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Cui M, Meng P, Wang S, Feng Q, Liu G, Zhao P. Differential effects of AKT1 and AKT2 on sleep-wake activity under basal conditions and in response to LPS challenge in mice. Sleep Biol Rhythms 2024; 22:411-421. [PMID: 38962788 PMCID: PMC11217225 DOI: 10.1007/s41105-024-00519-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 02/13/2024] [Indexed: 07/05/2024]
Abstract
Infectious challenge can trigger alterations in sleep-wake behavior. Accumulating evidence has shown that the serine/threonine kinases Akt1 and Akt2 are important targets in both physiological and infectious signaling processes. However, the involvement of Akt1 and Akt2 in sleep-wake activity under basal conditions and in response to inflammatory stimulation has not been established. In the present study, we assessed the precise role of Akt1 and Akt2 in sleep-wake behavior using electroencephalography (EEG)/electromyography (EMG) data from Akt1- and Akt2-deficient mice and wild-type (WT) mice. The results showed that both Akt1 and Akt2 deficiency affect sleep-wake activity, as indicated by reduced nonrapid eye movement (NREM) sleep and increased wakefulness in mutant mice compared to WT mice. Sleep amount and intensity (delta, theta and alpha activity) at night were also drastically attenuated in Akt1- and Akt2-deficient mice. Moreover, since Akt1 and Akt2 are involved in immune responses, we assessed their roles in the sleep response to the inflammatory stimulus lipopolysaccharide (LPS) throughout the following 24 h. We observed that the decrease in wakefulness and increase in NREM sleep induced by LPS were restored in Akt1 knockout mice but not in Akt2 knockout mice. Correspondingly, the decrease in the number of positive orexin-A neurons induced by LPS was abrogated in Akt1 knockout mice but not in Akt2 knockout mice. Our results revealed that both Akt1 and Akt2 deficiency affect the sleep response under basal conditions, but only Akt1 deficiency protects against the aberrant changes in sleep behavior induced by peripheral immune challenge. Supplementary Information The online version contains supplementary material available at 10.1007/s41105-024-00519-y.
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Affiliation(s)
- Meng Cui
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
| | - Pengfei Meng
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
| | - Shaohe Wang
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
| | - Qingyuan Feng
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
| | - Guangming Liu
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
| | - Peng Zhao
- Affiliated Hospital of Jiangnan University, 1000 Hefeng Road, Wuxi, 214000 Jiangsu Province People’s Republic of China
- Department of Basic Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122 Jiangsu People’s Republic of China
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2
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Guo J, Kong Z, Yang S, Da J, Chu L, Han G, Liu J, Tan Y, Zhang J. Therapeutic effects of orexin-A in sepsis-associated encephalopathy in mice. J Neuroinflammation 2024; 21:131. [PMID: 38760784 PMCID: PMC11102217 DOI: 10.1186/s12974-024-03111-w] [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: 02/12/2024] [Accepted: 04/25/2024] [Indexed: 05/19/2024] Open
Abstract
BACKGROUND Sepsis-associated encephalopathy (SAE) causes acute and long-term cognitive deficits. However, information on the prevention and treatment of cognitive dysfunction after sepsis is limited. The neuropeptide orexin-A (OXA) has been shown to play a protective role against neurological diseases by modulating the inflammatory response through the activation of OXR1 and OXR2 receptors. However, the role of OXA in mediating the neuroprotective effects of SAE has not yet been reported. METHODS A mouse model of SAE was induced using cecal ligation perforation (CLP) and treated via intranasal administration of exogenous OXA after surgery. Mouse survival, in addition to cognitive and anxiety behaviors, were assessed. Changes in neurons, cerebral edema, blood-brain barrier (BBB) permeability, and brain ultrastructure were monitored. Levels of pro-inflammatory factors (IL-1β, TNF-α) and microglial activation were also measured. The underlying molecular mechanisms were investigated by proteomics analysis and western blotting. RESULTS Intranasal OXA treatment reduced mortality, ameliorated cognitive and emotional deficits, and attenuated cerebral edema, BBB disruption, and ultrastructural brain damage in mice. In addition, OXA significantly reduced the expression of the pro-inflammatory factors IL-1β and TNF-α, and inhibited microglial activation. In addition, OXA downregulated the expression of the Rras and RAS proteins, and reduced the phosphorylation of P-38 and JNK, thus inhibiting activation of the MAPK pathway. JNJ-10,397,049 (an OXR2 blocker) reversed the effect of OXA, whereas SB-334,867 (an OXR1 blocker) did not. CONCLUSION This study demonstrated that the intranasal administration of moderate amounts of OXA protects the BBB and inhibits the activation of the OXR2/RAS/MAPK pathway to attenuate the outcome of SAE, suggesting that OXA may be a promising therapeutic approach for the management of SAE.
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Affiliation(s)
- Jing Guo
- GuiZhou University Medical College, Guiyang, 550025, Guizhou Province, China
| | - Zhuo Kong
- Department of Neurosurgery, Guizhou Provincial People's Hospital, Guiyang, China
| | - Sha Yang
- GuiZhou University Medical College, Guiyang, 550025, Guizhou Province, China
| | - Jingjing Da
- Department of Nephrology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Liangzhao Chu
- Department of Neurosurgery, the Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Guoqiang Han
- Department of Neurosurgery, Guizhou Provincial People's Hospital, Guiyang, China
| | - Jian Liu
- Department of Neurosurgery, Guizhou Provincial People's Hospital, Guiyang, China.
| | - Ying Tan
- Department of Neurosurgery, Guizhou Provincial People's Hospital, Guiyang, China.
| | - Jiqin Zhang
- Department of Anesthesiology, Guizhou Provincial People's Hospital, Guiyang, China.
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Bitsikas V, Cubizolles F, Schier AF. A vertebrate family without a functional Hypocretin/Orexin arousal system. Curr Biol 2024; 34:1532-1540.e4. [PMID: 38490200 DOI: 10.1016/j.cub.2024.02.022] [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: 05/31/2023] [Revised: 12/20/2023] [Accepted: 02/12/2024] [Indexed: 03/17/2024]
Abstract
The Hypocretin/Orexin signaling pathway suppresses sleep and promotes arousal, whereas the loss of Hypocretin/Orexin results in narcolepsy, including the involuntary loss of muscle tone (cataplexy).1 Here, we show that the South Asian fish species Chromobotia macracanthus exhibits a sleep-like state during which individuals stop swimming and rest on their side. Strikingly, we discovered that the Hypocretin/Orexin system is pseudogenized in C. macracanthus, but in contrast to Hypocretin-deficient mammals, C. macracanthus does not suffer from sudden behavioral arrests. Similarly, zebrafish mutations in hypocretin/orexin show no evident signs of cataplectic-like episodes. Notably, four additional species in the Botiidae family also lack a functional Hypocretin/Orexin system. These findings identify the first vertebrate family that does not rely on a functional Hypocretin/Orexin system for the regulation of sleep and arousal.
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Affiliation(s)
- Vassilis Bitsikas
- Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA; Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland
| | - Fabien Cubizolles
- Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland
| | - Alexander F Schier
- Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA; Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland.
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4
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Levi UI, Bintu MM, Daniella OC, Oyenike OAF, Agbonu AO, Adedamola AM, Ndidi E, Saka SF, Gela BV, Mbagwu SI, Edem EE, Olukayode OJ, James C. Neurobehavioral deficits, histoarchitectural alterations, parvalbumin neuronal damage and glial activation in the brain of male Wistar rat exposed to Landfill leachate. J Chem Neuroanat 2024; 136:102377. [PMID: 38176474 DOI: 10.1016/j.jchemneu.2023.102377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/28/2023] [Accepted: 12/15/2023] [Indexed: 01/06/2024]
Abstract
Concerns about inappropriate disposal of waste into unsanitary municipal solid waste landfills around the world have been on the increase, and this poses a public health challenge due to leachate production. The neurotoxic effect of Gwagwalada landfill leachate (GLL) was investigated in male adult Wistar rats. Rats were exposed to a 10% concentration of GLL for 21 days. The control group received tap water for the same period of the experiment. Our results showed that neurobehavior, absolute body and brain weights and brain histomorphology as well as parvalbumin interneurons were severely altered, with consequent astrogliosis and microgliosis after 21 days of administrating GLL. Specifically, there was severe loss and shrinkage of Purkinje cells, with their nucleus, and severe diffused vacuolations of the white matter tract of GLL-exposed rat brains. There was severe cell loss in the granular layer of the cerebellum resulting in a reduced thickness of the layer. Also, there was severe loss of dendritic arborization of the Purkinje cells in GLL-exposed rat brains, and damage as well as reduced populations of parvalbumin-containing fast-spiking GABAergic interneurons in various regions of the brain. In conclusion, data from the present study demonstrated the detrimental effects of Gwagwalada landfill leachate on the brain which may be implicated in neuropsychological conditions.
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Affiliation(s)
- Usende Ifukibot Levi
- Department of Veterinary Anatomy, University of Abuja, Nigeria; Department of Neurosurgery, Pennsylvania State College of Medicine, Hershey, PA, USA.
| | - Mofio M Bintu
- Department of Biological Sciences, University of Abuja, Abuja, Nigeria
| | | | | | - Adikpe Oluwa Agbonu
- Department of Veterinary Physiology and Biochemistry, University of Abuja, Abuja, Nigeria
| | | | - Enefe Ndidi
- Department of Veterinary Physiology and Biochemistry, University of Abuja, Abuja, Nigeria
| | - Sanni Fatimah Saka
- Department of Veterinary Physiology and Biochemistry, University of Abuja, Abuja, Nigeria
| | - Beselia V Gela
- Department of Neurosurgery, Pennsylvania State College of Medicine, Hershey, PA, USA; Department of Physiology and Pharmacology, Petre Schotadze Tbilisi Medical Academy, Tbilisi, Georgia
| | - Smart I Mbagwu
- Dept of Anatomy, Faculty of Basic Medical Sciences, Nnamdi Azikiwe University, Nigeria
| | - Edem Ekpenyong Edem
- Department of Human Anatomy, College of Medicine and Health Sciences, Afe Babalola University, Nigeria
| | | | - Connor James
- Department of Neurosurgery, Pennsylvania State College of Medicine, Hershey, PA, USA
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5
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Kolmos MG, Arribas AP, Kornum BR, Justinussen JL. Experimental sickness reduces hypocretin receptor 1 expression in the lateral hypothalamus and ventral tegmental area of female mice. Eur J Neurosci 2023; 58:4002-4010. [PMID: 37818927 DOI: 10.1111/ejn.16151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/23/2023] [Accepted: 09/11/2023] [Indexed: 10/13/2023]
Abstract
Recent studies have focused on how sickness behaviours, including lethargy, are coordinated in the brain in response to peripheral infections. Decreased hypocretin (orexin) signalling is associated with lethargy and previous research suggests that hypocretin signalling is downregulated during sickness. However, there are studies that find increases or no change in hypocretin signalling during sickness. It is further unknown whether hypocretin receptor expression changes during sickness. Using lipopolysaccharide (LPS) to induce sickness in female mice, we investigated how LPS-injection affects gene expression of hypocretin receptors and prepro-hypocretin as well as hypocretin-1 peptide concentrations in brain tissue. We found that hypocretin receptor 1 gene expression was downregulated during sickness in the lateral hypothalamus and ventral tegmental area, but not in the dorsal raphe nucleus or locus coeruleus. We found no changes in hypocretin receptor 2 expression. Using a gene expression calculation that accounts for primer efficiencies and multiple endogenous controls, we were unable to detect changes in prepro-hypocretin expression. Using radioimmunoassay, we found no change in hypocretin-1 peptide in rostral brain tissue. Our results indicate that hypocretin receptor expression can fluctuate during sickness, adding an additional level of complexity to understanding hypocretin signalling during sickness.
