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Plancoulaine S, Guyon A, Inocente CO, Germe P, Zhang M, Robert P, Lin JS, Franco P. Cerebrospinal Fluid Histamine Levels in Healthy Children and Potential Implication for SIDS: Observational Study in a French Tertiary Care Hospital. Front Pediatr 2022; 10:819496. [PMID: 35450108 PMCID: PMC9016218 DOI: 10.3389/fped.2022.819496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 03/09/2022] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE A defect of the waking systems could constitute a factor of vulnerability for sudden infant death syndrome (SIDS). A decrease in orexin levels, which promotes wakefulness and activates histaminergic neurons (another hypothalamic wake-promoting system) has already been demonstrated between 2 and 6 months. This work aims to study the levels of histamine (HA), tele-methylhistamine (t-MeHA), its direct metabolite, and t-MeHA/HA ratio in the cerebrospinal fluid (CSF) of healthy children, to evaluate the maturation of the histaminergic system and its possible involvement in SIDS. METHODS Seventy Eight French children between 0 and 20 years (48.7% boys) were included, all of whom had a clinical indication for lumbar puncture, but subsequently found to be normal. Measurements of HA and t-MeHA in CSF were performed by reverse phase liquid chromatography coupled to mass spectrometry detection. Statistical analyses were performed using Spearman correlations and Non-parametric pairwise ranking tests. RESULTS A negative correlation was found between age and CSF HA (r = -0.44, p < 10-4) and t-MeHA (r = -0.70, p < 10-4) levels. In pairwise comparisons, no difference in CSF HA and t-MeHA levels was observed between youngest age groups (i.e., 0-2 mo vs. 3-6 mo), but CSF HA and t-MeHA levels were significantly lower in older children (i.e., >6 mo vs. 0-6 mo). The CSF HA decrease with age was only observed in boys, who also presented global lower CSF HA levels than girls. CONCLUSION CSF HA and t-MeHA levels decrease with age in boys, and global levels are lower in boys than in girls. These results reveal changes in histaminergic transmission and metabolism during maturation. Whether lower CSF histamine values in boys compared to girls could contribute to their higher risk of SIDS warrants further research.
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Affiliation(s)
| | - Aurore Guyon
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France.,Bioprojet Biotech, Saint-Grégoire, France
| | - Clara-Odilia Inocente
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France
| | - Philippine Germe
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France
| | - Min Zhang
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France
| | | | - Jian-Sheng Lin
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France
| | - Patricia Franco
- Integrative Physiology of the Brain Arousal System, CRNL, INSERM-U1028, CNRS UMR5292, University Lyon 1, Lyon, France.,Pediatric Sleep Unit, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, University Lyon 1, Lyon, France
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Tang H, Zhu Q, Li W, Qin S, Gong Y, Wang H, Shioda S, Li S, Huang J, Liu B, Fang Y, Liu Y, Wang S, Guo Y, Xia Q, Guo Y, Xu Z. Neurophysiology and Treatment of Disorders of Consciousness Induced by Traumatic Brain Injury: Orexin Signaling as a Potential Therapeutic Target. Curr Pharm Des 2020; 25:4208-4220. [PMID: 31663471 DOI: 10.2174/1381612825666191029101830] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/21/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Traumatic brain injury (TBI) can cause disorders of consciousness (DOC) by impairing the neuronal circuits of the ascending reticular activating system (ARAS) structures, including the hypothalamus, which are responsible for the maintenance of the wakefulness and awareness. However, the effectiveness of drugs targeting ARAS activation is still inadequate, and novel therapeutic modalities are urgently needed. METHODS The goal of this work is to describe the neural loops of wakefulness, and explain how these elements participate in DOC, with emphasis on the identification of potential new therapeutic options for DOC induced by TBI. RESULTS Hypothalamus has been identified as a sleep/wake center, and its anterior and posterior regions have diverse roles in the regulation of the sleep/wake function. In particular, the posterior hypothalamus (PH) possesses several types of neurons, including the orexin neurons in the lateral hypothalamus (LH) with widespread projections to other wakefulness-related regions of the brain. Orexins have been known to affect feeding and appetite, and recently their profound effect on sleep disorders and DOC has been identified. Orexin antagonists are used for the treatment of insomnia, and orexin agonists can be used for narcolepsy. Additionally, several studies demonstrated that the agonists of orexin might be effective in the treatment of DOC, providing novel therapeutic opportunities in this field. CONCLUSION The hypothalamic-centered orexin has been adopted as the point of entry into the system of consciousness control, and modulators of orexin signaling opened several therapeutic opportunities for the treatment of DOC.
