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Bulygina VV, Kalinina TS, Lanshakov DA, Dygalo NN. Expression of Neurotrophic Factor 3 in the Hippocampus of Neonatal Rats after Administration of Dexamethasone. NEUROCHEM J+ 2019. [DOI: 10.1134/s181971241903005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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İşcan B, Tuzun F, Cilaker Micili S, Tugyan K, Duman N, Ozkan H, Kumral A. The effects of perinatal steroid therapy on growth factor levels during different stages of the developing brain. J Matern Fetal Neonatal Med 2017; 30:1820-1828. [PMID: 28052712 DOI: 10.1080/14767058.2016.1228051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Excess glucocorticoid (GC) exposure on the fetal brain during critical stages of development has considerable effects on the development of the central nervous system (CNS). This study thus aimed to evaluate the differential effects of GC exposure on critical growth factor levels during different stages of brain maturation. METHODS For this purpose, forty-two rat pups were divided into six groups based on the timing of betamethasone administration. Rats in the treatment groups were exposed to intraperitoneal betamethasone injections beginning at different time points (postnatal days 1, 2, and 3). Rats in the placebo group received the same volume of 0.9% saline via the same fashion. Pups were sacrificed at 24 h following the final injection for determining the neuronal density and immunohistochemical evaluation of critical growth factors. RESULTS In the groups treated with betamethasone on postnatal day 1 (P1) and P2, which correspond to 22-24 and 24-28 gestational weeks in humans, the neuronal count in the hippocampal regions was significantly lower than their control groups. However, if steroid therapy was administered on P3, corresponding to 28-32 weeks in humans, no difference was observed between the two groups. Growth factors were affected in different ways depending on the steroid administration time and evaluated region. CONCLUSIONS The results suggest that the modulating effect of steroids on neuron count and growth factor response depends on the stage of brain development at the time of exposure. Therefore, this may be one of the key determinants affecting the deleterious and beneficial effects of GCs on the CNS.
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Affiliation(s)
- Burçin İşcan
- a Division of Neonatology, Department of Pediatrics , School of Medicine, Dokuz Eylul University , Izmir , Turkey
| | - Funda Tuzun
- a Division of Neonatology, Department of Pediatrics , School of Medicine, Dokuz Eylul University , Izmir , Turkey
| | - Serap Cilaker Micili
- b Department of Histology, Faculty of Medicine , Dokuz Eylül University , Izmir , Turkey
| | - Kazim Tugyan
- b Department of Histology, Faculty of Medicine , Dokuz Eylül University , Izmir , Turkey
| | - Nuray Duman
- a Division of Neonatology, Department of Pediatrics , School of Medicine, Dokuz Eylul University , Izmir , Turkey
| | - Hasan Ozkan
- a Division of Neonatology, Department of Pediatrics , School of Medicine, Dokuz Eylul University , Izmir , Turkey
| | - Abdullah Kumral
- a Division of Neonatology, Department of Pediatrics , School of Medicine, Dokuz Eylul University , Izmir , Turkey
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Yasuda M, Shinoda M, Honda K, Fujita M, Kawata A, Nagashima H, Watanabe M, Shoji N, Takahashi O, Kimoto S, Iwata K. Maternal Separation Induces Orofacial Mechanical Allodynia in Adulthood. J Dent Res 2016; 95:1191-7. [DOI: 10.1177/0022034516661159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
It is well known that exposure to maternal separation (MS) in early life causes plastic changes in the nervous system in adulthood, occasionally resulting in ubiquitous chronic pain. However, the pathogenic mechanisms of pain hypersensitivity remain unclear. Here, the authors examined the involvement of corticosterone in orofacial mechanical hypersensitivity induced by MS. To establish a rat model of MS, pups were placed in isolated cages 180 min/d and kept in a temperature-controlled environment at 22 ± 2 °C for 14 d. Mechanical allodynia in the whisker pad skin in adulthood was induced by MS and was significantly suppressed by successive postnatal subcutaneous administration of the glucocorticoid receptor antagonist mifepristone. Corticosterone levels were increased in the serum of MS rats, and successive postnatal administration of subcutaneous corticosterone to naive rats induced mechanical allodynia in the whisker pad skin. The number of P2X3 receptor-immunoreactive (P2X3R-IR) trigeminal ganglion (TG) neurons innervating the whisker pad skin was significantly increased in MS rats and decreased following subcutaneous administration of mifepristone. The number of P2X3R-IR TG neurons innervating the whisker pad skin was also significantly increased following successive postnatal administration of subcutaneous corticosterone in naive rats. Moreover, the mechanical allodynia was suppressed 30 min after administration of the P2X3R antagonist A317491 to the whisker pad skin in MS rats. These findings suggest that the increase in P2X3R-IR TG neurons innervating the whisker pad skin via enhanced neonatal corticosterone signaling by MS plays an important role in orofacial mechanical allodynia in adulthood.
