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Fricker BA, Kelly AM. From grouping and cooperation to menstruation: Spiny mice (Acomys cahirinus) are an emerging mammalian model for sociality and beyond. Horm Behav 2024; 158:105462. [PMID: 38000170 DOI: 10.1016/j.yhbeh.2023.105462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/22/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023]
Abstract
While spiny mice are primarily used as a model for Type II diabetes and for studying complex tissue regeneration, they are also an emerging model for a variety of studies examining hormones, behavior, and the brain. We began studying the spiny mouse to take advantage of their highly gregarious phenotype to examine how the brain facilitates large group-living. However, this unique rodent can be readily bred and maintained in the lab and can be used to ask a wide variety of scientific questions. In this brief communication we provide an overview of studies that have used spiny mice for exploring physiology and behavior. Additionally, we describe how the spiny mouse can serve as a useful model for researchers interested in studying precocial development, menstruation, cooperation, and various grouping behaviors. With increasingly available technological advancements for non-traditional organisms, spiny mice are well-positioned to become a valuable organism in the behavioral neuroscience community.
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Affiliation(s)
- Brandon A Fricker
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA 30322, United States of America.
| | - Aubrey M Kelly
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA 30322, United States of America.
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2
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Mustapha O, Grochow T, Olopade J, Fietz SA. Neocortex neurogenesis and maturation in the African greater cane rat. Neural Dev 2023; 18:7. [PMID: 37833718 PMCID: PMC10571270 DOI: 10.1186/s13064-023-00175-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Neocortex development has been extensively studied in altricial rodents such as mouse and rat. Identification of alternative animal models along the "altricial-precocial" spectrum in order to better model and understand neocortex development is warranted. The Greater cane rat (GCR, Thyronomys swinderianus) is an indigenous precocial African rodent. Although basic aspects of brain development in the GCR have been documented, detailed information on neocortex development including the occurrence and abundance of the distinct types of neural progenitor cells (NPCs) in the GCR are lacking. METHODS GCR embryos and fetuses were obtained from timed pregnant dams between gestation days 50-140 and their neocortex was analyzed by immunofluorescence staining using characteristic marker proteins for NPCs, neurons and glia cells. Data were compared with existing data on closely related precocial and altricial species, i.e. guinea pig and dwarf rabbit. RESULTS The primary sequence of neuro- and gliogenesis, and neuronal maturation is preserved in the prenatal GCR neocortex. We show that the GCR exhibits a relatively long period of cortical neurogenesis of 70 days. The subventricular zone becomes the major NPC pool during mid-end stages of neurogenesis with Pax6 + NPCs constituting the major basal progenitor subtype in the GCR neocortex. Whereas dendrite formation in the GCR cortical plate appears to initiate immediately after the onset of neurogenesis, major aspects of axon formation and maturation, and astrogenesis do not begin until mid-neurogenesis. Similar to the guinea pig, the GCR neocortex exhibits a high maturation status, containing neurons with well-developed dendrites and myelinated axons and astrocytes at birth, thus providing further evidence for the notion that a great proportion of neocortex growth and maturation in precocial mammals occurs before birth. CONCLUSIONS Together, this work has deepened our understanding of neocortex development of the GCR, of the timing and the cellular differences that regulate brain growth and development within the altricial-precocial spectrum and its suitability as a research model for neurodevelopmental studies. The timelines of brain development provided by this study may serve as empirical reference data and foundation in future studies in order to model and better understand neurodevelopment and associated alterations.