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Affiliation(s)
- Huiling Tang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qiumei Zhu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Wei Li
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Siru Qin
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yinan Gong
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Hong Wang
- Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Seiji Shioda
- Peptide Drug Innovation, Global Research Center for Innovative Life Science, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa, Tokyo 142-8501, Japan
| | - Shanshan Li
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Jin Huang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Baohu Liu
- Department of Rehabilitation, Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuxin Fang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yangyang Liu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Shenjun Wang
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yongming Guo
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Qing Xia
- Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi Guo
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,College of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Zhifang Xu
- Acupuncture Research Center, Tianjin University of Traditional Chinese Medicine, Tianjin, China.,Acu-moxibustion and Tuina Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
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Kovalzon VM. Functional neurochemistry of sleep—waking cycle in pathogenesis of neurological diseases. Zh Nevrol Psikhiatr Im S S Korsakova 2017; 117:5-11. [DOI: 10.17116/jnevro2017117425-11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Parmentier R, Zhao Y, Perier M, Akaoka H, Lintunen M, Hou Y, Panula P, Watanabe T, Franco P, Lin JS. Role of histamine H1-receptor on behavioral states and wake maintenance during deficiency of a brain activating system: A study using a knockout mouse model. Neuropharmacology 2015; 106:20-34. [PMID: 26723880 DOI: 10.1016/j.neuropharm.2015.12.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 12/10/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
Abstract
Using knockout (KO) mice lacking the histamine (HA)-synthesizing enzyme (histidine decarboxylase, HDC), we have previously shown the importance of histaminergic neurons in maintaining wakefulness (W) under behavioral challenges. Since the central actions of HA are mediated by several receptor subtypes, it remains to be determined which one(s) could be responsible for such a role. We have therefore compared the cortical-EEG, sleep and W under baseline conditions or behavioral/pharmacological stimuli in littermate wild-type (WT) and H1-receptor KO (H1-/-) mice. We found that H1-/- mice shared several characteristics with HDC KO mice, i.e. 1) a decrease in W after lights-off despite its normal baseline daily amount; 2) a decreased EEG slow wave sleep (SWS)/W power ratio; 3) inability to maintain W in response to behavioral challenges demonstrated by a decreased sleep latency when facing various stimuli. These effects were mediated by central H1-receptors. Indeed, in WT mice, injection of triprolidine, a brain-penetrating H1-receptor antagonist increased SWS, whereas ciproxifan (H3-receptor antagonist/inverse agonist) elicited W; all these injections had no effect in H1-/- mice. Finally, H1-/- mice showed markedly greater changes in EEG power (notably in the 0.8-5 Hz band) and sleep-wake cycle than in WT mice after application of a cholinergic antagonist or an indirect agonist, i.e., scopolamine or physostigmine. Hence, the role of HA in wake-promotion is largely ensured by H1-receptors. An upregulated cholinergic system may account for a quasi-normal daily amount of W in HDC or H1-receptor KO mice and likely constitutes a major compensatory mechanism when the brain is facing deficiency of an activating system. This article is part of the Special Issue entitled 'Histamine Receptors'.
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Affiliation(s)
- Régis Parmentier
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France
| | - Yan Zhao
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France; Department of Physiology, Zhongshan Medical College, Sun Yat-Sen University, Guangzhou, China
| | - Magali Perier
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France
| | - Hideo Akaoka
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France
| | - Minnamaija Lintunen
- Department of Anatomy and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Yiping Hou
- Department of Neuroscience, Anatomy, Histology & Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Pertti Panula
- Department of Anatomy and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Takeshi Watanabe
- Unit for Immune Surveillance Research, Research Center for Allergy and Immunology, RIKEN Institute, Tsurumi-ku, Yokohama, Japan
| | - Patricia Franco
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France
| | - Jian-Sheng Lin
- Waking Team, Integrative Physiology of the Brain Arousal Systems, CRNL, INSERM-U1028, CNRS UMR5292, School of Medicine, Claude Bernard University, Lyon, France.
