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Jeczmien-Lazur JS, Sanetra AM, Pradel K, Izowit G, Chrobok L, Palus-Chramiec K, Piggins HD, Lewandowski MH. Metabolic cues impact non-oscillatory intergeniculate leaflet and ventral lateral geniculate nucleus: standard versus high-fat diet comparative study. J Physiol 2023; 601:979-1016. [PMID: 36661095 DOI: 10.1113/jp283757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 01/12/2023] [Indexed: 01/21/2023] Open
Abstract
The intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/VLG) are subcortical structures involved in entrainment of the brain's circadian system to photic and non-photic (e.g. metabolic and arousal) cues. Both receive information about environmental light from photoreceptors, exhibit infra-slow oscillations (ISO) in vivo, and connect to the master circadian clock. Although current evidence demonstrates that the IGL/VLG communicate metabolic information and are crucial for entrainment of circadian rhythms to time-restricted feeding, their sensitivity to food intake-related peptides has not been investigated yet. We examined the effect of metabolically relevant peptides on the spontaneous activity of IGL/VLG neurons. Using ex vivo and in vivo electrophysiological recordings as well as in situ hybridisation, we tested potential sensitivity of the IGL/VLG to anorexigenic and orexigenic peptides, such as cholecystokinin, glucagon-like peptide 1, oxyntomodulin, peptide YY, orexin A and ghrelin. We explored neuronal responses to these drugs during day and night, and in standard vs. high-fat diet conditions. We found that IGL/VLG neurons responded to all the substances tested, except peptide YY. Moreover, more neurons responded to anorexigenic drugs at night, while a high-fat diet affected the IGL/VLG sensitivity to orexigenic peptides. Interestingly, ISO neurons responded to light and orexin A, but did not respond to the other food intake-related peptides. In contrast, non-ISO cells were activated by metabolic peptides, with only some being responsive to light. Our results show for the first time that peptides involved in the body's energy homeostasis stimulate the thalamus and suggest functional separation of the IGL/VLG cells. KEY POINTS: The intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/VLG) of the rodent thalamus process various signals and participate in circadian entrainment. In both structures, cells exhibiting infra-slow oscillatory activity as well as non-rhythmically firing neurons being observed. Here, we reveal that only one of these two groups of cells responds to anorexigenic (cholecystokinin, glucagon-like peptide 1 and oxyntomodulin) and orexigenic (ghrelin and orexin A) peptides. Neuronal responses vary depending on the time of day (day vs. night) and on the diet (standard vs. high-fat diet). Additionally, we visualised receptors to the tested peptides in the IGL/VLG using in situ hybridisation. Our results suggest that two electrophysiologically different subpopulations of IGL/VLG neurons are involved in two separate functions: one related to the body's energy homeostasis and one associated with the subcortical visual system.
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Affiliation(s)
- Jagoda S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Gabriela Izowit
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland.,School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Hugh D Piggins
- School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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3
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Kumar D, Sharma A, Taliyan R, Urmera MT, Herrera Calderon O, Heinbockel T, Rahman S, Goyal R. Orchestration of the circadian clock and its association with Alzheimer's disease: Role of endocannabinoid signaling. Ageing Res Rev 2022; 73:101533. [PMID: 34844016 PMCID: PMC8729113 DOI: 10.1016/j.arr.2021.101533] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/24/2021] [Accepted: 11/22/2021] [Indexed: 01/03/2023]
Abstract
Circadian rhythms are 24-hour natural rhythms regulated by the suprachiasmatic nucleus, also known as the "master clock". The retino-hypothalamic tract entrains suprachiasmatic nucleus with photic information to synchronise endogenous circadian rhythms with the Earth's light-dark cycle. However, despite the robustness of circadian rhythms, an unhealthy lifestyle and chronic photic disturbances cause circadian rhythm disruption in the suprachiasmatic nucleus's TTFL loops via affecting glutamate and γ-aminobutyric acid-mediated neurotransmission in the suprachiasmatic nucleus. Recently, considerable evidence has been shown correlating CRd with the incidence of Alzheimer's disease. The present review aims to identify the existence and signalling of endocannabinoids in CRd induced Alzheimer's disease through retino-hypothalamic tract- suprachiasmatic nucleus-cortex. Immunohistochemistry has confirmed the expression of cannabinoid receptor 1 in the suprachiasmatic nucleus to modulate the circadian phases of the master clock. Literature also suggests that cannabinoids may alter activity of suprachiasmatic nucleus by influencing the activity of their major neurotransmitter γ-aminobutyric acid or by interacting indirectly with the suprachiasmatic nucleus's two other major inputs i.e., the geniculo-hypothalamic tract-mediated release of neuropeptide Y and serotonergic inputs from the dorsal raphe nuclei. Besides, the expression of cannabinoid receptor 2 ameliorates cognitive deficits via reduction of tauopathy and microglial activation. In conclusion, endocannabinoids may be identified as a putative target for correcting CRd and decelerating Alzheimer's disease.
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Affiliation(s)
- Deepak Kumar
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Solan, H.P., 173229, India
| | - Ashish Sharma
- School of Medicine, Washington University, St. Louis, USA
| | - Rajeev Taliyan
- Department of Pharmacy, Birla Institute of Technology Science, Pilani, Rajasthan, 333301, India
| | - Maiko T. Urmera
- Institute on Aging and Centre for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Oscar Herrera Calderon
- Department of Pharmacology, Bromatology and Toxicology, Faculty of Pharmacy and Biochemistry, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Thomas Heinbockel
- Howard University College of Medicine, Washington, District of Columbia, USA
| | - Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy South Dakota State University, Brookings, South Dakota, USA
| | - Rohit Goyal
- Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Solan, H.P., 173229, India.,Corresponding author: Dr Rohit Goyal, Professor, Department of Neuropharmacology, School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Solan, H.P., 173229, India, ; Mob. +91 98160 62679
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4
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Kumar D, Sharma A, Taliyan R, Urmera MT, Herrera-Calderon O, Heinbockel T, Rahman S, Goyal R. Orchestration of the circadian clock and its association with Alzheimer's disease: Role of endocannabinoid signaling. Ageing Res Rev 2022. [DOI: https://doi.org/10.1016/j.arr.2021.101533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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5
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Chrobok L, Pradel K, Janik ME, Sanetra AM, Bubka M, Myung J, Ridla Rahim A, Klich JD, Jeczmien-Lazur JS, Palus-Chramiec K, Lewandowski MH. Intrinsic circadian timekeeping properties of the thalamic lateral geniculate nucleus. J Neurosci Res 2021; 99:3306-3324. [PMID: 34758124 DOI: 10.1002/jnr.24973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/07/2021] [Accepted: 09/17/2021] [Indexed: 01/08/2023]
Abstract
Circadian rhythmicity in mammals is sustained by the central brain clock-the suprachiasmatic nucleus of the hypothalamus (SCN), entrained to the ambient light-dark conditions through a dense retinal input. However, recent discoveries of autonomous clock gene expression cast doubt on the supremacy of the SCN and suggest circadian timekeeping mechanisms devolve to local brain clocks. Here, we use a combination of molecular, electrophysiological, and optogenetic tools to evaluate intrinsic clock properties of the main retinorecipient thalamic center-the lateral geniculate nucleus (LGN) in male rats and mice. We identify the dorsolateral geniculate nucleus as a slave oscillator, which exhibits core clock gene expression exclusively in vivo. Additionally, we provide compelling evidence for intrinsic clock gene expression accompanied by circadian variation in neuronal activity in the intergeniculate leaflet and ventrolateral geniculate nucleus (VLG). Finally, our optogenetic experiments propose the VLG as a light-entrainable oscillator, whose phase may be advanced by retinal input at the beginning of the projected night. Altogether, this study for the first time demonstrates autonomous timekeeping mechanisms shaping circadian physiology of the LGN.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Marcelina Elzbieta Janik
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna Magdalena Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Monika Bubka
- Department of Glycoconjugate Biochemistry, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jihwan Myung
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Amalia Ridla Rahim
- Graduate Institute of Mind, Brain, and Consciousness, Taipei Medical University, Taipei, Taiwan.,Brain and Consciousness Research Centre, Taipei Medical University-Shuang Ho Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda Stanislawa Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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6
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Lu Q, Kim JY. Mammalian circadian networks mediated by the suprachiasmatic nucleus. FEBS J 2021; 289:6589-6604. [PMID: 34657394 DOI: 10.1111/febs.16233] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 10/09/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
The brain has a complex structure composed of hundreds of regions, forming networks to cooperate body functions. Therefore, understanding how various brain regions communicate with each other and with peripheral organs is important to understand human physiology. The suprachiasmatic nucleus (SCN) in the brain is the circadian pacemaker. The SCN receives photic information from the environment and conveys this to other parts of the brain and body to synchronize all circadian clocks. The circadian clock is an endogenous oscillator that generates daily rhythms in metabolism and physiology in almost all cells via a conserved transcriptional-translational negative feedback loop. So, the information flow from the environment to the SCN to other tissues synchronizes locally distributed circadian clocks to maintain homeostasis. Thus, understanding the circadian networks and how they adjust to environmental changes will better understand human physiology. This review will focus on circadian networks mediated by the SCN to understand how the environment, brain, and peripheral tissues form networks for cooperation.