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Affiliation(s)
- M. Yasuda
- Department of Oral Function and Restoration, Division of Pediatric Dentistry, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
| | - M. Shinoda
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
| | - K. Honda
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - M. Fujita
- Department of Oral Function and Restoration, Division of Pediatric Dentistry, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
| | - A. Kawata
- Department of Histology, Embryology and Neuroanatomy, Kanagawa Dental University, Yokosuka, Japan
| | - H. Nagashima
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
- Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan
| | - M. Watanabe
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
- Department of Periodontology, Nihon University School of Dentistry, Tokyo, Japan
| | - N. Shoji
- Division of Oral Diagnosis, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - O. Takahashi
- Department of Histology, Embryology and Neuroanatomy, Kanagawa Dental University, Yokosuka, Japan
| | - S. Kimoto
- Department of Oral Function and Restoration, Division of Pediatric Dentistry, Graduate School of Dentistry, Kanagawa Dental University, Yokosuka, Japan
| | - K. Iwata
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
- Division of Applied System Neuroscience Advanced Medical Research Center, Nihon University Graduate School of Medical Science, Tokyo, Japan
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Mo C, Pang TY, Ransome MI, Hill RA, Renoir T, Hannan AJ. High stress hormone levels accelerate the onset of memory deficits in male Huntington's disease mice. Neurobiol Dis 2014; 69:248-62. [DOI: 10.1016/j.nbd.2014.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 04/24/2014] [Accepted: 05/04/2014] [Indexed: 12/18/2022] Open
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Early repeated maternal separation induces alterations of hippocampus reelin expression in rats. J Biosci 2013; 38:27-33. [PMID: 23385810 DOI: 10.1007/s12038-012-9286-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The long-term effects of repeated maternal separation (MS) during early postnatal life on reelin expression in the hippocampus of developing rats were investigated in the present study. MS was carried out by separating Wistar rat pups singly from their mothers for 3 h a day during postnatal days (PND) 2-14. Reelin mRNA and protein levels in the hippocampus were determined using qRT-PCR and Western blotting, at PND 22, PND 60 and PND 90. MS resulted in the loss of body weight in the developing rats, and reelin mRNA and protein levels in the hippocampus generally were down-regulated over the developing period, but the reelin mRNA and protein levels in the hippocampus of 90-day-old male rats were up-regulated. These findings suggest that the long-term effects of MS on the expression levels of hippocampal reelin mRNA and protein depends on the age at which the stressed rats' brains were collected; reelin had important implications for the maternal-neonate interaction needed for normal brain development. In conclusion, repeated MS occurring during early postnatal life may cause the alterations of hippocampal reelin expression with the increasing age of developing rats.