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Affiliation(s)
- Mie Gunni Kolmos
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Alba Pérez Arribas
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Rahbek Kornum
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jessica Lauren Justinussen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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6
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Lopes PC, Faber-Hammond JJ, Siemonsma C, Patel S, Renn SCP. The social environment alters neural responses to a lipopolysaccharide challenge. Brain Behav Immun 2023; 110:162-174. [PMID: 36878331 DOI: 10.1016/j.bbi.2023.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
Sick animals display drastic changes in their behavioral patterns, including decreased activity, decreased food and water intake, and decreased interest in social interactions. These behaviors, collectively called "sickness behaviors", can be socially modulated. For example, when provided with mating opportunities, males of several species show reduced sickness behaviors. While the behavior is known to change, how the social environment affects neural molecular responses to sickness is not known. Here, we used a species, the zebra finch, Taeniopygia guttata, where males have been shown to decrease sickness behaviors when presented with novel females. Using this paradigm, we obtained samples from three brain regions (the hypothalamus, the bed nucleus of the stria terminalis, and the nucleus taeniae) from lipopolysaccharide (LPS) or control treated males housed under four different social environments. Manipulation of the social environment rapidly changed the strength and co-expression patterns of the neural molecular responses to the immune challenge in all brain regions tested, therefore suggesting that the social environment plays a significant role in determining the neural responses to an infection. In particular, brains of males paired with a novel female showed muted immune responses to LPS, as well as altered synaptic signaling. Neural metabolic activity in response to the LPS challenge was also affected by the social environment. Our results provide new insights into the effects of the social environment on brain responses to an infection, thereby improving our understanding of how the social environment can affect health.
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Affiliation(s)
- Patricia C Lopes
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA.
| | | | - Chandler Siemonsma
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA
| | - Sachin Patel
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA
| | - Suzy C P Renn
- Department of Biology, Reed College, Portland, OR, USA
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7
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Stapelberg NJC, Bui TA, Mansour V, Johnson S, Branjerdporn G, Adhikary S, Ashton K, Taylor N, Headrick JP. The pathophysiology of major depressive disorder through the lens of systems biology: Network analysis of the psycho-immune-neuroendocrine physiome. J Neuroimmunol 2022; 372:577959. [PMID: 36095861 DOI: 10.1016/j.jneuroim.2022.577959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 08/21/2022] [Accepted: 08/26/2022] [Indexed: 02/08/2023]
Abstract
BACKGROUND/AIMS The psycho-immune-neuroendocrine (PINE) network is a predominantly physiological (metabolomic) model constructed from the literature, inter-linking multiple biological processes associated with major depressive disorder (MDD), thereby integrating putative mechanistic pathways for MDD into a single network. MATERIAL AND METHODS Previously published metabolomic pathways for the PINE network based on literature searches conducted in 1991-2021 were used to construct an edge table summarizing all physiological pathways in pairs of origin nodes and target nodes. The Gephi software program was used to calculate network metrics from the edge table, including total degree and centrality measures, to ascertain key network nodes and construct a directed network graph. RESULTS An edge table and directional network graph of physiological relationships in the PINE network is presented. The network has properties consistent with complex biological systems, with analysis yielding key network nodes comprising pro-inflammatory cytokines (TNF- α, IL6 and IL1), glucocorticoids and corticotropin releasing hormone (CRH). These may represent central structural and regulatory elements in the context of MDD. CONCLUSION The identified hubs have a high degree of connection and are known to play roles in the progression from health to MDD. These nodes represent strategic targets for therapeutic intervention or prevention. Future work is required to build a weighted and dynamic simulation of the network PINE.
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Affiliation(s)
- Nicolas J C Stapelberg
- Bond University, Faculty of Health Sciences and Medicine, Robina, Australia; Gold Coast Health, Southport, Australia
| | | | - Verena Mansour
- Bond University, Faculty of Health Sciences and Medicine, Robina, Australia
| | | | - Grace Branjerdporn
- Gold Coast Health, Southport, Australia; Mater Young Adult Health Service, Mater Hospital, South Brisbane, Australia.
| | - Sam Adhikary
- Mater Young Adult Health Service, Mater Hospital, South Brisbane, Australia
| | - Kevin Ashton
- Bond University, Faculty of Health Sciences and Medicine, Robina, Australia
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8
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Usende IL, Olopade JO, Azeez IA, Andrioli A, Bankole MO, Olopade FE, Nafady AA, Bentivoglio M. Neuroecotoxicology: Effects of environmental heavy metal exposure on the brain of African giant rats and the contribution of vanadium to the neuropathology. IBRO Neurosci Rep 2022; 13:215-234. [PMID: 36590095 PMCID: PMC9795313 DOI: 10.1016/j.ibneur.2022.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023] Open
Abstract
Increased exploitation of minerals has led to pollution of confined environments as documented in Nigeria Niger Delta. Information on the effects on brain of such exposure is limited. Due to its exploratory activities, the African giant rat (Cricetomys gambianus) (AGR) provides a unique model for neuroecotoxicological research to determine levels of animal and human exposure to different pollutants. This study aims to unravel neuropathological features of AGR sampled from three agro-ecological zones of Nigeria. Fifteen AGR were sampled according to previously determined data on heavy metal exposure: high vanadium, high lead, and low metals. Eighteen AGR were collected from low metal zone and divided into two groups. Control group received vehicle while SMV exposed group received 3 mg/kg sodium metavanadate (SMV) intraperitoneally for 14days. Brain immunohistochemical analyses were conducted, and ultrastructural changes were studied in experimentally exposed group. Results showed significant loss of tyrosin hydroxylase, parvalbumin, orexin-A and melanin concentration hormone containing neuronal populations in brains obtained from high vanadium and high lead zones and in experimentally intoxicated SMV groups. Similarly, significant decrease numbers of dendritic arborations; extracellular matrix density, perineuronal nets; astrocytes and microglia activations are documented in same groups. Ultrastructural studies revealed mass denudation, cilia loss, disintegration of ependymal layer and intense destructions of myelin sheaths in SMV exposed group. These are the first "neuroecotoxicological" findings in distinct neuronal cells. The implications of these findings are highly relevant for human population living in these areas, not only in Nigeria but also in similarly polluted areas elsewhere in the world.
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Affiliation(s)
- Ifukibot Levi Usende
- Department of Veterinary Anatomy, University of Abuja, Nigeria,Department of Veterinary Anatomy, University of Ibadan, Nigeria,Corresponding author at: Department of Veterinary Anatomy, University of Abuja, Nigeria.
| | | | | | - Anna Andrioli
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - Molakun O. Bankole
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | | | - Allam A. Nafady
- Department of Veterinary Pathology, Electron Microscope Unit, Assuit University, Egypt
| | - Marina Bentivoglio
- Department of Neurological and Movement Sciences, University of Verona, Italy
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9
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Melzi S, Morel AL, Scoté-Blachon C, Liblau R, Dauvilliers Y, Peyron C. Histamine in murine narcolepsy: What do genetic and immune models tell us? Brain Pathol 2021; 32:e13027. [PMID: 34672414 PMCID: PMC8877734 DOI: 10.1111/bpa.13027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/14/2021] [Accepted: 09/27/2021] [Indexed: 12/20/2022] Open
Abstract
An increased number of histaminergic neurons, identified by labeling histidine‐decarboxylase (HDC) its synthesis enzyme, was unexpectedly found in patients with narcolepsy type 1 (NT1). In quest for enlightenment, we evaluate whether an increase in HDC cell number and expression level would be detected in mouse models of the disease, in order to provide proof of concepts reveling possible mechanisms of compensation for the loss of orexin neurons, and/or of induced expression as a consequence of local neuroinflammation, a state that likely accompanies NT1. To further explore the compensatory hypothesis, we also study the noradrenergic wake‐promoting system. Immunohistochemistry for HDC, orexin, and melanin‐concentrating hormone (MCH) was used to count neurons. Quantitative‐PCR of HDC, orexin, MCH, and tyrosine‐hydroxylase was performed to evaluate levels of mRNA expression in the hypothalamus or the dorsal pons. Both quantifications were achieved in genetic and neuroinflammatory models of narcolepsy with major orexin impairment, namely the orexin‐deficient (Orex‐KO) and orexin‐hemagglutinin (Orex‐HA) mice respectively. The number of HDC neurons and mRNA expression level were unchanged in Orex‐KO mice compared to controls. Similarly, we found no change in tyrosine‐hydroxylase mRNA expression in the dorsal pons between groups. Further, despite the presence of protracted local neuroinflammation as witnessed by the presence of reactive microglia, we found no change in the number of neurons nor the expression of HDC in Orex‐HA mice compared to controls. Importantly, no correlation was found in all conditions between HDC and orexin. Our findings indicate that, in mice, the expression of histamine and noradrenalin, two wake‐promoting systems, are not modulated by orexin level whether the lack of orexin is constitutive or induced at adult age, showing thus no compensation. They also show no recruitment of histamine by local neuroinflammation. Further studies will be needed to further define the role of histamine in the pathophysiology of NT1.
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Affiliation(s)
- Silvia Melzi
- Sleep Team, Center for Research in Neuroscience of LYON, CNRS UMR5292, INSERM U1028, University of Lyon1, Bron, France
| | - Anne-Laure Morel
- Sleep Team, Center for Research in Neuroscience of LYON, CNRS UMR5292, INSERM U1028, University of Lyon1, Bron, France
| | - Céline Scoté-Blachon
- Functional Neurogenetics platform, Center for Research in Neuroscience of LYON, CNRS UMR5292, INSERM U1028, University of Lyon1, Bron, France
| | - Roland Liblau
- Toulouse Institute for Infectious and Inflammatory diseases, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, UPS, University of Toulouse, Toulouse, France
| | - Yves Dauvilliers
- National Reference Centre for Orphan Diseases, Narcolepsy - Rare hypersomnia, Sleep Unit, Department of Neurology, CHU Montpellier, Institute for Neuroscience of Montpellier INM, INSERM U1298, University of Montpellier, Montpellier, France
| | - Christelle Peyron
- Sleep Team, Center for Research in Neuroscience of LYON, CNRS UMR5292, INSERM U1028, University of Lyon1, Bron, France
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10
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Borniger JC, de Lecea L. Peripheral Lipopolyssacharide Rapidly Silences REM-Active LH GABA Neurons. Front Behav Neurosci 2021; 15:649428. [PMID: 33716686 PMCID: PMC7946974 DOI: 10.3389/fnbeh.2021.649428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/02/2021] [Indexed: 12/04/2022] Open
Abstract
Immune factors (e.g., cytokines, chemokines) can alter the activity of neuronal circuits to promote "sickness behavior," a suite of adaptive actions that organisms exhibit in response to infection/injury in order to maximize their chances of recovery (i.e., return to homeostasis). This includes drastic alterations in sleep/wake states, locomotor activity, and food intake, among other behaviors. Despite the ample evidence highlighting interactions between the brain and systemic immunity, studies on how immune challenges alter the activity of genetically defined cell populations controlling arousal states are scarce. As the lateral hypothalamus (LH) serves a major integrative function in behavioral arousal, food intake, and monitoring and responding to changes in systemic physiology, we investigated how GABAergic neurons within this brain region alter their activity across normal sleep/wake states and in response to a peripheral immune challenge with bacterial endotoxin [lipopolysaccharides (LPS)]. Using fiber photometry (GCaMP6s Ca2+ signal) in tandem with electroencephalogram (EEG)/EMG recordings to determine arousal states, we observed that population activity of GABAergic neurons in the lateral hypothalamus (LHGABA) is highest during rapid-eye-movement sleep (REM), and this activity changes drastically across spontaneous arousal state transitions, with the lowest activity observed during non-REM sleep. Upon intraperitoneal LPS challenge, LHGABA neurons rapidly decrease their activity in tandem with elimination of REM sleep behavior (characteristic of cytokine-induced sickness). Together, these data suggest that peripheral immune challenges can rapidly (in < 40 min) alter subcortical neuronal circuits controlling arousal states. Additionally, we demonstrate that fiber photometry offers a sensitive and cell-type specific tool that can be applied to study the neuronal substrates of sickness behavior.