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Affiliation(s)
- Qingqing Lu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Jin Young Kim
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Tung Foundation Biomedical Sciences Centre, Hong Kong, China.,Shenzhen Research Institute, City University of Hong Kong, Shenzhen, China
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7
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Modulation of the Rat Intergeniculate Leaflet of the Thalamus Network by Norepinephrine. Neuroscience 2021; 469:1-16. [PMID: 34174371 DOI: 10.1016/j.neuroscience.2021.06.027] [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] [Received: 04/01/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022]
Abstract
Circadian rhythms are regulated by a set of brain structures, one of which is the Intergeniculate Leaflet of the Thalamus (IGL). The most recognised role of the IGL is the integration of a variety of stimuli affecting rhythmicity, such as lighting conditions, received by the eye, or light-independent (non-photic) cues, the information about which is delivered via the activation of the non-specific projections. One of them is the norepinephrinergic system originating in the brainstem Locus Coeruleus (LC). In order to investigate the effect of norepinephrine (NE) on the IGL neurons we have performed ex vivo recordings using the extracellular multi-electrode array technique as well as the intracellular whole-cell patch clamp. Using both agonists and antagonists of specific NE receptor subtypes, we confirmed the presence of functional α1-, α2- and β-adrenergic receptors within the investigated structure, allowing NE to exert multiple types of effects on different IGL neurons, mainly depolarisation of the neurons projecting to the Suprachiasmatic Nuclei - the master circadian pacemaker, and various responses exhibited by the cells creating the connection with the contralateral IGL. Moreover, NE was shown to affect IGL cells both directly and via modulation of the synaptic network, in particular the miniature inhibitory postsynaptic currents. To the best of our knowledge, these are the first studies to confirm the effects of NE on the activity of the IGL network.
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Shi HY, Xu W, Guo H, Dong H, Qu WM, Huang ZL. Lesion of intergeniculate leaflet GABAergic neurons attenuates sleep in mice exposed to light. Sleep 2021; 43:5573593. [PMID: 31552427 DOI: 10.1093/sleep/zsz212] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/16/2019] [Indexed: 11/12/2022] Open
Abstract
Light has immediate effects on sleep in rodents, but the neural pathways underlying the effect remain to be elucidated. The intergeniculate leaflet (IGL) containing GABAergic neurons receives direct retinal inputs. We hypothesized that IGL GABAergic neurons may mediate light-induced sleep. EEG/electromyogram recording, immunohistochemistry, electrophysiology, optogenetics, fiber photometry, behavioral tests, and cell-specific destruction were employed to investigate the role of IGL GABAergic neurons in the regulation of acute light-induced sleep. Here, EEG/electromyogram recordings revealed that acute light exposure during the nocturnal active phase in mice induced a significant increase in non-rapid eye movement and rapid eye movement sleep compared with controls. Immunohistochemistry showed that acute light exposure for 2 hours in the active phase induced an increase in c-Fos expression in the IGL, whereas lights-off in the rest phase inhibited it. Patch clamp coupled with optogenetics demonstrated that retinal ganglion cells had monosynaptic functional connections to IGL GABAergic neurons. Calcium activity by fiber photometry in freely behaving mice showed that light exposure increased the activity of IGL GABAergic neurons. Furthermore, lesion of IGL GABAergic neurons by caspase-3 virus significantly attenuated the sleep-promoting effect of light exposure during active phases. Collectively, these results clearly indicated that the IGL is one of key nuclei mediating light-induced sleep in mice.
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Affiliation(s)
- Huan-Ying Shi
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Wei Xu
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Han Guo
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Hui Dong
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Wei-Min Qu
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Zhi-Li Huang
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
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9
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Jha PK, Bouâouda H, Kalsbeek A, Challet E. Distinct feedback actions of behavioural arousal to the master circadian clock in nocturnal and diurnal mammals. Neurosci Biobehav Rev 2021; 123:48-60. [PMID: 33440199 DOI: 10.1016/j.neubiorev.2020.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/16/2020] [Accepted: 12/10/2020] [Indexed: 12/20/2022]
Abstract
The master clock in the suprachiasmatic nucleus (SCN) of the hypothalamus provides a temporal pattern of sleep and wake that - like many other behavioural and physiological rhythms - is oppositely phased in nocturnal and diurnal animals. The SCN primarily uses environmental light, perceived through the retina, to synchronize its endogenous circadian rhythms with the exact 24 h light/dark cycle of the outside world. The light responsiveness of the SCN is maximal during the night in both nocturnal and diurnal species. Behavioural arousal during the resting period not only perturbs sleep homeostasis, but also acts as a potent non-photic synchronizing cue. The feedback action of arousal on the SCN is mediated by processes involving several brain nuclei and neurotransmitters, which ultimately change the molecular functions of SCN pacemaker cells. Arousing stimuli during the sleeping period differentially affect the circadian system of nocturnal and diurnal species, as evidenced by the different circadian windows of sensitivity to behavioural arousal. In addition, arousing stimuli reduce and increase light resetting in nocturnal and diurnal species, respectively. It is important to address further question of circadian impairments associated with shift work and trans-meridian travel not only in the standard nocturnal laboratory animals but also in diurnal animal models.
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Affiliation(s)
- Pawan Kumar Jha
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; Department of Endocrinology and Metabolism, Amsterdam University Medical Center (AUMC), University of Amsterdam, the Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands.
| | - Hanan Bouâouda
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Amsterdam University Medical Center (AUMC), University of Amsterdam, the Netherlands; Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, the Netherlands
| | - Etienne Challet
- Circadian Clocks and Metabolism Team, Institute of Cellular and Integrative Neurosciences, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France
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Beier C, Zhang Z, Yurgel M, Hattar S. Projections of ipRGCs and conventional RGCs to retinorecipient brain nuclei. J Comp Neurol 2020; 529:1863-1875. [PMID: 33104235 PMCID: PMC10081000 DOI: 10.1002/cne.25061] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022]
Abstract
Retinal ganglion cells (RGCs), the output neurons of the retina, allow us to perceive our visual environment. RGCs respond to rod/cone input through the retinal circuitry, however, a small population of RGCs are in addition intrinsically photosensitive (ipRGCs) and project to unique targets in the brain to modulate a broad range of subconscious visual behaviors such as pupil constriction and circadian photoentrainment. Despite the discovery of ipRGCs nearly two decades ago, there is still little information about how or if conventional RGCs (non-ipRGCs) target ipRGC-recipient nuclei to influence subconscious visual behavior. Using a dual recombinase fluorescent reporter strategy, we showed that conventional RGCs innervate many subconscious ipRGC-recipient nuclei, apart from the suprachiasmatic nucleus. We revealed previously unrecognized stratification patterns of retinal innervation from ipRGCs and conventional RGCs in the ventral portion of the lateral geniculate nucleus. Further, we found that the percent innervation of ipRGCs and conventional RGCs across ipsi- and contralateral nuclei differ. Our data provide a blueprint to understand how conventional RGCs and ipRGCs innervate different brain regions to influence subconscious visual behaviors.
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Affiliation(s)
- Corinne Beier
- Section on Light and Circadian Rhythms, NIMH, NIH, Bethesda, Maryland, USA
| | - Ze Zhang
- Section on Light and Circadian Rhythms, NIMH, NIH, Bethesda, Maryland, USA
| | - Maria Yurgel
- Section on Light and Circadian Rhythms, NIMH, NIH, Bethesda, Maryland, USA
| | - Samer Hattar
- Section on Light and Circadian Rhythms, NIMH, NIH, Bethesda, Maryland, USA
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Carceller H, Guirado R, Nacher J. Dark exposure affects plasticity‐related molecules and interneurons throughout the visual system during adulthood. J Comp Neurol 2020; 528:1349-1366. [DOI: 10.1002/cne.24832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/16/2019] [Accepted: 11/22/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Hector Carceller
- Neurobiology Unit, Department of Cell Biology, Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED)Universitat de Valencia Valencia Spain
| | - Ramon Guirado
- Neurobiology Unit, Department of Cell Biology, Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED)Universitat de Valencia Valencia Spain
| | - Juan Nacher
- Neurobiology Unit, Department of Cell Biology, Interdisciplinary Research Structure for Biotechnology and Biomedicine (BIOTECMED)Universitat de Valencia Valencia Spain
- CIBERSAM: Spanish National Network for Research in Mental Health Madrid Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVA Valencia Spain
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12
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Fernandez DC, Komal R, Langel J, Ma J, Duy PQ, Penzo MA, Zhao H, Hattar S. Retinal innervation tunes circuits that drive nonphotic entrainment to food. Nature 2020; 581:194-198. [PMID: 32404998 PMCID: PMC7291822 DOI: 10.1038/s41586-020-2204-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 02/21/2020] [Indexed: 12/14/2022]
Abstract
Daily changes in light and food availability are major time cues that influence circadian timing1. However, little is known about the circuits that integrate these time cues to drive a coherent circadian output1-3. Here we investigate whether retinal inputs modulate entrainment to nonphotic cues such as time-restricted feeding. Photic information is relayed to the suprachiasmatic nucleus (SCN)-the central circadian pacemaker-and the intergeniculate leaflet (IGL) through intrinsically photosensitive retinal ganglion cells (ipRGCs)4. We show that adult mice that lack ipRGCs from the early postnatal stages have impaired entrainment to time-restricted feeding, whereas ablation of ipRGCs at later stages had no effect. Innervation of ipRGCs at early postnatal stages influences IGL neurons that express neuropeptide Y (NPY) (hereafter, IGLNPY neurons), guiding the assembly of a functional IGLNPY-SCN circuit. Moreover, silencing IGLNPY neurons in adult mice mimicked the deficits that were induced by ablation of ipRGCs in the early postnatal stages, and acute inhibition of IGLNPY terminals in the SCN decreased food-anticipatory activity. Thus, innervation of ipRGCs in the early postnatal period tunes the IGLNPY-SCN circuit to allow entrainment to time-restricted feeding.
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Affiliation(s)
- Diego Carlos Fernandez
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA.
| | - Ruchi Komal
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Jennifer Langel
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Jun Ma
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Phan Q Duy
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA.,MSTP, Yale University, New Haven, CT, USA
| | - Mario A Penzo
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Haiqing Zhao
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Samer Hattar
- National Institute of Mental Health (NIMH), National Institutes of Health (NIH), Bethesda, MD, USA.