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Abstract
BACKGROUND Cortisol plays a multifaceted role in major depression disorder (MDD). Diurnal rhythms are disturbed, there is increased resistance to the feedback action of glucocorticoids, excess cortisol may induce MDD, basal levels may be higher and the post-awakening cortisol surge accentuated in those at risk for MDD. Does this suggest new avenues for studying MDD or its clinical management? METHOD The relevant literature was reviewed. RESULTS Cortisol contributes to genetic variants for the risk for MDD and the way that environmental events amplify risk. The corticoids' influence begins prenatally, but continues into adulthood. The impact of cortisol at each phase depends not only on its interaction with other factors, such as psychological traits and genetic variants, but also on events that have, or have not, occurred previously. CONCLUSIONS This review suggests that the time is now right for serious consideration of the role of cortisol in a clinical context. Estimates of cortisol levels and the shape of the diurnal rhythm might well guide the understanding of subtypes of MDD and yield additional indicators for optimal treatment. Patients with disturbed cortisol rhythms might benefit from restitution of those rhythms; they may be distinct from those with more generally elevated levels, who might benefit from cortisol blockade. Higher levels of cortisol are a risk for subsequent depression. Should manipulation of cortisol or its receptors be considered as a preventive measure for some of those at very high risk of future MDD, or to reduce other cortisol-related consequences such as long-term cognitive decline?
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Affiliation(s)
- J Herbert
- Cambridge Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, UK.
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Suri D, Vaidya VA. Glucocorticoid regulation of brain-derived neurotrophic factor: relevance to hippocampal structural and functional plasticity. Neuroscience 2012; 239:196-213. [PMID: 22967840 DOI: 10.1016/j.neuroscience.2012.08.065] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/28/2012] [Accepted: 08/30/2012] [Indexed: 12/20/2022]
Abstract
Glucocorticoids serve as key stress response hormones that facilitate stress coping. However, sustained glucocorticoid exposure is associated with adverse consequences on the brain, in particular within the hippocampus. Chronic glucocorticoid exposure evokes neuronal cell damage and dendritic atrophy, reduces hippocampal neurogenesis and impairs synaptic plasticity. Glucocorticoids also alter expression and signaling of the neurotrophin, brain-derived neurotrophic factor (BDNF). Since BDNF is known to promote neuroplasticity, enhance cell survival, increase hippocampal neurogenesis and cellular excitability, it has been hypothesized that specific adverse effects of glucocorticoids may be mediated by attenuating BDNF expression and signaling. The purpose of this review is to summarize the current state of literature examining the influence of glucocorticoids on BDNF, and to address whether specific effects of glucocorticoids arise through perturbation of BDNF signaling. We integrate evidence of glucocorticoid regulation of BDNF at multiple levels, spanning from the well-documented glucocorticoid-induced changes in BDNF mRNA to studies examining alterations in BDNF receptor-mediated signaling. Further, we delineate potential lines of future investigation to address hitherto unexplored aspects of the influence of glucocorticoids on BDNF. Finally, we discuss the current understanding of the contribution of BDNF to the modulation of structural and functional plasticity by glucocorticoids, in particular in the context of the hippocampus. Understanding the mechanistic crosstalk between glucocorticoids and BDNF holds promise for the identification of potential therapeutic targets for disorders associated with the dysfunction of stress hormone pathways.
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Affiliation(s)
- D Suri
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India
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Badowska-Szalewska E, Spodnik E, Ludkiewicz B, Klejbor I, Moryś J. Nerve growth factor (NGF) immunoreactive neurons in the juvenile rat hippocampus: response to acute and long-term high-light open-field (HL-OF) or forced swim (FS) stress stimulation. Neuroscience 2011; 199:491-500. [PMID: 22027234 DOI: 10.1016/j.neuroscience.2011.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/13/2011] [Accepted: 10/09/2011] [Indexed: 12/30/2022]
Abstract
This study aimed at examining and comparing the influence of two different stress stimuli on the density (number of cells/mm²) of nerve growth factor (NGF) containing neurons in the hippocampal CA1 and CA3 pyramidal cell layers and the dentate gyrus (DG) granule cell layer in juvenile rats (P28; P-postnatal day). The high-light open-field (HL-OF) test and forced swim (FS) test were employed to investigate the effects of a single, 15-min acute exposure and repeated (15 min daily for 21 days) long-term exposure to stress. In order to detect NGF-ir neurons, immunohistochemical (-ir) techniques were used. In comparison with nonstressed animals, acute and long-term HL-OF or FS stimulation resulted in a marked increase (P<0.001) in the density of NGF-ir containing cells in all the hippocampal structures. The frequency of stress application (acute vs. long-term), however, did not have a substantial impact on the studied parameter, with the exception of the CA3 sector, where a decreased density (P<0.001) of NGF-ir neurons was observed after long-term exposure to FS. It may be concluded that a rise in the density of NGF-ir neurons in the juvenile rat hippocampus after exposure to HL-OF or FS stressors could have affected the activity of the hypothalamic-pituitary-adrenocortical (HPA) stress axis. Prolonged HL-OF or FS stress was probably aggravating enough not to trigger the habituation process. The type of stressor applied (HL-OF vs. FS) was not essentially a factor determining the density of NGF-ir cells in the hippocampus.
