590698 DOI: 10.1016/j.neuron.2018.10.001] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/24/2018] [Accepted: 09/28/2018] [Indexed: 01/07/2023]
Abstract
How do our brains determine whether something is good or bad? How is this computational goal implemented in biological systems? Given the critical importance of valence processing for survival, the brain has evolved multiple strategies to solve this problem at different levels. The psychological concept of "emotional valence" is now beginning to find grounding in neuroscience. This review aims to bridge the gap between psychology and neuroscience on the topic of emotional valence processing. Here, I highlight a subset of studies that exemplify circuit motifs that repeatedly appear as implementational systems in valence processing. The motifs I identify as being important in valence processing include (1) Labeled Lines, (2) Divergent Paths, (3) Opposing Components, and (4) Neuromodulatory Gain. Importantly, the functionality of neural substrates in valence processing is dynamic, context-dependent, and changing across short and long timescales due to synaptic plasticity, competing mechanisms, and homeostatic need.
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Affiliation(s)
- Kay M Tye
- Picower Institute for Learning and Memory, Dept of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Salk Institute for Biological Sciences, La Jolla, CA 92037, USA.
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17
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Adamantidis A, Lüthi A. Optogenetic Dissection of Sleep-Wake States In Vitro and In Vivo. Handb Exp Pharmacol 2018; 253:125-151. [PMID: 29687163 DOI: 10.1007/164_2018_94] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Optogenetic tools have revolutionized insights into the fundamentals of brain function. This is particularly true for our current understanding of sleep-wake regulation and sleep rhythms. This is illustrated here through a comprehensive and step-by-step review over the major brain areas involved in transitions between sleep and wake states and in sleep rhythmogenesis.
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Affiliation(s)
- Antoine Adamantidis
- Department of Neurology, Inselspital University Hospital, University of Bern, Bern, Switzerland. .,Department of Clinical Research (DKF), University of Bern, Bern, Switzerland.
| | - Anita Lüthi
- Department of Fundamental Neurosciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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18
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Gentile TA, Simmons SJ, Watson MN, Connelly KL, Brailoiu E, Zhang Y, Muschamp JW. Effects of Suvorexant, a Dual Orexin/Hypocretin Receptor Antagonist, on Impulsive Behavior Associated with Cocaine. Neuropsychopharmacology 2018; 43:1001-1009. [PMID: 28741623 PMCID: PMC5854790 DOI: 10.1038/npp.2017.158] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/10/2017] [Accepted: 07/16/2017] [Indexed: 11/09/2022]
Abstract
Hypothalamic hypocretin (orexin) peptides mediate arousal, attention, and reward processing. Fibers containing orexins project to brain structures that govern motivated behavior, including the ventral tegmental area (VTA). A number of psychiatric conditions, including attention deficit hyperactivity disorder (ADHD) and substance use disorders, are characterized by deficits in impulse control, however the relationship between orexin and impulsive behavior is incompletely characterized. The effects of systemic or centrally administered orexin receptor (OXR) antagonists on measures of impulsive-like behavior in rats were evaluated using the five-choice serial reaction time task (5-CSRTT) and delay discounting procedures. These paradigms were also used to test the capacity of OXR antagonists to attenuate acute cocaine-evoked impulsivity. Finally, immunohistochemistry and calcium imaging were used to assess potential cellular mechanisms by which OXR blockade may influence motor impulsivity. Suvorexant, a dual (OX1/2R) orexin receptor antagonist, reduced cocaine-evoked premature responses in 5-CSRTT when administered systemically or directly into VTA. Neither suvorexant nor OX1R- or OX2R-selective compounds (SB334867 or TCS-OX2-29, respectively) altered delay discounting. Finally, suvorexant did not alter Fos-immunoreactivity within tyrosine hydroxylase-immunolabeled neurons of VTA, but did attenuate cocaine- and orexin-induced increases in calcium transient amplitude within neurons of VTA. Results from the present studies suggest potential therapeutic utility of OXR antagonists in reducing psychostimulant-induced motor impulsivity. These findings also support the view that orexin transmission is closely involved in executive function in normal and pathological conditions.
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Affiliation(s)
- Taylor A Gentile
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Steven J Simmons
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Mia N Watson
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Krista L Connelly
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Eugen Brailoiu
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, NC, USA
| | - John W Muschamp
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA,Center for Substance Abuse Research, Department of Pharmacology, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street – MERB 849, Philadelphia, PA, 19140, USA, Tel: +1 215 707 8089, Fax: +1 215 707 6661, E-mail:
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19
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Eban-Rothschild A, Appelbaum L, de Lecea L. Neuronal Mechanisms for Sleep/Wake Regulation and Modulatory Drive. Neuropsychopharmacology 2018; 43:937-952. [PMID: 29206811 PMCID: PMC5854814 DOI: 10.1038/npp.2017.294] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/17/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
Abstract
Humans have been fascinated by sleep for millennia. After almost a century of scientific interrogation, significant progress has been made in understanding the neuronal regulation and functions of sleep. The application of new methods in neuroscience that enable the analysis of genetically defined neuronal circuits with unprecedented specificity and precision has been paramount in this endeavor. In this review, we first discuss electrophysiological and behavioral features of sleep/wake states and the principal neuronal populations involved in their regulation. Next, we describe the main modulatory drives of sleep and wakefulness, including homeostatic, circadian, and motivational processes. Finally, we describe a revised integrative model for sleep/wake regulation.