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Affiliation(s)
- Oluwaseun Mustapha
- Neuroscience Unit, Department of Veterinary Anatomy, College of Veterinary Medicine, Federal University of Agriculture Abeokuta, Abeokuta, Ogun State, Nigeria
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany
| | - Thomas Grochow
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany
| | - James Olopade
- Neuroscience Unit, Department of Veterinary Anatomy, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Simone A Fietz
- Institute of Veterinary Anatomy, Histology and Embryology, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
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Kelly AM, Seifert AW. Distribution of Vasopressin and Oxytocin Neurons in the Basal Forebrain and Midbrain of Spiny Mice (Acomys cahirinus). Neuroscience 2021; 468:16-28. [PMID: 34102266 DOI: 10.1016/j.neuroscience.2021.05.034] [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: 03/10/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/26/2022]
Abstract
The nonapeptides vasopressin (VP) and oxytocin (OT) are present in some form in most vertebrates. VP and OT play critical roles in modulating physiology and are well-studied for their influences on a variety of social behaviors, ranging from affiliation to aggression. Their anatomical distributions have been mapped for numerous species across taxa, demonstrating relatively strong evolutionary conservation in distributions throughout the basal forebrain and midbrain. Here we examined the distribution of VP-immunoreactive (-ir) and OT-ir neurons in a gregarious, cooperatively breeding rodent species, the spiny mouse (Acomys cahirinus), for which nonapeptide mapping does not yet exist. Immunohistochemical techniques revealed VP-ir and OT-ir neuronal populations throughout the hypothalamus and amygdala of males and females that are consistent with those of other rodents. However, a novel population of OT-ir neurons was observed in the median preoptic nucleus of both sexes, located dorsally to the anterior commissure. Furthermore, we found widespread sex differences in OT neuronal populations, with males having significantly more OT-ir neurons than females. However, we observed a sex difference in only one VP cell group - that of the bed nucleus of the stria terminalis (BST), a VP neuronal population that exhibits a phylogenetically widespread sexual dimorphism. These findings provide mapping distributions of VP and OT neurons in Acomys cahirinus. Spiny mice lend themselves to the study of mammalian cooperation and sociality, and the nonapeptide neuronal mapping presented here can serve as a basic foundation for the study of nonapeptide-mediated behavior in a group of highly social rodents.
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Affiliation(s)
- Aubrey M Kelly
- Department of Psychology, Emory University, 36 Eagle Row, Atlanta, GA 30322, USA.
| | - Ashley W Seifert
- Department of Biology, University of Kentucky, 675 Rose Street, Lexington KY 40508, USA
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Kalusa M, Heinrich MD, Sauerland C, Morawski M, Fietz SA. Developmental Differences in Neocortex Neurogenesis and Maturation Between the Altricial Dwarf Rabbit and Precocial Guinea Pig. Front Neuroanat 2021; 15:678385. [PMID: 34135738 PMCID: PMC8200626 DOI: 10.3389/fnana.2021.678385] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/06/2021] [Indexed: 11/13/2022] Open
Abstract
Mammals are born on a precocial-altricial continuum. Altricial species produce helpless neonates with closed distant organs incapable of locomotion, whereas precocial species give birth to well-developed young that possess sophisticated sensory and locomotor capabilities. Previous studies suggest that distinct patterns of cortex development differ between precocial and altricial species. This study compares patterns of neocortex neurogenesis and maturation in the precocial guinea pig and altricial dwarf rabbit, both belonging to the taxon of Glires. We show that the principal order of neurodevelopmental events is preserved in the neocortex of both species. Moreover, we show that neurogenesis starts at a later postconceptional day and takes longer in absolute gestational days in the precocial than the altricial neocortex. Intriguingly, our data indicate that the dwarf rabbit neocortex contains a higher abundance of highly proliferative basal progenitors than the guinea pig, which might underlie its higher encephalization quotient, demonstrating that the amount of neuron production is determined by complex regulation of multiple factors. Furthermore, we show that the guinea pig neocortex exhibits a higher maturation status at birth, thus providing evidence for the notions that precocial species might have acquired the morphological machinery required to attain their high functional state at birth and that brain expansion in the precocial newborn is mainly due to prenatally initiating processes of gliogenesis and neuron differentiation instead of increased neurogenesis. Together, this study reveals important insights into the timing and cellular differences that regulate mammalian brain growth and maturation and provides a better understanding of the evolution of mammalian altriciality and presociality.