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Yu L, Zhang XY, Cao SL, Peng SY, Ji DY, Zhu JN, Wang JJ. Na(+) -Ca(2+) Exchanger, Leak K(+) Channel and Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel Comediate the Histamine-Induced Excitation on Rat Inferior Vestibular Nucleus Neurons. CNS Neurosci Ther 2015; 22:184-93. [PMID: 26387685 DOI: 10.1111/cns.12451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 08/11/2015] [Accepted: 08/14/2015] [Indexed: 12/11/2022] Open
Abstract
AIMS Antihistaminergic drugs have traditionally been used to treat vestibular disorders in the clinic. As a potential central target for antihistaminergic drugs, the inferior vestibular nucleus (IVN) is the largest subnucleus of the central vestibular nuclear complex and is considered responsible for vestibular-autonomic responses and integration of vestibular, cerebellar, and multisensory signals. However, the role of histamine on the IVN, particularly the underlying mechanisms, is still not clear. METHODS Using whole-cell patch-clamp recordings on rat brain slices, histamine-induced effect on IVN neurons and the underlying receptor and ionic mechanisms were investigated. RESULTS We found that histamine remarkably depolarized both spontaneous firing neurons and silent neurons in IVN via both histamine H1 and histamine H2 receptors. Furthermore, Na(+) -Ca(2+) exchangers (NCXs) and background leak K(+) channels linked to H1 receptors and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels coupled to H2 receptors comediate the histamine-induced depolarization on IVN neurons. CONCLUSION These results demonstrate the multiple ionic mechanisms underlying the excitatory modulation of histamine/central histaminergic system on IVN neurons and the related vestibular reflexes and functions. The findings also suggest potential targets for the treatment of vestibular disorders in the clinic, at the level of ionic channels in central vestibular nuclei.
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Affiliation(s)
- Lei Yu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Xiao-Yang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Shu-Liang Cao
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Shi-Yu Peng
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Deng-Yu Ji
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jing-Ning Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Jian-Jun Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biological Science and Technology, School of Life Sciences, Nanjing University, Nanjing, China
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Yang YC, Hu CC, Lai YC. Non-additive modulation of synaptic transmission by serotonin, adenosine, and cholinergic modulators in the sensory thalamus. Front Cell Neurosci 2015; 9:60. [PMID: 25852468 PMCID: PMC4360759 DOI: 10.3389/fncel.2015.00060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/09/2015] [Indexed: 11/13/2022] Open
Abstract
The thalamus relays sensory information to the cortex. Oscillatory activities of the thalamocortical network are modulated by monoamines, acetylcholine, and adenosine, and could be the key features characteristic of different vigilance states. Although the thalamus is almost always subject to the actions of more than just one neuromodulators, reports on the modulatory effect of coexisting neuromodulators on thalamic synaptic transmission are unexpectedly scarce. We found that, if present alone, monoamine or adenosine decreases retinothalamic synaptic strength and short-term depression, whereas cholinergic modulators generally enhance postsynaptic response to presynaptic activity. However, coexistence of different modulators tends to produce non-additive effect, not predictable based on the action of individual modulators. Acetylcholine, acting via nicotinic receptors, can interact with either serotonin or adenosine to abolish most short-term synaptic depression. Moreover, the coexistence of adenosine and monoamine, with or without acetylcholine, results in robustly decreased synaptic strength and transforms short-term synaptic depression to facilitation. These findings are consistent with a view that acetylcholine is essential for an "enriched" sensory flow through the thalamus, and the flow is trimmed down by concomitant monoamine or adenosine (presumably for the wakefulness and rapid-eye movement, or REM, sleep states, respectively). In contrast, concomitant adenosine and monoamine would lead to a markedly "deprived" (and high-pass filtered) sensory flow, and thus the dramatic decrease of monoamine may constitute the basic demarcation between non-REM and REM sleep. The collective actions of different neuromodulators on thalamic synaptic transmission thus could be indispensable for the understanding of network responsiveness in different vigilance states.