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Affiliation(s)
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
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20
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Yu X, Franks NP, Wisden W. Sleep and Sedative States Induced by Targeting the Histamine and Noradrenergic Systems. Front Neural Circuits 2018; 12:4. [PMID: 29434539 PMCID: PMC5790777 DOI: 10.3389/fncir.2018.00004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/11/2018] [Indexed: 01/07/2023] Open
Abstract
Sedatives target just a handful of receptors and ion channels. But we have no satisfying explanation for how activating these receptors produces sedation. In particular, do sedatives act at restricted brain locations and circuitries or more widely? Two prominent sedative drugs in clinical use are zolpidem, a GABAA receptor positive allosteric modulator, and dexmedetomidine (DEX), a selective α2 adrenergic receptor agonist. By targeting hypothalamic neuromodulatory systems both drugs induce a sleep-like state, but in different ways: zolpidem primarily reduces the latency to NREM sleep, and is a controlled substance taken by many people to help them sleep; DEX produces prominent slow wave activity in the electroencephalogram (EEG) resembling stage 2 NREM sleep, but with complications of hypothermia and lowered blood pressure—it is used for long term sedation in hospital intensive care units—under DEX-induced sedation patients are arousable and responsive, and this drug reduces the risk of delirium. DEX, and another α2 adrenergic agonist xylazine, are also widely used in veterinary clinics to sedate animals. Here we review how these two different classes of sedatives, zolpidem and dexmedetomideine, can selectively interact with some nodal points of the circuitry that promote wakefulness allowing the transition to NREM sleep. Zolpidem enhances GABAergic transmission onto histamine neurons in the hypothalamic tuberomammillary nucleus (TMN) to hasten the transition to NREM sleep, and DEX interacts with neurons in the preoptic hypothalamic area that induce sleep and body cooling. This knowledge may aid the design of more precise acting sedatives, and at the same time, reveal more about the natural sleep-wake circuitry.
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Affiliation(s)
- Xiao Yu
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Nicholas P Franks
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Centre for Neurotechnology, Imperial College London, London, United Kingdom.,UK Dementia Research Institute, Imperial College London, London, United Kingdom
| | - William Wisden
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Centre for Neurotechnology, Imperial College London, London, United Kingdom.,UK Dementia Research Institute, Imperial College London, London, United Kingdom
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21
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22
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Locus Coeruleus and Dopamine-Dependent Memory Consolidation. Neural Plast 2017; 2017:8602690. [PMID: 29123927 PMCID: PMC5662828 DOI: 10.1155/2017/8602690] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/06/2017] [Accepted: 06/18/2017] [Indexed: 12/12/2022] Open
Abstract
Most everyday memories including many episodic-like memories that we may form automatically in the hippocampus (HPC) are forgotten, while some of them are retained for a long time by a memory stabilization process, called initial memory consolidation. Specifically, the retention of everyday memory is enhanced, in humans and animals, when something novel happens shortly before or after the time of encoding. Converging evidence has indicated that dopamine (DA) signaling via D1/D5 receptors in HPC is required for persistence of synaptic plasticity and memory, thereby playing an important role in the novelty-associated memory enhancement. In this review paper, we aim to provide an overview of the key findings related to D1/D5 receptor-dependent persistence of synaptic plasticity and memory in HPC, especially focusing on the emerging evidence for a role of the locus coeruleus (LC) in DA-dependent memory consolidation. We then refer to candidate brain areas and circuits that might be responsible for detection and transmission of the environmental novelty signal and molecular and anatomical evidence for the LC-DA system. We also discuss molecular mechanisms that might mediate the environmental novelty-associated memory enhancement, including plasticity-related proteins that are involved in initial memory consolidation processes in HPC.
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23
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Ulke C, Huang J, Schwabedal JTC, Surova G, Mergl R, Hensch T. Coupling and dynamics of cortical and autonomic signals are linked to central inhibition during the wake-sleep transition. Sci Rep 2017; 7:11804. [PMID: 28924202 PMCID: PMC5603599 DOI: 10.1038/s41598-017-09513-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/25/2017] [Indexed: 01/04/2023] Open
Abstract
Maintaining temporal coordination across physiological systems is crucial at the wake-sleep transition. As shown in recent studies, the degree of coordination between brain and autonomic arousal influences attention, which highlights a previously unrecognised point of potential failure in the attention system. To investigate how cortical and autonomic dynamics are linked to the attentive process we analysed electroencephalogram, electrocardiogram and skin conductance data of 39 healthy adults recorded during a 2-h resting-state oddball experiment. We related cross-correlations to fluctuation periods of cortical and autonomic signals and correlated obtained measures to event-related potentials N1 and P2, reflecting excitatory and inhibitory processes. Increasing alignment of cortical and autonomic signals and longer periods of vigilance fluctuations corresponded to a larger and earlier P2; no such relations were found for N1. We compared two groups, with (I) and without measurable (II) delay in cortico-autonomic correlations. Individuals in Group II had more stable vigilance fluctuations, larger and earlier P2 and fell asleep more frequently than individuals in Group I. Our results support the hypothesis of a link between cortico-autonomic coupling and dynamics and central inhibition. Quantifying this link could help refine classification in psychiatric disorders with attention and sleep-related symptoms, particularly in ADHD, depression, and insomnia.
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Affiliation(s)
- Christine Ulke
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany. .,Research Center of the German Depression Foundation, Leipzig, Germany.
| | - Jue Huang
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | | | - Galina Surova
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Roland Mergl
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
| | - Tilman Hensch
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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24
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Abstract
The discovery of the orexin system represents the single major progress in the sleep field of the last three to four decades. The two orexin peptides and their two receptors play a major role in arousal and sleep/wake cycles. Defects in the orexin system lead to narcolepsy with cataplexy in humans and dogs and can be experimentally reproduced in rodents. At least six orexin receptor antagonists have reached Phase II or Phase III clinical trials in insomnia, five of which are dual orexin receptor antagonists (DORAs) that target both OX1 and OX2 receptors (OX2Rs). All clinically tested DORAs induce and maintain sleep: suvorexant, recently registered in the USA and Japan for insomnia, represents the first hypnotic principle that acts in a completely different manner from the current standard medications. It is clear, however, that in the clinic, all DORAs promote sleep primarily by increasing rapid eye movement (REM) and are almost devoid of effects on slow-wave (SWS) sleep. At present, there is no consensus on whether the sole promotion of REM sleep has a negative impact in patients suffering from insomnia. However, sleep onset REM (SOREM), which has been documented with DORAs, is clearly an undesirable effect, especially for narcoleptic patients and also in fragile populations (e.g. elderly patients) where REM-associated loss of muscle tone may promote an elevated risk of falls. Debate thus remains as to the ideal orexin agent to achieve a balanced increase in REM and non-rapid eye movement (NREM) sleep. Here, we review the evidence that an OX2R antagonist should be at least equivalent, or perhaps superior, to a DORA for the treatment of insomnia. An OX2R antagonist may produce more balanced sleep than a DORA. Rodent sleep experiments show that the OX2R is the primary target of orexin receptor antagonists in sleep modulation. Furthermore, an OX2R antagonist should, in theory, have a lower narcoleptic/cataplexic potential. In the clinic, the situation remains equivocal, since OX2R antagonists are in early stages: MK-1064 has completed Phase I, and MIN202 is currently in clinical Phase II/III trials. However, data from insomnia patients have not yet been released. Promotional material suggests that balanced sleep is indeed induced by MIN-202, whereas in volunteers MK-1064 has been reported to act similarly to DORAs.