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Affiliation(s)
- Mirjam Kalusa
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Maren D Heinrich
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Christine Sauerland
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
| | - Markus Morawski
- Medical Faculty, Paul Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
| | - Simone A Fietz
- Faculty of Veterinary Medicine, Institute of Veterinary Anatomy, Histology and Embryology, University of Leipzig, Leipzig, Germany
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Stevens S, Mohan S. Opioid withdrawal behavior in spiny mice: A novel preclinical model of neonatal opioid withdrawal syndrome (NOWS). Heliyon 2021; 7:e06694. [PMID: 33898824 PMCID: PMC8056230 DOI: 10.1016/j.heliyon.2021.e06694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/28/2021] [Accepted: 03/30/2021] [Indexed: 11/15/2022] Open
Abstract
As the opioid epidemic continues to grow, opioid use among pregnant women is increasing significantly. This has led to a steady rise in the number of infants born with neonatal opioid withdrawal syndrome (NOWS). Although short-term withdrawal symptoms associated with NOWS are well characterized, there are many gaps in our understanding of the short and long-term effects of prenatal opioid exposure. Current animal models of NOWS are limited by shortened gestational periods, large litter sizes, and primary organogenesis occurring after birth. This often leads to postnatal treatment to mimic drug exposure during third-trimester development. Using the unique rodent species Acomys cahirinus, more commonly known as spiny mice, which have an extended 40-day gestation period, small litter sizes, and increased in utero organogenesis we aim to study the short-term effects of prenatal morphine exposure by assessing withdrawal behavior. To model maternal opioid use, dams were treated daily with morphine (10 and 30 mg/kg S.C.) beginning on gestation day 19 until the day of birth; this resulted in a cumulative exposure of 19-21 days. Withdrawal behaviors for each pup were recorded daily between postnatal days 0-7 (PND 0-7). Our study found that prenatal morphine exposure in spiny mice led to an increase in withdrawal behavior throughout the early postnatal period and validated the use of this species as a novel pre-clinical model of NOWS. We are hopeful this rodent model will further our understanding of the short and long-term consequences of prenatal opioid exposure on neurodevelopment and behavior.
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Affiliation(s)
- Sarah Stevens
- Department of Pharmaceutical Science and Research, Marshall University, School of Pharmacy, Huntington, WV 25701, USA
| | - Shekher Mohan
- Department of Pharmaceutical Sciences, Manchester University, College of Pharmacy, Fort Wayne, IN 46845, USA.,Department of Integrative Physiology and Pharmacology, Liberty University, College of Osteopathic Medicine, Lynchburg, VA 24502, USA
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Abstract
The spiny mouse, Acomys spp., is a recently described model organism for regeneration studies. For a mammal, it displays surprising powers of regeneration because it does not fibrose (i.e. scar) in response to tissue injury as most other mammals, including humans, do. In this Primer article, we review these regenerative abilities, highlighting the phylogenetic position of the spiny mouse relative to other rodents. We also briefly describe the Acomys tissues that have been used for regeneration studies and the common features of their regeneration compared with the typical mammalian response. Finally, we discuss the contribution that Acomys has made in understanding the general principles of regeneration and elaborate hypotheses as to why this mammal is successful at regenerating.
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Affiliation(s)
- Malcolm Maden
- Department of Biology & UF Genetics Institute, University of Florida, PO Box 118525, Gainesville, FL 32611, USA
| | - Justin A Varholick
- Department of Biology & UF Genetics Institute, University of Florida, PO Box 118525, Gainesville, FL 32611, USA
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Powrie YSL, Smith C. Central intracrine DHEA synthesis in ageing-related neuroinflammation and neurodegeneration: therapeutic potential? J Neuroinflammation 2018; 15:289. [PMID: 30326923 PMCID: PMC6192186 DOI: 10.1186/s12974-018-1324-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 09/24/2018] [Indexed: 02/06/2023] Open
Abstract
It is a well-known fact that DHEA declines on ageing and that it is linked to ageing-related neurodegeneration, which is characterised by gradual cognitive decline. Although DHEA is also associated with inflammation in the periphery, the link between DHEA and neuroinflammation in this context is less clear. This review drew from different bodies of literature to provide a more comprehensive picture of peripheral vs central endocrine shifts with advanced age—specifically in terms of DHEA. From this, we have formulated the hypothesis that DHEA decline is also linked to neuroinflammation and that increased localised availability of DHEA may have both therapeutic and preventative benefit to limit neurodegeneration. We provide a comprehensive discussion of literature on the potential for extragonadal DHEA synthesis by neuroglial cells and reflect on the feasibility of therapeutic manipulation of localised, central DHEA synthesis.
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Affiliation(s)
- Y S L Powrie
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602, South Africa
| | - C Smith
- Department of Physiological Sciences, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602, South Africa.