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Affiliation(s)
- Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan ; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan
| | - Chun-Chang Hu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan ; Department of Neurosurgery, Chang-Gung Memorial Hospital Linkou, Taiwan
| | - Yi-Chen Lai
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan
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Szabadi E. Selective targets for arousal-modifying drugs: implications for the treatment of sleep disorders. Drug Discov Today 2014; 19:701-8. [DOI: 10.1016/j.drudis.2014.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 11/21/2013] [Accepted: 01/02/2014] [Indexed: 12/11/2022]
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9
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Yang YC, Hu CC, Huang CS, Chou PY. Thalamic synaptic transmission of sensory information modulated by synergistic interaction of adenosine and serotonin. J Neurochem 2013; 128:852-63. [DOI: 10.1111/jnc.12499] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 01/01/2023]
Affiliation(s)
- Ya-Chin Yang
- Department of Biomedical Sciences; College of Medicine, Chang Gung University; Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Chun-Chang Hu
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Chen-Syuan Huang
- Department of Biomedical Sciences; College of Medicine, Chang Gung University; Tao-Yuan Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Tao-Yuan Taiwan
| | - Pei-Yu Chou
- Graduate Institute of Biomedical Sciences, College of Medicine; Chang Gung University; Tao-Yuan Taiwan
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10
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Motofei IG, Rowland DL. The ventral-hypothalamic input route: a common neural network for abstract cognition and sexuality. BJU Int 2013; 113:296-303. [PMID: 24053436 DOI: 10.1111/bju.12399] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Classically, external receptors of the body transmit information from the environment to the cerebral cortex via the thalamus. This review explains and argues that only concrete external information is transmitted from peripheral receptors to the cortex via a thalamic route, while abstract and sexual external information are actually transmitted from peripheral receptors to the cortex through a cognitive hypothalamic route. Sexual function typically implies participation of two distinct partners, ensuring reproduction in many species including humans. Human sexual response involves participation of multiple (environmental, biological, psychological) kinds of stimuli and processing, so the understanding of sexual control and response supposes integration between the classical physiological mechanisms with the more complex processes of our 'mind'. Cognition and sexuality are two relational functions, which are dependent on concrete (colours, sounds, etc.) and/or abstract (gestures, facial expression, how you move, the way you say something seemingly trivial, etc.) environmental cues. Abstract cues are encoded independent of the specific object features of the stimuli, suggesting that such cues should be transmitted and interpreted within the brain through a system different than the classical thalamo-cortical network that operates on concrete (material) information. Indeed, data show that the cerebral cortex is capable of interpreting two distinct (concrete and abstract) formats of information via distinct and non-compatible brain areas. We expand upon this abstract-concrete dichotomy of the brain, positing that the two distinct cortical networks should be uploaded with distinct information from the environment via two distinct informational input routes. These two routes would be represented by the two distinct routes of the ascending reticular activating system (ARAS), namely the classical/dorsal thalamic input route for concrete information and the ventral hypothalamic input route for abstract cognition and sexuality. Physiologically, the hypothalamic (dual-autonomic) route of the ARAS that processes abstract and sexual information is incompatible with the thalamic (somatic) route of the ARAS that processes concrete information, such that the two distinct routes would be needed to support the mind processes (awareness, consciousness, sexuality) through their own informational inputs from the environment. Informationally, the concrete external data are differentiated from abstract and sexual external data, so that they should be transmitted to cortex through distinct input routes. Pathologically, the hardware and/or software impairments of the hypothalamic default-mode network generate disturbed messages within the brain (related to information transmitted on this route), laying at the basis of mental and sexual disorders. The novel conceptualisations presented in the present paper help address issues surrounding the mind-brain dichotomy and, in doing so, suggest new possible avenues for exploration in the treatment and interventions for cognitive and sexual problems.
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Affiliation(s)
- Ion G Motofei
- Department of Surgery and Urology, St. Pantelimon Hospital and Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
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Abstract
The central noradrenergic neurone, like the peripheral sympathetic neurone, is characterized by a diffusely arborizing terminal axonal network. The central neurones aggregate in distinct brainstem nuclei, of which the locus coeruleus (LC) is the most prominent. LC neurones project widely to most areas of the neuraxis, where they mediate dual effects: neuronal excitation by α₁-adrenoceptors and inhibition by α₂-adrenoceptors. The LC plays an important role in physiological regulatory networks. In the sleep/arousal network the LC promotes wakefulness, via excitatory projections to the cerebral cortex and other wakefulness-promoting nuclei, and inhibitory projections to sleep-promoting nuclei. The LC, together with other pontine noradrenergic nuclei, modulates autonomic functions by excitatory projections to preganglionic sympathetic, and inhibitory projections to preganglionic parasympathetic neurones. The LC also modulates the acute effects of light on physiological functions ('photomodulation'): stimulation of arousal and sympathetic activity by light via the LC opposes the inhibitory effects of light mediated by the ventrolateral preoptic nucleus on arousal and by the paraventricular nucleus on sympathetic activity. Photostimulation of arousal by light via the LC may enable diurnal animals to function during daytime. LC neurones degenerate early and progressively in Parkinson's disease and Alzheimer's disease, leading to cognitive impairment, depression and sleep disturbance.
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Affiliation(s)
- Elemer Szabadi
- Division of Psychiatry, University of Nottingham, Nottingham, UK.