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Affiliation(s)
- Laura H Jacobson
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Sui Chen
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Sanjida Mir
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Daniel Hoyer
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, 30 Royal Parade, Parkville, VIC, 3052, Australia.
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
- Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA.
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25
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Optogenetic Investigation of Arousal Circuits. Int J Mol Sci 2017; 18:ijms18081773. [PMID: 28809797 PMCID: PMC5578162 DOI: 10.3390/ijms18081773] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 12/13/2022] Open
Abstract
Modulation between sleep and wake states is controlled by a number of heterogeneous neuron populations. Due to the topological proximity and genetic co-localization of the neurons underlying sleep-wake state modulation optogenetic methods offer a significant improvement in the ability to benefit from both the precision of genetic targeting and millisecond temporal control. Beginning with an overview of the neuron populations mediating arousal, this review outlines the progress that has been made in the investigation of arousal circuits since the incorporation of optogenetic techniques and the first in vivo application of optogenetic stimulation in hypocretin neurons in the lateral hypothalamus. This overview is followed by a discussion of the future progress that can be made by incorporating more recent technological developments into the research of neural circuits.
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26
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Elbaz I, Levitas-Djerbi T, Appelbaum L. The Hypocretin/Orexin Neuronal Networks in Zebrafish. Curr Top Behav Neurosci 2017; 33:75-92. [PMID: 28012092 DOI: 10.1007/7854_2016_59] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The hypothalamic Hypocretin/Orexin (Hcrt) neurons secrete two Hcrt neuropeptides. These neurons and peptides play a major role in the regulation of feeding, sleep wake cycle, reward-seeking, addiction, and stress. Loss of Hcrt neurons causes the sleep disorder narcolepsy. The zebrafish has become an attractive model to study the Hcrt neuronal network because it is a transparent vertebrate that enables simple genetic manipulation, imaging of the structure and function of neuronal circuits in live animals, and high-throughput monitoring of behavioral performance during both day and night. The zebrafish Hcrt network comprises ~16-60 neurons, which similar to mammals, are located in the hypothalamus and widely innervate the brain and spinal cord, and regulate various fundamental behaviors such as feeding, sleep, and wakefulness. Here we review how the zebrafish contributes to the study of the Hcrt neuronal system molecularly, anatomically, physiologically, and pathologically.
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Affiliation(s)
- Idan Elbaz
- The Mina & Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Talia Levitas-Djerbi
- The Mina & Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel
| | - Lior Appelbaum
- The Mina & Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel.
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27
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Lavezzi AM, Ferrero S, Roncati L, Matturri L, Pusiol T. Impaired orexin receptor expression in the Kölliker-Fuse nucleus in sudden infant death syndrome: possible involvement of this nucleus in arousal pathophysiology. Neurol Res 2016; 38:706-16. [PMID: 27353953 DOI: 10.1080/01616412.2016.1201632] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES As well known, the sudden infant death syndrome (SIDS) is characterized by the sudden death of a seemingly healthy infant during sleep, frequently resulted from a deficit in arousal phase. Awakening from sleep requires a fully developed and functioning neuronal respiratory network to modulate the ventilation as needed. The pontine Kölliker-Fuse nucleus (KFN) plays a pivotal role in breathing control, thanks to its interconnections with the widespread serotonin and noradrenaline neurons in the brainstem. Numerous studies to date have focused on the implication of orexin, a neuropeptide synthesized by neurons of the lateral hypothalamus, with major projections to the brainstem raphé nuclei and locus coeruleus, in arousal, a neurobiological process closely linked to breathing modifications. The aim of our research has been to demonstrate that also the KFN is a fundamental component of the orexin system, actively involved in arousal. METHODS We have evaluated the expression and distribution of the orexin receptors (orexin-1 and orexin-2 receptors) particularly in the rostral pons, where the KFN is located, of 25 SIDS cases and 18 controls. RESULTS An intense orexin-1 innervation around the KF neurons has been detected in almost all the controls and only in 20% of SIDS cases. DISCUSSION On the basis of these results, we believe that: (1) the KFN plays a leading role not only in providing a regular breathing rhythm but also in the coordination of the sleep-to-wake transition; (2) a defective orexin expression in the KFN could prevent arousal, thus assuming a crucial importance in causing SIDS.