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Pinheiro G, Prata DF, Araújo IM, Tiscornia G. The African spiny mouse ( Acomys spp.) as an emerging model for development and regeneration. Lab Anim 2018; 52:565-576. [PMID: 29699452 DOI: 10.1177/0023677218769921] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The African spiny mouse ( Acomys spp.) is an emerging animal model with remarkable biological characteristics that make it a subject of interest for a broad range of research fields. Typically a desert species adapted to a low-calorie diet, spiny mice develop diabetes-related symptoms when switched to high-energy diets. Spiny mice undergo relatively long gestation periods and have small litters of highly developed pups, making them an adequate model for late organogenesis and perinatal biology. Recently, they have been shown to have remarkable healing and regeneration capabilities, which make them unique among mammals. In this work, we describe our experience in housing a colony of African spiny mice and cover all basic aspects of feeding, maintenance and breeding for research purposes.
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Affiliation(s)
- Gonçalo Pinheiro
- 1 Center for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,2 Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal
| | - Diogo Filipe Prata
- 1 Center for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,2 Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal
| | - Inês Maria Araújo
- 1 Center for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,2 Department of Biomedical Sciences and Medicine, University of Algarve, Faro, Portugal.,3 Algarve Biomedical Center, University of Algarve, Faro, Portugal
| | - Gustavo Tiscornia
- 1 Center for Biomedical Research (CBMR), University of Algarve, Faro, Portugal.,3 Algarve Biomedical Center, University of Algarve, Faro, Portugal.,4 Clínica Eugin, Research and Innovation Department, Spain
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9
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Millar LJ, Shi L, Hoerder-Suabedissen A, Molnár Z. Neonatal Hypoxia Ischaemia: Mechanisms, Models, and Therapeutic Challenges. Front Cell Neurosci 2017; 11:78. [PMID: 28533743 PMCID: PMC5420571 DOI: 10.3389/fncel.2017.00078] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Neonatal hypoxia-ischaemia (HI) is the most common cause of death and disability in human neonates, and is often associated with persistent motor, sensory, and cognitive impairment. Improved intensive care technology has increased survival without preventing neurological disorder, increasing morbidity throughout the adult population. Early preventative or neuroprotective interventions have the potential to rescue brain development in neonates, yet only one therapeutic intervention is currently licensed for use in developed countries. Recent investigations of the transient cortical layer known as subplate, especially regarding subplate's secretory role, opens up a novel set of potential molecular modulators of neonatal HI injury. This review examines the biological mechanisms of human neonatal HI, discusses evidence for the relevance of subplate-secreted molecules to this condition, and evaluates available animal models. Neuroserpin, a neuronally released neuroprotective factor, is discussed as a case study for developing new potential pharmacological interventions for use post-ischaemic injury.
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Affiliation(s)
- Lancelot J. Millar
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
| | - Lei Shi
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
- JNU-HKUST Joint Laboratory for Neuroscience and Innovative Drug Research, College of Pharmacy, Jinan UniversityGuangzhou, China
| | | | - Zoltán Molnár
- Molnár Group, Department of Physiology, Anatomy and Genetics, University of OxfordOxford, UK
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Quinn TA, Ratnayake U, Dickinson H, Castillo-Melendez M, Walker DW. The feto-placental unit, and potential roles of dehydroepiandrosterone (DHEA) in prenatal and postnatal brain development: A re-examination using the spiny mouse. J Steroid Biochem Mol Biol 2016; 160:204-13. [PMID: 26485665 DOI: 10.1016/j.jsbmb.2015.09.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 12/12/2022]
Abstract