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Silva CC, Domínguez R. Clock control of mammalian reproductive cycles: Looking beyond the pre-ovulatory surge of gonadotropins. Rev Endocr Metab Disord 2020; 21:149-163. [PMID: 31828563 DOI: 10.1007/s11154-019-09525-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Several aspects of the physiology and behavior of organisms are expressed rhythmically with a 24-h periodicity and hence called circadian rhythms. Such rhythms are thought to be an adaptive response that allows to anticipate cyclic events in the environment. In mammals, the circadian system is a hierarchically organized net of endogenous oscillators driven by the hypothalamic suprachiasmatic nucleus (SCN). This system is synchronized by the environment throughout afferent pathways and in turn it organizes the activity of tissues by means of humoral secretions and neuronal projections. It has been shown that reproductive cycles are regulated by the circadian system. In rodents, the lesion of the SCN results on alterations of the estrous cycle, sexual behavior, tonic and phasic secretion of gonadotropin releasing hormone (GnRH)/gonadotropins and in the failure of ovulation. Most of the studies regarding the circadian control of reproduction, in particular of ovulation, have only focused on the participation of the SCN in the triggering of the proestrus surge of gonadotropins. Here we review aspects of the evolution and organization of the circadian system with particular focus on its relationship with the reproductive cycle of laboratory rodents. Experimental evidence of circadian control of neuroendocrine events indispensable for ovulation that occur prior to proestrus are discussed. In order to offer a working model of the circadian regulation of reproduction, its participation on aspects ranging from gamete production, neuroendocrine regulation, sexual behavior, mating coordination, pregnancy and deliver of the product should be assessed experimentally.
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Affiliation(s)
- Carlos-Camilo Silva
- Chronobiology of Reproduction Research Lab-UIBR, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, Mexico
- Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México, México City, Mexico
| | - Roberto Domínguez
- Chronobiology of Reproduction Research Lab-UIBR, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, México City, Mexico.
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14
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Su J, Charalambakis NE, Sabbagh U, Somaiya RD, Monavarfeshani A, Guido W, Fox MA. Retinal inputs signal astrocytes to recruit interneurons into visual thalamus. Proc Natl Acad Sci U S A 2020; 117:2671-2682. [PMID: 31964831 PMCID: PMC7007527 DOI: 10.1073/pnas.1913053117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Inhibitory interneurons comprise a fraction of the total neurons in the visual thalamus but are essential for sharpening receptive field properties and improving contrast-gain of retinogeniculate transmission. During early development, these interneurons undergo long-range migration from germinal zones, a process regulated by the innervation of the visual thalamus by retinal ganglion cells. Here, using transcriptomic approaches, we identified a motogenic cue, fibroblast growth factor 15 (FGF15), whose expression in the visual thalamus is regulated by retinal input. Targeted deletion of functional FGF15 in mice led to a reduction in thalamic GABAergic interneurons similar to that observed in the absence of retinal input. This loss may be attributed, at least in part, to misrouting of interneurons into nonvisual thalamic nuclei. Unexpectedly, expression analysis revealed that FGF15 is generated by thalamic astrocytes and not retino-recipient neurons. Thus, these data show that retinal inputs signal through astrocytes to direct the long-range recruitment of interneurons into the visual thalamus.
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Affiliation(s)
- Jianmin Su
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
| | - Naomi E Charalambakis
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202
| | - Ubadah Sabbagh
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061
| | - Rachana D Somaiya
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA 24061
| | - Aboozar Monavarfeshani
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202;
| | - Michael A Fox
- Center for Neurobiology Research, Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA 24016;
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
- Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016
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15
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Palus-Chramiec K, Chrobok L, Kepczynski M, Lewandowski MH. Orexin A depolarises rat intergeniculate leaflet neurons through non-selective cation channels. Eur J Neurosci 2019; 50:2683-2693. [PMID: 30803080 DOI: 10.1111/ejn.14394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/22/2022]
Abstract
Orexins/hypocretins are hypothalamic neuropeptides that have a variety of functions, including maintenance of arousal, control over the sleep/wake cycle, reward and feeding. Accumulating evidence links orexins to the time-keeping system with a documented action in the master clock-the suprachiasmatic nucleus. The intergeniculate leaflet (IGL) is a thalamic structure with the well-known function of collecting photic and non-photic cues to adjust the rhythm of the suprachiasmatic nucleus to changing environmental conditions. The IGL consists of GABAergic neurons that are intrinsically active, even in slice preparations. Our previous studies revealed the excitatory postsynaptic effects of orexins on single IGL neurons, even though the ionic mechanism underlying this effect remained elusive. Therefore, in this study, we used patch clamp electrophysiology to identify the ions and distinct ion channels responsible for the observed depolarisations. The major finding of this article is that the orexin A-evoked depolarisation of IGL neurons depends on non-selective cation channels, implicating the orexinergic tone in establishing the basal firing rate in these cells. The data presented here strengthen the mutual connections between the time-keeping and orexinergic systems.
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Affiliation(s)
- Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
| | - Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
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16
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Bienkowski MS, Benavidez NL, Wu K, Gou L, Becerra M, Dong HW. Extrastriate connectivity of the mouse dorsal lateral geniculate thalamic nucleus. J Comp Neurol 2019; 527:1419-1442. [PMID: 30620046 DOI: 10.1002/cne.24627] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 11/14/2018] [Accepted: 12/10/2018] [Indexed: 12/12/2022]
Abstract
The mammalian visual system is one of the most well-studied brain systems. Visual information from the retina is relayed to the dorsal lateral geniculate nucleus of the thalamus (LGd). The LGd then projects topographically to primary visual cortex (VISp) to mediate visual perception. In this view, the VISp is a critical network hub where visual information must traverse LGd-VISp circuits to reach higher order "extrastriate" visual cortices, which surround the VISp on its medial and lateral borders. However, decades of conflicting reports in a variety of mammals support or refute the existence of extrastriate LGd connections that can bypass the VISp. Here, we provide evidence of bidirectional extrastriate connectivity with the mouse LGd. Using small, discrete coinjections of anterograde and retrograde tracers within the thalamus and cortex, our cross-validated approach identified bidirectional connectivity between LGd and extrastriate visual cortices. We find robust reciprocal connectivity of the medial extrastriate regions with LGd neurons distributed along the "ventral strip" border with the intergeniculate leaflet. In contrast, LGd input to lateral extrastriate regions is sparse, but lateral extrastriate regions return stronger descending projections to localized LGd areas. We show further evidence that axons from lateral extrastriate regions can overlap onto medial extrastriate-projecting LGd neurons in the ventral strip, providing a putative subcortical LGd pathway for communication between medial and lateral extrastriate regions. Overall, our findings support the existence of extrastriate LGd circuits and provide novel understanding of LGd organization in rodent visual system.
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Affiliation(s)
- Michael S Bienkowski
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Nora L Benavidez
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Kevin Wu
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Lin Gou
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Marlene Becerra
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Hong-Wei Dong
- USC Stevens Neuroimaging and Informatics Institute, Center for Integrative Connectomics, Keck School of Medicine of University of Southern California, Los Angeles, California
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17
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Pienaar A, Walmsley L, Hayter E, Howarth M, Brown TM. Commissural communication allows mouse intergeniculate leaflet and ventral lateral geniculate neurons to encode interocular differences in irradiance. J Physiol 2018; 596:5461-5481. [PMID: 30240498 PMCID: PMC6235944 DOI: 10.1113/jp276917] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/19/2018] [Indexed: 01/09/2023] Open
Abstract
Key points Unlike other visual thalamic regions, the intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/vLGN) possess extensive reciprocal commissural connections, the functions of which are unknown. Using electrophysiological approaches, it is shown that commissural projecting IGL/vLGN cells are primarily activated by light increments to the contralateral eye while cells receiving commissural input typically exhibit antagonistic binocular responses. Across antagonistic cells, the nature of the commissural input (excitatory or inhibitory) corresponds to the presence of ipsilateral ON or OFF visual responses and in both cases antagonistic responses disappear following inactivation of the contralateral thalamus. The steady state firing rates of antagonistic cells uniquely encode interocular differences in irradiance. There is a pivotal role for IGL/vLGN commissural signalling in generating new sensory properties that are potentially useful for the proposed contributions of these nuclei to visuomotor/vestibular and circadian control.
Abstract The intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/vLGN) are portions of the visual thalamus implicated in circadian and visuomotor/vestibular control. A defining feature of IGL/vLGN organisation is the presence of extensive reciprocal commissural connections, the functions of which are at present unknown. Here we use a combination of multielectrode recording, electrical microstimulation, thalamic inactivation and a range of visual stimuli in mice to address this deficit. Our data indicate that, like most IGL/vLGN cells, those that project commissurally primarily convey contralateral ON visual signals while most IGL/vLGN neurons that receive this input exhibit antagonistic binocular responses (i.e. excitatory responses driven by one eye and inhibitory responses driven by the other), enabling them to encode interocular differences in irradiance. We also confirm that this property derives from commissural input since, following inactivation of the contralateral visual thalamus, these cells instead display monocular contralateral‐driven ON responses. Our data thereby reveal a fundamental role for commissural signalling in generating new visual response properties at the level of the visual thalamus. Unlike other visual thalamic regions, the intergeniculate leaflet and ventral lateral geniculate nucleus (IGL/vLGN) possess extensive reciprocal commissural connections, the functions of which are unknown. Using electrophysiological approaches, it is shown that commissural projecting IGL/vLGN cells are primarily activated by light increments to the contralateral eye while cells receiving commissural input typically exhibit antagonistic binocular responses. Across antagonistic cells, the nature of the commissural input (excitatory or inhibitory) corresponds to the presence of ipsilateral ON or OFF visual responses and in both cases antagonistic responses disappear following inactivation of the contralateral thalamus. The steady state firing rates of antagonistic cells uniquely encode interocular differences in irradiance. There is a pivotal role for IGL/vLGN commissural signalling in generating new sensory properties that are potentially useful for the proposed contributions of these nuclei to visuomotor/vestibular and circadian control.