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Affiliation(s)
- Jeremy C. Borniger
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, United States
- Stanford University School of Medicine, Stanford, CA, United States
| | - Luis de Lecea
- Stanford University School of Medicine, Stanford, CA, United States
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11
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Sander C, Braun N, Modes F, Schlake HP, Eling P, Hildebrandt H. Can biofeedback-based training alleviate fatigue and vigilance performance in fatigued MS patients? Neuropsychol Rehabil 2020; 32:131-147. [PMID: 32851896 DOI: 10.1080/09602011.2020.1808023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
MS related fatigue might be related to autonomous nervous system (ANS) dysfunctions or to inflammation related vagal (hyper-) activation. Consequently, influencing ANS status may lead to relieve of fatigue. We used two opposite biofeedback interventions to either increase sympathetic ("self-alert training", SAT) or parasympathetic activation ("progressive muscle relaxation", PMR). We recorded fatigue status of patients before and after a challenging vigilance task, their behavioural performance on this task, their skin conductance response (SCR), and parameters indicating parasympathetic activity concerning heart rate variability (HRV). We repeated these recordings after the biofeedback training sessions. Patients of the SAT group were able to learn to increase their SCR voluntarily. Patients of the PMR group showed increasing parameters indicating parasympathetic modulation of the HRV. The vigilance task increased their feeling of fatigue. However, there was no effect of biofeedback training on either fatigue status or performance on the vigilance task. Our results show that MS patients can learn to change voluntarily their ANS activity using biofeedback instructions based on SCR and this can be used in future studies to test the postulated link between ANS and fatigue. However, in this experimental intervention we were unable to document a relation between ANS activity and fatigue.Trial registration: ClinicalTrials.gov identifier: NCT03268187.
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Affiliation(s)
- Carina Sander
- Institute of Psychology, University of Oldenburg, Oldenburg, Germany.,Median Klinik Wilhelmshaven, Wilhelmshaven, Germany
| | - Niclas Braun
- Department and Polyclinic for Psychiatry and Psychotherapy, Universitätsklinikum Bonn AöR, Bonn, Germany
| | - Fenja Modes
- Institute of Psychology, University of Oldenburg, Oldenburg, Germany
| | | | - Paul Eling
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, Netherlands
| | - Helmut Hildebrandt
- Institute of Psychology, University of Oldenburg, Oldenburg, Germany.,Department of Neurology, Klinikum Bremen-Ost, Bremen, Germany
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12
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The brain-adipocyte-gut network: Linking obesity and depression subtypes. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2019; 18:1121-1144. [PMID: 30112671 DOI: 10.3758/s13415-018-0626-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Major depressive disorder (MDD) and obesity are dominant and inter-related health burdens. Obesity is a risk factor for MDD, and there is evidence MDD increases risk of obesity. However, description of a bidirectional relationship between obesity and MDD is misleading, as closer examination reveals distinct unidirectional relationships in MDD subtypes. MDD is frequently associated with weight loss, although obesity promotes MDD. In contrast, MDD with atypical features (MDD-AF) is characterised by subsequent weight gain and obesity. The bases of these distinct associations remain to be detailed, with conflicting findings clouding interpretation. These associations can be viewed within a systems biology framework-the psycho-immune neuroendocrine (PINE) network shared between MDD and metabolic disorders. Shared PINE subsystem perturbations may underlie increased MDD in overweight and obese people (obesity-associated depression), while obesity in MDD-AF (depression-associated obesity) involves more complex interactions between behavioural and biomolecular changes. In the former, the chronic PINE dysfunction triggering MDD is augmented by obesity-dependent dysregulation in shared networks, including inflammatory, leptin-ghrelin, neuroendocrine, and gut microbiome systems, influenced by chronic image-associated psychological stress (particularly in younger or female patients). In MDD-AF, behavioural dysregulation, including hypersensitivity to interpersonal rejection, fundamentally underpins energy imbalance (involving hyperphagia, lethargy, hypersomnia), with evolving obesity exaggerating these drivers via positive feedback (and potentially augmenting PINE disruption). In both settings, sex and age are important determinants of outcome, associated with differences in emotional versus cognitive dysregulation. A systems biology approach is recommended for further research into the pathophysiological networks underlying MDD and linking depression and obesity.
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13
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Hanken K, Sander C, Schlake HP, Kastrup A, Eling P, Hildebrandt H. Fatigue in Multiple Sclerosis is related to relapses, autonomic dysfunctions and introversion: A quasi-experimental study. Mult Scler Relat Disord 2019; 36:101401. [PMID: 31563074 DOI: 10.1016/j.msard.2019.101401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/31/2019] [Accepted: 09/16/2019] [Indexed: 11/26/2022]
Abstract
BACKGROUND Fatigue in Multiple Sclerosis (MS) might be partially due to inflammatory processes. If so, relapses should increase the fatigue level. METHODS Two groups of MS patients participated in this study. One suffered from a relapse and was treated by Methylprednisolone. The other group experienced a deterioration of their neurological condition but no relapse and received neurological rehabilitation. We assessed fatigue before admission, at admission and after discharge (t1, t2, t3). Furthermore, autonomic dysfunctions, depressive mood, apathy and extraversion were assessed at admission. Changes in fatigue were analysed with ANCOVAs and fatigue levels were analysed with regression analyses using clinical data and scores for depressive mood, apathy, extraversion and autonomic dysfunctions. RESULTS Only patients suffering from a relapse showed a significant increment in fatigue from t1 to t2. Regression analyses revealed that autonomic dysfunctions and introversion best explained the fatigue level. CONCLUSIONS This study shows that a relapse is accompanied by an increase in MS-related fatigue. Moreover, autonomic dysfunctions and introversion, more than depression and apathy, play a major role in the explanation of MS-related fatigue. This finding represents additional evidence for the relationship between inflammation, vagal afferent signaling, autonomic dysfunctions, introversion and the feeling of MS-related fatigue.
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Affiliation(s)
- Katrin Hanken
- Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany.
| | - Carina Sander
- Median Klinik Wilhelmshaven, Department of Neurological Rehabilitation, Germany; Institute of Psychology, University of Oldenburg, Oldenburg, Germany
| | - Hans-Peter Schlake
- Median Klinik Wilhelmshaven, Department of Neurological Rehabilitation, Germany
| | - Andreas Kastrup
- Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany
| | - Paul Eling
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, the Netherlands
| | - Helmut Hildebrandt
- Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany; Institute of Psychology, University of Oldenburg, Oldenburg, Germany
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14
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Duffy CM, Hofmeister JJ, Nixon JP, Butterick TA. High fat diet increases cognitive decline and neuroinflammation in a model of orexin loss. Neurobiol Learn Mem 2018; 157:41-47. [PMID: 30471346 DOI: 10.1016/j.nlm.2018.11.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/26/2018] [Accepted: 11/16/2018] [Indexed: 12/23/2022]
Abstract
Midlife obesity is a risk factor for cognitive decline and is associated with the earlier onset of Alzheimer's disease (AD). Diets high in saturated fat potentiate the onset of obesity, microglial activation, and neuroinflammation. Signaling deficiencies in the hypothalamic peptide orexin and/or orexin fiber loss are linked to neurodegeneration, cognitive impairment, and neuroinflammation. Prior studies show that orexin is neuroprotective, suppresses neuroinflammation, and that treatment with orexin improves cognitive processes in orexin/ataxin-3 (O/A3) mice, a transgenic mouse model of orexin neurodegeneration. Our overall hypothesis is that loss of orexin contributes to high fat diet (HFD)-induced hippocampal neuroinflammation and cognitive decline. To examine this, we tested male O/A3 mice (7-8 mo. of age) in a two-way active avoidance (TWAA) hippocampus-dependent memory task. We tested whether (1) orexin loss impaired cognitive function; (2) HFD worsened cognitive impairment; and (3) HFD increased microglial activation and neuroinflammation. O/A3 mice showed significant impairments in TWAA task learning vs. wild type (WT) mice (increased escapes p < 0.05, reduced avoidances p < 0.0001). Mice were then placed on HFD (45% total fat, 31.4% saturated fat) or remained on normal chow (NC; 4% total fat and 1% saturated fat), and TWAA was retested at 2 and 4 weeks. Learning impairment was evident at both 2 and 4 weeks in O/A3 mice fed HFD for following diet exposure vs. WT mice on normal chow or HFD (increased escapes, reduced avoidances p < 0.05). Additionally, O/A3 mice had increased gene expression of the microglial activation marker Iba-1 (measured via qRT-PCR, p < 0.001). Further characterization of the microglial immune response genes in hippocampal tissue revealed a significant increase in CX3 chemokine receptor 1 (CX3CR1), tumor necrosis factor-alpha (TNF-α) and the mitochondria-associated enzyme immune responsive gene-1 (Irg1). Collectively, our results indicate that orexin loss impairs memory, and that HFD accelerates hippocampus-dependent learning deficits and the onset of neuroinflammation.
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Affiliation(s)
- C M Duffy
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States
| | - J J Hofmeister
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - J P Nixon
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States
| | - T A Butterick
- Minneapolis Veterans Affairs Health Care System, Minneapolis, MN, United States; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, United States; Minneapolis Center for Veterans Research and Education, Minneapolis, MN, United States.
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15
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Maldonado JR. Delirium pathophysiology: An updated hypothesis of the etiology of acute brain failure. Int J Geriatr Psychiatry 2018; 33:1428-1457. [PMID: 29278283 DOI: 10.1002/gps.4823] [Citation(s) in RCA: 282] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 09/19/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Delirium is the most common neuropsychiatric syndrome encountered by clinicians dealing with older adults and the medically ill and is best characterized by 5 core domains: cognitive deficits, attentional deficits, circadian rhythm dysregulation, emotional dysregulation, and alteration in psychomotor functioning. DESIGN An extensive literature review and consolidation of published data into a novel interpretation of known pathophysiological causes of delirium. RESULTS Available data suggest that numerous pathological factors may serve as precipitants for delirium, each having differential effects depending on patient-specific patient physiological characteristics (substrate). On the basis of an extensive literature search, a newly proposed theory, the systems integration failure hypothesis, was developed to bring together the most salient previously described theories, by describing the various contributions from each into a complex web of pathways-highlighting areas of intersection and commonalities and explaining how the variable contribution of these may lead to the development of various cognitive and behavioral dysfunctions characteristic of delirium. The specific cognitive and behavioral manifestations of the specific delirium picture result from a combination of neurotransmitter function and availability, variability in integration and processing of sensory information, motor responses to both external and internal cues, and the degree of breakdown in neuronal network connectivity, hence the term acute brain failure. CONCLUSIONS The systems integration failure hypothesis attempts to explain how the various proposed delirium pathophysiologic theories interact with each other, causing various clinically observed delirium phenotypes. A better understanding of the underlying pathophysiology of delirium may eventually assist in designing better prevention and management approaches.