Synthesis of dehydroepiandrosterone (DHEA) by the fetal adrenal gland is important for placental oestrogen production, and may also be important for modulating the effects of glucocorticoids on the developing brain. We have preciously shown that the enzymes and accessory proteins needed for DHEA synthesis-cytochrome P450 enzyme 17α-hydroxylase/17,20 lyase (P450c17), cytochrome-b5 (Cytb5), 3β-hydroxysteroid dehydrogenase (3βHSD)-are expressed in the adrenal gland from 30 days gestation, and DHEA, cortisol and aldosterone are present in fetal plasma from this time. Explant culture of fetal adrenal tissue showed that the spiny mouse adrenal gland, can synthesize and secrete DHEA from at least 0.75 of gestation, and suggest that DHEA may have an important role(s) in placental biosynthesis of oestrogens and in modulating the actions of glucocorticoids in the developing brain in this species. Post-natally, increased immuno-expression of P450c17 and Cytb5 expression in the zona reticularis of the adrenal gland and a significant increase in the synthesis and secretion of DHEA in plasma from 8 to 20 days of age in the spiny mouse, are representative of a period of high adrenal androgen production consistent with the human phenomenon of adrenarche. The studies summarised in this review also show that DHEA is produced de novo in the developing brain of the spiny mouse. These results showed that the spiny mouse brain can indeed produce DHEA from pregnenolone in a time-dependant manner, and coupled with the identification of P450c17 and Cytb5 protein in several regions of the brain, support the idea that DHEA is an endogenous neuro-active steroid in this species. Together, the studies outlined in this review indicate that the androgen DHEA is an important hormone of adrenal and Central Nervous System (CNS) origin in the fetal and postnatal spiny mouse. Disturbance of the development of these fetal tissues, and/or of the relationship between the fetal adrenal gland and placenta during pregnancy, may have significant consequences for fetal development, placental function, and maturation of the brain. It is proposed that such disturbances of normal adrenal function could account for some of the neuropathologies that arise in juvenile and adult offspring following illness and stress experienced by the mother during pregnancy.
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Affiliation(s)
- Tracey A Quinn
- The Ritchie Centre, Hudson Institute of Medical Research, Australia; Department of Obstetrics & Gynaecology, Monash Medical Centre, Monash University, Clayton 3168, Australia
| | - Udani Ratnayake
- The Ritchie Centre, Hudson Institute of Medical Research, Australia; The Florey Institute of Neuroscience and Mental Health, Melbourne University, Australia
| | - Hayley Dickinson
- The Ritchie Centre, Hudson Institute of Medical Research, Australia; Department of Obstetrics & Gynaecology, Monash Medical Centre, Monash University, Clayton 3168, Australia
| | - Margie Castillo-Melendez
- The Ritchie Centre, Hudson Institute of Medical Research, Australia; Department of Obstetrics & Gynaecology, Monash Medical Centre, Monash University, Clayton 3168, Australia; The Florey Institute of Neuroscience and Mental Health, Melbourne University, Australia
| | - David W Walker
- The Ritchie Centre, Hudson Institute of Medical Research, Australia; Department of Obstetrics & Gynaecology, Monash Medical Centre, Monash University, Clayton 3168, Australia.
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Ratnayake U, Quinn T, LaRosa DA, Dickinson H, Walker DW. Prenatal exposure to the viral mimetic poly I:C alters fetal brain cytokine expression and postnatal behaviour. Dev Neurosci 2014; 36:83-94. [PMID: 24863806 DOI: 10.1159/000362205] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 03/13/2014] [Indexed: 11/19/2022] Open
Abstract
An increased incidence of mental illness disorders is found in children and adolescents born to mothers who experienced an infection-based illness during pregnancy. Animal models to study the prenatal origin of such outcomes of pregnancy have largely used conventional rodents, which are immature (altricial) at birth compared with the human neonate. In this study, we used the precocial spiny mouse (Acomys cahirinus), whose offspring have completed organogenesis at birth, and administered a single subcutaneous injection of a 5 mg/kg dose of the viral mimetic poly I:C (polyriboinosinic-polyribocytidylic acid) at mid gestation (20 days; term is 39 days). Prenatal exposure to poly I:C caused a transient weight loss in the pregnant dam, produced a downregulation of the proinflammatory cytokine tumour necrosis factor-α in the fetal brain, and resulted in abnormalities in sensorimotor gating and reduced social interaction, memory and learning in juvenile offspring. No changes in exploratory activity or anxiety and fear behaviours were found between the treatment groups. This study provides evidence that, in a rodent model that more closely resembles human brain development, prenatal infection can lead to behavioural abnormalities in postnatal life.
