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Constantin S, Quignon C, Pizano K, Shostak DM, Wray S. Vasoactive intestinal peptide excites GnRH neurons via KCa3.1, a potential player in the slow afterhyperpolarization current. Front Cell Neurosci 2024; 18:1354095. [PMID: 38633445 PMCID: PMC11021707 DOI: 10.3389/fncel.2024.1354095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 03/05/2024] [Indexed: 04/19/2024] Open
Abstract
Vasoactive intestinal peptide (VIP) is an important component of the suprachiasmatic nucleus (SCN) which relays circadian information to neuronal populations, including GnRH neurons. Human and animal studies have shown an impact of disrupted daily rhythms (chronic shift work, temporal food restriction, clock gene disruption) on both male and female reproduction and fertility. To date, how VIP modulates GnRH neurons remains unknown. Calcium imaging and electrophysiology on primary GnRH neurons in explants and adult mouse brain slice, respectively, were used to address this question. We found VIP excites GnRH neurons via the VIP receptor, VPAC2. The downstream signaling pathway uses both Gs protein/adenylyl cyclase/protein kinase A (PKA) and phospholipase C/phosphatidylinositol 4,5-bisphosphate (PIP2) depletion. Furthermore, we identified a UCL2077-sensitive target, likely contributing to the slow afterhyperpolarization current (IAHP), as the PKA and PIP2 depletion target, and the KCa3.1 channel as a specific target. Thus, VIP/VPAC2 provides an example of Gs protein-coupled receptor-triggered excitation in GnRH neurons, modulating GnRH neurons likely via the slow IAHP. The possible identification of KCa3.1 in the GnRH neuron slow IAHP may provide a new therapeutical target for fertility treatments.
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Affiliation(s)
| | | | | | | | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, MD, United States
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Van Loh BM, Yaw AM, Breuer JA, Jackson B, Nguyen D, Jang K, Ramos F, Ho EV, Cui LJ, Gillette DLM, Sempere LF, Gorman MR, Tonsfeldt KJ, Mellon PL, Hoffmann HM. The transcription factor VAX1 in VIP neurons of the suprachiasmatic nucleus impacts circadian rhythm generation, depressive-like behavior, and the reproductive axis in a sex-specific manner in mice. Front Endocrinol (Lausanne) 2023; 14:1269672. [PMID: 38205198 PMCID: PMC10777845 DOI: 10.3389/fendo.2023.1269672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 11/28/2023] [Indexed: 01/12/2024] Open
Abstract
Background The suprachiasmatic nucleus (SCN) within the hypothalamus is a key brain structure required to relay light information to the body and synchronize cell and tissue level rhythms and hormone release. Specific subpopulations of SCN neurons, defined by their peptide expression, regulate defined SCN output. Here we focus on the vasoactive intestinal peptide (VIP) expressing neurons of the SCN. SCN VIP neurons are known to regulate circadian rhythms and reproductive function. Methods To specifically study SCN VIP neurons, we generated a novel knock out mouse line by conditionally deleting the SCN enriched transcription factor, Ventral Anterior Homeobox 1 (Vax1), in VIP neurons (Vax1Vip; Vax1fl/fl:VipCre). Results We found that Vax1Vip females presented with lengthened estrous cycles, reduced circulating estrogen, and increased depressive-like behavior. Further, Vax1Vip males and females presented with a shortened circadian period in locomotor activity and ex vivo SCN circadian period. On a molecular level, the shortening of the SCN period was driven, at least partially, by a direct regulatory role of VAX1 on the circadian clock genes Bmal1 and Per2. Interestingly, Vax1Vip females presented with increased expression of arginine vasopressin (Avp) in the paraventricular nucleus, which resulted in increased circulating corticosterone. SCN VIP and AVP neurons regulate the reproductive gonadotropin-releasing hormone (GnRH) and kisspeptin neurons. To determine how the reproductive neuroendocrine network was impacted in Vax1Vip mice, we assessed GnRH sensitivity to a kisspeptin challenge in vivo. We found that GnRH neurons in Vax1Vip females, but not males, had an increased sensitivity to kisspeptin, leading to increased luteinizing hormone release. Interestingly, Vax1Vip males showed a small, but significant increase in total sperm and a modest delay in pubertal onset. Both male and female Vax1Vip mice were fertile and generated litters comparable in size and frequency to controls. Conclusion Together, these data identify VAX1 in SCN VIP neurons as a neurological overlap between circadian timekeeping, female reproduction, and depressive-like symptoms in mice, and provide novel insight into the role of SCN VIP neurons.
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Affiliation(s)
- Brooke M. Van Loh
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
| | - Alexandra M. Yaw
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
| | - Joseph A. Breuer
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Brooke Jackson
- Department of Radiology and Precision Health Program, Michigan State University, East Lansing, MI, United States
| | - Duong Nguyen
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
| | - Krystal Jang
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
| | - Fabiola Ramos
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
| | - Emily V. Ho
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Laura J. Cui
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Dominique L. M. Gillette
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Lorenzo F. Sempere
- Department of Radiology and Precision Health Program, Michigan State University, East Lansing, MI, United States
| | - Michael R. Gorman
- Department of Psychology, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Karen J. Tonsfeldt
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Pamela L. Mellon
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, United States
| | - Hanne M. Hoffmann
- Department of Animal Science and the Reproductive and Developmental Sciences Program, Michigan State University, East Lansing, MI, United States
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Reproductive Science and Medicine, University of California, San Diego, La Jolla, CA, United States
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Ahmad SF, Chandrababu Shailaja C, Vaishnav S, Kumar A, Gaur GK, Janga SC, Ahmad SM, Malla WA, Dutt T. Read-depth based approach on whole genome resequencing data reveals important insights into the copy number variation (CNV) map of major global buffalo breeds. BMC Genomics 2023; 24:616. [PMID: 37845620 PMCID: PMC10580622 DOI: 10.1186/s12864-023-09720-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Elucidating genome-wide structural variants including copy number variations (CNVs) have gained increased significance in recent times owing to their contribution to genetic diversity and association with important pathophysiological states. The present study aimed to elucidate the high-resolution CNV map of six different global buffalo breeds using whole genome resequencing data at two coverages (10X and 30X). Post-quality control, the sequence reads were aligned to the latest draft release of the Bubaline genome. The genome-wide CNVs were elucidated using a read-depth approach in CNVnator with different bin sizes. Adjacent CNVs were concatenated into copy number variation regions (CNVRs) in different breeds and their genomic coverage was elucidated. RESULTS Overall, the average size of CNVR was lower at 30X coverage, providing finer details. Most of the CNVRs were either deletion or duplication type while the occurrence of mixed events was lesser in number on a comparative basis in all breeds. The average CNVR size was lower at 30X coverage (0.201 Mb) as compared to 10X (0.013 Mb) with the finest variants in Banni buffaloes. The maximum number of CNVs was observed in Murrah (2627) and Pandharpuri (25,688) at 10X and 30X coverages, respectively. Whereas the minimum number of CNVs were scored in Surti at both coverages (2092 and 17,373). On the other hand, the highest and lowest number of CNVRs were scored in Jaffarabadi (833 and 10,179 events) and Surti (783 and 7553 events) at both coverages. Deletion events overnumbered duplications in all breeds at both coverages. Gene profiling of common overlapped genes and longest CNVRs provided important insights into the evolutionary history of these breeds and indicate the genomic regions under selection in respective breeds. CONCLUSION The present study is the first of its kind to elucidate the high-resolution CNV map in major buffalo populations using a read-depth approach on whole genome resequencing data. The results revealed important insights into the divergence of major global buffalo breeds along the evolutionary timescale.