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Affiliation(s)
- E Badowska-Szalewska
- Department of Anatomy and Neurobiology, Medical University of Gdańsk, Dębinki 1 Street, 80-211 Gdańsk, Poland.
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Kumar P, Venners SA, Fu L, Pearson C, Ortiz K, Wang X. Association of antenatal steroid use with cord blood immune biomarkers in preterm births. Early Hum Dev 2011; 87:559-64. [PMID: 21576006 PMCID: PMC3140537 DOI: 10.1016/j.earlhumdev.2011.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/30/2011] [Accepted: 04/20/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To evaluate the effect of maternal administration of antenatal steroids (ANS) on cord blood cytokine levels at birth in preterm infants. METHODS Cord blood cytokine concentrations were measured for pro-inflammatory cytokines (IL-1β, IL-6, and IL-8); anti-inflammatory cytokines (IL-4, IL-10 and TGF-β); and neurotrophic cytokines (BDNF, NT-3, and NT-4) in two hundred preterm infants. Data were analyzed using multivariable linear regression to model the independent and joint effects of ANS and inflammation on mean log cord blood cytokine concentrations adjusted for gestational age and Apgar scores. RESULTS Exposure to ANS had no significant effect on the cord blood concentrations of cytokines measured in this study. All three pro-inflammatory cytokine levels and levels of IL-10 were significantly increased and cord blood levels of TGF-β and NT-3 were significantly decreased in infants with placental inflammation. CONCLUSION Although exposure to ANS did not have any significant effect on cord blood levels of cytokines, there was a trend toward the attenuation of inflammatory response and higher levels of neurotrophic cytokines in infants born to mothers with placental inflammation and exposure to ANS compared to infants born to mothers with placental inflammation and no ANS exposure.
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Affiliation(s)
- Praveen Kumar
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| | - Scott A Venners
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 4X8
| | - Lingling Fu
- Department of Pediatrics, Boston University School of Medicine, Boston, MA, United States 02118
| | - Colleen Pearson
- Department of Pediatrics, Boston University School of Medicine, Boston, MA, United States 02118
| | - Katherin Ortiz
- Department of Pediatrics, Boston University School of Medicine, Boston, MA, United States 02118
| | - Xiaobin Wang
- Department of Pediatrics, Northwestern University Feinberg School of Medicine and Children’s Memorial Hospital and Children’s Memorial Research Center, Chicago, IL, United States 60611
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Fortress AM, Buhusi M, Helke KL, Granholm ACE. Cholinergic Degeneration and Alterations in the TrkA and p75NTR Balance as a Result of Pro-NGF Injection into Aged Rats. J Aging Res 2011; 2011:460543. [PMID: 21785728 PMCID: PMC3140182 DOI: 10.4061/2011/460543] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 04/04/2011] [Indexed: 01/22/2023] Open
Abstract
Learning and memory impairments occurring with Alzheimer's disease (AD) are associated with degeneration of the basal forebrain cholinergic neurons (BFCNs). BFCNs extend their axons to the hippocampus where they bind nerve growth factor (NGF) which is retrogradely transported to the cell body. While NGF is necessary for BFCN survival and function via binding to the high-affinity receptor TrkA, its uncleaved precursor, pro-NGF has been proposed to induce neurodegeneration via binding to the p75NTR and its coreceptor sortilin. Basal forebrain TrkA and NGF are downregulated with aging while pro-NGF is increased. Given these data, the focus of this paper was to determine a mechanism for how pro-NGF accumulation may induce BFCN degeneration. Twenty-four hours after a single injection of pro-NGF into hippocampus, we found increased hippocampal p75NTR levels, decreased hippocampal TrkA levels, and cholinergic degeneration. The data suggest that the increase in p75NTR with AD may be mediated by elevated pro-NGF levels as a result of decreased cleavage, and that pro-NGF may be partially responsible for age-related degenerative changes observed in the basal forebrain. This paper is the first in vivo evidence that pro-NGF can affect BFCNs and may do so by regulating expression of p75NTR neurotrophin receptors.