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Affiliation(s)
- Udani Ratnayake
- Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Vic., Australia
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Quinn TA, Ratnayake U, Castillo-Melendez M, Moritz KM, Dickinson H, Walker DW. Adrenal steroidogenesis following prenatal dexamethasone exposure in the spiny mouse. J Endocrinol 2014; 221:347-62. [PMID: 24594617 DOI: 10.1530/joe-13-0514] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Antenatal stress disturbs the development of the fetal hypothalamic-pituitary-adrenal axis and adrenal steroidogenesis. We investigated the effect of brief maternal exposure to high glucocorticoids (dexamethasone (DEX)) at mid- and late-pregnancy on adrenal structure and production of steroids in spiny mouse. Pregnant spiny mice were treated for 60 h with 125 μg/kg DEX or saline s.c. by osmotic minipump at day 20 (0.5) or 30 (0.75) of gestation. Immunohistochemical expression of steroidogenic acute regulatory-protein (StAR), 3β-hydroxysteroid dehydrogenase (3βHSD), 17-hydroxylase,17-20lyase (P450C17), and cytochromeb5 (CYTB5) was determined in adrenals on postnatal (P) day 170±20. DHEA, testosterone, and cortisol were measured by RIA. Maternal DEX at 20 days significantly reduced the expression of STAR, P450C17 (CYP17A1), and CYTB5 in the adrenal zona reticularis (ZR) of adult offspring, with greater change in male vs female offspring (P<0.05). Plasma DHEA was decreased in male offspring from DEX-treated (6.84±1.24 ng/ml) vs saline-treated (13±0.06 ng/ml; P=0.01) dams, and the DHEA:cortisol ratio was lower in males (P<0.05). Testosterone levels increased in male offspring from DEX (266.03±50.75 pg/ml) vs saline (83.47±32.3 pg/ml, P<0.05)-treated dams. DEX treatment at 0.75 gestation had no significant effect on any parameters measured. This study shows that brief exposure to excess glucocorticoid has long-term impacts on the ZR and adrenal steroidogenesis, affecting the secretion of DHEA and testosterone in male offspring, an effect produced at 0.5 but not at 0.75 gestation. DHEA is important for brain development, and its suppression in adult life might contribute to the neurobehavioral pathologies that can arise after illness and stress during pregnancy.
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Affiliation(s)
- Tracey A Quinn
- Monash Institute of Medical Research, The Ritchie Centre, Monash University, 27-31 Wright Street, Clayton, Victoria 3168, Australia The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria 3010, Australia School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia Department of Obstetrics and Gynaecology, Monash Medical Centre, Monash University, Clayton, Victoria 3168, Australia
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Ratnayake U, Quinn TA, Castillo-Melendez M, Dickinson H, Walker DW. Behaviour and hippocampus-specific changes in spiny mouse neonates after treatment of the mother with the viral-mimetic Poly I:C at mid-pregnancy. Brain Behav Immun 2012; 26:1288-99. [PMID: 22960545 DOI: 10.1016/j.bbi.2012.08.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/22/2012] [Accepted: 08/22/2012] [Indexed: 12/20/2022] Open
Abstract
Epidemiological studies have suggested a link between prenatal exposure to bacterial or viral infections and subsequent development of mental disorders such as schizophrenia and autism. Animal models to study the prenatal origin of such outcomes of pregnancy have largely used conventional rodents which are immature at birth compared to the human neonate, and doses of the infective agent (i.e., lipopolysaccharide, Poly I:C) have been large enough to cause sickness behaviour in the mother. In this study we have used the spiny mouse (Acomys cahirinus) whose offspring have completed organogenesis at birth, and a single subcutaneous injection of a low (0.5mg/kg) dose of polyriboinosinic-polyribocytidilic acid (Poly I:C) at mid gestation (20 days, term is 39 days). The treatment had no effect on maternal, fetal or neonatal survival, or postnatal growth of the offspring. However, offspring showed significant impairments in non-spatial memory and learning tasks, and motor activity. Brain histology examined at 1 and 100 days of age revealed significant decreases in reelin, increased GFAP expression, and increased numbers of activated microglia, specifically in the hippocampus. This study provides evidence that a prenatal subclinical infection can have profound effects on brain development that are long-lasting.
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Affiliation(s)
- Udani Ratnayake
- Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Melbourne 3168, Australia.