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16
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Health, pre-disease and critical transition to disease in the psycho-immune-neuroendocrine network: Are there distinct states in the progression from health to major depressive disorder? Physiol Behav 2018; 198:108-119. [PMID: 30393143 DOI: 10.1016/j.physbeh.2018.10.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/01/2018] [Accepted: 10/25/2018] [Indexed: 01/03/2023]
Abstract
The psycho-immune-neuroendocrine (PINE) network is a regulatory network of interrelated physiological pathways that have been implicated in major depressive disorder (MDD). A model of disease progression for MDD is presented where the stable, healthy state of the PINE network (PINE physiome) undergoes progressive pathophysiological changes to an unstable but reversible pre-disease state (PINE pre-diseasome) with chronic stress. The PINE network may then undergo critical transition to a stable, possibly irreversible disease state of MDD (PINE pathome). Critical transition to disease is heralded by early warning signs which are detectible by biomarkers specific to the PINE network and may be used as a screening test for MDD. Critical transition to MDD may be different for each individual, as it is reliant on diathesis, which comprises genetic predisposition, intrauterine and developmental factors. Finally, we propose the PINE pre-disease state may form a "universal pre-disease state" for several non-communicable diseases (NCDs), and critical transition of the PINE network may lead to one of several frequently associated disease states (influenced by diathesis), supporting the existence of a common Chronic Illness Risk Network (CIRN). This may provide insight into both the puzzle of multifinality and the growing clinical challenge of multimorbidity.
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17
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Zaretsky DV, Kline H, Zaretskaia MV, Brown MB, Durant PJ, Alves NJ, Rusyniak DE. Disinhibiting neurons in the dorsomedial hypothalamus delays the onset of exertional fatigue and exhaustion in rats exercising in a warm environment. Brain Res 2018; 1689:12-20. [PMID: 29577887 DOI: 10.1016/j.brainres.2018.03.026] [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] [Received: 11/08/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/31/2022]
Abstract
Stimulants cause hyperthermia, in part, by increasing heat generation through exercise. Stimulants also delay the onset of fatigue and exhaustion allowing animals to exercise longer. If used in a warm environment, this combination (increased exercise and decreased fatigue) can cause heat stroke. The dorsomedial hypothalamus (DMH) is involved in mediating locomotion from stimulants. Furthermore, inhibiting the DMH decreases locomotion and prevents hyperthermia in rats given stimulants in a warm environment. Whether the DMH is involved in mediating exercise-induced fatigue and exhaustion is not known. We hypothesized that disinhibiting neurons in the dorsomedial hypothalamus (DMH) would delay the onset of fatigue and exhaustion in animals exercising in a warm environment. To test this hypothesis, we used automated video tracking software to measure fatigue and exhaustion. In rats, using wearable mini-pumps, we demonstrated that disinhibiting the DMH, via bicuculline perfusion (5 µM), increased the duration of exercise in a warm environment as compared to control animals (25 ± 3 min vs 15 ± 2 min). Bicuculline-perfused animals also had higher temperatures at exhaustion (41.4 ± 0.2 °C vs 40.0 ± 0.4 °C). Disinhibiting neurons in the DMH also increased the time to fatigue. Our data show that the same region of the hypothalamus that is involved in mediating locomotion to stimulants, is also involved in controlling exhaustion and fatigue. These findings have implications for understanding the cause and treatment of stimulant-induced-hyperthermia.
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Affiliation(s)
- Dmitry V Zaretsky
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Hannah Kline
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Maria V Zaretskaia
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mary Beth Brown
- Department of Physical Therapy, Indiana University School of Health and Rehabilitation Sciences, USA
| | - Pamela J Durant
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nathan J Alves
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daniel E Rusyniak
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.
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18
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Dantzer R. Neuroimmune Interactions: From the Brain to the Immune System and Vice Versa. Physiol Rev 2018; 98:477-504. [PMID: 29351513 PMCID: PMC5866360 DOI: 10.1152/physrev.00039.2016] [Citation(s) in RCA: 539] [Impact Index Per Article: 89.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/05/2017] [Accepted: 06/18/2017] [Indexed: 12/14/2022] Open
Abstract
Because of the compartmentalization of disciplines that shaped the academic landscape of biology and biomedical sciences in the past, physiological systems have long been studied in isolation from each other. This has particularly been the case for the immune system. As a consequence of its ties with pathology and microbiology, immunology as a discipline has largely grown independently of physiology. Accordingly, it has taken a long time for immunologists to accept the concept that the immune system is not self-regulated but functions in close association with the nervous system. These associations are present at different levels of organization. At the local level, there is clear evidence for the production and use of immune factors by the central nervous system and for the production and use of neuroendocrine mediators by the immune system. Short-range interactions between immune cells and peripheral nerve endings innervating immune organs allow the immune system to recruit local neuronal elements for fine tuning of the immune response. Reciprocally, immune cells and mediators play a regulatory role in the nervous system and participate in the elimination and plasticity of synapses during development as well as in synaptic plasticity at adulthood. At the whole organism level, long-range interactions between immune cells and the central nervous system allow the immune system to engage the rest of the body in the fight against infection from pathogenic microorganisms and permit the nervous system to regulate immune functioning. Alterations in communication pathways between the immune system and the nervous system can account for many pathological conditions that were initially attributed to strict organ dysfunction. This applies in particular to psychiatric disorders and several immune-mediated diseases. This review will show how our understanding of this balance between long-range and short-range interactions between the immune system and the central nervous system has evolved over time, since the first demonstrations of immune influences on brain functions. The necessary complementarity of these two modes of communication will then be discussed. Finally, a few examples will illustrate how dysfunction in these communication pathways results in what was formerly considered in psychiatry and immunology to be strict organ pathologies.
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Affiliation(s)
- Robert Dantzer
- Department of Symptom Research, University of Texas MD Anderson Cancer Center , Houston, Texas
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19
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Toyoda H, Honda Y, Tanaka S, Miyagawa T, Honda M, Honda K, Tokunaga K, Kodama T. Narcolepsy susceptibility gene CCR3 modulates sleep-wake patterns in mice. PLoS One 2017; 12:e0187888. [PMID: 29186205 PMCID: PMC5706730 DOI: 10.1371/journal.pone.0187888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/27/2017] [Indexed: 12/25/2022] Open
Abstract
Narcolepsy is caused by the loss of hypocretin (Hcrt) neurons and is associated with multiple genetic and environmental factors. Although abnormalities in immunity are suggested to be involved in the etiology of narcolepsy, no decisive mechanism has been established. We previously reported chemokine (C-C motif) receptor 3 (CCR3) as a novel susceptibility gene for narcolepsy. To understand the role of CCR3 in the development of narcolepsy, we investigated sleep-wake patterns of Ccr3 knockout (KO) mice. Ccr3 KO mice exhibited fragmented sleep patterns in the light phase, whereas the overall sleep structure in the dark phase did not differ between Ccr3 KO mice and wild-type (WT) littermates. Intraperitoneal injection of lipopolysaccharide (LPS) promoted wakefulness and suppressed both REM and NREM sleep in the light phase in both Ccr3 KO and WT mice. Conversely, LPS suppressed wakefulness and promoted NREM sleep in the dark phase in both genotypes. After LPS administration, the proportion of time spent in wakefulness was higher, and the proportion of time spent in NREM sleep was lower in Ccr3 KO compared to WT mice only in the light phase. LPS-induced changes in sleep patterns were larger in Ccr3 KO compared to WT mice. Furthermore, we quantified the number of Hcrt neurons and found that Ccr3 KO mice had fewer Hcrt neurons in the lateral hypothalamus compared to WT mice. We found abnormalities in sleep patterns in the resting phase and in the number of Hcrt neurons in Ccr3 KO mice. These observations suggest a role for CCR3 in sleep-wake regulation in narcolepsy patients.
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Affiliation(s)
- Hiromi Toyoda
- Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- * E-mail:
| | - Yoshiko Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Susumu Tanaka
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Taku Miyagawa
- Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Makoto Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
- Seiwa Hospital, Institute of Neuropsychiatry, Tokyo, Japan
| | - Kazuki Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Katsushi Tokunaga
- Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tohru Kodama
- Sleep Disorders Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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20
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Kooshki R, Abbasnejad M, Esmaeili-Mahani S, Raoof M. The Modulatory Role of Orexin 1 Receptor in CA1 on Orofacial Pain-induced Learning and Memory Deficits in Rats. Basic Clin Neurosci 2017; 8:213-222. [PMID: 28781729 PMCID: PMC5535327 DOI: 10.18869/nirp.bcn.8.3.213] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Introduction: Cognitive impairment is commonly associated with pain. The modulatory role of orexin 1 receptor (OX1R) in pain pathways as well as learning and memory processes is reported in several studies. The current study was designed to investigate the possible role of CA1-hippocampal OX1R on spatial learning and memory of rats following capsaicin-induced orofacial pain. Methods: Orofacial pain was induced by subcutaneous intra lip injection of capsaicin (100 μg). CA1 administration of orexin A and its selective antagonist (SB-334867-A) were performed 20 minutes prior to capsaicin injection. Learning and spatial memory performances were assessed by Morris Water Maze (MWM) task. Results: Capsaicin treated rats showed impairment in spatial learning and memory. In addition, pretreatment with orexin A (20 and 40 nM/rat) significantly attenuated learning and memory impairment in capsaicin-treated rats. Conversely, blockage of OX1R via SB-334867-A (40 and 80 nM/rat) significantly exaggerated learning and memory loss in capsaicin-treated rats. Conclusion: The obtained results indicated that CA1 OX1R may be involved in modulation of capsaicin –induced spatial learning and memory impairment.
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Affiliation(s)
- Razieh Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Maryam Raoof
- Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.,Department of Endodontics, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran
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21
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Le Thuc O, Cansell C, Bourourou M, Denis RG, Stobbe K, Devaux N, Guyon A, Cazareth J, Heurteaux C, Rostène W, Luquet S, Blondeau N, Nahon JL, Rovère C. Central CCL2 signaling onto MCH neurons mediates metabolic and behavioral adaptation to inflammation. EMBO Rep 2016; 17:1738-1752. [PMID: 27733491 DOI: 10.15252/embr.201541499] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 08/25/2016] [Accepted: 08/30/2016] [Indexed: 12/30/2022] Open
Abstract
Sickness behavior defines the endocrine, autonomic, behavioral, and metabolic responses associated with infection. While inflammatory responses were suggested to be instrumental in the loss of appetite and body weight, the molecular underpinning remains unknown. Here, we show that systemic or central lipopolysaccharide (LPS) injection results in specific hypothalamic changes characterized by a precocious increase in the chemokine ligand 2 (CCL2) followed by an increase in pro-inflammatory cytokines and a decrease in the orexigenic neuropeptide melanin-concentrating hormone (MCH). We therefore hypothesized that CCL2 could be the central relay for the loss in body weight induced by the inflammatory signal LPS. We find that central delivery of CCL2 promotes neuroinflammation and the decrease in MCH and body weight. MCH neurons express CCL2 receptor and respond to CCL2 by decreasing both electrical activity and MCH release. Pharmacological or genetic inhibition of CCL2 signaling opposes the response to LPS at both molecular and physiologic levels. We conclude that CCL2 signaling onto MCH neurons represents a core mechanism that relays peripheral inflammation to sickness behavior.