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Affiliation(s)
- Sheikh Firdous Ahmad
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
| | - Celus Chandrababu Shailaja
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Sakshi Vaishnav
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Amit Kumar
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Gyanendra Kumar Gaur
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Sarath Chandra Janga
- Luddy School of Informatics, Computing & Engineering, Indiana University Indianapolis (IUI), Indianapolis, 46202, USA
| | - Syed Mudasir Ahmad
- Division of Animal Biotechnology, Faculty of Veterinary Sciences and AH, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, Jammu & Kashmir, 190006, India.
| | - Waseem Akram Malla
- Division of Veterinary Biotechnology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Triveni Dutt
- Division of Animal Genetics, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
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Ago Y, Van C, Condro MC, Hrncir H, Diep AL, Rajbhandari AK, Fanselow MS, Hashimoto H, MacKenzie-Graham AJ, Waschek JA. Overexpression of VIPR2 in mice results in microencephaly with paradoxical increased white matter volume. Exp Neurol 2023; 362:114339. [PMID: 36717013 DOI: 10.1016/j.expneurol.2023.114339] [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: 05/18/2022] [Revised: 01/10/2023] [Accepted: 01/24/2023] [Indexed: 01/28/2023]
Abstract
Large scale studies in populations of European and Han Chinese ancestry found a series of rare gain-of-function microduplications in VIPR2, encoding VPAC2, a receptor that binds vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide with high affinity, that were associated with an up to 13-fold increased risk for schizophrenia. To address how VPAC2 receptor overactivity might affect brain development, we used a well-characterized Nestin-Cre mouse strain and a knock-in approach to overexpress human VPAC2 in the central nervous system. Mice that overexpressed VPAC2 were found to exhibit a significant reduction in brain weight. Magnetic resonance imaging analysis confirmed a decrease in brain size, a specific reduction in the hippocampus grey matter volume and a paradoxical increase in whole-brain white matter volume. Sex-specific changes in behavior such as impaired prepulse inhibition and contextual fear memory were observed in VPAC2 overexpressing mice. The data indicate that the VPAC2 receptor may play a critical role in brain morphogenesis and suggest that overactive VPAC2 signaling during development plays a mechanistic role in some forms of schizophrenia.
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Affiliation(s)
- Yukio Ago
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan; Department of Cellular and Molecular Pharmacology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Hiroshima 734-8553, Japan.
| | - Christina Van
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Interdepartmental Doctoral Program, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Michael C Condro
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Haley Hrncir
- Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Anna L Diep
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Abha K Rajbhandari
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Psychology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; Staglin Center for Brain and Behavioral Health, University of California Los Angeles, Los Angeles, CA 90095, USA; Departments of Psychiatry and Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael S Fanselow
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Psychology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095, USA; Staglin Center for Brain and Behavioral Health, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka 565-0871, Japan; Division of Bioscience, Institute for Datability Science, Osaka University, Suita, Osaka 565-0871, Japan; Open and Transdisciplinary Research Initiatives, Osaka University, Suita, Osaka 565-0871, Japan; Department of Molecular Pharmaceutical Science, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
| | - Allan J MacKenzie-Graham
- Ahmanson-Lovelace Brain Mapping Center, Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - James A Waschek
- Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
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Ni R, Shu Y, Luo P, Zhou J. Sexual dimorphism in the bed nucleus of the stria terminalis, medial preoptic area and suprachiasmatic nucleus in male and female tree shrews. J Anat 2022; 240:528-540. [PMID: 34642936 PMCID: PMC8819044 DOI: 10.1111/joa.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 02/05/2023] Open
Abstract
Sex differences in behaviour partly arise from the sexual dimorphism of brain anatomy between males and females. However, the sexual dimorphism of the tree shrew brain is unclear. In the present study, we examined the detailed distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-ir) neurons and fibres in the suprachiasmatic nucleus (SCN) and VIP-ir fibres in the bed nucleus of the stria terminalis (BST) of male and female tree shrews. The overall volume of the SCN in male tree shrews was comparable with that in females. However, males showed a significantly higher density of VIP-ir cells and fibres in the SCN than females. The shape of the VIP-stained area in coronal sections was arched, elongated or oval in the lateral division (STL) and the anterior part of the medial division (STMA) of the BST and oval or round in the posterior part of the medial division of the BST (STMP). The volume of the VIP-stained BST in male tree shrews was similar to that in females. The overall distribution of VIP-ir fibres was similar between the sexes throughout the BST except within the STMA, where darkly stained fibres were observed in males, whereas lightly stained fibres were observed in females. Furthermore, male tree shrews showed a significantly higher intensity of Nissl staining in the medial preoptic area (MPA) and the ventral part of the medial division of the BST than females. These findings are the first to reveal sexual dimorphism in the SCN, BST and MPA of the tree shrew brain, providing neuroanatomical evidence of sexual dimorphism in these regions related to their roles in sex differences in physiology and behaviour.