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Affiliation(s)
- Anna Maria Lavezzi
- a 'Lino Rossi' Research Center for the study and prevention of unexpected perinatal death and SIDS, Department of Biomedical, Surgical and Dental Sciences , University of Milan , Milan , Italy
| | - Stefano Ferrero
- a 'Lino Rossi' Research Center for the study and prevention of unexpected perinatal death and SIDS, Department of Biomedical, Surgical and Dental Sciences , University of Milan , Milan , Italy.,b Division of Pathology , Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico , Milan , Italy
| | - Luca Roncati
- c Institute of Pathology, Hospital of Rovereto (Trento) , Italy.,d Department of Diagnostic and Clinical Medicine and of Public Health, Section of Pathology , University of Modena and Reggio Emilia, Policlinico Hospital , Modena , Italy
| | - Luigi Matturri
- a 'Lino Rossi' Research Center for the study and prevention of unexpected perinatal death and SIDS, Department of Biomedical, Surgical and Dental Sciences , University of Milan , Milan , Italy
| | - Teresa Pusiol
- c Institute of Pathology, Hospital of Rovereto (Trento) , Italy
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Ketamine and propofol have opposite effects on postanesthetic sleep architecture in rats: relevance to the endogenous sleep-wakefulness substances orexin and melanin-concentrating hormone. J Anesth 2016; 30:437-43. [PMID: 26984688 DOI: 10.1007/s00540-016-2161-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 03/08/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Anesthesia and surgery disturb sleep. Disturbed sleep adversely affects postoperative complications involving the cardiovascular system, diabetes, and infection. General anesthetics share neuronal mechanisms involving endogenous sleep-wakefulness-related substances, such as orexin (OX) and melanin-concentrating hormone (MCH). We evaluated changes in sleep architecture and the concentration of OX and MCH during the peri-anesthetic period. METHODS To examine sleep architecture, male Sprague-Dawley rats weighing 350-450 g received ketamine 100 mg/kg (n = 9) or propofol 80 mg/kg (n = 6) by intraperitoneal injection. Electroencephalography was recorded from 2 days pre- to 5 days postanesthesia. To quantify levels of OX and MCH, 144 similar rats received the same doses of ketamine (n = 80) or propofol (n = 64). Brain concentrations of these substances were determined at 0, 20, 60, and 120 min after anesthetic administration. RESULTS Ketamine decreased OX content in the hypothalamus during the anesthesia period. OX content was restored to pre-anesthesia levels in the hypothalamus and pons. Both anesthetics increased brain MCH content in the postanesthetic period, with the degree of increase being greater with propofol. Ketamine enhanced wakefulness and inhibited non-rapid eye movement sleep (NREMS) immediately after anesthesia. Conversely, propofol inhibited wakefulness and enhanced NREMS in that period. Ketamine inhibited wakefulness and enhanced NREMS during the dark phase on the first postanesthesia day. CONCLUSIONS Anesthetics affect various endogenous sleep-wakefulness-related substances; however, the modulation pattern may depend on the type of anesthetic. The process of postanesthetic sleep disturbance was agent specific. Our results provide fundamental evidence to treat anesthetic-related sleep disturbance.
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H1N1 influenza virus induces narcolepsy-like sleep disruption and targets sleep-wake regulatory neurons in mice. Proc Natl Acad Sci U S A 2015; 113:E368-77. [PMID: 26668381 DOI: 10.1073/pnas.1521463112] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An increased incidence in the sleep-disorder narcolepsy has been associated with the 2009-2010 pandemic of H1N1 influenza virus in China and with mass vaccination campaigns against influenza during the pandemic in Finland and Sweden. Pathogenetic mechanisms of narcolepsy have so far mainly focused on autoimmunity. We here tested an alternative working hypothesis involving a direct role of influenza virus infection in the pathogenesis of narcolepsy in susceptible subjects. We show that infection with H1N1 influenza virus in mice that lack B and T cells (Recombinant activating gene 1-deficient mice) can lead to narcoleptic-like sleep-wake fragmentation and sleep structure alterations. Interestingly, the infection targeted brainstem and hypothalamic neurons, including orexin/hypocretin-producing neurons that regulate sleep-wake stability and are affected in narcolepsy. Because changes occurred in the absence of adaptive autoimmune responses, the findings show that brain infections with H1N1 virus have the potential to cause per se narcoleptic-like sleep disruption.
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Song C, Knöpfel T. Optogenetics enlightens neuroscience drug discovery. Nat Rev Drug Discov 2015; 15:97-109. [DOI: 10.1038/nrd.2015.15] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Laque A, Yu S, Qualls-Creekmore E, Gettys S, Schwartzenburg C, Bui K, Rhodes C, Berthoud HR, Morrison CD, Richards BK, Münzberg H. Leptin modulates nutrient reward via inhibitory galanin action on orexin neurons. Mol Metab 2015; 4:706-17. [PMID: 26500842 PMCID: PMC4588437 DOI: 10.1016/j.molmet.2015.07.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 07/01/2015] [Accepted: 07/06/2015] [Indexed: 11/30/2022] Open
Abstract
Objective Leptin modulates food reward via central leptin receptor (LepRb) expressing neurons. Food reward requires stimulation of midbrain dopamine neurons and is modulated by central leptin action, but the exact central mechanisms remain unclear. Stimulatory and inhibitory leptin actions on dopamine neurons have been reported, e.g. by indirect actions on orexin neurons or via direct innervation of dopamine neurons in the ventral tegmental area. Methods We showed earlier that LepRb neurons in the lateral hypothalamus (LHA) co-express the inhibitory acting neuropeptide galanin (GAL-LepRb neurons). We studied the involvement of GAL-LepRb neurons to regulate nutrient reward in mice with selective LepRb deletion from galanin neurons (GAL-LepRbKO mice). Results We found that the rewarding value and preference for sucrose over fat was increased in GAL-LepRbKO mice compared to controls. LHA GAL-LepRb neurons innervate orexin neurons, but not the VTA. Further, expression of galanin and its receptor GalR1 are decreased in the LHA of GAL-LepRbKO mice, resulting in increased activation of orexin neurons. Conclusion We suggest galanin as an important mediator of leptin action to modulate nutrient reward by inhibiting orexin neurons. GAL-LepRbKO shows ↓ galanin and ↓ GalR1 mRNA, ↑ body weight gain. GAL-LepRbKO shows ↑ orexin/hypocretin neuronal activation. GAL-LepRb neurons innervate local orexin/hypocretin and noradrenergic locus coeruleus neurons. Leptin regulates natural reward and body weight via GAL-LepRb neurons.
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Affiliation(s)
- Amanda Laque
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Sangho Yu
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Emily Qualls-Creekmore
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Sarah Gettys
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Candice Schwartzenburg
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Kelly Bui
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | | | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Christopher D Morrison
- Neurosignaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Brenda K Richards
- Genetics of Eating Behavior Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
| | - Heike Münzberg
- Central Leptin Signaling Laboratory, Pennington Biomedical Research Center, LSU System, Baton Rouge, LA, USA
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Abstract
The sleep disorder narcolepsy is caused by the loss of orexinergic neurones in the lateral hypothalamus. A troublesome symptom of narcolepsy is cataplexy, the sudden loss of muscle tone in response to strong emotions. It can be alleviated by antidepressants and sodium oxybate (γ-hydroxybutyric acid (GHB)). It is likely that the noradrenergic nucleus locus coeruleus (LC) is involved since it is essential for the maintenance of muscle tone, and ceases to fire during cataplectic attacks. Furthermore, alpha-2 adrenoceptors proliferate in the LC in cataplexy, probably due to 'heterologous denervation supersensitivity' resulting from the loss/weakening of the orexinergic input to the LC. This would lead to the sensitization of the autoinhibition mechanism of LC neurones mediated by inhibitory alpha-2 adrenoceptors ('autoreceptors'). Thus the excitatory input from the amygdala to the LC, activated by an emotional stimulus, would lead to the 'switching off' of LC activity via the supersensitive auto-inhibition mechanism. GHB is an agonist at both γ-aminobutyric acid (GABA) GABA (B) and GHB receptors that may be a subtype of an extrasynaptic GABA(A) receptor. GHB may prevent a cataplectic attack by dampening the tone of LC neurones via the stimulation of inhibitory extrasynaptic GABA receptors in the LC, and thus increasing the threshold for autoinhibition.