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Affiliation(s)
- Ophélia Le Thuc
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Céline Cansell
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Miled Bourourou
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Raphaël Gp Denis
- Univ Paris Diderot Sorbonne Paris Cité Unité de Biologie Fonctionnelle et Adaptative CNRS UMR 8251, Paris, France
| | - Katharina Stobbe
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Nadège Devaux
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Alice Guyon
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Julie Cazareth
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | | | - William Rostène
- Institut de la Vision UMRS 968-Université Pierre et Marie Curie, Paris, France
| | - Serge Luquet
- Univ Paris Diderot Sorbonne Paris Cité Unité de Biologie Fonctionnelle et Adaptative CNRS UMR 8251, Paris, France
| | - Nicolas Blondeau
- Université Côte d'Azur, Nice, France.,CNRS, IPMC, Sophia Antipolis, France
| | - Jean-Louis Nahon
- Université Côte d'Azur, Nice, France .,CNRS, IPMC, Sophia Antipolis, France.,Station de Primatologie UPS846 CNRS, Rousset-sur-Arc, France
| | - Carole Rovère
- Université Côte d'Azur, Nice, France .,CNRS, IPMC, Sophia Antipolis, France
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22
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Tanaka S, Takizawa N, Honda Y, Koike T, Oe S, Toyoda H, Kodama T, Yamada H. Hypocretin/orexin loss changes the hypothalamic immune response. Brain Behav Immun 2016; 57:58-67. [PMID: 27318095 DOI: 10.1016/j.bbi.2016.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 12/26/2022] Open
Abstract
Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy.
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Affiliation(s)
- Susumu Tanaka
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan; SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Nae Takizawa
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiko Honda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Taro Koike
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Souichi Oe
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Hiromi Toyoda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tohru Kodama
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Yamada
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
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Liu Y, Huang Y, Liu T, Wu H, Cui H, Gautron L. Lipopolysacharide Rapidly and Completely Suppresses AgRP Neuron-Mediated Food Intake in Male Mice. Endocrinology 2016; 157:2380-92. [PMID: 27111742 PMCID: PMC4891783 DOI: 10.1210/en.2015-2081] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although Agouti-related peptide (AgRP) neurons play a key role in the regulation of food intake, their contribution to the anorexia caused by proinflammatory insults has yet to be identified. Using a combination of neuroanatomical and pharmacogenetics experiments, this study sought to investigate the importance of AgRP neurons and downstream targets in the anorexia caused by the peripheral administration of a moderate dose of lipopolysaccharide (LPS) (100 μg/kg, ip). First, in the C57/Bl6 mouse, we demonstrated that LPS induced c-fos in select AgRP-innervated brain sites involved in feeding but not in any arcuate proopiomelanocortin neurons. Double immunohistochemistry further showed that LPS selectively induced c-Fos in a large subset of melanocortin 4 receptor-expressing neurons in the lateral parabrachial nucleus. Secondly, we used pharmacogenetics to stimulate the activity of AgRP neurons during the course of LPS-induced anorexia. In AgRP-Cre mice expressing the designer receptor hM3Dq-Gq only in AgRP neurons, the administration of the designer drug clozapine-N-oxide (CNO) induced robust food intake. Strikingly, CNO-mediated food intake was rapidly and completely blunted by the coadministration of LPS. Neuroanatomical experiments further indicated that LPS did not interfere with the ability of CNO to stimulate c-Fos in AgRP neurons. In summary, our findings combined together support the view that the stimulation of select AgRP-innervated brain sites and target neurons, rather than the inhibition of AgRP neurons themselves, is likely to contribute to the rapid suppression of food intake observed during acute bacterial endotoxemia.
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Affiliation(s)
- Yang Liu
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
| | - Ying Huang
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
| | - Tiemin Liu
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
| | - Hua Wu
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
| | - Huxing Cui
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
| | - Laurent Gautron
- Division of Hypothalamic Research and Department of Internal Medicine (Y.L., Y.H., T.L., L.G.), The University of Texas Southwestern Medical Center, Dallas, Texas 75390; Department of Orthopedics (Y.L., H.W.), Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China 430030; and Department of Pharmacology (H.C.), Center for Hypertension Research, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Carver College of Medicine, Iowa City, Iowa 52242
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Dudele A, Fischer CW, Elfving B, Wegener G, Wang T, Lund S. Chronic exposure to low doses of lipopolysaccharide and high-fat feeding increases body mass without affecting glucose tolerance in female rats. Physiol Rep 2015; 3:3/11/e12584. [PMID: 26537342 PMCID: PMC4673625 DOI: 10.14814/phy2.12584] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Obesity-related inflammation may have a causal role in the development of diabetes and insulin resistance, and studies using animal models of chronic experimental endotoxemia have shown the link. However, many studies use only males, and much less is known about the role of obesity-related inflammation in females. Therefore, we addressed how experimentally induced chronic inflammation affects body mass, energy intake, and glucose metabolism in female rats. Adult female Sprague Dawley rats were instrumented with slow release pellets that delivered a constant daily dose of 53 or 207 μg of lipopolysaccharide (LPS) per rat for 60 days. Control rats were instrumented with vehicle pellets. Due to inflammatory nature of high-fat diet (HFD) half of the rats received HFD (60% of calories from lard), while the other half remained on control diet to detect possible interactions between two modes of induced inflammation. Our results showed that chronic LPS administration increased female rat body mass and calorie intake in a dose-dependent manner, and that HFD further exacerbated these effects. Despite these effects, no effects of LPS and HFD were evident on female rat glucose metabolism. Only LPS elevated expression of inflammatory markers in the hypothalamus. To conclude, female rats respond to experimentally induced chronic inflammation by increasing body mass, but do not develop glucose intolerance in the given period of time.
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Affiliation(s)
- Anete Dudele
- Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Christina W Fischer
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Betina Elfving
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Gregers Wegener
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Risskov, Denmark
| | - Tobias Wang
- Section for Zoophysiology, Department of Bioscience, Aarhus University, Aarhus, Denmark
| | - Sten Lund
- Medical Research Laboratory, Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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25
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Suppression of Locomotor Activity in Female C57Bl/6J Mice Treated with Interleukin-1β: Investigating a Method for the Study of Fatigue in Laboratory Animals. PLoS One 2015; 10:e0140678. [PMID: 26469939 PMCID: PMC4607158 DOI: 10.1371/journal.pone.0140678] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 09/29/2015] [Indexed: 12/04/2022] Open
Abstract
Fatigue is a disabling symptom in patients with multiple sclerosis and Parkinson’s Disease, and is also common in patients with traumatic brain injury, cancer, and inflammatory disorders. Little is known about the neurobiology of fatigue, in part due to the lack of an approach to induce fatigue in laboratory animals. Fatigue is a common response to systemic challenge by pathogens, a response in part mediated through action of the pro-inflammatory cytokine interleukin-1 beta (IL-1β). We investigated the behavioral responses of mice to IL-1β. Female C57Bl/6J mice of 3 ages were administered IL-1β at various doses i.p. Interleukin-1β reduced locomotor activity, and sensitivity increased with age. Further experiments were conducted with middle-aged females. Centrally administered IL-1β dose-dependently reduced locomotor activity. Using doses of IL-1β that caused suppression of locomotor activity, we measured minimal signs of sickness, such as hyperthermia, pain or anhedonia (as measured with abdominal temperature probes, pre-treatment with the analgesic buprenorphine and through sucrose preference, respectively), all of which are responses commonly reported with higher doses. We found that middle-aged orexin-/- mice showed equivalent effects of IL-1β on locomotor activity as seen in wild-type controls, suggesting that orexins are not necessary for IL-1β -induced reductions in wheel-running. Given that the availability and success of therapeutic treatments for fatigue is currently limited, we examined the effectiveness of two potential clinical treatments, modafinil and methylphenidate. We found that these treatments were variably successful in restoring locomotor activity after IL-1β administration. This provides one step toward development of a satisfactory animal model of the multidimensional experience of fatigue, a model that could allow us to determine possible pathways through which inflammation induces fatigue, and could lead to novel treatments for reversal of fatigue.
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26
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Sickness: From the focus on cytokines, prostaglandins, and complement factors to the perspectives of neurons. Neurosci Biobehav Rev 2015; 57:30-45. [PMID: 26363665 DOI: 10.1016/j.neubiorev.2015.07.015] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/06/2015] [Accepted: 07/31/2015] [Indexed: 12/29/2022]
Abstract
Systemic inflammation leads to a variety of physiological (e.g. fever) and behavioral (e.g. anorexia, immobility, social withdrawal, depressed mood, disturbed sleep) responses that are collectively known as sickness. While these phenomena have been studied for the past few decades, the neurobiological mechanisms by which sickness occurs remain unclear. In this review, we first revisit how the body senses and responds to infections and injuries by eliciting systemic inflammation. Next, we focus on how peripheral inflammatory molecules such as cytokines, prostaglandins, and activated complement factors communicate with the brain to trigger neuroinflammation and sickness. Since depression also involves inflammation, we further elaborate on the interrelationship between sickness and depression. Finally, we discuss how immune activation can modulate neurons in the brain, and suggest future perspectives to help unravel how changes in neuronal functions relate to sickness responses.
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Abstract
Type 1 narcolepsy is a sleep disorder characterized by excessive daytime sleepiness with unintentional sleep attacks and cataplexy. The disorder is caused by a loss of hypocretinergic neurons in the brain. The specific loss of these neurons in narcolepsy is thought to result from an autoimmune attack, and this is supported by evidence of both environmental and genetic factors pointing toward an involvement of the immune system. However, definitive proof of an autoimmune etiology is still missing. Several different immune-mediated disorders targeting neurons are known, and many of these are believed to be caused by autoreactive CD8(+) T cells. In this paper, we review the current knowledge on CD8(+) T cell-mediated neuronal damage on the basis of our understanding of other autoimmune disorders and experimental studies. We identify major histocompatibility complex class I presentation of autoantigens on neurons as a possible mechanism in the development of the disease, and propose T cell-mediated pathogenesis, with cytotoxic CD8(+) T cells targeting the hypocretinergic neurons, as a central element.
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Affiliation(s)
- Matilda Degn
- Department of Diagnostics, Molecular Sleep Laboratory, Rigshospitalet Glostrup, Glostrup, Denmark
| | - Birgitte Rahbek Kornum
- Department of Diagnostics, Molecular Sleep Laboratory, Rigshospitalet Glostrup, Glostrup, Denmark.,Department of Neurophysiology, Danish Center for Sleep Medicine, Rigshospitalet Glostrup, Glostrup, Denmark
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28
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Brown JA, Woodworth HL, Leinninger GM. To ingest or rest? Specialized roles of lateral hypothalamic area neurons in coordinating energy balance. Front Syst Neurosci 2015; 9:9. [PMID: 25741247 PMCID: PMC4332303 DOI: 10.3389/fnsys.2015.00009] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/15/2015] [Indexed: 12/26/2022] Open
Abstract
Survival depends on an organism’s ability to sense nutrient status and accordingly regulate intake and energy expenditure behaviors. Uncoupling of energy sensing and behavior, however, underlies energy balance disorders such as anorexia or obesity. The hypothalamus regulates energy balance, and in particular the lateral hypothalamic area (LHA) is poised to coordinate peripheral cues of energy status and behaviors that impact weight, such as drinking, locomotor behavior, arousal/sleep and autonomic output. There are several populations of LHA neurons that are defined by their neuropeptide content and contribute to energy balance. LHA neurons that express the neuropeptides melanin-concentrating hormone (MCH) or orexins/hypocretins (OX) are best characterized and these neurons play important roles in regulating ingestion, arousal, locomotor behavior and autonomic function via distinct neuronal circuits. Recently, another population of LHA neurons containing the neuropeptide Neurotensin (Nts) has been implicated in coordinating anorectic stimuli and behavior to regulate hydration and energy balance. Understanding the specific roles of MCH, OX and Nts neurons in harmonizing energy sensing and behavior thus has the potential to inform pharmacological strategies to modify behaviors and treat energy balance disorders.