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Affiliation(s)
- A Pienaar
- Faculty of Biology, Medicine and Health, School of Medicine, University of Manchester, Manchester, UK
| | - L Walmsley
- Faculty of Biology, Medicine and Health, School of Medicine, University of Manchester, Manchester, UK
| | - E Hayter
- Faculty of Biology, Medicine and Health, School of Medicine, University of Manchester, Manchester, UK
| | - M Howarth
- Faculty of Biology, Medicine and Health, School of Medicine, University of Manchester, Manchester, UK
| | - T M Brown
- Faculty of Biology, Medicine and Health, School of Medicine, University of Manchester, Manchester, UK
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18
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Distributions of GABAergic and glutamatergic neurons in the brains of a diurnal and nocturnal rodent. Brain Res 2018; 1700:152-159. [PMID: 30153458 DOI: 10.1016/j.brainres.2018.08.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/25/2018] [Accepted: 08/17/2018] [Indexed: 12/26/2022]
Abstract
Light influences the daily patterning of activity by both synchronizing internal clocks to environmental light-dark cycles and acutely modulating arousal states, a process known as masking. Masking responses are completely reversed in diurnal and nocturnal species. In nocturnal rodents, masking is mediated through a subset of intrinsically photosensitive retinal ganglion cells (ipRGCs) whose projections are similar in diurnal and nocturnal rodents. This raises the possibility that differences in responsivity to signals that these cells release might underlie chronotype differences in masking. We explored one aspect of this hypothesis by examining the distribution of excitatory and inhibitory neuronal populations in many ipRGC target areas of a diurnal species (Nile grass rat) and a nocturnal one (Norway rat). We discovered that while many of these regions were very similar in these two species, there were striking differences in the ventral lateral geniculate nucleus (vLGN; higher density of glutamate cells in Norway rats) and in the lateral habenula (LHb; GABAeric cells present in grass rats, but not Norway rats). These patterns raise the possibility that the vLGN and LHb contribute to differences in masking and/or circadian regulation of diurnal and nocturnal species.
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19
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Santana NNM, Barros MAS, Medeiros HHA, Santana MAD, Silva LL, Morais PLAG, Ladd FVL, Cavalcante JS, Lima RRM, Cavalcante JC, Costa MSMO, Engelberth RCJG, Nascimento Jr. ES. The Suprachiasmatic Nucleus and the Intergeniculate Leaflet of the Flat-Faced Fruit-Eating Bat ( Artibeus planirostris): Retinal Projections and Neurochemical Anatomy. Front Neuroanat 2018; 12:36. [PMID: 29867376 PMCID: PMC5962671 DOI: 10.3389/fnana.2018.00036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 04/20/2018] [Indexed: 12/27/2022] Open
Abstract
In mammals, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian timing system. The SCN, classically known as the master circadian clock, generates rhythms and synchronizes them to environmental cues. The IGL is a key structure that modulates SCN activity. Strategies on the use of time by animals can provide important clues about how some species are adapted to competitive process in nature. Few studies have provided information about temporal niche in bats with special attention on the neural substrate underlies circadian rhythms. The aim of this study was to investigate these circadian centers with respect to their cytoarchitecture, chemical content and retinal projections in the flat-faced fruit-eating bat (Artibeus planirostris), a chiropteran endemic to South America. Unlike other species of phyllostomid bats, the flat-faced fruit-eating bat's peak of activity occurs 5 h after sunset. This raises several questions about the structure and function of the SCN and IGL in this species. We carried out a mapping of the retinal projections and cytoarchitectural study of the nuclei using qualitative and quantitative approaches. Based on relative optical density findings, the SCN and IGL of the flat-faced fruit-eating bat receive bilaterally symmetric retinal innervation. The SCN contains vasopressin (VP) and vasoactive intestinal polypeptide (VIP) neurons with neuropeptide Y (NPY), serotonin (5-HT) and glutamic acid decarboxylase (GAD) immunopositive fibers/terminals and is marked by intense glial fibrillary acidic protein (GFAP) immunoreactivity. The IGL contains NPY perikarya as well as GAD and 5-HT immunopositive terminals and is characterized by dense GFAP immunostaining. In addition, stereological tools were combined with Nissl stained sections to estimate the volumes of the circadian centers. Taken together, the present results in the flat-faced fruit-eating bat reveal some differences compared to other bat species which might explain the divergence in the hourly activity among bats in order to reduce the competitive potential and resource partitioning in nature.
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Affiliation(s)
- Nelyane N. M. Santana
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Helder H. A. Medeiros
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Melquisedec A. D. Santana
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Lara L. Silva
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Paulo L. A. G. Morais
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Fernando V. L. Ladd
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Jeferson S. Cavalcante
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Ruthnaldo R. M. Lima
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Judney C. Cavalcante
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Miriam S. M. O. Costa
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Rovena C. J. G. Engelberth
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Expedito S. Nascimento Jr.
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
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20
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Fiuza FP, Aquino ACQ, Câmara DA, Cavalcanti JRLP, Nascimento Júnior ES, Lima RH, Engelberth RCGJ, Cavalcante JS. Region-specific glial hyperplasia and neuronal stability of rat lateral geniculate nucleus during aging. Exp Gerontol 2017; 100:91-99. [PMID: 29113752 DOI: 10.1016/j.exger.2017.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/20/2017] [Accepted: 11/03/2017] [Indexed: 10/18/2022]
Abstract
The normal aging process is accompanied by functional declines in image-forming and non-image forming visual systems. Among the components of these systems, the thalamic lateral geniculate nucleus (LGN) offers a good model for aging studies since its three anatomical subdivisions, namely dorsal lateral geniculate nucleus (dLGN), intergeniculate leaflet (IGL) and ventral lateral geniculate nucleus (vLGN), receives light information from retina and projects to different brain areas involved in visual-related functions. Nevertheless, there is very little data available about quantitative morphological aspects in LGN across lifespan. In this study, we used design-based stereology to estimate the number of neurons, glial cells, the glia/neuron ratio and the volume of the LGN of Wistar rats from 3, 13 or 23months of age. We examined each LGN subdivision processed by immunohistochemistry for NeuN and Nissl counterstain. We observed no significant age-related neuronal loss in any nuclei and a 21% and 33% significant increase in dLGN and IGL glial cells of 23month-old rats. We also observed the glia/neuron relation increases in dLGN of 13month-old rats and in dLGN, IGL and vLGN internal portion of 23month-old ones. Moreover, we report an age-related increase in IGL volume. These results show region-specific glial hyperplasia during aging within LGN nuclei, perhaps due to compensatory responses to inflammation. In addition, we observed the glia/neuron ratio as a more sensitive parameter to quantify age-related alterations. Hence, we provide an updated and expanded quantitative characterization of these visual-related thalamic nuclei and its variability across lifespan.
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Affiliation(s)
- Felipe P Fiuza
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil.
| | - Antônio Carlos Q Aquino
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Diego A Câmara
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - José Rodolfo L P Cavalcanti
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Health Science Center, University of State of Rio Grande do Norte, 59607-360 Mossoró, RN, Brazil
| | - Expedito S Nascimento Júnior
- Laboratory of Neuroanatomy, Department of Morphology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Ramon H Lima
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Rovena Clara G J Engelberth
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Jeferson S Cavalcante
- Laboratory of Neurochemical Studies, Department of Physiology, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
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21
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Brown TM. Using light to tell the time of day: sensory coding in the mammalian circadian visual network. ACTA ACUST UNITED AC 2017; 219:1779-92. [PMID: 27307539 PMCID: PMC4920240 DOI: 10.1242/jeb.132167] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/09/2016] [Indexed: 12/31/2022]
Abstract
Circadian clocks are a near-ubiquitous feature of biology, allowing organisms to optimise their physiology to make the most efficient use of resources and adjust behaviour to maximise survival over the solar day. To fulfil this role, circadian clocks require information about time in the external world. This is most reliably obtained by measuring the pronounced changes in illumination associated with the earth's rotation. In mammals, these changes are exclusively detected in the retina and are relayed by direct and indirect neural pathways to the master circadian clock in the hypothalamic suprachiasmatic nuclei. Recent work reveals a surprising level of complexity in this sensory control of the circadian system, including the participation of multiple photoreceptive pathways conveying distinct aspects of visual and/or time-of-day information. In this Review, I summarise these important recent advances, present hypotheses as to the functions and neural origins of these sensory signals, highlight key challenges for future research and discuss the implications of our current knowledge for animals and humans in the modern world.