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Dickinson H, Griffiths T, Walker DW, Jenkin G. Application of clinical indices of fetal growth and wellbeing to a novel laboratory species, the spiny mouse. Reprod Biol 2008; 8:229-43. [DOI: 10.1016/s1642-431x(12)60014-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Nagarajan R, Clancy B. Phylogenetic proximity revealed by neurodevelopmental event timings. Neuroinformatics 2008; 6:71-9. [PMID: 18498062 DOI: 10.1007/s12021-008-9013-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 02/12/2008] [Indexed: 10/22/2022]
Abstract
Statistical properties such as distribution and correlation signatures were investigated using a temporal database of common neurodevelopmental events in the three species most frequently used in experimental studies, rat, mouse, and macaque. There was a fine nexus between phylogenetic proximity and empirically derived dates of the occurrences of 40 common events including the neurogenesis of cortical layers and outgrowth milestones of developing axonal projections. Exponential and power-law approximations to the distribution of the events reveal strikingly similar decay patterns in rats and mice when compared to macaques. Subsequent hierarchical clustering of the common event timings also captures phylogenetic proximity, an association further supported by multivariate linear regression data. These preliminary results suggest that statistical analyses of the timing of developmental milestones may offer a novel measure of phylogenetic classifications. This may have added pragmatic value in the specific support it offers for the reliability of rat/mouse comparative modeling, as well as in the broader implications for the potential of meta-analyses using databases assembled from the extensive empirical literature.
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Affiliation(s)
- Radhakrishnan Nagarajan
- Department of Biostatistics, University of Arkansas for Medical Sciences, COPH/UAMS, Room 3234, 4301 W Markham, Slot 781, Little Rock, AR 72205-7199, USA.
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16
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Clancy B, Kersh B, Hyde J, Darlington RB, Anand KJS, Finlay BL. Web-based method for translating neurodevelopment from laboratory species to humans. Neuroinformatics 2007; 5:79-94. [PMID: 17426354 DOI: 10.1385/ni:5:1:79] [Citation(s) in RCA: 238] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/14/2023]
Abstract
Biomedical researchers and medical professionals are regularly required to compare a vast quantity of neurodevelopmental literature obtained from an assortment of mammals whose brains grow at diverse rates, including fast developing experimental rodent species and slower developing humans. In this article, we introduce a database-driven website, which was created to address this problem using statistical-based algorithms to integrate hundreds of empirically derived developing neural events in 10 mammalian species (http://translatingtime.net/). The site, based on a statistical model that has evolved over the past decade, currently incorporates 102 different neurodevelopmental events obtained from 10 species: hamsters, mice, rats, rabbits, spiny mice, guinea pigs, ferrets, cats, rhesus monkeys, and humans. Data are arranged in a Structured Query Language database, which allows comparative brain development measured in postconception days to be converted and accessed in real time, using Hypertext Preprocessor language. Algorithms applied to the database also allow predictions for dates of specific neurodevelopmental events where empirical data are not available, including for the human embryo and fetus. By designing a web-based portal, we seek to make these comparative data readily available to all those who need to efficiently estimate the timing of neurodevelopmental events in the human fetus, laboratory species, or across several different species. In an effort to further refine and expand the applicability of this database, we include a mechanism to submit additional data.
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Affiliation(s)
- Barbara Clancy
- Department of Biology, University of Central Arkansas, Conway, Arkansas 72035, USA.
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17
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Hendricks SJ, Brunjes PC, Hill DL. Taste bud cell dynamics during normal and sodium-restricted development. J Comp Neurol 2004; 472:173-82. [PMID: 15048685 DOI: 10.1002/cne.20064] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Taste bud volume increases over the postnatal period to match the number of neurons providing innervation. To clarify age-related changes in fungiform taste bud volume, the current study investigated developmental changes in taste bud cell number, proliferation rate, and life span. Taste bud growth can largely be accounted for by addition of cytokeratin-19-positive taste bud cells. Examination of taste bud cell kinetics with 3H-thymidine autoradiography revealed that cell life span and turnover periods were not altered during normal development but that cells were produced more rapidly in young rats, a prominent modification that could lead to increased taste bud size. By comparison, dietary sodium restriction instituted during pre- and postnatal development results in small taste buds at adulthood as a result of fewer cytokeratin-19-positive cells. The dietary manipulation also had profound influences on taste bud growth kinetics, including an increased latency for cells to enter the taste bud and longer life span and turnover periods. These studies provide fundamental, new information about taste bud development under normal conditions and after environmental manipulations that impact nerve/target matching.