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Affiliation(s)
- Ashley M Fortress
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
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Susceptibility to stress in transgenic mice overexpressing TrkC, a model of panic disorder. J Psychiatr Res 2010; 44:157-67. [PMID: 19698958 DOI: 10.1016/j.jpsychires.2009.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 07/24/2009] [Accepted: 07/27/2009] [Indexed: 12/21/2022]
Abstract
Stressful life events increase the susceptibility for subsequent onset of psychiatric disorders in humans. Previous research has implicated neurotrophins in the onset of some stress-related diseases, such as major depression disorder, post-traumatic stress disorder or panic disorder. We have tested the hypothesis that the neurotrophin-3 (NT-3)/TrkC system is a genetic interface mediating the deleterious effects of stress on the initiation of panic disorder and other pathologies. To this aim, we have analyzed the functionality of HPA axis and the behavioral consequences of different types of stressful conditions in a mouse model of panic disorder, which overexpresses TrkC, the high affinity-receptor for NT-3 (TgNTRK3). Our results reveal that TgNTRK3 mice exhibit an altered circadian corticosterone rhythm that is reversed by clonidine treatment, but normal expression of genes involved in the control of the hypothalamus-pituitary-adrenal (HPA) axis (CRH, GR) and normal corticosterone response to acute and chronic stressors. In contrast, they exhibit an altered pattern of activation of stress-related brain areas and showed enhanced anxiety-related behavior and more passive strategies than wild types under some chronic stress conditions. We conclude that TgNTRK3 mice present differences in their response to stress characterized by subtle changes in the HPA axis, marked changes in acute stress-induced brain activation and altered coping strategies, suggesting a key role of TrkC receptor in the stress neural circuitry and in the behavioral consequences of chronic stress.
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Cirulli F, Alleva E. The NGF saga: from animal models of psychosocial stress to stress-related psychopathology. Front Neuroendocrinol 2009; 30:379-95. [PMID: 19442684 DOI: 10.1016/j.yfrne.2009.05.002] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 04/17/2009] [Accepted: 05/04/2009] [Indexed: 01/15/2023]
Abstract
The role of the neurotrophins Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) has been expanding over the last years from trophic factors involved in brain growth and differentiation, to much more complex messengers, involved in psycho-neuro-endocrine adaptations. Much of this research stems from a series of studies inspired by the life-long work of the Nobel laureate Rita Levi-Montalcini. A new field of research started when NGF was found to be released in the bloodstream as a result of psychosocial stressors in male mice. Subsequent studies have shown that, in humans, highly arousing situations also result in increased blood levels of NGF, underlying the unique role of this neurotrophin, compared to other neuroendocrine effectors, and its sensitivity to environmental variables endowed by a social nature. Data are reviewed to support the hypothesis that this neurotrophic factor, together with BDNF, could be involved in the neurobiological changes underlying physiological and pathological reactions to stress that can result in increased vulnerability to disease in humans, including risk for anxiety disorders, or in the complex pathophysiology associated with mood disorders. Indeed, numerous data indicate that neurotrophins are present in brain hypothalamic areas involved in the regulation of hypothalamic-pituitary-adrenal axis, circadian rhythms and metabolism. In addition, there is now evidence that, in addition to the nervous system, neurotrophins exert their effects in various tissue compartments as they are produced by a variety of non-neuronal cell types such as endocrine and immune cells, adipocytes, endothelial cells, keratinocytes, thus being in a position to coordinate brain and body reactions to external challenges. Aim of this review is to discuss the evidence suggesting a role for neurotrophins as multifunctional signaling molecules activated during allostatic responses to stressful events and their involvement in the complex pathophysiology underlying stress-related psychopathology.