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GABAergic inhibition of histaminergic neurons regulates active waking but not the sleep-wake switch or propofol-induced loss of consciousness. J Neurosci 2012; 32:13062-75. [PMID: 22993424 DOI: 10.1523/jneurosci.2931-12.2012] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The activity of histaminergic neurons in the tuberomammillary nucleus (TMN) of the hypothalamus correlates with an animal's behavioral state and maintains arousal. We examined how GABAergic inputs onto histaminergic neurons regulate this behavior. A prominent hypothesis, the "flip-flop" model, predicts that increased and sustained GABAergic drive onto these cells promotes sleep. Similarly, because of the histaminergic neurons' key hub-like place in the arousal circuitry, it has also been suggested that anesthetics such as propofol induce loss of consciousness by acting primarily at histaminergic neurons. We tested both these hypotheses in mice by genetically removing ionotropic GABA(A) or metabotropic GABA(B) receptors from histidine decarboxylase-expressing neurons. At the cellular level, histaminergic neurons deficient in synaptic GABA(A) receptors were significantly more excitable and were insensitive to the anesthetic propofol. At the behavioral level, EEG profiles were recorded in nontethered mice over 24 h. Surprisingly, GABAergic transmission onto histaminergic neurons had no effect in regulating the natural sleep-wake cycle and, in the case of GABA(A) receptors, for propofol-induced loss of righting reflex. The latter finding makes it unlikely that the histaminergic TMN has a central role in anesthesia. GABA(B) receptors on histaminergic neurons were dispensable for all behaviors examined. Synaptic inhibition of histaminergic cells by GABA(A) receptors, however, was essential for habituation to a novel environment.
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Kukkonen JP. Physiology of the orexinergic/hypocretinergic system: a revisit in 2012. Am J Physiol Cell Physiol 2012; 304:C2-32. [PMID: 23034387 DOI: 10.1152/ajpcell.00227.2012] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The neuropeptides orexins and their G protein-coupled receptors, OX(1) and OX(2), were discovered in 1998, and since then, their role has been investigated in many functions mediated by the central nervous system, including sleep and wakefulness, appetite/metabolism, stress response, reward/addiction, and analgesia. Orexins also have peripheral actions of less clear physiological significance still. Cellular responses to the orexin receptor activity are highly diverse. The receptors couple to at least three families of heterotrimeric G proteins and other proteins that ultimately regulate entities such as phospholipases and kinases, which impact on neuronal excitation, synaptic plasticity, and cell death. This article is a 10-year update of my previous review on the physiology of the orexinergic/hypocretinergic system. I seek to provide a comprehensive update of orexin physiology that spans from the molecular players in orexin receptor signaling to the systemic responses yet emphasizing the cellular physiological aspects of this system.
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Affiliation(s)
- Jyrki P Kukkonen
- Dept. of Veterinary Biosciences, University of Helsinki, Finland.
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The sleep relay--the role of the thalamus in central and decentral sleep regulation. Pflugers Arch 2011; 463:53-71. [PMID: 21912835 DOI: 10.1007/s00424-011-1014-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 08/08/2011] [Accepted: 08/11/2011] [Indexed: 10/17/2022]
Abstract
Surprisingly, the concept of sleep, its necessity and function, the mechanisms of action, and its elicitors are far from being completely understood. A key to sleep function is to determine how and when sleep is induced. The aim of this review is to merge the classical concepts of central sleep regulation by the brainstem and hypothalamus with the recent findings on decentral sleep regulation in local neuronal assemblies and sleep regulatory substances that create a scenario in which sleep is both local and use dependent. The interface between these concepts is provided by thalamic cellular and network mechanisms that support rhythmogenesis of sleep-related activity. The brainstem and the hypothalamus centrally set the pace for sleep-related activity throughout the brain. Decentral regulation of the sleep-wake cycle was shown in the cortex, and the homeostat of non-rapid-eye-movement sleep is made up by molecular networks of sleep regulatory substances, allowing individual neurons or small neuronal assemblies to enter sleep-like states. Thalamic neurons provide state-dependent gating of sensory information via their ability to produce different patterns of electrogenic activity during wakefulness and sleep. Many mechanisms of sleep homeostasis or sleep-like states of neuronal assemblies, e.g. by the action of adenosine, can also be found in thalamic neurons, and we summarize cellular and network mechanisms of the thalamus that may elicit non-REM sleep. It is argued that both central and decentral regulators ultimately target the thalamus to induce global sleep-related oscillatory activity. We propose that future studies should integrate ideas of central, decentral, and thalamic sleep generation.
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