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Affiliation(s)
- Susan J Hendricks
- Virginia Merrill Bloedel Hearing Research Center and Department of Otolaryngology, University of Washington, Seattle, Washington 98195-7923, USA
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18
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Abstract
Conservation of the order in which events occur in developing mammalian brains permits use of regression theory to model the timing of neural development. Following a small adjustment to account for a systematic variability in primate cortical and limbic systems, the model is used to generate a 95-event/nine-species matrix that predicts aspects of neurogenesis and axonal outgrowth in the brains of developing mice, hamsters, rats, spiny mice, rabbits, ferrets, cats, monkeys, and humans. Although data are compiled from species in which the timing of birth and the rate of maturation vary widely, the model proves statistically accurate, with practical implications for improving estimation of milestones of neural development, particularly for humans. Using the three-factor model (species, neural events, and primate adjustments), we produce predictions for the timing of 493 neural occurrences in developing mammalian brains that either have not yet been, or cannot be, empirically derived. We also relate the timing of neural events across the nine species in the form of a reference table calibrated to the development of laboratory rats. This 'translation' table will assist in attempts to equate the neurodevelopmental literature across species with either large or small differences in gestation and maturation, and also permit studies done in a variety of mammals to be applied to better understand human development. The comparative data indicate that humans, although conventionally considered an altricial species, are neurally advanced at birth relative to the other species studied.
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Affiliation(s)
- B Clancy
- Cornell University, Department of Psychology, Uris Hall, Ithaca, NY 14853, USA
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Reep RL. Cortical layer VII and persistent subplate cells in mammalian brains. BRAIN, BEHAVIOR AND EVOLUTION 2000; 56:212-34. [PMID: 11155000 DOI: 10.1159/000047206] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Layer VII is the deepest cortical layer in rats, and consists of a thin layer of persistent subplate cells overlain by a cell-sparse, myelin-rich stratum through which many corticocortical axons travel. Layer VII neurons participate in local and long-distance corticocortical connections. The present study was undertaken to determine whether layer VII is a typical feature in rodent brains, and to determine which other mammalian taxa exhibit a layer VII. The adult brains of 144 species from 22 orders were examined. Of these, 43 species in 6 orders exhibit a layer VII. These include the sciurognath Rodentia, Insectivora, Paucituberculata, Paramelemorphia, some Xenarthra, and some Chiroptera. In all taxa interstitial cells were observed scattered throughout the white matter. The observed distribution of layer VII in this sample of mammalian taxa suggests that layer VII is a typical feature in some orders, but is not present in most orders. The heterogeneous distribution of layer VII in the Rodentia and Chiroptera suggests that species-level developmental dynamics are involved. It is hypothesized that the timing of subplate apoptosis in relation to the establishment of corticocortical connections is the major factor that determines whether layer VII is present in the adult stage.
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Affiliation(s)
- R L Reep
- Department of Physiological Sciences, College of Veterinary Medicine and Brain Institute, University of Florida, Gainesville, Fla., USA.
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Abstract
Analysis of data collected on 131 species of primates, bats, and insectivores showed that the sizes of brain components, from medulla to forebrain, are highly predictable from absolute brain size by a nonlinear function. The order of neurogenesis was found to be highly conserved across a wide range of mammals and to correlate with the relative enlargement of structures as brain size increases, with disproportionately large growth occurring in late-generated structures. Because the order of neurogenesis is conserved, the most likely brain alteration resulting from selection for any behavioral ability may be a coordinated enlargement of the entire nonolfactory brain.
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Affiliation(s)
- B L Finlay
- Department of Psychology, Uris Hall, Cornell University, Ithaca, NY 14853, USA
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Bignami G, Dell'Omo G, Alleva E. Species specificity of organ toxicity: behavioral differences. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1995; 17:375-94. [PMID: 7786175 DOI: 10.1007/978-3-642-79451-3_33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- G Bignami
- Laboratory of Organ and System Pathophysiology, Istituto Superiore di Sanità, Rome, Italy
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