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Affiliation(s)
- Francesca Cirulli
- Section of Behavioural Neurosciences, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità Rome, Viale Regina Elena 299, I-00161 Roma, Italy.
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Li L, Kong L, Fang X, Jiang C, Wang Y, Zhong Z, Sun Q, Gu G, Zheng D, Meng R, Kang J. SH2-B beta expression in alveolar macrophages in BAL fluid of asthmatic guinea pigs and its role in NGF-TrkA-mediated asthma. Respirology 2009; 14:60-8. [PMID: 19144050 DOI: 10.1111/j.1440-1843.2008.01417.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Nerve growth factor (NGF)/tyrosine kinase receptor A (TrkA) signalling may play an important role in the pathogenesis of asthma, and SH2-B beta, a TrkA-binding protein, modulates the NGF signalling pathway. In this study, SH2-B beta expression in alveolar macrophages (AM) in guinea pig BAL fluid and its role in asthma pathogenesis through the NGF-TrkA signalling pathway were investigated. METHODS Guinea pigs were randomized into five groups: control, a model of asthma, anti-SH2-B beta antibody treatment, anti-NGF antibody treatment and anti-TrkA antibody treatment. The asthmatic model was established in guinea pigs by inhalation of ovalbumin. Specific anti-SH2-B beta, anti-NGF and anti-TrkA antibodies were administered and AM were isolated from BAL fluid to assess SH2-B beta expression using an immunofluorescence assay. SH2-B beta and TrkA protein expression were determined by western blotting, IL-1 beta and IL-4 levels in the BAL fluid supernatants were determined by ELISA, and pathological changes in the bronchi and lung tissues were examined by HE staining. RESULTS Lymphocyte, eosinophil and total inflammatory cell numbers in BAL fluid were significantly higher in the asthma model group than in the other groups (P < 0.01). NGF expression in the asthma model group was significantly higher than that in the PBS control group (P < 0.01). SH2-B beta was expressed in AM of control animals and expression was significantly higher in the asthma model than in the other groups (P < 0.01). TrkA protein expression was significantly higher in the asthma model group than in the PBS group (P < 0.01), and treatment with anti-NGF antibody resulted in significant reduction of TrkA expression (P < 0.01). CONCLUSIONS SH2-B beta is expressed in AM of normal guinea pigs, and SH2-B beta may participate in asthma pathogenesis through the NGF-TrkA signalling pathway.
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Affiliation(s)
- Li Li
- Institute of Respiratory Diseases, First Affiliated Hospital of China Medical University, Shenyang, Liaoning Province, China
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Quadros PS, Schlueter LJ, Wagner CK. Distribution of progesterone receptor immunoreactivity in the midbrain and hindbrain of postnatal rats. Dev Neurobiol 2008; 68:1378-90. [PMID: 18712784 DOI: 10.1002/dneu.20664] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Nuclear steroid hormone receptors are powerful transcription factors and therefore have the potential to influence and regulate fundamental processes of neural development. The expression of progesterone receptors (PR) has been described in the developing forebrain of rats and mice, and the mammalian brain may be exposed to significant amounts of progesterone, either from maternal sources and/or de novo synthesis of progesterone from cholesterol within the brain. The present study examined the distribution of PR immunoreactive (PRir) cells within the midbrain and hindbrain of postnatal rats. The results demonstrate that PR is transiently expressed within the first 2 weeks of life in specific motor, sensory and reticular core nuclei as well as within midbrain dopaminergic cell groups such as the substantia nigra and the ventral tegmental area. Additionally, robust PRir was observed in cells of the lower rhombic lip, a transient structure giving rise to precerebellar nuclei. These results suggest that progestins and progesterone receptors may play a fundamental role in the postnatal development of numerous midbrain and hindbrain nuclei, including some areas implicated in human disorders. Additionally, these findings contribute to the increasing evidence that steroid hormones and their receptors influence neural development in a wide range of brain areas, including many not typically associated with reproduction or neuroendocrine function.