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Affiliation(s)
- Rong‐Jun Ni
- Psychiatric Laboratory and Mental Health CenterWest China Hospital of Sichuan UniversityChengduChina
- Huaxi Brain Research CenterWest China Hospital of Sichuan UniversityChengduChina
| | - Yu‐Mian Shu
- School of Architecture and Civil EngineeringChengdu UniversityChengduChina
| | - Peng‐Hao Luo
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Jiang‐Ning Zhou
- Chinese Academy of Science Key Laboratory of Brain Function and DiseasesSchool of Life SciencesUniversity of Science and Technology of ChinaHefeiChina
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Rohr KE, Inda T, Evans JA. Vasopressin Resets the Central Circadian Clock in a Manner Influenced by Sex and Vasoactive Intestinal Polypeptide Signaling. Neuroendocrinology 2022; 112:904-916. [PMID: 34856551 PMCID: PMC9160207 DOI: 10.1159/000521286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 12/01/2021] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIMS Circadian rhythms in behavior and physiology are programmed by the suprachiasmatic nucleus (SCN) of the hypothalamus. A subset of SCN neurons produce the neuropeptide arginine vasopressin (AVP), but it remains unclear whether AVP signaling influences the SCN clock directly. METHODS Here, we test that AVP signaling acting through V1A and V1B receptors influences molecular rhythms in SCN neurons. V1 receptor agonists were applied ex vivo to PERIOD2::LUCIFERASE SCN slices, allowing for real-time monitoring of changes in molecular clock function. RESULTS V1A/B agonists reset the phase of the SCN molecular clock in a time-dependent manner, with larger magnitude responses by the female SCN. Further, we found evidence that both Gαq and Gαs signaling pathways interact with V1A/B-induced SCN resetting, and that this response requires vasoactive intestinal polypeptide (VIP) signaling. CONCLUSIONS Collectively, this work indicates that AVP signaling resets SCN molecular rhythms in conjunction with VIP signaling and in a manner influenced by sex. This highlights the utility of studying clock function in both sexes and suggests that signal integration in central clock circuits regulates emergent properties important for the control of daily rhythms in behavior and physiology.
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Affiliation(s)
| | | | - Jennifer A. Evans
- Corresponding author: 560 N 16 St, Schroeder Complex, Room 446, Milwaukee, WI 53233, Phone: 414 288-5732, Fax: 414-288-6564,
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Joye DAM, Evans JA. Sex differences in daily timekeeping and circadian clock circuits. Semin Cell Dev Biol 2021; 126:45-55. [PMID: 33994299 DOI: 10.1016/j.semcdb.2021.04.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/24/2021] [Accepted: 04/29/2021] [Indexed: 11/19/2022]
Abstract
The circadian system regulates behavior and physiology in many ways important for health. Circadian rhythms are expressed by nearly every cell in the body, and this large system is coordinated by a central clock in the suprachiasmatic nucleus (SCN). Sex differences in daily rhythms are evident in humans and understanding how circadian function is modulated by biological sex is an important goal. This review highlights work examining effects of sex and gonadal hormones on daily rhythms, with a focus on behavior and SCN circuitry in animal models commonly used in pre-clinical studies. Many questions remain in this area of the field, which would benefit from further work investigating this topic.
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Affiliation(s)
- Deborah A M Joye
- Marquette University, Department of Biomedical Sciences, Milwaukee, WI, USA
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, Milwaukee, WI, USA.
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Abstract
Female reproductive success relies on proper integration of circadian- and ovarian- signals to the hypothalamic-pituitary-gonadal axis in order to synchronize the preovulatory LH surge at the end of the ovarian follicular stage with the onset of the main active period. In this study, we used a combination of neuroanatomical and electrophysiological approaches to assess whether the hypothalamic neurons expressing Arg-Phe amide-related peptide (RFRP-3), a gonadotropin inhibitory peptide, exhibit daily and estrous stage dependent variations in female mice. Furthermore, we investigated whether arginine vasopressin (AVP), a circadian peptide produced by the suprachiamatic nucleus regulates RFRP-3 neurons. The number of c-Fos–positive RFRP-3 immunoreactive neurons is significantly reduced at the day-to-night transition with no difference between diestrus and proestrus. Contrastingly, RFRP neuron firing rate is higher in proestrus as compared to diestrus, independently of the time of the day. AVP immunoreactive fibers contact RFRP neurons with the highest density observed during the late afternoon of diestrus and proestrus. Application of AVP increases RFRP neurons firing in the afternoon (ZT6-10) of diestrus, but not at the same time point of proestrus, indicating that AVP signaling on RFRP neurons may depend on circulating ovarian steroids. Together, these studies show that RFRP neurons integrate both daily and estrogenic signals, which downstream may help to properly time the preovulatory LH surge.
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Rohr KE, Telega A, Savaglio A, Evans JA. Vasopressin regulates daily rhythms and circadian clock circuits in a manner influenced by sex. Horm Behav 2021; 127:104888. [PMID: 33202247 PMCID: PMC7855892 DOI: 10.1016/j.yhbeh.2020.104888] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/30/2020] [Accepted: 11/04/2020] [Indexed: 12/17/2022]
Abstract
Arginine vasopressin (AVP) is a neurohormone that alters cellular physiology through both endocrine and synaptic signaling. Circadian rhythms in AVP release and other biological processes are driven by the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Loss of vasopressin signaling alters circadian behavior, but the basis of these effects remains unclear. Here we investigate the role of AVP signaling in circadian timekeeping by analyzing behavior and SCN function in a novel AVP-deficient mouse model. Consistent with previous work, loss of AVP signaling increases water consumption and accelerates recovery to simulated jetlag. We expand on these results to show that loss of AVP increases period, imprecision and plasticity of behavioral rhythms under constant darkness. Interestingly, the effect of AVP deficiency on circadian period was influenced by sex, with loss of AVP lengthening period in females but not males. Examining SCN function directly with ex vivo bioluminescence imaging of clock protein expression, we demonstrate that loss of AVP signaling modulates the period, precision, and phase relationships of SCN neurons in both sexes. This pattern of results suggests that there are likely sex differences in downstream targets of the SCN. Collectively, this work indicates that AVP signaling modulates circadian circuits in a manner influenced by sex, which provides new insight into sexual dimorphisms in the regulation of daily rhythms.
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Affiliation(s)
- Kayla E Rohr
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Adam Telega
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Alexandra Savaglio
- Marquette University, Department of Biomedical Sciences, United States of America
| | - Jennifer A Evans
- Marquette University, Department of Biomedical Sciences, United States of America.
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Vieyra-Valdez E, Linares-Culebro R, Rosas-Gavilán G, Ramírez-Hernández D, Domínguez-Casalá R, Morales-Ledesma L. Roles of the cholinergic system and vagal innervation in the regulation of GnRH secretion and ovulation: Experimental evidence. Brain Res Bull 2020; 165:129-138. [PMID: 32966849 DOI: 10.1016/j.brainresbull.2020.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 09/04/2020] [Accepted: 09/14/2020] [Indexed: 12/20/2022]
Abstract
Reproduction is the biological process that sustains life. It is regulated by a neuro-hormonal mechanism that is synchronized by the interaction among the hypothalamus, hypophysis, and ovaries. Ovulation is regulated by the secretion of the gonadotropin-releasing hormone (GnRH), which stimulates the release of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In addition to these neuroendocrine signals, other signals originating from the central nervous system, hypophysis, thyroid, adrenal glands, and the ovary itself are also involved. One of the neurotransmission systems involved in the regulation of ovulation is the cholinergic system, which not only participates in the regulation of reproductive functions but also modulates motor coordination, thermoregulation, and cognitive function. In mammals, the vagus nerve is one of the pathways through which acetylcholine reaches the ovary, and this pathway also participates in the regulation of ovulation. However, this regulation depends on the age of the animal (prepubertal or adult) and its endocrine status. The present review analyzes evidence of the roles of the central and peripheral cholinergic system and vagal innervation in the regulation of GnRH secretion and ovulation as well as their roles in the development and persistence of polycystic ovary syndrome (PCOS).