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Affiliation(s)
- Juliette A Brown
- Department of Pharmacology and Toxicology, Michigan State University East Lansing, MI, USA ; Center for Integrative Toxicology East Lansing, MI, USA
| | | | - Gina M Leinninger
- Center for Integrative Toxicology East Lansing, MI, USA ; Department of Physiology, Michigan State University East Lansing, MI, USA
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29
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Morris G, Berk M, Galecki P, Walder K, Maes M. The Neuro-Immune Pathophysiology of Central and Peripheral Fatigue in Systemic Immune-Inflammatory and Neuro-Immune Diseases. Mol Neurobiol 2015; 53:1195-1219. [PMID: 25598355 DOI: 10.1007/s12035-015-9090-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/05/2015] [Indexed: 01/18/2023]
Abstract
Many patients with systemic immune-inflammatory and neuro-inflammatory disorders, including depression, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's disease, cancer, cardiovascular disorder, Parkinson's disease, multiple sclerosis, stroke, and chronic fatigue syndrome/myalgic encephalomyelitis, endure pathological levels of fatigue. The aim of this narrative review is to delineate the wide array of pathways that may underpin the incapacitating fatigue occurring in systemic and neuro-inflammatory disorders. A wide array of immune, inflammatory, oxidative and nitrosative stress (O&NS), bioenergetic, and neurophysiological abnormalities are involved in the etiopathology of these disease states and may underpin the incapacitating fatigue that accompanies these disorders. This range of abnormalities comprises: increased levels of pro-inflammatory cytokines, e.g., interleukin-1 (IL-1), IL-6, tumor necrosis factor (TNF) α and interferon (IFN) α; O&NS-induced muscle fatigue; activation of the Toll-Like Receptor Cycle through pathogen-associated (PAMPs) and damage-associated (DAMPs) molecular patterns, including heat shock proteins; altered glutaminergic and dopaminergic neurotransmission; mitochondrial dysfunctions; and O&NS-induced defects in the sodium-potassium pump. Fatigue is also associated with altered activities in specific brain regions and muscle pathology, such as reductions in maximum voluntary muscle force, downregulation of the mitochondrial biogenesis master gene peroxisome proliferator-activated receptor gamma coactivator 1-alpha, a shift to glycolysis and buildup of toxic metabolites within myocytes. As such, both mental and physical fatigue, which frequently accompany immune-inflammatory and neuro-inflammatory disorders, are the consequence of interactions between multiple systemic and central pathways.
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Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Bryn Road seaside 87, Llanelli, SA152LW, Wales, UK
| | - Michael Berk
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, P.O. Box 291, Geelong, 3220, Australia.,Orygen Youth Health Research Centre and the Centre of Youth Mental Health, Poplar Road 35, Parkville, 3052, Australia.,The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Kenneth Myer Building, Royal Parade 30, Parkville, 3052, Australia.,Department of Psychiatry, University of Melbourne, Level 1 North, Main Block, Royal Melbourne Hospital, Parkville, 3052, Australia
| | - Piotr Galecki
- Department of Adult Psychiatry, Medical University of Lodz, Lodz, Poland
| | - Ken Walder
- Metabolic Research Unit, Deakin University, Geelong, Australia
| | - Michael Maes
- IMPACT Strategic Research Centre, School of Medicine, Deakin University, P.O. Box 291, Geelong, 3220, Australia. .,Department of Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. .,Health Sciences Graduate Program, Health Sciences Center, State University of Londrina, Londrina, Brazil. .,Impact Strategic Research Center, Deakin University, Geelong, Australia.
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30
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Palomba M, Seke-Etet PF, Laperchia C, Tiberio L, Xu YZ, Colavito V, Grassi-Zucconi G, Bentivoglio M. Alterations of orexinergic and melanin-concentrating hormone neurons in experimental sleeping sickness. Neuroscience 2015; 290:185-95. [PMID: 25595977 DOI: 10.1016/j.neuroscience.2014.12.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 12/12/2014] [Accepted: 12/23/2014] [Indexed: 01/24/2023]
Abstract
Human African trypanosomiasis or sleeping sickness is a severe, neglected tropical disease caused by the extracellular parasite Trypanosoma brucei. The disease, which leads to chronic neuroinflammation, is characterized by sleep and wake disturbances, documented also in rodent models. In rats and mice infected with Trypanosoma brucei brucei, we here tested the hypothesis that the disease could target neurons of the lateral hypothalamus (LH) containing orexin (OX)-A or melanin-concentrating hormone (MCH), implicated in sleep/wake regulation. In the cerebrospinal fluid of infected rats, the OX-A level was significantly decreased early after parasite neuroinvasion, and returned to the control level at an advanced disease stage. The number of immunohistochemically characterized OX-A and MCH neurons decreased significantly in infected rats during disease progression and in infected mice at an advanced disease stage. A marked reduction of the complexity of dendritic arborizations of OX-A neurons was documented in infected mice. The evaluation of NeuN-immunoreactive neurons did not reveal significant neuronal loss in the LH of infected mice, thus suggesting a potential selective vulnerability of OX-A and MCH neurons. Immunophenotyping and quantitative analysis showed in infected mice marked activation of microglial cells surrounding OX-A neurons. Day/night oscillation of c-Fos baseline expression was used as marker of OX-A neuron activity in mice. In control animals Fos was expressed in a higher proportion of OX-A neurons in the night (activity) phase than in the day (rest) phase. Interestingly, in infected mice the diurnal spontaneous Fos oscillation was reversed, with a proportion of OX-A/Fos neurons significantly higher at daytime than at nighttime. Altogether the findings reveal a progressive decrease of OX-A and MCH neurons and dysregulation of OX-A neuron diurnal activity in rodent models of sleeping sickness. The data point to the involvement of these peptidergic neurons in the pathogenesis of sleep/wake alterations in the disease and to their vulnerability to inflammatory signaling.
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Affiliation(s)
- M Palomba
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - P F Seke-Etet
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - C Laperchia
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - L Tiberio
- Department of Molecular and Translational Medicine, University of Brescia, Italy
| | - Y-Z Xu
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - V Colavito
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - G Grassi-Zucconi
- Department of Neurological and Movement Sciences, University of Verona, Italy
| | - M Bentivoglio
- Department of Neurological and Movement Sciences, University of Verona, Italy.
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31
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Gaykema RPA, Nguyen XMT, Boehret JM, Lambeth PS, Joy-Gaba J, Warthen DM, Scott MM. Characterization of excitatory and inhibitory neuron activation in the mouse medial prefrontal cortex following palatable food ingestion and food driven exploratory behavior. Front Neuroanat 2014; 8:60. [PMID: 25071465 PMCID: PMC4076747 DOI: 10.3389/fnana.2014.00060] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/12/2014] [Indexed: 02/03/2023] Open
Abstract
The medial prefrontal cortex (mPFC) is implicated in aspects of executive function, that include the modulation of attentional and memory processes involved in goal selection. Food-seeking behavior has been shown to involve activation of the mPFC, both during the execution of strategies designed to obtain food and during the consumption of food itself. As these behaviors likely require differential engagement of the prefrontal cortex, we hypothesized that the pattern of neuronal activation would also be behavior dependent. In this study we describe, for the first time, the expression of Fos in different layers and cell types of the infralimbic/dorsal peduncular and prelimbic/anterior cingulate subdivisions of mouse mPFC following both the consumption of palatable food and following exploratory activity of the animal directed at obtaining food reward. While both manipulations led to increases of Fos expression in principal excitatory neurons relative to control, food-directed exploratory activity produced a significantly greater increase in Fos expression than observed in the food intake condition. Consequently, we hypothesized that mPFC interneuron activation would also be differentially engaged by these manipulations. Interestingly, Fos expression patterns differed substantially between treatments and interneuron subtype, illustrating how the differential engagement of subsets of mPFC interneurons depends on the behavioral state. In our experiments, both vasoactive intestinal peptide- and parvalbumin-expressing neurons showed enhanced Fos expression only during the food-dependent exploratory task and not during food intake. Conversely, elevations in arcuate and paraventricular hypothalamic fos expression were only observed following food intake and not following food driven exploration. Our data suggest that select activation of these cell types may be required to support high cognitive demand states such as observed during exploration while being dispensable during the ingestion of freely available food.
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Affiliation(s)
- Ronald P A Gaykema
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Xuan-Mai T Nguyen
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Jessica M Boehret
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Philip S Lambeth
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Jonathan Joy-Gaba
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Daniel M Warthen
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
| | - Michael M Scott
- Department of Pharmacology, School of Medicine, University of Virginia, Charlottesville VA, USA
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32
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Clark IA, Vissel B. Inflammation-sleep interface in brain disease: TNF, insulin, orexin. J Neuroinflammation 2014; 11:51. [PMID: 24655719 PMCID: PMC3994460 DOI: 10.1186/1742-2094-11-51] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 03/11/2014] [Indexed: 12/28/2022] Open
Abstract
The depth, pattern, timing and duration of unconsciousness, including sleep, vary greatly in inflammatory disease, and are regarded as reliable indicators of disease severity. Similarly, these indicators are applicable to the encephalopathies of sepsis, malaria, and trypanosomiasis, and to viral diseases such as influenza and AIDS. They are also applicable to sterile neuroinflammatory states, including Alzheimer’s disease, Parkinson’s disease, traumatic brain injury, stroke and type-2 diabetes, as well as in iatrogenic brain states following brain irradiation and chemotherapy. Here we make the case that the cycles of unconsciousness that constitute normal sleep, as well as its aberrations, which range from sickness behavior through daytime sleepiness to the coma of inflammatory disease states, have common origins that involve increased inflammatory cytokines and consequent insulin resistance and loss of appetite due to reduction in orexigenic activity. Orexin reduction has broad implications, which are as yet little appreciated in the chronic inflammatory conditions listed, whether they be infectious or sterile in origin. Not only is reduction in orexin levels characterized by loss of appetite, it is associated with inappropriate and excessive sleep and, when dramatic and chronic, leads to coma. Moreover, such reduction is associated with impaired cognition and a reduction in motor control. We propose that advanced understanding and appreciation of the importance of orexin as a key regulator of pathways involved in the maintenance of normal appetite, sleep patterns, cognition, and motor control may afford novel treatment opportunities.
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Affiliation(s)
- Ian A Clark
- Biomedical Sciences and Biochemistry, Research School of Biology, Australian National University, Acton, Canberra, Australian Capital Territory 0200, Australia.