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Affiliation(s)
- Elemer Szabadi
- Developmental Psychiatry, University of Nottingham, Nottingham, UK
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Abstract
Sleep and wake are fundamental behavioral states whose molecular regulation remains mysterious. Brain states and body functions change dramatically between sleep and wake, are regulated by circadian and homeostatic processes, and depend on the nutritional and emotional condition of the animal. Sleep-wake transitions require the coordination of several brain regions and engage multiple neurochemical systems, including neuropeptides. Neuropeptides serve two main functions in sleep-wake regulation. First, they represent physiological states such as energy level or stress in response to environmental and internal stimuli. Second, neuropeptides excite or inhibit their target neurons to induce, stabilize, or switch between sleep-wake states. Thus, neuropeptides integrate physiological subsystems such as circadian time, previous neuron usage, energy homeostasis, and stress and growth status to generate appropriate sleep-wake behaviors. We review the roles of more than 20 neuropeptides in sleep and wake to lay the foundation for future studies uncovering the mechanisms that underlie the initiation, maintenance, and exit of sleep and wake states.
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Affiliation(s)
- Constance Richter
- Department of Molecular and Cellular Biology, Center for Brain Science, Division of Sleep Biology, Harvard University, Cambridge, Massachusetts 02138; ,
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Sorooshyari S, Huerta R, de Lecea L. A Framework for Quantitative Modeling of Neural Circuits Involved in Sleep-to-Wake Transition. Front Neurol 2015; 6:32. [PMID: 25767461 PMCID: PMC4341569 DOI: 10.3389/fneur.2015.00032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/08/2015] [Indexed: 12/14/2022] Open
Abstract
Identifying the neuronal circuits and dynamics of sleep-to-wake transition is essential to understanding brain regulation of behavioral states, including sleep–wake cycles, arousal, and hyperarousal. Recent work by different laboratories has used optogenetics to determine the role of individual neuromodulators in state transitions. The optogenetically driven data do not yet provide a multi-dimensional schematic of the mechanisms underlying changes in vigilance states. This work presents a modeling framework to interpret, assist, and drive research on the sleep-regulatory network. We identify feedback, redundancy, and gating hierarchy as three fundamental aspects of this model. The presented model is expected to expand as additional data on the contribution of each transmitter to a vigilance state becomes available. Incorporation of conductance-based models of neuronal ensembles into this model and existing models of cortical excitability will provide more comprehensive insight into sleep dynamics as well as sleep and arousal-related disorders.
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Affiliation(s)
| | - Ramón Huerta
- BioCircuits Institute, University of California San Diego , La Jolla, CA , USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine , Stanford, CA , USA
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35
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Zhang Z, Ferretti V, Güntan İ, Moro A, Steinberg EA, Ye Z, Zecharia AY, Yu X, Vyssotski AL, Brickley SG, Yustos R, Pillidge ZE, Harding EC, Wisden W, Franks NP. Neuronal ensembles sufficient for recovery sleep and the sedative actions of α2 adrenergic agonists. Nat Neurosci 2015; 18:553-561. [PMID: 25706476 PMCID: PMC4836567 DOI: 10.1038/nn.3957] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/21/2015] [Indexed: 12/31/2022]
Abstract
Do sedatives engage natural sleep pathways? It is usually assumed that anesthetic-induced sedation and loss-of-righting-reflex (LORR) arise by influencing the same circuitry to lesser or greater extents. For the α2 adrenergic receptor agonist dexmedetomidine, we find that sedation and LORR are in fact distinct states, requiring different brain areas, the preoptic hypothalamic area and locus coeruleus (LC) respectively. Selective knockdown of α2A adrenergic receptors from the LC abolished dexmedetomidine-induced LORR, but not sedation. Instead, we found that dexmedetomidine-induced sedation resembles the deep recovery sleep that follows sleep deprivation. We used TetTag-pharmacogenetics in mice to functionally mark neurons activated in the preoptic hypothalamus during dexmedetomidine-induced sedation or recovery sleep. The neuronal ensembles could then be selectively reactivated. In both cases NREM sleep, with the accompanying drop in body temperature, was recapitulated. Thus α2 adrenergic receptor-induced sedation and recovery sleep share hypothalamic circuitry sufficient for producing these behavioral states.
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Affiliation(s)
- Zhe Zhang
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Valentina Ferretti
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - İlke Güntan
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Alessandro Moro
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Eleonora A Steinberg
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Zhiwen Ye
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Anna Y Zecharia
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Xiao Yu
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zürich/ETH Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Stephen G Brickley
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Raquel Yustos
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Zoe E Pillidge
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Edward C Harding
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - William Wisden
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
| | - Nicholas P Franks
- Department of Life Sciences Imperial College London, South Kensington, SW7 2AZ, U.K
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Xie XS. The neuronal circuit between nociceptin/orphanin FQ and hypocretins/orexins coordinately modulates stress-induced analgesia and anxiety-related behavior. VITAMINS AND HORMONES 2015; 97:295-321. [PMID: 25677777 DOI: 10.1016/bs.vh.2014.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The neuropeptide nociceptin/orphanin FQ (N/OFQ), acting on its receptors (NOP), modulates a variety of biological functions and neurobehavior including nociception, stress responses, water and food-intake, locomotor activity, and spatial attention. N/OFQ is conventionally regarded as an "antiopiate" peptide in the brain because central administration of N/OFQ attenuates stress-induced analgesia (SIA) and produces anxiolytic effects. However, naloxone-irreversible SIA and anxiolytic action are unlikely to be mediated by the opiate system. Both N/OFQ and NOP receptors are expressed most abundantly in the hypothalamus, where two other neuropeptides, the hypocretins/orexins (Hcrts), are exclusively synthesized in the lateral hypothalamic area. N/OFQ and Hcrt regulate most cellular physiological responses in opposite directions (e.g., ion channel modulation and second messenger coupling), and produce differential modulations for almost all neurobehavior assessed, including sleep/wake, locomotion, and rewarding behaviors. This chapter focuses on recent studies that provide evidence at a neuroanatomical level showing that a local neuronal circuit linking N/OFQ to Hcrt neurons exists. Functionally, N/OFQ depresses Hcrt neuronal activity at the cellular level, and modulates stress responses, especially SIA and anxiety-related behavior in the whole organism. N/OFQ exerts its attenuation of SIA and anxiolytic action on fear-induced anxiety through direct modulation of Hcrt neuronal activity. The information obtained from these studies has provided insights into how interaction between the Hcrt and N/OFQ systems positively and negatively modulates the complex and integrated stress responses.