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Affiliation(s)
- Elizabeth Vieyra-Valdez
- Biology of Reproduction Research Unit, Physiology of Reproduction Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico; Biology of Reproduction Research Unit, Laboratorio de Investigación en Cronobiología y Reproducción, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico.
| | - Rosa Linares-Culebro
- Biology of Reproduction Research Unit, Physiology of Reproduction Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico.
| | - Gabriela Rosas-Gavilán
- Biology of Reproduction Research Unit, Physiology of Reproduction Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico.
| | - Deyra Ramírez-Hernández
- Facultad de Estudios Superiores Zaragoza Campus III, UNAM, CP90640, San Miguel Contla, Tlaxcala, Mexico.
| | - Roberto Domínguez-Casalá
- Biology of Reproduction Research Unit, Laboratorio de Investigación en Cronobiología y Reproducción, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico.
| | - Leticia Morales-Ledesma
- Biology of Reproduction Research Unit, Physiology of Reproduction Laboratory, Facultad de Estudios Superiores Zaragoza, UNAM, AP 9-020, CP 15000, México City, Mexico.
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11
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Brown AMC, Gervais NJ. Role of Ovarian Hormones in the Modulation of Sleep in Females Across the Adult Lifespan. Endocrinology 2020; 161:5879359. [PMID: 32735650 PMCID: PMC7450669 DOI: 10.1210/endocr/bqaa128] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Ovarian hormones, including 17β-estradiol, are implicated in numerous physiological processes, including sleep. Beginning at puberty, girls report more sleep complaints than boys, which is maintained throughout the reproductive life stage. Sleep problems are exacerbated during the menopausal transition, evidenced by greater risk for sleep disorders. There is emerging evidence that menopause-associated hormone loss contributes to this elevated risk, but age is also an important factor. The extent to which menopause-associated sleep disturbance persists into postmenopause above and beyond the effects of age remains unknown. Untreated sleep disturbances have important implications for cognitive health, as they are emerging as risk factors for dementia. Given that sleep loss impairs memory, an important knowledge gap concerns the role played by menopause-associated hormone loss in exacerbating sleep disturbance and, ultimately, cognitive function in aging women. In this review, we take a translational approach to illustrate the contribution of ovarian hormones in maintaining the sleep-wake cycle in younger and middle-aged females, with evidence implicating 17β-estradiol in supporting the memory-promoting effects of sleep. Sleep physiology is briefly reviewed before turning to behavioral and neural evidence from young females linking 17β-estradiol to sleep-wake cycle maintenance. Implications of menopause-associated 17β-estradiol loss is also reviewed before discussing how ovarian hormones may support the memory-promoting effects of sleep, and why menopause may exacerbate pathological aging via effects on sleep. While still in its infancy, this research area offers a new sex-based perspective on aging research, with a focus on a modifiable risk factor for pathological aging.
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Affiliation(s)
- Alana M C Brown
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Nicole J Gervais
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
- Correspondence: Nicole J. Gervais, University of Toronto, Department of Psychology, 100 St. George Street, Toronto, ON, Canada M5S 3G3. E-mail:
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12
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De Nobrega AK, Luz KV, Lyons LC. Resetting the Aging Clock: Implications for Managing Age-Related Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1260:193-265. [PMID: 32304036 DOI: 10.1007/978-3-030-42667-5_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Worldwide, individuals are living longer due to medical and scientific advances, increased availability of medical care and changes in public health policies. Consequently, increasing attention has been focused on managing chronic conditions and age-related diseases to ensure healthy aging. The endogenous circadian system regulates molecular, physiological and behavioral rhythms orchestrating functional coordination and processes across tissues and organs. Circadian disruption or desynchronization of circadian oscillators increases disease risk and appears to accelerate aging. Reciprocally, aging weakens circadian function aggravating age-related diseases and pathologies. In this review, we summarize the molecular composition and structural organization of the circadian system in mammals and humans, and evaluate the technological and societal factors contributing to the increasing incidence of circadian disorders. Furthermore, we discuss the adverse effects of circadian dysfunction on aging and longevity and the bidirectional interactions through which aging affects circadian function using examples from mammalian research models and humans. Additionally, we review promising methods for managing healthy aging through behavioral and pharmacological reinforcement of the circadian system. Understanding age-related changes in the circadian clock and minimizing circadian dysfunction may be crucial components to promote healthy aging.
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Affiliation(s)
- Aliza K De Nobrega
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Kristine V Luz
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL, USA
| | - Lisa C Lyons
- Department of Biological Science, Program in Neuroscience, Florida State University, Tallahassee, FL, USA.
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13
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Bates K, Herzog ED. Maternal-Fetal Circadian Communication During Pregnancy. Front Endocrinol (Lausanne) 2020; 11:198. [PMID: 32351448 PMCID: PMC7174624 DOI: 10.3389/fendo.2020.00198] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/19/2020] [Indexed: 12/21/2022] Open
Abstract
This article reviews evidence for maternal-fetal communication about the time of day. We explore the hypothesis that key maternal hormones synchronize daily rhythms in the fetus to regulate gestation duration. These findings may help to predict and prevent preterm birth.
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14
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Yan L, Smale L, Nunez AA. Circadian and photic modulation of daily rhythms in diurnal mammals. Eur J Neurosci 2020; 51:551-566. [PMID: 30269362 PMCID: PMC6441382 DOI: 10.1111/ejn.14172] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/02/2018] [Accepted: 08/16/2018] [Indexed: 12/22/2022]
Abstract
The temporal niche that an animal occupies includes a coordinated suite of behavioral and physiological processes that set diurnal and nocturnal animals apart. The daily rhythms of the two chronotypes are regulated by both the circadian system and direct responses to light, a process called masking. Here we review the literature on circadian regulations and masking responses in diurnal mammals, focusing on our work using the diurnal Nile grass rat (Arvicanthis niloticus) and comparing our findings with those derived from other diurnal and nocturnal models. There are certainly similarities between the circadian systems of diurnal and nocturnal mammals, especially in the phase and functioning of the principal circadian oscillator within the hypothalamic suprachiasmatic nucleus (SCN). However, the downstream pathways, direct or indirect from the SCN, lead to drastic differences in the phase of extra-SCN oscillators, with most showing a complete reversal from the phase seen in nocturnal species. This reversal, however, is not universal and in some cases the phases of extra-SCN oscillators are only a few hours apart between diurnal and nocturnal species. The behavioral masking responses in general are opposite between diurnal and nocturnal species, and are matched by differential responses to light and dark in several retinorecipient sites in their brain. The available anatomical and functional data suggest that diurnal brains are not simply a phase-reversed version of nocturnal ones, and work with diurnal models contribute significantly to a better understanding of the circadian and photic modulation of daily rhythms in our own diurnal species.