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Affiliation(s)
- Princy S Quadros
- Department of Biological Sciences, Delaware State University, Dover, DE 19901, USA.
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Abstract
+/-3,4-Methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that has become a popular drug of abuse and has been shown to deplete serotonin in the brains of users and animals exposed to it. To date, most studies have investigated the effects of MDMA on adult animals. With a majority of users of MDMA being young adults, the chances of the users becoming pregnant and exposing the fetuses to MDMA are also a concern. Evidence to date has shown that developmental exposure to MDMA results in learning and memory impairments in the Morris water maze, a task known to be sensitive to hippocampal disruption, when the animals are tested as adults. Developmental MDMA exposure leads to hypoactivity in the offspring as adults but does not affect outcome on tests of anxiety. MDMA administration decreases pup weight, increases corticosterone and brain-derived neurotrophic factor levels during treatment while decreasing brain levels of serotonin; a decrease that initially dissipates and then reappears in adulthood. Neonatal MDMA exposure increases the sensitivity of the serotonin 1A receptor, a possible mechanism underlying the learning and memory deficits seen. Taken together, the evidence shows that MDMA exposure has adverse effects on the developing brain and behavior. The animal and human data on developmental MDMA exposure are reviewed and their public health implications discussed.
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Grace CE, Schaefer TL, Herring NR, Skelton MR, McCrea AE, Vorhees CV, Williams MT. (+)-Methamphetamine increases corticosterone in plasma and BDNF in brain more than forced swim or isolation in neonatal rats. Synapse 2008; 62:110-21. [PMID: 17992688 DOI: 10.1002/syn.20470] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
(+)-Methamphetamine (MA) administered on postnatal days (P) 11-15 (four times/day) results in increased corticosterone that overlaps the stress hyporesponsive period (SHRP; P2-14) and leads to later learning and memory deficits. Elevated corticosterone during the SHRP results in neurotrophin changes and long-term effects on learning. We determined whether two known stressors could mimic the effects of MA [10 (mg/kg)/dose] administration in neonatal rats. Stressors were four 15-min sessions of forced swim or isolation (confinement in forced swim tubes without water). Saline and weighed-only controls were included and all five treatments were represented within each litter. Corticosterone in plasma and brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in neostriatum and hippocampus were examined after one or four treatments on P11 or P15 (0.5, 1.75, 6.5, or 24 h after first dose). MA increased corticosterone and BDNF; forced swim and isolation also increased corticosterone, but to a lesser extent than MA, and neither stressor increased BDNF. NGF was unaffected by saline treatment, but there was a minor reduction in NGF in the forced swim group compared with the weighed-only group. The data show that MA is more potent at releasing corticosterone and increasing BDNF than short-term, repeated episodes of forced swim or isolation. The possible relationship between these changes and the long-term cognitive effects of developmental MA administration are discussed.