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Affiliation(s)
- Xinmin Simon Xie
- AfaSci Research Laboratories, Redwood City, California, USA; Department of Anesthesia, Stanford University School of Medicine, Stanford, California, USA.
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Levitas-Djerbi T, Yelin-Bekerman L, Lerer-Goldshtein T, Appelbaum L. Hypothalamic leptin-neurotensin-hypocretin neuronal networks in zebrafish. J Comp Neurol 2015; 523:831-48. [PMID: 25421126 DOI: 10.1002/cne.23716] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/17/2014] [Accepted: 11/20/2014] [Indexed: 01/11/2023]
Abstract
Neurotensin (NTS) is a 13 amino acid neuropeptide that is expressed in the hypothalamus. In mammals, NTS-producing neurons that express leptin receptor (LepRb) regulate the function of hypocretin/orexin (HCRT) and dopamine neurons. Thus, the hypothalamic leptin-NTS-HCRT neuronal network orchestrates key homeostatic output, including sleep, feeding, and reward. However, the intricate mechanisms of the circuitry and the unique role of NTS-expressing neurons remain unclear. We studied the NTS neuronal networks in zebrafish and cloned the genes encoding the NTS neuropeptide and receptor (NTSR). Similar to mammals, the ligand is expressed primarily in the hypothalamus, while the receptor is expressed widely throughout the brain in zebrafish. A portion of hypothalamic nts-expressing neurons are inhibitory and some coexpress leptin receptor (lepR1). As in mammals, NTS and HCRT neurons are localized adjacently in the hypothalamus. To track the development and axonal projection of NTS neurons, the NTS promoter was isolated. Transgenesis and double labeling of NTS and HCRT neurons showed that NTS axons project toward HCRT neurons, some of which express ntsr. Moreover, another target of NTS neurons is ntsr-expressing dopaminergeric neurons. These findings suggest structural circuitry between leptin, NTS, and hypocretinergic or dopaminergic neurons and establish the zebrafish as a model to study the role of these neuronal circuits in the regulation of feeding, sleep, and reward.
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Affiliation(s)
- Talia Levitas-Djerbi
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 5290002, Israel; The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 5290002, Israel
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What optogenetic stimulation is telling us (and failing to tell us) about fast neurotransmitters and neuromodulators in brain circuits for wake-sleep regulation. Curr Opin Neurobiol 2014; 29:165-71. [PMID: 25064179 DOI: 10.1016/j.conb.2014.07.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 07/07/2014] [Accepted: 07/07/2014] [Indexed: 12/19/2022]
Abstract
In the last eight years optogenetic tools have been widely used to identify functional synaptic connectivity between specific neuronal populations. Most of our knowledge comes from the photo-activation of channelrhodopsin-2 (ChR2) expressing inputs that release glutamate and GABA. More recent studies have been reporting releases of acetylcholine and biogenic amines but direct evidence for photo-evoked released of neuropeptides is still limited particularly in brain slice studies. The high fidelity in the responses with photo-evoked amino-acid transmission is ideal for ChR2-assisted circuit mapping and this approach has been successfully used in different fields of neuroscience. Conversely, neuropeptides employ a slow mode of communication and might require higher frequency and prolonged stimulations to be released. These factors may have contributed to the apparent lack of success for optogenetic release of neuropeptides. In addition, once released, neuropeptides often act on multiple sites and at various distances from the site of release resulting in a greater complexity of postsynaptic responses. Here, we focus on what optogenetics is telling us-and failing to tell us-about fast neurotransmitters and neuropeptides.
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Castro DC, Berridge KC. Advances in the neurobiological bases for food 'liking' versus 'wanting'. Physiol Behav 2014; 136:22-30. [PMID: 24874776 DOI: 10.1016/j.physbeh.2014.05.022] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 04/29/2014] [Accepted: 05/19/2014] [Indexed: 02/04/2023]
Abstract
The neural basis of food sensory pleasure has become an increasingly studied topic in neuroscience and psychology. Progress has been aided by the discovery of localized brain subregions called hedonic hotspots in the early 2000s, which are able to causally amplify positive affective reactions to palatable tastes ('liking') in response to particular neurochemical or neurobiological stimulations. Those hedonic mechanisms are at least partly distinct from larger mesocorticolimbic circuitry that generates the incentive motivation to eat ('wanting'). In this review, we aim to describe findings on these brain hedonic hotspots, especially in the nucleus accumbens and ventral pallidum, and discuss their role in generating food pleasure and appetite.