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Affiliation(s)
- Timothy M Brown
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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22
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Ubaldo-Reyes L, Buijs R, Escobar C, Ángeles-Castellanos M. Scheduled meal accelerates entrainment to a 6-h phase advance by shifting central and peripheral oscillations in rats. Eur J Neurosci 2017; 46:1875-1886. [DOI: 10.1111/ejn.13633] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 04/24/2017] [Accepted: 06/20/2017] [Indexed: 12/11/2022]
Affiliation(s)
- L.M. Ubaldo-Reyes
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
| | - R.M. Buijs
- Laboratorio Mecanismos de Integración Hipotalámica; Instituto de Investigaciones Biomédicas; Universidad Nacional Autónoma de México; México DF Mexico
| | - C. Escobar
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
| | - M. Ángeles-Castellanos
- Departamento de Anatomía; Facultad de Medicina; Universidad Nacional Autónoma de México; México DF 04510 Mexico
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23
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Hanna L, Walmsley L, Pienaar A, Howarth M, Brown TM. Geniculohypothalamic GABAergic projections gate suprachiasmatic nucleus responses to retinal input. J Physiol 2017; 595:3621-3649. [PMID: 28217893 DOI: 10.1113/jp273850] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/13/2017] [Indexed: 01/28/2023] Open
Abstract
KEY POINTS Visual input to the suprachiasmatic nucleus circadian clock is critical for animals to adapt their physiology and behaviour in line with the solar day. In addition to direct retinal projections, the clock receives input from the visual thalamus, although the role of this geniculohypothalamic pathway in circadian photoreception is poorly understood. In the present study, we develop a novel brain slice preparation that preserves the geniculohypothalamic pathway to show that GABAergic thalamic neurons inhibit retinally-driven activity in the central clock in a circadian time-dependent manner. We also show that in vivo manipulation of thalamic signalling adjusts specific features of the hypothalamic light response, indicating that the geniculohypothalamic pathway is primarily activated by crossed retinal inputs. Our data provide a mechanism by which geniculohypothalamic signals can adjust the magnitude of circadian and more acute hypothalamic light responses according to time-of-day and establish an important new model for future investigations of the circadian visual system. ABSTRACT Sensory input to the master mammalian circadian clock, the suprachiasmatic nucleus (SCN), is vital in allowing animals to optimize physiology and behaviour alongside daily changes in the environment. Retinal inputs encoding changes in external illumination provide the principle source of such information. The SCN also receives input from other retinorecipient brain regions, primarily via the geniculohypothalamic tract (GHT), although the contribution of these indirect projections to circadian photoreception is currently poorly understood. To address this deficit, in the present study, we established an in vitro mouse brain slice preparation that retains connectivity across the extended circadian system. Using multi-electrode recordings, we first confirm that this preparation retains intact optic projections to the SCN, thalamus and pretectum and a functional GHT. We next show that optogenetic activation of GHT neurons selectively suppresses SCN responses to retinal input, and also that this effect exhibits a pronounced day/night variation and involves a GABAergic mechanism. This inhibitory action was not associated with overt circadian rhythmicity in GHT output, indicating modulation at the SCN level. Finally, we use in vivo electrophysiological recordings alongside pharmacological inactivation or optogenetic excitation to show that GHT signalling actively modulates specific features of the SCN light response, indicating that GHT cells are primarily activated by crossed retinal projections. Taken together, our data establish a new model for studying network communication in the extended circadian system and provide novel insight into the roles of GHT-signalling, revealing a mechanism by which thalamic activity can help gate retinal input to the SCN according to time of day.
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Affiliation(s)
- Lydia Hanna
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Lauren Walmsley
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Abigail Pienaar
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Michael Howarth
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
| | - Timothy M Brown
- Faculty of Biology Medicine and Health, University of Manchester, Manchester, UK
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24
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Engelberth RCGJ, Silva KDDA, Fiuza FP, Soares JG, Costa MSMO, Lima RRDM, Nascimento ESD, Santos JRD, Cavalcanti JRLP, Cavalcante JS. Retinal, NPY- and 5ht- inputs to the aged suprachiasmatic nucleus in common marmosets (Callithrix jacchus). Neurosci Res 2017; 121:54-59. [PMID: 28288865 DOI: 10.1016/j.neures.2017.03.005] [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: 08/05/2016] [Revised: 11/02/2016] [Accepted: 03/09/2017] [Indexed: 01/08/2023]
Abstract
The circadian timing system (CTS) anticipates optimal physiological patterns in response to environmental fluctuations, such as light-dark cycle. Since age-related disruption of circadian synchronization is linked to several pathological conditions, we characterized alterations of neurochemical constituents and retinal projections to the major pacemaker of CTS, the suprachiasmatic nucleus (SCN), in adult and aged marmosets. We used intraocular injections of neural tracer Cholera toxin b (CTb) to report age-related reductions in CTb, neuropeptide Y and serotonin immunoreactivities. Considering these projections arise in SCN from nuclei that relay environmental information to entrain the circadian clock, we provide important anatomical correlates to age-associated physiological deficits.
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Affiliation(s)
- Rovena C G J Engelberth
- Laboratory of Neurochemical Studies, Physiology Department, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil.
| | - Kayo D de Azevedo Silva
- Laboratory of Neurochemical Studies, Physiology Department, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Felipe Porto Fiuza
- Laboratory of Neurochemical Studies, Physiology Department, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
| | - Joacil Germano Soares
- Laboratory of Neuroanatomy, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Miriam S M O Costa
- Laboratory of Neuroanatomy, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Ruthnaldo R de Melo Lima
- Laboratory of Neuroanatomy, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Expedito Silva do Nascimento
- Laboratory of Neuroanatomy, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - José R Dos Santos
- Department of Biosciences, Federal University of Sergipe, Itabaiana, Sergipe, Brazil
| | - José R L P Cavalcanti
- Laboratory of Experimental Neurology, Department of Biomedical Sciences, Health Science Center, University of State of Rio Grande do Norte, Mossoró, RN, Brazil
| | - Jeferson S Cavalcante
- Laboratory of Neurochemical Studies, Physiology Department, Biosciences Center, Federal University of Rio Grande do Norte, 59072-970 Natal, RN, Brazil
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Enkephalin and neuropeptide-Y interaction in the intergeniculate leaflet network, a part of the mammalian biological clock. Neuroscience 2017; 343:10-20. [DOI: 10.1016/j.neuroscience.2016.11.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 11/20/2022]
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Albers HE, Walton JC, Gamble KL, McNeill JK, Hummer DL. The dynamics of GABA signaling: Revelations from the circadian pacemaker in the suprachiasmatic nucleus. Front Neuroendocrinol 2017; 44:35-82. [PMID: 27894927 PMCID: PMC5225159 DOI: 10.1016/j.yfrne.2016.11.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/16/2016] [Accepted: 11/22/2016] [Indexed: 12/31/2022]
Abstract
Virtually every neuron within the suprachiasmatic nucleus (SCN) communicates via GABAergic signaling. The extracellular levels of GABA within the SCN are determined by a complex interaction of synthesis and transport, as well as synaptic and non-synaptic release. The response to GABA is mediated by GABAA receptors that respond to both phasic and tonic GABA release and that can produce excitatory as well as inhibitory cellular responses. GABA also influences circadian control through the exclusively inhibitory effects of GABAB receptors. Both GABA and neuropeptide signaling occur within the SCN, although the functional consequences of the interactions of these signals are not well understood. This review considers the role of GABA in the circadian pacemaker, in the mechanisms responsible for the generation of circadian rhythms, in the ability of non-photic stimuli to reset the phase of the pacemaker, and in the ability of the day-night cycle to entrain the pacemaker.
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Affiliation(s)
- H Elliott Albers
- Center for Behavioral Neuroscience, Atlanta, GA 30302, United States; Neuroscience Institute, Georgia State University, Atlanta, GA 30302, United States.
| | - James C Walton
- Center for Behavioral Neuroscience, Atlanta, GA 30302, United States; Neuroscience Institute, Georgia State University, Atlanta, GA 30302, United States
| | - Karen L Gamble
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - John K McNeill
- Center for Behavioral Neuroscience, Atlanta, GA 30302, United States; Neuroscience Institute, Georgia State University, Atlanta, GA 30302, United States
| | - Daniel L Hummer
- Center for Behavioral Neuroscience, Atlanta, GA 30302, United States; Department of Psychology, Morehouse College, Atlanta, GA 30314, United States
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Monavarfeshani A, Sabbagh U, Fox MA. Not a one-trick pony: Diverse connectivity and functions of the rodent lateral geniculate complex. Vis Neurosci 2017; 34:E012. [PMID: 28965517 PMCID: PMC5755970 DOI: 10.1017/s0952523817000098] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Often mislabeled as a simple relay of sensory information, the thalamus is a complicated structure with diverse functions. This diversity is exemplified by roles visual thalamus plays in processing and transmitting light-derived stimuli. Such light-derived signals are transmitted to the thalamus by retinal ganglion cells (RGCs), the sole projection neurons of the retina. Axons from RGCs innervate more than ten distinct nuclei within thalamus, including those of the lateral geniculate complex. Nuclei within the lateral geniculate complex of nocturnal rodents, which include the dorsal lateral geniculate nucleus (dLGN), ventral lateral geniculate nucleus (vLGN), and intergeniculate leaflet (IGL), are each densely innervated by retinal projections, yet, exhibit distinct cytoarchitecture and connectivity. These features suggest that each nucleus within this complex plays a unique role in processing and transmitting light-derived signals. Here, we review the diverse cytoarchitecture and connectivity of these nuclei in nocturnal rodents, in an effort to highlight roles for dLGN in vision and for vLGN and IGL in visuomotor, vestibular, ocular, and circadian function.
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Affiliation(s)
- Aboozar Monavarfeshani
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
| | - Ubadah Sabbagh
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
| | - Michael A Fox
- Developmental and Translational Neurobiology Center,Virginia Tech Carilion Research Institute,Roanoke,Virginia
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Chrobok L, Palus K, Jeczmien-Lazur JS, Chrzanowska A, Kepczynski M, Lewandowski MH. Disinhibition of the intergeniculate leaflet network in the WAG/Rij rat model of absence epilepsy. Exp Neurol 2016; 289:103-116. [PMID: 28041911 DOI: 10.1016/j.expneurol.2016.12.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 12/21/2016] [Accepted: 12/25/2016] [Indexed: 01/18/2023]
Abstract
The intergeniculate leaflet (IGL) of the thalamus is a retinorecipient structure implicated in orchestrating circadian rhythmicity. The IGL network is highly GABAergic and consists mainly of neuropeptide Y-synthesising and enkephalinergic neurons. A high density of GFAP-immunoreactive astrocytes has been observed in the IGL, with a probable function in guarding neuronal inhibition. Interestingly, putatively enkephalinergic IGL neurons generate action potentials with an infra-slow oscillatory (ISO) pattern in vivo in urethane anesthetised Wistar rats, under light-on conditions only. Absence epilepsy (AE) is a disease characterised by spike-wave discharges present in the encephalogram, directly caused by hypersynchronous thalamo-cortical oscillations. Many pathologies connected with the arousal system, such as abnormalities in sleep architecture and an insufficient brain sleep-promoting system accompany the epileptic phenotype. We hypothesise that disturbances in the function of biological clock structures, controlling this rhythmic physiological process, may be responsible for the observed pathomechanism. To test this hypothesis, we performed an in vitro patch-clamp study on WAG/Rij rats, a well-validated genetic model of AE, in order to assess dampened GABAergic synaptic transmission in the IGL expressed as a lower IPSC amplitude and reduced sIPSC frequency. Moreover, our in vivo extracellular recordings showed higher firing rate of ISO IGL neurons with an abnormal reaction to a change in constant illumination (maintenance of rhythmic neuronal activity in darkness) in the AE model. Additional immunohistochemical experiments indicated astrogliosis in the area of the IGL, which may partially underlie the observed changes in inhibition. Altogether, the data presented here show for the first time the disinhibition of IGL neurons in a model of AE, thereby proposing the possible involvement of circadian-related brain structures in the epileptic phenotype.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University in Krakow, Krakow, Poland.
| | - Katarzyna Palus
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University in Krakow, Krakow, Poland.
| | | | - Anna Chrzanowska
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University in Krakow, Krakow, Poland.