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Affiliation(s)
- Lily Yan
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824, United States
| | - Laura Smale
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824, United States
| | - Antonio A. Nunez
- Department of Psychology and Neuroscience Program, Michigan State University, East Lansing, MI 48824, United States
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15
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Circadian regulation of depression: A role for serotonin. Front Neuroendocrinol 2019; 54:100746. [PMID: 31002895 PMCID: PMC9826732 DOI: 10.1016/j.yfrne.2019.04.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/13/2019] [Accepted: 04/15/2019] [Indexed: 01/11/2023]
Abstract
Synchronizing circadian (24 h) rhythms in physiology and behavior with the environmental light-dark cycle is critical for maintaining optimal health. Dysregulation of the circadian system increases susceptibility to numerous pathological conditions including major depressive disorder. Stress is a common etiological factor in the development of depression and the circadian system is highly interconnected to stress-sensitive neurotransmitter systems such as the serotonin (5-hydroxytryptamine, 5-HT) system. Thus, here we propose that stress-induced perturbation of the 5-HT system disrupts circadian processes and increases susceptibility to depression. In this review, we first provide an overview of the basic components of the circadian system. Next, we discuss evidence that circadian dysfunction is associated with changes in mood in humans and rodent models. Finally, we provide evidence that 5-HT is a critical factor linking dysregulation of the circadian system and mood. Determining how these two systems interact may provide novel therapeutic targets for depression.
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16
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Hannou L, Roy P, Ballester Roig MN, Mongrain V. Transcriptional control of synaptic components by the clock machinery. Eur J Neurosci 2019; 51:241-267. [DOI: 10.1111/ejn.14294] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/01/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Lydia Hannou
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of PsychiatryUniversité de Montréal Montreal Quebec Canada
| | - Pierre‐Gabriel Roy
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
| | - Maria Neus Ballester Roig
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
| | - Valérie Mongrain
- Center for Advanced Research in Sleep Medicine and Research CenterHôpital du Sacré‐Cœur de Montréal (CIUSSS‐NIM) Montreal Quebec Canada
- Department of NeuroscienceUniversité de Montréal Montreal Quebec Canada
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17
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Simonneaux V, Piet R. Neuroendocrine pathways driving daily rhythms in the hypothalamic pituitary gonadal axis of female rodents. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Dardente H, Wyse CA, Lincoln GA, Wagner GC, Hazlerigg DG. Effects of Photoperiod Extension on Clock Gene and Neuropeptide RNA Expression in the SCN of the Soay Sheep. PLoS One 2016; 11:e0159201. [PMID: 27458725 PMCID: PMC4961288 DOI: 10.1371/journal.pone.0159201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/28/2016] [Indexed: 01/23/2023] Open
Abstract
In mammals, changing daylength (photoperiod) is the main synchronizer of seasonal functions. The photoperiodic information is transmitted through the retino-hypothalamic tract to the suprachiasmatic nuclei (SCN), site of the master circadian clock. To investigate effects of day length change on the sheep SCN, we used in-situ hybridization to assess the daily temporal organization of expression of circadian clock genes (Per1, Per2, Bmal1 and Fbxl21) and neuropeptides (Vip, Grp and Avp) in animals acclimated to a short photoperiod (SP; 8h of light) and at 3 or 15 days following transfer to a long photoperiod (LP3, LP15, respectively; 16h of light), achieved by an acute 8-h delay of lights off. We found that waveforms of SCN gene expression conformed to those previously seen in LP acclimated animals within 3 days of transfer to LP. Mean levels of expression for Per1-2 and Fbxl21 were nearly 2-fold higher in the LP15 than in the SP group. The expression of Vip was arrhythmic and unaffected by photoperiod, while, in contrast to rodents, Grp expression was not detectable within the sheep SCN. Expression of the circadian output gene Avp cycled robustly in all photoperiod groups with no detectable change in phasing. Overall these data suggest that synchronizing effects of light on SCN circadian organisation proceed similarly in ungulates and in rodents, despite differences in neuropeptide gene expression.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380, Nouzilly, France
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- * E-mail: (DGH); (HD)
| | - Cathy A. Wyse
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Veterinary school, Bearsden Road, Glasgow, G61 1QH, United Kingdom
| | - Gerald A. Lincoln
- Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, United Kingdom
| | - Gabriela C. Wagner
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
| | - David G. Hazlerigg
- Institute of Biological and Environmental Sciences, Zoology Building, Tillydrone Avenue, University of Aberdeen, Aberdeen, AB24 2TZ, United Kingdom
- Department of Arctic and Marine Biology, Faculty of BioSciences, Fisheries and Economy, University of Tromsø, 9037, Tromsø, Norway
- * E-mail: (DGH); (HD)
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19
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Evans JA. Collective timekeeping among cells of the master circadian clock. J Endocrinol 2016; 230:R27-49. [PMID: 27154335 PMCID: PMC4938744 DOI: 10.1530/joe-16-0054] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/06/2016] [Indexed: 01/09/2023]
Abstract
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus is the master circadian clock that coordinates daily rhythms in behavior and physiology in mammals. Like other hypothalamic nuclei, the SCN displays an impressive array of distinct cell types characterized by differences in neurotransmitter and neuropeptide expression. Individual SCN neurons and glia are able to display self-sustained circadian rhythms in cellular function that are regulated at the molecular level by a 24h transcriptional-translational feedback loop. Remarkably, SCN cells are able to harmonize with one another to sustain coherent rhythms at the tissue level. Mechanisms of cellular communication in the SCN network are not completely understood, but recent progress has provided insight into the functional roles of several SCN signaling factors. This review discusses SCN organization, how intercellular communication is critical for maintaining network function, and the signaling mechanisms that play a role in this process. Despite recent progress, our understanding of SCN circuitry and coupling is far from complete. Further work is needed to map SCN circuitry fully and define the signaling mechanisms that allow for collective timekeeping in the SCN network.