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Affiliation(s)
- D C Castro
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - K C Berridge
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109, USA
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40
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Weymann KB, Wood LJ, Zhu X, Marks DL. A role for orexin in cytotoxic chemotherapy-induced fatigue. Brain Behav Immun 2014; 37:84-94. [PMID: 24216337 PMCID: PMC3951615 DOI: 10.1016/j.bbi.2013.11.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/16/2013] [Accepted: 11/01/2013] [Indexed: 02/08/2023] Open
Abstract
Fatigue is the most common symptom related to cytotoxic chemotherapeutic treatment of cancer. Peripheral inflammation associated with cytotoxic chemotherapy is likely a causal factor of fatigue. The neural mechanisms by which cytotoxic chemotherapy associated inflammation induces fatigue behavior are not known. This lack of knowledge hinders development of interventions to reduce or prevent this disabling symptom. Infection induced fatigue/lethargy in rodents is mediated by suppression of hypothalamic orexin activity. Orexin is critical for maintaining wakefulness and motivated behavior. Though there are differences between infection and cytotoxic chemotherapy in some symptoms, both induce peripheral inflammation and fatigue. Based on these similarities we hypothesized that cytotoxic chemotherapy induces fatigue by disrupting orexin neuron activity. We found that a single dose of a cytotoxic chemotherapy cocktail (cyclophosphamide, adriamycin, 5-fluorouracil - CAF) induced fatigue/lethargy in mice and rats as evidenced by a significant decline in voluntary locomotor activity measured by telemetry. CAF induced inflammatory gene expression - IL-1R1 (p<0.001), IL-6 (p<0.01), TNFα (p<0.01), and MCP-1 (p<0.05) - in the rodent hypothalamus 6-24h after treatment during maximum fatigue/lethargy. CAF decreased orexin neuron activity as reflected by decreased nuclear cFos localization in orexin neurons 24h after treatment (p<0.05) and by decreased orexin-A in cerebrospinal fluid 16 h after treatment (p<0.001). Most importantly, we found that central administration of 1 μg orexin-A restored activity in CAF-treated rats (p<0.05). These results demonstrate that cytotoxic chemotherapy induces hypothalamic inflammation and that suppression of hypothalamic orexin neuron activity has a causal role in cytotoxic chemotherapy-induced fatigue in rodents.
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Affiliation(s)
- K B Weymann
- Oregon Health & Science University, Portland, OR 97239, United States.
| | - L J Wood
- Oregon Health & Science University, Portland, OR 97239, United States; School of Nursing, MGH Institute of Health Professions, Boston, MA 02129, United States.
| | - X Zhu
- Oregon Health & Science University, Portland, OR 97239, United States.
| | - D L Marks
- Oregon Health & Science University, Portland, OR 97239, United States.
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Woods IG, Schoppik D, Shi VJ, Zimmerman S, Coleman HA, Greenwood J, Soucy ER, Schier AF. Neuropeptidergic signaling partitions arousal behaviors in zebrafish. J Neurosci 2014; 34:3142-60. [PMID: 24573274 PMCID: PMC3935080 DOI: 10.1523/jneurosci.3529-13.2014] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 01/01/2014] [Accepted: 01/07/2014] [Indexed: 11/21/2022] Open
Abstract
Animals modulate their arousal state to ensure that their sensory responsiveness and locomotor activity match environmental demands. Neuropeptides can regulate arousal, but studies of their roles in vertebrates have been constrained by the vast array of neuropeptides and their pleiotropic effects. To overcome these limitations, we systematically dissected the neuropeptidergic modulation of arousal in larval zebrafish. We quantified spontaneous locomotor activity and responsiveness to sensory stimuli after genetically induced expression of seven evolutionarily conserved neuropeptides, including adenylate cyclase activating polypeptide 1b (adcyap1b), cocaine-related and amphetamine-related transcript (cart), cholecystokinin (cck), calcitonin gene-related peptide (cgrp), galanin, hypocretin, and nociceptin. Our study reveals that arousal behaviors are dissociable: neuropeptide expression uncoupled spontaneous activity from sensory responsiveness, and uncovered modality-specific effects upon sensory responsiveness. Principal components analysis and phenotypic clustering revealed both shared and divergent features of neuropeptidergic functions: hypocretin and cgrp stimulated spontaneous locomotor activity, whereas galanin and nociceptin attenuated these behaviors. In contrast, cart and adcyap1b enhanced sensory responsiveness yet had minimal impacts on spontaneous activity, and cck expression induced the opposite effects. Furthermore, hypocretin and nociceptin induced modality-specific differences in responsiveness to changes in illumination. Our study provides the first systematic and high-throughput analysis of neuropeptidergic modulation of arousal, demonstrates that arousal can be partitioned into independent behavioral components, and reveals novel and conserved functions of neuropeptides in regulating arousal.
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Affiliation(s)
- Ian G. Woods
- Department of Biology, Ithaca College, Ithaca, New York 14850, and
- Department of Molecular and Cellular Biology and
| | | | | | | | - Haley A. Coleman
- Department of Biology, Ithaca College, Ithaca, New York 14850, and
| | - Joel Greenwood
- Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
| | - Edward R. Soucy
- Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
| | - Alexander F. Schier
- Department of Molecular and Cellular Biology and
- Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
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Physiologically-based modeling of sleep-wake regulatory networks. Math Biosci 2014; 250:54-68. [PMID: 24530893 DOI: 10.1016/j.mbs.2014.01.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 01/23/2014] [Accepted: 01/31/2014] [Indexed: 12/27/2022]
Abstract
Mathematical modeling has played a significant role in building our understanding of sleep-wake and circadian behavior. Over the past 40 years, phenomenological models, including the two-process model and oscillator models, helped frame experimental results and guide progress in understanding the interaction of homeostatic and circadian influences on sleep and understanding the generation of rapid eye movement sleep cycling. Recent advances in the clarification of the neural anatomy and physiology involved in the regulation of sleep and circadian rhythms have motivated the development of more detailed and physiologically-based mathematical models that extend the approach introduced by the classical reciprocal-interaction model. Using mathematical formalisms developed in the field of computational neuroscience to model neuronal population activity, these models investigate the dynamics of proposed conceptual models of sleep-wake regulatory networks with a focus on generating appropriate sleep and wake state transition patterns as well as simulating disease states and experimental protocols. In this review, we discuss several recent physiologically-based mathematical models of sleep-wake regulatory networks. We identify common features among these models in their network structures, model dynamics and approaches for model validation. We describe how the model analysis technique of fast-slow decomposition, which exploits the naturally occurring multiple timescales of sleep-wake behavior, can be applied to understand model dynamics in these networks. Our purpose in identifying commonalities among these models is to propel understanding of both the mathematical models and their underlying conceptual models, and focus directions for future experimental and theoretical work.