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland.
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology, Jagiellonian University in Krakow, Krakow, Poland.
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Aptel F, Weinreb RN, Chiquet C, Mansouri K. 24-h monitoring devices and nyctohemeral rhythms of intraocular pressure. Prog Retin Eye Res 2016; 55:108-148. [PMID: 27477112 DOI: 10.1016/j.preteyeres.2016.07.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/07/2016] [Accepted: 07/12/2016] [Indexed: 01/26/2023]
Abstract
Intraocular pressure (IOP) is not a fixed value and varies over both the short term and periods lasting several months or years. In particular, IOP is known to vary throughout the 24-h period of a day, defined as a nyctohemeral rhythm in humans. In clinical practice, it is crucial to evaluate the changes in IOP over 24 h in several situations, including the diagnosis of ocular hypertension and glaucoma (IOP is often higher at night) and to optimize the therapeutic management of glaucoma. Until recently, all evaluations of 24-h IOP rhythm were performed using repeated IOP measurements, requiring individuals to be awakened for nocturnal measurements. This method may be imperfect, because it is not physiologic and disturbs the sleep architecture, and also because it provides a limited number of time point measurements not sufficient to finely asses IOP changes. These limitations may have biased previous descriptions of physiological IOP rhythm. Recently, extraocular and intraocular devices integrating a pressure sensor for continuous IOP monitoring have been developed and are available for use in humans. The objective of this article is to present the contributions of these new 24-h monitoring devices for the study of the nyctohemeral rhythms. In healthy subjects and untreated glaucoma subjects, a nyctohemeral rhythm is consistently found and frequently characterized by a mean diurnal IOP lower than the mean nocturnal IOP, with a diurnal bathyphase - usually in the middle or at the end of the afternoon - and a nocturnal acrophase, usually in the middle or at the end of the night.
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Affiliation(s)
- Florent Aptel
- Inserm U1042, Hypoxia and Physiopathology Laboratory, University Grenoble Alpes, Grenoble, France; Department of Ophthalmology, University Hospital, CHU Grenoble, Grenoble, France
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Center and Department of Ophthalmology, University of California, San Diego, La Jolla, CA, USA
| | - Christophe Chiquet
- Inserm U1042, Hypoxia and Physiopathology Laboratory, University Grenoble Alpes, Grenoble, France; Department of Ophthalmology, University Hospital, CHU Grenoble, Grenoble, France
| | - Kaweh Mansouri
- Glaucoma Center, Montchoisi Clinic, Swiss Vision Network, Lausanne, Switzerland; Department of Ophthalmology, University of Colorado School of Medicine, Denver, CO, USA.
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Chrobok L, Palus K, Lewandowski MH. Two distinct subpopulations of neurons in the thalamic intergeniculate leaflet identified by subthreshold currents. Neuroscience 2016; 329:306-17. [DOI: 10.1016/j.neuroscience.2016.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/04/2016] [Accepted: 05/07/2016] [Indexed: 10/21/2022]
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Park JH, Paul MJ, Butler MP, Zucker I. Binocular Interactions in the Entrainment and Phase Shifting of Locomotor Activity Rhythms in Syrian Hamsters. J Biol Rhythms 2016; 20:49-59. [PMID: 15654070 DOI: 10.1177/0748730404272967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To assess binocular interactions and possible ocular dominance in entrainment of circadian rhythms, Syrian hamsters maintained in LL were subjected for several weeks to schedules of eye occlusion with opaque contact lenses. In separate groups, the opaque lens was inserted into the left or right eye for 12 h at the same clock time each day. The left and right eyes of other groups were alternately occluded for 12 h each day, with initial occlusion of either the left or right eye for different groups. Amajority of hamsters entrained their locomotor activity rhythm when 1 eye was occluded for 12 h. The modified visual input imposed by covering 1 eye is sufficient to induce entrainment. Locomotor rhythms of most animals in which the 2 eyes were alternately occluded for 12 h each day phasedelayed onset of activity during the 1st few days of the lensing procedure; activity onset then free ran with • < 24 h for several weeks until entraining with • of 24 h regardless of whether the left or right eye was initially occluded. Entrainment eventually occurred when activity onset coincided with occlusion of the eye contralateral to the one that was first lensed. Photic and nonphotic explanations for eventual entrainment of locomotor rhythms are discussed, and evidence for asymmetrical photic input from the 2 eyes to the SCN is considered
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Affiliation(s)
- Jin Ho Park
- Department of Psychology, University of California, Berkeley, CA 94720-1650, USA.
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Orexins excite ventrolateral geniculate nucleus neurons predominantly via OX2 receptors. Neuropharmacology 2016; 103:236-46. [DOI: 10.1016/j.neuropharm.2015.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 11/12/2015] [Accepted: 12/09/2015] [Indexed: 11/22/2022]
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Fiuza FP, Silva KDA, Pessoa RA, Pontes ALB, Cavalcanti RLP, Pires RS, Soares JG, Nascimento Júnior ES, Costa MSMO, Engelberth RCGJ, Cavalcante JS. Age-related changes in neurochemical components and retinal projections of rat intergeniculate leaflet. AGE (DORDRECHT, NETHERLANDS) 2016; 38:4. [PMID: 26718202 PMCID: PMC5005876 DOI: 10.1007/s11357-015-9867-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
Aging leads to several anatomical and functional deficits in circadian timing system. In previous works, we observed morphological alterations with age in hypothalamic suprachiasmatic nuclei, one central component of this system. However, there are few data regarding aging effects on other central components of this system, such as thalamic intergeniculate leaflet (IGL). In this context, we studied possible age-related alterations in neurochemical components and retinal projections of rat IGL. For this goal, young (3 months), adult (13 months), and aged (23 months) Wistar rats were submitted to an intraocular injection of neural tracer, cholera toxin subunit b (CTb), 5 days before a tissue fixation process by paraformaldehyde perfusion. Optical density measurements and cell count were performed at digital pictures of brain tissue slices processed by immunostaining for glutamic acid decarboxylase (GAD), enkephalin (ENK), neuropeptide Y (NPY) and CTb, characteristic markers of IGL and its retinal terminals. We found a significant age-related loss in NPY immunoreactive neurons, but not in immunoreactivity to GAD and ENK. We also found a decline of retinal projections to IGL with age. We conclude aging impairs both a photic environmental clue afferent to IGL and a neurochemical expression which has an important modulatory circadian function, providing strong anatomical correlates to functional deficits of the aged biological clock.
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Affiliation(s)
- Felipe P Fiuza
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Kayo D A Silva
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Renata A Pessoa
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - André L B Pontes
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Rodolfo L P Cavalcanti
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Raquel S Pires
- Neuroscience Center, University of São Paulo City, São Paulo, SP, Brazil
| | - Joacil G Soares
- Laboratory of Neuroanatomy, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | | | - Miriam S M O Costa
- Laboratory of Neuroanatomy, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Rovena C G J Engelberth
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - Jeferson S Cavalcante
- Laboratory of Neurochemical Studies, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
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Vujovic N, Gooley JJ, Jhou TC, Saper CB. Projections from the subparaventricular zone define four channels of output from the circadian timing system. J Comp Neurol 2015; 523:2714-37. [PMID: 26010698 DOI: 10.1002/cne.23812] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 01/22/2023]
Abstract
The subparaventricular zone of the hypothalamus (SPZ) is the main efferent target of neural projections from the suprachiasmatic nucleus (SCN) and an important relay for the circadian timing system. Although the SPZ is fairly homogeneous cytoarchitecturally and neurochemically, it has been divided into distinct functional and connectional subdivisions. The dorsal subdivision of the SPZ (dSPZ) plays an important role in relaying signals from the SCN controlling body temperature rhythms, while the ventral subdivision (vSPZ) is critical for rhythms of sleep and locomotor activity (Lu et al. [] J Neurosci 21:4864-4874). On the other hand, the medial part of the SPZ receives input mainly from the dorsomedial SCN, whereas the lateral SPZ receives input from the ventrolateral SCN and the retinohypothalamic tract (Leak and Moore [] J Comp Neurol 433:312-334). We therefore investigated whether there are corresponding differences in efferent outputs from these four quadrants of the SPZ (dorsolateral, ventrolateral, dorsomedial, and ventromedial) by a combination of anterograde and retrograde tracing. We found that, while all four subdivisions of the SPZ share a similar backbone of major projection pathways to the septal region, thalamus, hypothalamus, and brainstem, each segment of the SPZ has a specific set of targets where its projections dominate. Furthermore, we observed intra-SPZ projections of varying densities between the four subdivisions. Taken together, this pattern of organization suggests that the circadian timing system may have several parallel neural outflow pathways that provide a road map for understanding how they subserve different functions.