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Affiliation(s)
- Jennifer A Evans
- Department of Biomedical SciencesMarquette University, Milwaukee, WI, USA
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20
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Royston SE, Bunick D, Mahoney MM. Oestradiol Exposure Early in Life Programs Daily and Circadian Activity Rhythms in Adult Mice. J Neuroendocrinol 2016; 28. [PMID: 26560973 DOI: 10.1111/jne.12335] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 12/26/2022]
Abstract
Hormone signalling during critical periods organises the adult circadian timekeeping system by altering adult hormone sensitivity and shaping fundamental properties of circadian rhythmicity. However, the timing of when developmental oestrogens modify the timekeeping system is poorly understood. To test the hypothesis that alterations in postnatal oestrogenic signalling organise adult daily activity rhythms, we utilised aromatase knockout mice (ArKO), which lack the enzyme required for oestradiol synthesis. ArKO and wild-type (WT) males and females were administered either oestradiol (E) or oil (OIL) daily for the first 5 postnatal days (p1-5E and p1-5OIL , respectively) because this time encompasses the emergence of clock gene rhythmicity and light responsiveness in the suprachiasmatic nucleus, a bilateral hypothalamic structure regarded as the 'master oscillator'. After sexual maturation, gonadectomy and exogenous oestradiol supplementation, locomotor parameters were assessed. We determined that altered oestrogenic signalling in early life exerts organisational control over the expression of daily and circadian activity rhythms in adult mice. Specifically, p1-5E reduced total wheel running activity in male and female ArKO and female WT mice but had no effect on WT male activity levels. In females, wheel running was consolidated by p1-5E to the early versus late evening, a phenomenon characteristic of male mice. The time of peak activity was advanced by p1-5E in WT and ArKO females but not males. P1-5E shortened the length of the active phase (alpha) in WT males but had no effect on ArKO males or females of either genotypes. Finally, p1-5E altered the magnitude of photic-induced shifts, suggesting that developmental oestrogenic signalling impacts adult circadian functions. In the present study, we further define both a critical period of development of the adult timekeeping system and the role that oestrogenic signalling plays in the expression of daily and circadian activity rhythms throughout life.
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Affiliation(s)
- S E Royston
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Medical Scholars Program, University of Illinois College of Medicine, Urbana, IL, USA
| | - D Bunick
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - M M Mahoney
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana, IL, USA
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21
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Bailey M, Silver R. Sex differences in circadian timing systems: implications for disease. Front Neuroendocrinol 2014; 35:111-39. [PMID: 24287074 PMCID: PMC4041593 DOI: 10.1016/j.yfrne.2013.11.003] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/13/2013] [Accepted: 11/17/2013] [Indexed: 12/22/2022]
Abstract
Virtually every eukaryotic cell has an endogenous circadian clock and a biological sex. These cell-based clocks have been conceptualized as oscillators whose phase can be reset by internal signals such as hormones, and external cues such as light. The present review highlights the inter-relationship between circadian clocks and sex differences. In mammals, the suprachiasmatic nucleus (SCN) serves as a master clock synchronizing the phase of clocks throughout the body. Gonadal steroid receptors are expressed in almost every site that receives direct SCN input. Here we review sex differences in the circadian timing system in the hypothalamic-pituitary-gonadal axis (HPG), the hypothalamic-adrenal-pituitary (HPA) axis, and sleep-arousal systems. We also point to ways in which disruption of circadian rhythms within these systems differs in the sexes and is associated with dysfunction and disease. Understanding sex differentiated circadian timing systems can lead to improved treatment strategies for these conditions.
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Affiliation(s)
- Matthew Bailey
- Department of Psychology, Columbia University, United States.
| | - Rae Silver
- Department of Psychology, Columbia University, United States; Department of Psychology, Barnard College, United States; Department of Pathology and Cell Biology, Columbia University Medical Center, United States.
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22
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Karnas D, Hicks D, Mordel J, Pévet P, Meissl H. Intrinsic photosensitive retinal ganglion cells in the diurnal rodent, Arvicanthis ansorgei. PLoS One 2013; 8:e73343. [PMID: 23951350 PMCID: PMC3739746 DOI: 10.1371/journal.pone.0073343] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/29/2013] [Indexed: 01/15/2023] Open
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) represent a new class of photoreceptors which support a variety of non-image forming physiological functions, such as circadian photoentrainment, pupillary light reflex and masking responses to light. In view of the recently proposed role of retinal inputs for the regulation of diurnal and nocturnal behavior, we performed the first deep analysis of the ipRGC system in a diurnal rodent model, Arvicanthisansorgei, and compared the anatomical and physiological properties of ipRGCs with those of nocturnal mice. Based on somata location, stratification pattern and melanopsin expression, we identified two main ipRGC types in the retina of Arvicanthis: M1, constituting 74% of all ipRGCs and non-M1 (consisting mainly of the M2 type) constituting the following 25%. The displaced ipRGCs were rarely encountered. Phenotypical staining patterns of ganglion cell markers showed a preferential expression of Brn3 and neurofilaments in non-M1 ipRGCs. In general, the anatomical properties and molecular phenotyping of ipRGCs in Arvicanthis resemble ipRGCs of the mouse retina, however the percentage of M1 cells is considerably higher in the diurnal animal. Multi-electrode array recordings (MEA) identified in newborn retinas of Arvicanthis three response types of ipRGCs (type I, II and III) which are distinguished by their light sensitivity, response strength, latency and duration. Type I ipRGCs exhibited a high sensitivity to short light flashes and showed, contrary to mouse type I ipRGCs, robust light responses to 10 ms flashes. The morphological, molecular and physiological analysis reveals very few differences between mouse and Arvicanthis ipRGCs. These data imply that the influence of retinal inputs in defining the temporal niche could be related to a stronger cone input into ipRGCs in the cone-rich Arvicanthis retina, and to the higher sensitivity of type I ipRGCs and elevated proportion of M1 cells.