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Khan AM. Controlling feeding behavior by chemical or gene-directed targeting in the brain: what's so spatial about our methods? Front Neurosci 2013; 7:182. [PMID: 24385950 PMCID: PMC3866545 DOI: 10.3389/fnins.2013.00182] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 09/20/2013] [Indexed: 12/26/2022] Open
Abstract
Intracranial chemical injection (ICI) methods have been used to identify the locations in the brain where feeding behavior can be controlled acutely. Scientists conducting ICI studies often document their injection site locations, thereby leaving kernels of valuable location data for others to use to further characterize feeding control circuits. Unfortunately, this rich dataset has not yet been formally contextualized with other published neuroanatomical data. In particular, axonal tracing studies have delineated several neural circuits originating in the same areas where ICI injection feeding-control sites have been documented, but it remains unclear whether these circuits participate in feeding control. Comparing injection sites with other types of location data would require careful anatomical registration between the datasets. Here, a conceptual framework is presented for how such anatomical registration efforts can be performed. For example, by using a simple atlas alignment tool, a hypothalamic locus sensitive to the orexigenic effects of neuropeptide Y (NPY) can be aligned accurately with the locations of neurons labeled by anterograde tracers or those known to express NPY receptors or feeding-related peptides. This approach can also be applied to those intracranial "gene-directed" injection (IGI) methods (e.g., site-specific recombinase methods, RNA expression or interference, optogenetics, and pharmacosynthetics) that involve viral injections to targeted neuronal populations. Spatial alignment efforts can be accelerated if location data from ICI/IGI methods are mapped to stereotaxic brain atlases to allow powerful neuroinformatics tools to overlay different types of data in the same reference space. Atlas-based mapping will be critical for community-based sharing of location data for feeding control circuits, and will accelerate our understanding of structure-function relationships in the brain for mammalian models of obesity and metabolic disorders.
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Affiliation(s)
- Arshad M. Khan
- UTEP Systems Neuroscience Laboratory, Department of Biological Sciences, Border Biomedical Research Center, University of Texas at El PasoEl Paso, TX, USA
- Neurobiology Section, Department of Biological Sciences, University of Southern CaliforniaLos Angeles, CA, USA
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Tortorella S, Rodrigo-Angulo ML, Núñez A, Garzón M. Synaptic interactions between perifornical lateral hypothalamic area, locus coeruleus nucleus and the oral pontine reticular nucleus are implicated in the stage succession during sleep-wakefulness cycle. Front Neurosci 2013; 7:216. [PMID: 24311996 PMCID: PMC3832796 DOI: 10.3389/fnins.2013.00216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 10/30/2013] [Indexed: 11/14/2022] Open
Abstract
The perifornical area in the posterior lateral hypothalamus (PeFLH) has been implicated in several physiological functions including the sleep-wakefulness regulation. The PeFLH area contains several cell types including those expressing orexins (Orx; also known as hypocretins), mainly located in the PeF nucleus. The aim of the present study was to elucidate the synaptic interactions between Orx neurons located in the PeFLH area and different brainstem neurons involved in the generation of wakefulness and sleep stages such as the locus coeruleus (LC) nucleus (contributing to wakefulness) and the oral pontine reticular nucleus (PnO) nucleus (contributing to REM sleep). Anatomical data demonstrated the existence of a neuronal network involving the PeFLH area, LC, and the PnO nuclei that would control the sleep-wake cycle. Electrophysiological experiments indicated that PeFLH area had an excitatory effect on LC neurons. PeFLH stimulation increased the firing rate of LC neurons and induced an activation of the EEG. The excitatory effect evoked by PeFLH stimulation in LC neurons was blocked by the injection of the Orx-1 receptor antagonist SB-334867 into the LC. Similar electrical stimulation of the PeFLH area evoked an inhibition of PnO neurons by activation of GABAergic receptors because the effect was blocked by bicuculline application into the PnO. Our data also revealed that the LC and PnO nuclei exerted a feedback control on neuronal activity of PeFLH area. Electrical stimulation of LC facilitated firing activity of PeFLH neurons by activation of catecholaminergic receptors whereas PnO stimulation inhibited PeFLH neurons by activation of GABAergic receptors. In conclusion, Orx neurons of the PeFLH area seem to be an important organizer of the wakefulness and sleep stages in order to maintain a normal succession of stages during the sleep-wakefulness cycle.
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Affiliation(s)
- Silvia Tortorella
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Research Institute, Universidad Autonoma de Madrid, La Paz University Hospital (IDIPAZ) Madrid, Spain
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Shah C, Sharma TR, Kablinger A. Controversies in the use of second generation antipsychotics as sleep agent. Pharmacol Res 2013; 79:1-8. [PMID: 24184858 DOI: 10.1016/j.phrs.2013.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 10/15/2013] [Accepted: 10/21/2013] [Indexed: 10/26/2022]
Abstract
A growing number of patients present in clinics with complaints of insomnia. Over the past century, great advances have been made in our knowledge of mechanisms of sleep and wakefulness. Understanding sleep neurochemistry has led to better management of different types of insomnias with a variety of non-pharmacological and pharmacological treatments. Unfortunately, the increasing development and availability of second generation antipsychotics (SGA) have prompted their frequent use exclusively for insomnia. However, to date, no large randomized-controlled or placebo-controlled studies have shown the utility of SGAs in the realm of treating insomnia. Many clinicians use SGAs as "off-label" for sleep induction and maintenance, but this practice needs to be readdressed given their potential risks and the current lack of evidence base. This review will highlight the neurochemistry related to sleep, the mechanisms of action by which SGA may have some benefit in treating insomnia, and the risks associated with their utilization.
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Affiliation(s)
- Chintan Shah
- Carilion Clinic Virginia Tech-Carilion School of Medicine, Psychiatry Residency Program, Roanoke, VA, United States
| | - Taral R Sharma
- Carilion Clinic Virginia Tech-Carilion School of Medicine, Psychiatry Residency Program, Roanoke, VA, United States
| | - Anita Kablinger
- Carilion Clinic Virginia Tech-Carilion School of Medicine, Psychiatry Residency Program, Roanoke, VA, United States.
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Role of attention in the generation and modulation of tinnitus. Neurosci Biobehav Rev 2013; 37:1754-73. [DOI: 10.1016/j.neubiorev.2013.07.007] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 06/24/2013] [Accepted: 07/11/2013] [Indexed: 01/23/2023]
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