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Affiliation(s)
- Nina Vujovic
- Department of Neurology, Program in Neuroscience, and Division of Sleep Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, 02215
| | - Joshua J Gooley
- Department of Neurology, Program in Neuroscience, and Division of Sleep Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, 02215
| | - Thomas C Jhou
- Department of Neurology, Program in Neuroscience, and Division of Sleep Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, 02215
| | - Clifford B Saper
- Department of Neurology, Program in Neuroscience, and Division of Sleep Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, 02215
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Palus K, Chrobok L, Lewandowski M. Orexins/hypocretins modulate the activity of NPY-positive and -negative neurons in the rat intergeniculate leaflet via OX1 and OX2 receptors. Neuroscience 2015; 300:370-80. [DOI: 10.1016/j.neuroscience.2015.05.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 05/15/2015] [Accepted: 05/16/2015] [Indexed: 01/11/2023]
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Chidlow G, Wood JPM, Casson RJ. Expression of inducible heat shock proteins Hsp27 and Hsp70 in the visual pathway of rats subjected to various models of retinal ganglion cell injury. PLoS One 2014; 9:e114838. [PMID: 25535743 PMCID: PMC4275305 DOI: 10.1371/journal.pone.0114838] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/14/2014] [Indexed: 01/09/2023] Open
Abstract
Inducible heat shock proteins (Hsps) are upregulated in the central nervous system in response to a wide variety of injuries. Surprisingly, however, no coherent picture has emerged regarding the magnitude, duration and cellular distribution of inducible Hsps in the visual system following injury to retinal ganglion cells (RGCs). The current study sought, therefore, to achieve the following two objectives. The first aim of this study was to systematically characterise the patterns of Hsp27 and −70 expression in the retina and optic nerve in four discrete models of retinal ganglion cell (RGC) degeneration: axonal injury (ON crush), somato-dendritic injury (NMDA-induced excitotoxicity), chronic hypoperfusion (bilateral occlusion of the carotid arteris) and experimental glaucoma. The second aim was to document Hsp27 and −70 expression in the optic tract, the subcortical retinorecipient areas of the brain, and the visual cortex during Wallerian degeneration of RGC axons. Hsp27 was robustly upregulated in the retina in each injury paradigm, with the chronic models, 2VO and experimental glaucoma, displaying a more persistent Hsp27 transcriptional response than the acute models. Hsp27 expression was always associated with astrocytes and with a subset of RGCs in each of the models excluding NMDA. Hsp27 was present within astrocytes of the optic nerve/optic tract in control rats. During Wallerian degeneration, Hsp27 was upregulated in the optic nerve/optic tract and expressed de novo by astrocytes in the lateral geniculate nucleus and the stratum opticum of the superior colliculus. Conversely, the results of our study indicate Hsp70 was minimally induced in any of the models of injury, either in the retina, or in the optic nerve/optic tract, or in the subcortical, retinorecipient areas of the brain. The findings of the present study augment our understanding of the involvement of Hsp27 and Hsp70 in the response of the visual system to RGC degeneration.
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Affiliation(s)
- Glyn Chidlow
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
- * E-mail:
| | - John P. M. Wood
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
| | - Robert J. Casson
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
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Gall AJ, Yan L, Smale L, Nunez AA. Intergeniculate leaflet lesions result in differential activation of brain regions following the presentation of photic stimuli in Nile grass rats. Neurosci Lett 2014; 579:101-5. [PMID: 25038414 PMCID: PMC4138276 DOI: 10.1016/j.neulet.2014.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/26/2014] [Accepted: 07/04/2014] [Indexed: 11/21/2022]
Abstract
The intergeniculate leaflet (IGL) plays an important role in the entrainment of circadian rhythms and the mediation of acute behavioral responses to light (i.e., masking). Recently, we reported that IGL lesions in diurnal grass rats result in a reversal in masking responses to light as compared to controls. Here, we used Fos as a marker of neural activation to examine the mechanisms by which the IGL may influence this masking effect of light in grass rats. Specifically, we examined the patterns of Fos activation in retinorecipient areas and in brain regions that receive IGL inputs following 1-h light pulses given during the early night in IGL-lesioned and sham-operated grass rats. Three patterns emerged: (1) IGL lesions had no effect on the Fos response to light, (2) IGL lesions resulted in a reversal in Fos responses to light, and (3) IGL lesions resulted in a lack of a Fos response to light. Of specific interest were the suprachiasmatic nucleus (SCN) and the olivary pretectal nucleus (OPT), both of which are retinorecipient and connect reciprocally with the IGL. Light-induced Fos expression in the SCN was unaffected by IGL lesions, whereas the OPT exhibited a significant reduction in Fos expression following a light pulse in animals with IGL lesions. Altogether, our results suggest that the OPT, but not the SCN, exhibits a reversal in Fos responses to light following IGL lesions that reverse masking responses in diurnal grass rats. Our results suggest that interconnections between the IGL and downstream brain areas (e.g., OPT) may play a role in determining the direction of the behavioral response to light.
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Affiliation(s)
- Andrew J Gall
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI, USA.
| | - Lily Yan
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - Laura Smale
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - Antonio A Nunez
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI, USA
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Abstract
OBJECTIVE The objective of the current article is to review the shared pathophysiological mechanisms which may underlie the clinical association between headaches and sleep disorders. BACKGROUND The association between sleep and headache is well documented in terms of clinical phenotypes. Disrupted sleep-wake patterns appear to predispose individuals to headache attacks and increase the risk of chronification, while sleep is one of the longest established abortive strategies. In agreement, narcoleptic patients show an increased prevalence of migraine compared to the general population and specific familial sleep disorders have been identified to be comorbid with migraine with aura. CONCLUSION The pathophysiology and pharmacology of headache and sleep disorders involves an array of neural networks which likely underlie their shared clinical association. While it is difficult to differentiate between cause and effect, or simply a spurious relationship the striking brainstem, hypothalamic and thalamic convergence would suggest a bidirectional influence.
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Affiliation(s)
- Philip R Holland
- Department of Clinical Neuroscience, Institute of Psychiatry, King's College London, UK
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The neuroinvasive profiles of H129 (herpes simplex virus type 1) recombinants with putative anterograde-only transneuronal spread properties. Brain Struct Funct 2014; 220:1395-420. [PMID: 24585022 DOI: 10.1007/s00429-014-0733-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 02/11/2014] [Indexed: 10/25/2022]
Abstract
The use of viruses as transneuronal tracers has become an increasingly powerful technique for defining the synaptic organization of neural networks. Although a number of recombinant alpha herpesviruses are known to spread selectively in the retrograde direction through neural circuits only one strain, the H129 strain of herpes simplex virus type 1, is reported to selectively spread in the anterograde direction. However, it is unclear from the literature whether there is an absolute block or an attenuation of retrograde spread of H129. Here, we demonstrate efficient anterograde spread, and temporally delayed retrograde spread, of H129 and three novel recombinants. In vitro studies revealed no differences in anterograde and retrograde spread of parental H129 and its recombinants through superior cervical ganglion neurons. In vivo injections of rat striatum revealed a clear bias of anterograde spread, although evidence of deficient retrograde transport was also present. Evidence of temporally delayed retrograde transneuronal spread of H129 in the retina was observed following injection of the lateral geniculate nucleus. The data also demonstrated that three novel recombinants efficiently express unique fluorescent reporters and have the capacity to infect the same neurons in dual infection paradigms. From these experiments we conclude that H129 and its recombinants not only efficiently infect neurons through anterograde transneuronal passage, but also are capable of temporally delayed retrograde transneuronal spread. In addition, the capacity to produce dual infection of projection targets following anterograde transneuronal passage provides an important addition to viral transneuronal tracing technology.
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Effect of acute and chronic bilateral visual deafferentation on c-Fos immunoreactivity in the visual system of adult rats. Exp Brain Res 2013; 229:595-607. [DOI: 10.1007/s00221-013-3623-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 06/12/2013] [Indexed: 12/24/2022]
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Gall AJ, Smale L, Yan L, Nunez AA. Lesions of the Intergeniculate Leaflet Lead to a Reorganization in Circadian Regulation and a Reversal in Masking Responses to Photic Stimuli in the Nile Grass Rat. PLoS One 2013; 8:e67387. [PMID: 23840688 PMCID: PMC3686741 DOI: 10.1371/journal.pone.0067387] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 05/17/2013] [Indexed: 11/19/2022] Open
Abstract
Light influences the daily patterning of behavior by entraining circadian rhythms and through its acute effects on activity levels (masking). Mechanisms of entrainment are quite similar across species, but masking can be very different. Specifically, in diurnal species, light generally increases locomotor activity (positive masking), and in nocturnal ones, it generally suppresses it (negative masking). The intergeniculate leaflet (IGL), a subdivision of the lateral geniculate complex, receives direct retinal input and is reciprocally connected with the primary circadian clock, the suprachiasmatic nucleus (SCN). Here, we evaluated the influence of the IGL on masking and the circadian system in a diurnal rodent, the Nile grass rat (Arvicanthis niloticus), by determining the effects of bilateral IGL lesions on general activity under different lighting conditions. To examine masking responses, light or dark pulses were delivered in the dark or light phase, respectively. Light pulses at Zeitgeber time (ZT) 14 increased activity in control animals but decreased it in animals with IGL lesions. Dark pulses had no effect on controls, but significantly increased activity in lesioned animals at ZT0. Lesions also significantly increased activity, primarily during the dark phase of a 12:12 light/dark cycle, and during the subjective night when animals were kept in constant conditions. Taken together, our results suggest that the IGL plays a vital role in the maintenance of both the species-typical masking responses to light, and the circadian contribution to diurnality in grass rats.