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33
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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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34
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Orexinergic activity modulates altered vital signs and pituitary hormone secretion in experimental sepsis. Crit Care Med 2013; 41:e368-75. [PMID: 24105451 DOI: 10.1097/ccm.0b013e31828e9843] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Sepsis is a common, lethal poorly understood disorder affecting nearly a million Americans annually. The syndrome is characterized by altered cardiodynamics, respiration, metabolism, pituitary function, arousal, and impaired interaction among organ systems. The immunologic and endocrine systems, which are in part responsible for organ-organ communication, have been studied extensively in sepsis. However, little is known about sepsis-induced changes in central nervous system activity. HYPOTHESIS A defect in hypothalamic neurons secreting the neurotransmitter orexin modulates physiologic derangements in sepsis. DESIGN Animal study. SETTING University Research Laboratory. INTERVENTIONS Male C57Bl6 mice were made septic using cecal ligation and puncture. Data were collected 24 or 48 hours later, blood was collected, animals were killed, and brain tissue was harvested, fixed, and sectioned. Hypothalamic sections were subjected to immunohistochemistry using antibodies to orexin and c-Fos, a marker of neuronal activity. In a separate cohort of mice, cannulas were placed in the right lateral cerebral ventricle. Cecal ligation and puncture was performed 1 week later. At 24 or 48 hours post-cecal ligation and puncture, vital signs were measured, and1 µL of saline with or without 3 nmol orexin-A was infused. Vital signs were repeated at 25 or 49 hours post-cecal ligation and puncture, blood was collected, animals were killed, and brains were removed, fixed, sectioned, and stained. MEASUREMENTS AND MAIN RESULTS Orexinergic activity decreased six-fold following cecal ligation and puncture. This change was associated with decreases in arousal, temperature, and heart and respiratory rates. Levels of selected pituitary hormones increased 24 hours post-cecal ligation and puncture but were significantly lower than baseline at 48 hours. Injection of orexin-A increased vital signs to baseline levels. Hormone levels were unaffected at 25 hours but increased to supranormal levels at 49 hours. CONCLUSIONS Sepsis-induced changes in activity, vital signs, and pituitary hormones are modulated by the orexinergic system. This finding implicates central nervous system dysfunction in the pathogenesis of sepsis, suggesting further study of neurological dysfunction to identify novel approaches to management.
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Maldonado JR. Neuropathogenesis of delirium: review of current etiologic theories and common pathways. Am J Geriatr Psychiatry 2013; 21:1190-222. [PMID: 24206937 DOI: 10.1016/j.jagp.2013.09.005] [Citation(s) in RCA: 406] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 09/10/2013] [Accepted: 09/13/2013] [Indexed: 12/20/2022]
Abstract
Delirium is a neurobehavioral syndrome caused by dysregulation of neuronal activity secondary to systemic disturbances. Over time, a number of theories have been proposed in an attempt to explain the processes leading to the development of delirium. Each proposed theory has focused on a specific mechanism or pathologic process (e.g., dopamine excess or acetylcholine deficiency theories), observational and experiential evidence (e.g., sleep deprivation, aging), or empirical data (e.g., specific pharmacologic agents' association with postoperative delirium, intraoperative hypoxia). This article represents a review of published literature and summarizes the top seven proposed theories and their interrelation. This review includes the "neuroinflammatory," "neuronal aging," "oxidative stress," "neurotransmitter deficiency," "neuroendocrine," "diurnal dysregulation," and "network disconnectivity" hypotheses. Most of these theories are complementary, rather than competing, with many areas of intersection and reciprocal influence. The literature suggests that many factors or mechanisms included in these theories lead to a final common outcome associated with an alteration in neurotransmitter synthesis, function, and/or availability that mediates the complex behavioral and cognitive changes observed in delirium. In general, the most commonly described neurotransmitter changes associated with delirium include deficiencies in acetylcholine and/or melatonin availability; excess in dopamine, norepinephrine, and/or glutamate release; and variable alterations (e.g., either a decreased or increased activity, depending on delirium presentation and cause) in serotonin, histamine, and/or γ-aminobutyric acid. In the end, it is unlikely that any one of these theories is fully capable of explaining the etiology or phenomenologic manifestations of delirium but rather that two or more of these, if not all, act together to lead to the biochemical derangement and, ultimately, to the complex cognitive and behavioral changes characteristic of delirium.
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Affiliation(s)
- José R Maldonado
- Departments of Psychiatry, Internal Medicine & Surgery and the Psychosomatic Medicine Service, Stanford University School of Medicine, and Board of Directors, American Delirium Society, Stanford, CA.
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The neuroimmune basis of fatigue. Trends Neurosci 2013; 37:39-46. [PMID: 24239063 DOI: 10.1016/j.tins.2013.10.003] [Citation(s) in RCA: 229] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/15/2013] [Accepted: 10/18/2013] [Indexed: 12/11/2022]
Abstract
The exact nature and pathophysiology of fatigue remain largely elusive despite its high prevalence in physically ill patients. Studies on the relationship between the immune system and the central nervous system provide a new perspective on the mechanisms of fatigue. Inflammatory mediators that are released by activated innate immune cells at the periphery and in the central nervous system alter the metabolism and activity of neurotransmitters, generate neurotoxic compounds, decrease neurotrophic factors, and profoundly disturb the neuronal environment. The resulting alterations in fronto-striatal networks together with the activation of insula by inflammatory interoceptive stimuli underlie the many dimensions of fatigue including reduced incentive motivation, decreased behavioral flexibility, uncertainty about usefulness of actions, and awareness of fatigue.
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Murta V, Ferrari CC. Influence of Peripheral inflammation on the progression of multiple sclerosis: Evidence from the clinic and experimental animal models. Mol Cell Neurosci 2013; 53:6-13. [DOI: 10.1016/j.mcn.2012.06.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 06/14/2012] [Accepted: 06/26/2012] [Indexed: 12/21/2022] Open
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Parsons MP, Belanger-Willoughby N, Linehan V, Hirasawa M. ATP-sensitive potassium channels mediate the thermosensory response of orexin neurons. J Physiol 2012; 590:4707-15. [PMID: 22802589 DOI: 10.1113/jphysiol.2012.236497] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
High body temperatures are generally associated with somnolence, lethargy, hypophagia and anhedonia. Orexin neurons have been suggested to play a role in such sickness behaviours due to their known functions in appetite, behavioural and autonomic activation. Furthermore, the activity of orexin neurons is inhibited by lipopolysaccharide that induces fever. However, the cellular mechanism(s) underlying this suppression of orexin neurons was unknown. We used patch-clamp recordings in acute rat brain slices to demonstrate that orexin neurons, including those projecting to the wake-promoting locus coeruleus, are inhibited by increasing the ambient temperature by a 2-4°C increment between 26 and 40°C. This effect was not mediated by conventional thermosensing mechanisms but instead involved the activation of ATP-sensitive potassium (KATP) channels. Since KATP channels can also sense energy substrate levels and cellular metabolism, our results suggest that orexin neurons can integrate the state of energy balance and body temperature, and adjust their output accordingly. Thus, the thermosensitivity of orexin neurons may be an important part of maintaining energy homeostasis during hyperthermia and fever.
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Affiliation(s)
- Matthew P Parsons
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University, 300 Prince Philip Drive, St John's, NL, A1B 3V6, Canada
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Maes M, Berk M, Goehler L, Song C, Anderson G, Gałecki P, Leonard B. Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways. BMC Med 2012; 10:66. [PMID: 22747645 PMCID: PMC3391987 DOI: 10.1186/1741-7015-10-66] [Citation(s) in RCA: 403] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 06/29/2012] [Indexed: 12/21/2022] Open
Abstract
It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers.
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Affiliation(s)
- Michael Maes
- Maes Clinics @ TRIA, Piyavate Hospital, 998 Rimklongsamsen Road, Bangkok 10310, Thailand.
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Lin Y, Sarfraz Y, Jensen A, Dunn AJ, Stone EA. Participation of brainstem monoaminergic nuclei in behavioral depression. Pharmacol Biochem Behav 2011; 100:330-9. [PMID: 21893082 DOI: 10.1016/j.pbb.2011.08.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/16/2011] [Accepted: 08/22/2011] [Indexed: 01/15/2023]
Abstract
Several lines of research have now suggested the controversial hypothesis that the central noradrenergic system acts to exacerbate depression as opposed to having an antidepressant function. If correct, lesions of this system should increase resistance to depression, which has been partially but weakly supported by previous studies. The present study reexamined this question using two more recent methods to lesion noradrenergic neurons in mice: intraventricular (ivt) administration of either the noradrenergic neurotoxin, DSP4, or of a dopamine-β-hydroxylase-saporin immunotoxin (DBH-SAP ITX) prepared for mice. Both agents given 2 weeks prior were found to significantly increase resistance to depressive behavior in several tests including acute and repeated forced swims, tail suspension and endotoxin-induced anhedonia. Both agents also increased locomotor activity in the open field. Cell counts of brainstem monoaminergic neurons, however, showed that both methods produced only partial lesions of the locus coeruleus and also affected the dorsal raphe or ventral tegmental area. Both the cell damage and the antidepressant and hyperactive effects of ivt DSP4 were prevented by a prior i.p. injection of the NE uptake blocker, reboxetine. The results are seen to be consistent with recent pharmacological experiments showing that noradrenergic and serotonergic systems function to inhibit active behavior. Comparison with previous studies utilizing more complete and selective LC lesions suggest that mouse strain, lesion size or involvement of multiple neuronal systems are critical variables in the behavioral and affective effects of monoaminergic lesions and that antidepressant effects and hyperactivity may be more likely to occur if lesions are partial and/or involve multiple monoaminergic systems.
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Affiliation(s)
- Yan Lin
- Department of Psychiatry, New York University Langone School of Medicine, 550 First Ave, New York, NY 10016, United States
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41
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Grossberg AJ, Zhu X, Leinninger GM, Levasseur PR, Braun TP, Myers MG, Marks DL. Inflammation-induced lethargy is mediated by suppression of orexin neuron activity. J Neurosci 2011; 31:11376-86. [PMID: 21813697 PMCID: PMC3155688 DOI: 10.1523/jneurosci.2311-11.2011] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 06/13/2011] [Accepted: 06/28/2011] [Indexed: 11/21/2022] Open
Abstract
In response to illness, animals subvert normal homeostasis and divert their energy utilization to fight infection. An important and unexplored feature of this response is the suppression of physical activity and foraging behavior in the setting of negative energy balance. Inflammatory signaling in the hypothalamus mediates the febrile and anorectic responses to disease, but the mechanism by which locomotor activity (LMA) is suppressed has not been described. Lateral hypothalamic orexin (Ox) neurons link energy status with LMA, and deficiencies in Ox signaling lead to hypoactivity and hypophagia. In the present work, we examine the effect of endotoxin-induced inflammation on Ox neuron biology and LMA in rats. Our results demonstrate a vital role for diminished Ox signaling in mediating inflammation-induced lethargy. This work defines a specific population of inflammation-sensitive, arousal-associated Ox neurons and identifies a proximal neural target for inflammatory signaling to Ox neurons, while eliminating several others.