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Affiliation(s)
- Diana Karnas
- Neuroanatomical Department, Max Planck Institute for Brain Research, Frankfurt/M, Germany
- Institute for Cellular and Integrative Neuroscience, CNRS UPR-3212 Strasbourg University, Strasbourg, France
| | - David Hicks
- Institute for Cellular and Integrative Neuroscience, CNRS UPR-3212 Strasbourg University, Strasbourg, France
- * E-mail: (HM); (DH)
| | - Jérôme Mordel
- Neuroanatomical Department, Max Planck Institute for Brain Research, Frankfurt/M, Germany
- Institute for Cellular and Integrative Neuroscience, CNRS UPR-3212 Strasbourg University, Strasbourg, France
| | - Paul Pévet
- Institute for Cellular and Integrative Neuroscience, CNRS UPR-3212 Strasbourg University, Strasbourg, France
| | - Hilmar Meissl
- Neuroanatomical Department, Max Planck Institute for Brain Research, Frankfurt/M, Germany
- * E-mail: (HM); (DH)
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23
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Kuljis DA, Loh DH, Truong D, Vosko AM, Ong ML, McClusky R, Arnold AP, Colwell CS. Gonadal- and sex-chromosome-dependent sex differences in the circadian system. Endocrinology 2013; 154:1501-12. [PMID: 23439698 PMCID: PMC3602630 DOI: 10.1210/en.2012-1921] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Compelling reasons to study the role of sex in the circadian system include the higher rates of sleep disorders in women than in men and evidence that sex steroids modulate circadian control of locomotor activity. To address the issue of sex differences in the circadian system, we examined daily and circadian rhythms in wheel-running activity, electrical activity within the suprachiasmatic nucleus, and PER2::LUC-driven bioluminescence of gonadally-intact adult male and female C57BL/6J mice. We observed greater precision of activity onset in 12-hour light, 12-hour dark cycle for male mice, longer activity duration in 24 hours of constant darkness for female mice, and phase-delayed PER2::LUC bioluminescence rhythm in female pituitary and liver. Next, in order to investigate whether sex differences in behavior are sex chromosome or gonadal sex dependent, we used the 4 core genotypes (FCG) mouse model, in which sex chromosome complement is independent of gonadal phenotype. Gonadal males had more androgen receptor expression in the suprachiasmatic nucleus and behaviorally reduced photic phase shift response compared with gonadal female FCG mice. Removal of circulating gonadal hormones in adults, to test activational vs organizational effects of sex revealed that XX animals have longer activity duration than XY animals regardless of gonadal phenotype. Additionally, we observed that the activational effects of gonadal hormones were more important for regulating activity levels in gonadal male mice than in gonadal female FCG mice. Taken together, sex differences in the circadian rhythms of activity, neuronal physiology, and gene expression were subtle but provide important clues for understanding the pathophysiology of the circadian system.
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Affiliation(s)
- Dika A Kuljis
- Department of Neurobiology, University of California LosAngeles, Los Angeles, California 90024, USA
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24
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Hagenauer MH, Lee TM. The neuroendocrine control of the circadian system: adolescent chronotype. Front Neuroendocrinol 2012; 33:211-29. [PMID: 22634481 PMCID: PMC4762453 DOI: 10.1016/j.yfrne.2012.04.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 04/03/2012] [Accepted: 04/07/2012] [Indexed: 10/28/2022]
Abstract
Scientists, public health and school officials are paying growing attention to the mechanism underlying the delayed sleep patterns common in human adolescents. Data suggest that a propensity towards evening chronotype develops during puberty, and may be caused by developmental alterations in internal daily timekeeping. New support for this theory has emerged from recent studies which show that pubertal changes in chronotype occur in many laboratory species similar to human adolescents. Using these species as models, we find that pubertal changes in chronotype differ by sex, are internally generated, and driven by reproductive hormones. These chronotype changes are accompanied by alterations in the fundamental properties of the circadian timekeeping system, including endogenous rhythm period and sensitivity to environmental time cues. After comparing the developmental progression of chronotype in different species, we propose a theory regarding the ecological relevance of adolescent chronotype, and provide suggestions for improving the sleep of human adolescents.
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25
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Hummer DL, Peckham EM, Lee TM. Estradiol acts during a post-pubertal sensitive period to shorten free-running circadian period in maleOctodon degus. Eur J Neurosci 2012; 36:3051-8. [DOI: 10.1111/j.1460-9568.2012.08228.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Cambras T, Díez-Noguera A. Effects of forward and backward transitions in light intensities in tau-illuminance curves of the rat motor activity rhythm under constant dim light. Chronobiol Int 2012; 29:693-701. [PMID: 22734570 DOI: 10.3109/07420528.2012.680556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Circadian rhythms are strongly influenced by light intensity, the effects of which may persist beyond the duration of light exposure (aftereffects). Here, the authors constructed period-illuminance curves for the motor activity circadian rhythm of male and female rats by recording the effects of a series of small upward and downward steps in light intensity (illuminance ranging between .01 lux of dim red light and 1 lux of white light) on their activity. In all cases, stepwise changes were made in five logarithmic steps (irradiance: dim red light: .692 µW/cm(2) and white light: .006, .016, .044, .12, and .315 µW/cm(2), corresponding, respectively, to .02, .05, .14, .13, and 1 lux measured at cage level), with changes in intensity every 2 wks. One group of rats (DLD) started in dim red light, moved up to 1 lux white light, and then back down to the original light intensity. Another group (LDL) started at 1 lux, moved down to .01 lux, and then back up to the original intensity. Motor activity data were recorded throughout the experiment and tau values, the percentage of variance explained by the rhythm, and the mean motor activity for each stage and group were calculated. The results show differences in the dynamics of tau values between the DLD and LDL groups and between males and females. In the LDL group, the tau values of both males and females were dependent on light intensity, and were similar for the forward and backward transitions. In other words, no aftereffects were found, and no differences were detected between males and females. In the DLD group, however, differences were found between males and females. Males had a tau value of 24 h 20 min under dim red light, 25 h 40 min under 1 lux, and 24 h 50 min on return to dim red light. It is noticeable that the tau values of the backward branch of the illuminance curve contradicted classical predictions, since at .38 and .14 lux the tau values were shorter than those found under the same intensities after exposure to 1 lux. Females became arrhythmic at 1 lux, and only one half of them recovered their circadian rhythm at .02 lux. The other one half remained arrhythmic even under dim red light. Thus, some of the results of this paper contradict the predictions of standard descriptions of the functioning of the circadian clock, possibly due to the effects of dim light.
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Affiliation(s)
- Trinitat Cambras
- Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Spain
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27
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Li JD, Hu WP, Zhou QY. The circadian output signals from the suprachiasmatic nuclei. PROGRESS IN BRAIN RESEARCH 2012; 199:119-127. [DOI: 10.1016/b978-0-444-59427-3.00028-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Chronic oestrogen replacement in ovariectomised rats attenuates food intake and augments c-Fos expression in the suprachiasmatic nucleus specifically during the light phase. Br J Nutr 2011; 106:1283-9. [DOI: 10.1017/s0007114511001607] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oestrogen replacement in ovariectomised (OVX) rats has been reported to attenuate food intake, especially during the light phase. To gain better insight into the central mechanism of oestrogen-induced reduction of food intake, we examined the effect of chronic oestrogen replacement in OVX rats on c-Fos expression in the suprachiasmatic nucleus (SCN) and on food intake during the light and dark phases. Eight-week-old female rats were ovariectomised and implanted with either an oestradiol (E2) or a vehicle pellet (Veh) subcutaneously. The animals were housed in an environment with a 12 h light–12 h dark cycle with the lights on at 07.00 hours. The amount of spontaneous food intake relative to each animal's body weight was significantly less for the E2 group than for the Veh group during the light phase, but there were no differences shown between these groups during the dark phase. There were no differences shown in the number of c-Fos-immunoreactive cells in the SCN in the E2 group compared with the Veh group during the early dark phase (22.00 hours; Zeitgeber time 15.00 (ZT15)), but the number was significantly higher than in the Veh group during the early light phase (10.00 hours; ZT3). This finding suggests that chronic oestrogen replacement chronically enhances SCN activity, specifically during the light phase. The oestrogen-induced enhancement of SCN activity during the light phase is possibly involved in the light phase-specific attenuation of food intake by oestrogen replacement in OVX rats.