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Affiliation(s)
- Andrew J. Gall
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
| | - Laura Smale
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Lily Yan
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Antonio A. Nunez
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, Michigan, United States of America
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Saderi N, Cazarez-Márquez F, Buijs FN, Salgado-Delgado RC, Guzman-Ruiz MA, del Carmen Basualdo M, Escobar C, Buijs RM. The NPY intergeniculate leaflet projections to the suprachiasmatic nucleus transmit metabolic conditions. Neuroscience 2013; 246:291-300. [PMID: 23680526 DOI: 10.1016/j.neuroscience.2013.05.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/02/2013] [Accepted: 05/03/2013] [Indexed: 11/27/2022]
Abstract
The intergeniculate leaflet (IGL) is classically known as the area of the Thalamic Lateral Geniculate Complex providing the suprachiasmatic nucleus (SCN) non-photic information. In the present study we investigated whether this information might be related to the metabolic state of the animal. The following groups of male Wistar rats were used for analysis of neuropeptide Y (NPY) and c-Fos in the IGL and SCN. (1) Fed ad libitum. (2) Fasted for 48 h. (3) Fasted for 48 h followed by refeeding for 3 h. (4) Monosodium glutamate-lesioned and 48 h fasted. (5) Electrolytic lesion in the IGL and 48 h fasted. The results were quantified by optical densitometry. Neuronal tracers were injected in two brain areas that receive metabolic information from the periphery, the arcuate nucleus (ARC) and Nucleus of the Tractus Solitarius to investigate whether there is an anatomical relationship with the IGL. Lesion studies showed the IGL, and not the ARC, as origin of most NPY projections to the SCN. Fasting induced important changes in the NPY expression in the IGL, coinciding with similar changes of NPY/glutamate decarboxylase projections of the IGL to the SCN. These changes revealed that the IGL is involved in the transmission of metabolic information to the SCN. In fasted animals IGL lesion resulted in a significant increase of c-Fos in the SCN as compared to intact fasted animals demonstrating the inhibitory influence of the IGL to the SCN in fasting conditions. When the animal after fasting was refed, an increase of c-Fos in the SCN indicated a removal of this inhibitory input. Together these observations show that in addition to increased inhibitory IGL input during fasting, the negative metabolic condition also results in increased excitatory input to the SCN via other pathways. Consequently the present observations show that at least part of the non-photic input to the SCN, arising from the IGL contains information about metabolic conditions.
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Affiliation(s)
- N Saderi
- Laboratory of Hypothalamic Integration Mechanism, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, Ciudad Universitaria, 04510 Mexico DF, Mexico
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Gaillard F, Karten HJ, Sauvé Y. Retinorecipient areas in the diurnal murine rodentArvicanthis niloticus: A disproportionally large superior colliculus. J Comp Neurol 2013; 521:1699-726. [DOI: 10.1002/cne.23303] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Revised: 07/01/2012] [Accepted: 01/04/2013] [Indexed: 12/24/2022]
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Blasiak A, Blasiak T, Lewandowski MH, Hossain MA, Wade JD, Gundlach AL. Relaxin-3 innervation of the intergeniculate leaflet of the rat thalamus - neuronal tract-tracing and in vitro electrophysiological studies. Eur J Neurosci 2013; 37:1284-94. [PMID: 23432696 DOI: 10.1111/ejn.12155] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/16/2013] [Indexed: 11/29/2022]
Abstract
Behavioural state is controlled by a range of neural systems that are sensitive to internal and external stimuli. The relaxin-3 and relaxin family peptide receptor 3 (RXFP3) system has emerged as a putative ascending arousal network with putative involvement in regulation of stress responses, neuroendocrine control, feeding and metabolism, circadian activity and cognition. Relaxin-3/γ-aminobutyric acid neuron populations have been identified in the nucleus incertus, pontine raphe nucleus, periaqueductal grey (PAG) and an area dorsal to the substantia nigra. Relaxin-3-positive fibres/terminals densely innervate arousal-related structures in the brainstem, hypothalamus and limbic forebrain, but the functional significance of the heterogeneous relaxin-3 neuron distribution and its inputs to specific brain areas are unclear. Therefore, in this study, we used neuronal tract-tracing and immunofluorescence staining to explore the source of the dense relaxin-3 innervation of the intergeniculate leaflet (IGL) of the thalamus, a component of the neural circadian timing system. Confocal microscopy analysis revealed that relaxin-3-positive neurons retrogradely labelled from the IGL were predominantly present in the PAG and these neurons expressed corticotropin-releasing factor receptor-like immunoreactivity. Subsequently, whole-cell patch-clamp recordings revealed heterogeneous effects of RXFP3 activation in the IGL by the RXFP3 agonist, relaxin-3 B-chain/insulin-like peptide-5 A-chain (R3/I5). Identified, neuropeptide Y-positive IGL neurons, known to influence suprachiasmatic nucleus activity, were excited by R3/I5, whereas neurons of unidentified neurotransmitter content were either depolarized or displayed a decrease in action potential firing and/or membrane potential hyperpolarization. Our data identify a PAG to IGL relaxin-3/RXFP3 pathway that might convey stress-related information to key elements of the circadian system and influence behavioural state rhythmicity.
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Affiliation(s)
- Anna Blasiak
- Department of Neurophysiology and Chronobiology, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland.
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Differential firing pattern and response to lighting conditions of rat intergeniculate leaflet neurons projecting to suprachiasmatic nucleus or contralateral intergeniculate leaflet. Neuroscience 2013; 228:315-24. [DOI: 10.1016/j.neuroscience.2012.10.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/19/2012] [Accepted: 10/19/2012] [Indexed: 11/21/2022]
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Adjene JO, Igbigbi PS, Nwose EU. Histological effects of chronic administration of efavirenz on lateral geniculate body of adult Wistar rats. NORTH AMERICAN JOURNAL OF MEDICAL SCIENCES 2012; 2:1-4. [PMID: 22624105 PMCID: PMC3354381 DOI: 10.4297/najms.2010.11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background: The effects of chronic administration of efavirenz commonly used as part of highly active antiretroviral therapy (HAART) for the treatment of Human Immunodeficiency Virus (HIV) type-1 on the weight of the brain and inferior colliculus of adult Wistar rats was carefully studied. Methods and Materials The rats of both sexes (n = 24), with average weight of 200g were randomly assigned into two treatment (A & B) (n=16) and Control (c) (n=8) groups. The rats in the treatment group received 600mg/70kg bogy weight of efavirenz dissolved in distilled water daily for 30days through the orogastric tube. The control group received equal volume of distilled through the same route. All rats were fed with grower's mash and given water liberally. The rats were sacrificed by cervical dislocation method on the thirty-first day of the experiment and the lateral geniculate body was carefully dissected out and quickly fixed in 10% formal saline for histological study. Results The findings indicate that rats in the treated group showed some cellular degenerative changes like sparse cellular population, pyknotic nuclei with some microcystic changes and edema in the stroma of the lateral geniculate body as compared to the control group. Conclusion Chronic administration of efavirenz may have an adverse effect on the visual sensibilities by affecting the microanatomy of the lateral geniculate body of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.
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Morin LP. Neuroanatomy of the extended circadian rhythm system. Exp Neurol 2012; 243:4-20. [PMID: 22766204 DOI: 10.1016/j.expneurol.2012.06.026] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/19/2012] [Accepted: 06/24/2012] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN), site of the primary clock in the circadian rhythm system, has three major afferent connections. The most important consists of a retinohypothalamic projection through which photic information, received by classical rod/cone photoreceptors and intrinsically photoreceptive retinal ganglion cells, gains access to the clock. This information influences phase and period of circadian rhythms. The two other robust afferent projections are the median raphe serotonergic pathway and the geniculohypothalamic (GHT), NPY-containing pathway from the thalamic intergeniculate leaflet (IGL). Beyond this simple framework, the number of anatomical routes that could theoretically be involved in rhythm regulation is enormous, with the SCN projecting to 15 regions and being directly innervated by about 35. If multisynaptic afferents to the SCN are included, the number expands to approximately brain 85 areas providing input to the SCN. The IGL, a known contributor to circadian rhythm regulation, has a still greater level of complexity. This nucleus connects abundantly throughout the brain (to approximately 100 regions) by pathways that are largely bilateral and reciprocal. Few of these sites have been evaluated for their contributions to circadian rhythm regulation, although most have a theoretical possibility of doing so via the GHT. The anatomy of IGL connections suggests that one of its functions may be regulation of eye movements during sleep. Together, neural circuits of the SCN and IGL are complex and interconnected. As yet, few have been tested with respect to their involvement in rhythm regulation.
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Affiliation(s)
- Lawrence P Morin
- Department of Psychiatry, Stony Brook University Medical Center, Stony Brook, NY 11794-8101, USA.
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Retinal projections and neurochemical characterization of the pregeniculate nucleus of the common marmoset (Callithrix jacchus). J Chem Neuroanat 2012; 44:34-44. [PMID: 22531294 DOI: 10.1016/j.jchemneu.2012.04.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/22/2012] [Accepted: 04/07/2012] [Indexed: 11/23/2022]
Abstract
In mammals, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian timing system. The SCN is the site of the endogenous biological clock that generates rhythms and synchronizes them to environmental cues. The IGL is a key structure that modulates SCN activity and is responsible for the transmission of non-photic information to the SCN, thus participating in the integration between photic and non-photic stimuli. Both the SCN and IGL receive projections of retinal ganglion cells and the IGL is connected to the SCN through the geniculohypothalamic tract. Little is known about these structures in the primate brain and the pregeniculate nucleus (PGN) has been suggested to be the primate equivalent of the rodent IGL. The aim of this study was to characterize the PGN of a primate, the common marmoset (Callithrix jacchus), and to analyze its retinal afferents. Here, the marmoset PGN was found to be organized into three subsectors based on neuronal size, pattern of retinal projections, and the distribution of neuropeptide Y-, GAD-, serotonin-, enkephalin- and substance P-labeled terminals. This pattern indicates that the marmoset PGN is equivalent to the IGL. This detailed description contributes to the understanding of the circadian timing system in this primate species considering the importance of the IGL within the context of circadian regulation.
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