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MESH Headings
- Analysis of Variance
- Animals
- Dark Adaptation/drug effects
- Disease Models, Animal
- Drug Administration Routes
- Enzyme-Linked Immunosorbent Assay/methods
- Food Deprivation
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- Green Fluorescent Proteins/genetics
- I-kappa B Proteins/genetics
- I-kappa B Proteins/metabolism
- Inflammation/chemically induced
- Inflammation/complications
- Injections, Intraventricular/methods
- Interleukin-1beta/pharmacology
- Interleukin-6/blood
- Intracellular Signaling Peptides and Proteins/metabolism
- Intracellular Signaling Peptides and Proteins/pharmacology
- Lateral Ventricles/drug effects
- Lateral Ventricles/physiology
- Lethargy/drug therapy
- Lethargy/etiology
- Lethargy/pathology
- Male
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Mice, Transgenic
- Motor Activity/drug effects
- Motor Activity/physiology
- NF-KappaB Inhibitor alpha
- Neoplasm Transplantation/methods
- Neurons/drug effects
- Neurons/metabolism
- Neuropeptides/metabolism
- Neuropeptides/pharmacology
- Neurotensin/genetics
- Orexins
- Photoperiod
- Polysaccharides/adverse effects
- Proto-Oncogene Proteins c-fos/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred F344
- Rats, Sprague-Dawley
- Receptors, Corticotropin/antagonists & inhibitors
- Receptors, Interleukin-11/genetics
- Receptors, Interleukin-11/metabolism
- Receptors, OSM-LIF/genetics
- Receptors, OSM-LIF/metabolism
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Affiliation(s)
- Aaron J. Grossberg
- Neuroscience Graduate Program, and
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239, and
| | - XinXia Zhu
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239, and
| | - Gina M. Leinninger
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, and
| | - Peter R. Levasseur
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239, and
| | - Theodore P. Braun
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239, and
| | - Martin G. Myers
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, and
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
| | - Daniel L. Marks
- Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, Oregon 97239, and
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Sanders RD. Hypothesis for the pathophysiology of delirium: Role of baseline brain network connectivity and changes in inhibitory tone. Med Hypotheses 2011; 77:140-3. [DOI: 10.1016/j.mehy.2011.03.048] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 03/23/2011] [Indexed: 01/06/2023]
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The role of orexin-1 receptors in physiologic responses evoked by microinjection of PgE2 or muscimol into the medial preoptic area. Neurosci Lett 2011; 498:162-6. [PMID: 21596094 DOI: 10.1016/j.neulet.2011.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/27/2011] [Accepted: 05/02/2011] [Indexed: 11/23/2022]
Abstract
The medial preoptic area (mPOA) of the hypothalamus has long been thought to play an important role in both fever production and thermoregulation. Microinjections of prostaglandin E2 (PgE2) or the GABA(A) agonist muscimol into the mPOA cause similar increases in body temperature, heart rate, and blood pressure. Microinjections of these compounds however evoke different behavioral responses with muscimol increasing and PgE2 having no effect on locomotion. The purpose of this study was to determine the role of orexin-1 receptors in mediating these dissimilar responses. Systemic injections of the orexin-1 receptor antagonist SB-334867 reduced temperature and cardiovascular responses produced by microinjections of muscimol, but had no effect on either response produced by PgE2. SB-334867 did not significantly decrease locomotion evoked by microinjections of muscimol into the mPOA. These data suggest that there are two central nervous system circuits involved in increasing body temperature, heart rate and blood pressure: one circuit activated by muscimol, involving orexin neurons, and a separate orexin-independent circuit activated by PgE2.
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Abstract
PURPOSE OF REVIEW Cachexia occurs in various inflammatory diseases and is characterized by weight loss and muscle wasting. Pro-inflammatory cytokines modulate the activity of neuropeptides and hormones that control energy homeostasis and/or illness behaviors. This review summarizes recent (published within the past 18 months) literature regarding neuropeptides and hormones that have been implicated in the pathophysiology of cachexia, and that are likely to have therapeutic potential for preventing or reversing cachexia in various disease states. RECENT FINDINGS Hypothalamic pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons are downstream targets for pro-inflammatory cytokines. Genetic or pharmacological blockade of melanocortin receptor signaling preserves lean body mass and attenuates anorexia in experimental models of cachexia. Orally available melanocortin receptor antagonists have been developed and tested in cachectic animals with favorable results. Ghrelin and ghrelin mimetics increase appetite and preserve lean body mass in cachectic patients with diverse underlying diseases. Additional neuropeptide-expressing neurons in the hypothalamus (e.g., orexin neurons) might play a role in cachexia-associated lethargy. SUMMARY Promising outcomes from recent preclinical studies and/or early clinical trials with melanocortin receptor antagonists and ghrelin mimetics raise hopes that safe and effective anti-cachexia drugs will soon become available for widespread clinical use.
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Gaykema RPA, Goehler LE. Ascending caudal medullary catecholamine pathways drive sickness-induced deficits in exploratory behavior: brain substrates for fatigue? Brain Behav Immun 2011; 25:443-60. [PMID: 21075199 PMCID: PMC3039108 DOI: 10.1016/j.bbi.2010.11.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 11/05/2010] [Accepted: 11/05/2010] [Indexed: 11/16/2022] Open
Abstract
Immune challenges can lead to marked behavioral changes, including fatigue, reduced social interest, anorexia, and somnolence, but the precise neuronal mechanisms that underlie sickness behavior remain elusive. Part of the neurocircuitry influencing behavior associated with illness likely includes viscerosensory nuclei located in the caudal brainstem, based on findings that inactivation of the dorsal vagal complex (DVC) can prevent social withdrawal. These brainstem nuclei contribute multiple neuronal projections that target different components of autonomic and stress-related neurocircuitry. In particular, catecholaminergic neurons in the ventrolateral medulla (VLM) and DVC target the hypothalamus and drive neuroendocrine responses to immune challenge, but their particular role in sickness behavior is not known. To test whether this catecholamine pathway also mediates sickness behavior, we compared effects of DVC inactivation with targeted lesion of the catecholamine pathway on exploratory behavior, which provides an index of motivation and fatigue, and associated patterns of brain activation assessed by immunohistochemical detection of c-Fos protein. LPS treatment dramatically reduced exploratory behavior, and produced a pattern of increased c-Fos expression in brain regions associated with stress and autonomic adjustments paraventricular hypothalamus (PVN), bed nucleus of the stria terminalis (BST), central amygdala (CEA), whereas activation was reduced in regions involved in exploratory behavior (hippocampus, dorsal striatum, ventral tuberomammillary nucleus, and ventral tegmental area). Both DVC inactivation and catecholamine lesion prevented reductions in exploratory behavior and completely blocked the inhibitory LPS effects on c-Fos expression in the behavior-associated regions. In contrast, LPS-induced activation in the CEA and BST was inhibited by DVC inactivation but not by catecholamine lesion. The findings support the idea that parallel pathways from immune-sensory caudal brainstem sources target distinct populations of forebrain neurons that likely mediate different aspects of sickness. The caudal medullary catecholaminergic projections to the hypothalamus may significantly contribute to brain mechanisms that induce behavioral "fatigue" in the context of physiological stressors.
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Affiliation(s)
- Ronald P A Gaykema
- Center for the Study of Complementary and Alternative Therapies, University of Virginia School of Nursing, Charlottesville, VA 22908, USA
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Gautron L, Layé S. Neurobiology of inflammation-associated anorexia. Front Neurosci 2010; 3:59. [PMID: 20582290 PMCID: PMC2858622 DOI: 10.3389/neuro.23.003.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 12/16/2009] [Indexed: 12/23/2022] Open
Abstract
Compelling data demonstrate that inflammation-associated anorexia directly results from the action of pro-inflammatory factors, primarily cytokines and prostaglandins E2, on the nervous system. For instance, the aforementioned pro-inflammatory factors can stimulate the activity of peripheral sensory neurons, and induce their own de novo synthesis and release into the brain parenchyma and cerebrospinal fluid. Ultimately, it results in the mobilization of a specific neural circuit that shuts down appetite. The present article describes the different cell groups and neurotransmitters involved in inflammation-associated anorexia and examines how they interact with neural systems regulating feeding such as the melanocortin system. A better understanding of the neurobiological mechanisms underlying inflammation-associated anorexia will help to develop appetite stimulants for cancer and AIDS patients.
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Affiliation(s)
- Laurent Gautron
- The University of Texas Southwestern Medical Center Dallas, TX, USA
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47
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Hollis JH, Lemus M, Evetts MJ, Oldfield BJ. Central interleukin-10 attenuates lipopolysaccharide-induced changes in food intake, energy expenditure and hypothalamic Fos expression. Neuropharmacology 2009; 58:730-8. [PMID: 20045008 DOI: 10.1016/j.neuropharm.2009.12.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 12/13/2009] [Accepted: 12/18/2009] [Indexed: 10/20/2022]
Abstract
Lipopolysaccharide (LPS) is often used to mimic acute infection and induces hypophagia, the selective partitioning of fat for energy, and fever. Interleukin-10 (IL-10) is an anti-inflammatory cytokine expressed in the brain which attenuates LPS-induced hypophagia; however the potential sites of interaction within the brain have not been investigated. Hypothalamic orexin (ORX) and melanin-concentrating hormone (MCH) regulate energy expenditure and food intake although the regulation of these neuropeptides through the interactions between central IL-10 and the inflammatory consequences of peripheral LPS have not been investigated. The present study in the rat investigated during the dark phase of the light-dark cycle the ability of central IL-10 (250 ng, i.c.v.) to attenuate the changes in food intake, energy substrate partitioning, and central Fos expression within the hypothalamus to peripheral LPS (100 microg/kg, i.p.); Fos expression changes specifically within ORX and MCH neurons were also investigated. Central IL-10 attenuated the peripheral LPS-induced hypophagia, reduction in motor activity, fever and reduction in respiratory exchange ratio. Central IL-10 also attenuated peripheral LPS-induced increases in Fos expression within ORX neurons and decreases in Fos expression within unidentified cells of the caudal arcuate nucleus. In contrast, both IL-10 and LPS injection independently decreased Fos expression within MCH neurons. The present study provides further insight into the interactions within the brain between the anti-inflammatory cytokine IL-10, the inflammatory consequences of LPS, and neuropeptides known to regulate energy expenditure and food intake.
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Affiliation(s)
- Jacob H Hollis
- Department of Physiology, Monash University, Victoria, Australia.
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Gaykema RPA, Daniels TE, Shapiro NJ, Thacker GC, Park SM, Goehler LE. Immune challenge and satiety-related activation of both distinct and overlapping neuronal populations in the brainstem indicate parallel pathways for viscerosensory signaling. Brain Res 2009; 1294:61-79. [PMID: 19646973 PMCID: PMC2748103 DOI: 10.1016/j.brainres.2009.07.076] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 01/26/2023]
Abstract
Caudal brainstem viscerosensory nuclei convey information about the body's internal state to forebrain regions implicated in feeding behavior and responses to immune challenge, and may modulate ingestive behavior following immune activation. Illness-induced appetite loss might be attributed to accentuated "satiety" pathways, activation of a distinct "danger channel" separate from satiety pathways, or both. To evaluate neural substrates that could mediate the effects of illness on ingestive behavior, we analyzed the pattern and phenotypes of medullary neurons responsive to consumption of a preferred food, sweetened milk, and to intraperitoneal lipopolysaccharide challenge that reduced sweetened milk intake. Brainstem sections were stained for c-Fos, dopamine beta-hydroxylase, phenylethanolamine-N-methyltransferase, and glucagon-like peptide-1 (GLP-1) immunoreactivity. Sweetened milk intake activated many neurons throughout the nucleus of the solitary tract (NTS), including A2 noradrenergic neurons in the caudal half of the NTS. LPS challenge activated a similar population of neurons in the NTS, in addition to rostral C2 adrenergic and mid-level A2 noradrenergic neurons in the NTS, many C1 and A1 neurons in the ventrolateral medulla, and in GLP-1 neurons in the dorsal medullary reticular nucleus. Increased numbers of activated GLP-1 neurons in the NTS were only associated with sweetened milk ingestion. Evidence for parallel processing was reflected in the parabrachial nucleus, where sweetened milk intake resulted in activation of the inner external lateral, ventrolateral and central medial portions, whereas LPS challenge induced c-Fos expression in the outer external lateral portions. Thus, signals generated in response to potentially dangerous physiological conditions seem to be propagated via specific populations of catecholaminergic neurons in the NTS and VLM, and likely include a pathway through the external lateral PBN. The data indicate that immune challenge engages multiple ascending neural pathways including both a distinct catecholaminergic "danger" pathway, and a possibly multimodal pathway derived from the NTS.
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Affiliation(s)
- Ronald P A Gaykema
- Laboratory of Neuroimmunology and Behavior, Center for the Study of Complementary and Alternative Therapies, University of Virginia School of Nursing, P.O. Box 800782 Charlottesville, VA 22908-0782, USA
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