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Deurveilher S, Rusak B, Semba K. Female reproductive hormones alter sleep architecture in ovariectomized rats. Sleep 2011; 34:519-30. [PMID: 21461331 DOI: 10.1093/sleep/34.4.519] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
STUDY OBJECTIVES Treating ovariectomized rats with physiological levels of estradiol and/or progesterone affects aspects of both baseline (24 h) sleep and recovery (18 h) sleep after 6 h of sleep deprivation. We have extended the analysis of these effects by examining several additional parameters of sleep architecture using the same data set as in our previous study (Deurveilher et al. SLEEP 2009;32(7):865-877). DESIGN Sleep in ovariectomized rats implanted with oil, 17 β-estradiol and/or progesterone capsules was recorded using EEG and EMG before, during, and after 6 h of sleep deprivation during the light phase of a 12/12 h light/dark cycle. MEASUREMENTS AND RESULTS During the baseline dark, but not light, phase, treatments with estradiol alone or combined with progesterone decreased the mean duration of non-rapid eye movement sleep (NREMS) episodes and the number of REMS episodes, while also increasing brief awakenings, consistent with the previously reported lower baseline NREMS and REMS amounts. Following sleep deprivation, the hormonal treatments caused a larger percentage increase from baseline in the mean durations of NREMS and REMS episodes, and a larger percentage decrease in brief awakenings, consistent with the previously reported larger increase in recovery REMS amount. There were no hormonal effects on NREMS and REMS EEG power values, other than on recovery NREMS delta power, as previously reported. CONCLUSIONS Physiological levels of estradiol and/or progesterone in female rats modulate sleep architecture differently at baseline and after acute sleep loss, fragmenting baseline sleep while consolidating recovery sleep. These hormones also play a role in the diurnal pattern of NREMS maintenance.
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Affiliation(s)
- Samüel Deurveilher
- Department of Anatomy & Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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30
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Ramanathan C, Stowie A, Smale L, Nunez AA. Phase preference for the display of activity is associated with the phase of extra-suprachiasmatic nucleus oscillators within and between species. Neuroscience 2010; 170:758-72. [PMID: 20682334 PMCID: PMC2950020 DOI: 10.1016/j.neuroscience.2010.07.053] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 07/25/2010] [Accepted: 07/26/2010] [Indexed: 12/21/2022]
Abstract
Many features of the suprachiasmatic nucleus (SCN) are the same in diurnal and nocturnal animals, suggesting that differences in phase preference are determined by mechanisms downstream from the SCN. Here, we examined this hypothesis by characterizing rhythmic expression of Period 1 (PER1) and Period 2 (PER2) in several extra-SCN areas in the brains of a diurnal murid rodent, Arvicanthis niloticus (grass rats). In the shell of the nucleus accumbens, dorsal striatum, piriform cortex, and CA1 of the hippocampus, both PER1 and PER2 were rhythmic, with peak expression occurring at ZT10. PER1 in the dentate gyrus also peaked at ZT10, but PER2 was arrhythmic in this region. In general, these patterns are 180 degrees out of phase with those reported for nocturnal species. In a second study, we examined inter-individual differences in the multioscillator system of grass rats. Here, we housed grass rats in cages with running wheels, under which conditions some individuals spontaneously adopt a day active (DA) and others a night active (NA) phase preference. In the majority of the extra-SCN regions sampled, the patterns of PER1 and PER2 expression of NA grass rats resembled those of nocturnal species, while those of DA grass rats were similar to the ones seen in grass without access to running wheels. In contrast, the rhythmic expression of both PER proteins was identical in the SCN and ventral subparaventricular zone (vSPZ) of DA and NA animals. Differences in the phase of oscillators downstream from the SCN, and perhaps the vSPZ, appear to determine the phase preference of particular species, as well as that of members of a diurnal species that show voluntary phase reversals. The latter observation has important implications for the understanding of health problems associated with human shift work.
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Affiliation(s)
- Chidambaram Ramanathan
- Department of Psychology, Michigan State University, East Lansing, MI 48824
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Adam Stowie
- Department of Psychology, Michigan State University, East Lansing, MI 48824
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
| | - Laura Smale
- Department of Psychology, Michigan State University, East Lansing, MI 48824
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
- Department of Zoology, Michigan State University, East Lansing, MI 48824
| | - Antonio A. Nunez
- Department of Psychology, Michigan State University, East Lansing, MI 48824
- Neuroscience Program, Michigan State University, East Lansing, MI 48824
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31
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Schwartz MD, Urbanski HF, Nunez AA, Smale L. Projections of the suprachiasmatic nucleus and ventral subparaventricular zone in the Nile grass rat (Arvicanthis niloticus). Brain Res 2010; 1367:146-61. [PMID: 20971082 DOI: 10.1016/j.brainres.2010.10.058] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/14/2010] [Accepted: 10/14/2010] [Indexed: 12/31/2022]
Abstract
The phases of many circadian rhythms differ between diurnal and nocturnal species. However, rhythms within the hypothalamic suprachiasmatic nucleus (SCN), which contains the central circadian pacemaker, are very similar, suggesting that the mechanisms underlying phase preference lie downstream of the SCN. Rhythms in Fos expression in the ventral subparaventricular zone (vSPVZ), a major target of the SCN, differ substantially between diurnal Nile grass rats and nocturnal lab rats, raising the possibility that the vSPVZ modulates the effects of SCN signals at its targets. To understand better how and where the SCN and vSPVZ communicate circadian signals within the grass rat brain, we mapped their projections using the anterograde tracer biotinylated dextran amine (BDA). Adult female grass rats received unilateral BDA injections directed at the SCN or vSPVZ and their brains were perfusion-fixed several days later. Immunohistochemistry revealed that the distribution patterns of SCN and vSPVZ efferents were very similar. Labeled fibers originating in each region were heavily concentrated in the medial preoptic area, paraventricular thalamic nucleus, the subparaventricular zone, and the hypothalamic paraventricular and dorsomedial nuclei. BDA-labeled fibers from the SCN and vSPVZ formed appositions with orexin neurons and gonadotropin-releasing hormone neurons, two cell populations whose rhythms in Fos expression track temporally reversed patterns of locomotor and reproductive behavior, respectively, in diurnal and nocturnal rodents. These data demonstrate that projections of the SCN and vSPVZ are highly conserved in diurnal and nocturnal rodents, and the vSPVZ projections may enable it to modulate the responsiveness of target cells to signals from the SCN.
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Affiliation(s)
- Michael D Schwartz
- Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
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