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Affiliation(s)
- Curtis E Grace
- Division of Neurology, Cincinnati Children's Research Foundation, Cincinnati, Ohio 45229-3039, USA
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17
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Marais L, van Rensburg SJ, van Zyl JM, Stein DJ, Daniels WMU. Maternal separation of rat pups increases the risk of developing depressive-like behavior after subsequent chronic stress by altering corticosterone and neurotrophin levels in the hippocampus. Neurosci Res 2008; 61:106-12. [PMID: 18329744 DOI: 10.1016/j.neures.2008.01.011] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 01/03/2008] [Accepted: 01/25/2008] [Indexed: 11/18/2022]
Abstract
Children that are abused have an increased risk for developing psychiatric disorders later in life, because of the negative effects of stress on the developing brain. We used a maternal separation model in rats to see how neurotrophins, stress hormones, behavior and the anti-oxidant potential of serum are affected. Rat pups were separated from their mothers for 3h/day on days 2-14. Maternal separation caused changes in levels of NGF and NT-3 in the dorsal and ventral hippocampus, increased basal corticosterone levels and decreased ACTH levels after acute restraint stress. The anti-oxidant potential of the rat serum was significantly lower in the maternal separation group. Depressive-like behavior, measured during a forced swim test, was seen in maternally separated rats after additional chronic stress during adulthood. Maternal separation caused downregulation of neurotrophins in the ventral hippocampus, possibly as an effect of high corticosterone levels, but compensatory mechanisms against cell death may be involved as neurotrophin levels increased in the dorsal hippocampus. Decreased anti-oxidant potential of serum could have been an effect of downregulated neurotrophin levels.
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Affiliation(s)
- Lelanie Marais
- Department of Biomedical Sciences, Division of Medical Physiology, Stellenbosch University, Tygerberg 7505, South Africa.
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18
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Lehmann K, Rodriguez EG, Kratz O, Moll GH, Dawirs RR, Teuchert-Noodt G. Early preweaning methamphetamine and postweaning rearing conditions interfere with the development of peripheral stress parameters and neural growth factors in gerbils. Int J Neurosci 2007; 117:1621-38. [PMID: 17917931 DOI: 10.1080/00207450600934937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Adrenal steroid hormones and neuronal growth factors are two interacting systemic factors that mediate the environment's influence on the brain's structure and function. In order to further elucidate their role and relationship in the effects of early stressful experience and isolated rearing (IR), this study measured blood corticosterone titres and relative adrenal weights and assessed nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) concentrations in brain regions of both hemispheres of young adult Mongolian gerbils injected on postnatal day 14 with a single high dose of methamphetamine (MA) or saline and raised after weaning either in an enriched or an impoverished environment. Irrespective of MA challenge, IR decreased corticosterone titres to about half, but increased relative adrenal weights. BDNF concentrations were decreased by IR in saline-injected animals in the left prefrontal and parietal cortices and right entorhinal and hippocampal cortices, and in the subcortical regions of both hemispheres. NGF concentrations were unaltered by IR in saline-injected animals, but increased in MA challenged animals in the entorhinal/hippocampal cortices and subcortical areas of both hemispheres. MA application induced shifts of the lateral asymmetry in NGF contents in prefrontal and entorhinal cortices. The results suggest that an early pharmacological traumatization can set a switch for further brain development, and that growth factor concentrations might possibly be influenced by peripheral stress hormones.
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Affiliation(s)
- Konrad Lehmann
- Department of Neuroanatomy, Faculty of Biology, Bielefeld, Germany.
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19
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Skelton MR, Williams MT, Schaefer TL, Vorhees CV. Neonatal (+)-methamphetamine increases brain derived neurotrophic factor, but not nerve growth factor, during treatment and results in long-term spatial learning deficits. Psychoneuroendocrinology 2007; 32:734-45. [PMID: 17606327 PMCID: PMC2756096 DOI: 10.1016/j.psyneuen.2007.05.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 04/11/2007] [Accepted: 05/07/2007] [Indexed: 01/09/2023]
Abstract
In this study, brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were examined at five time points [postnatal day (P)11, 15, 20, 21, and 68 (the latter with or without behavioral testing)] during and after P11-20 (+)-methamphetamine (MA) (10 mg/kg 4 x day) treatment. BDNF in MA-treated animals was elevated on P15 and P20 in the hippocampus but not in the hypothalamus and was unchanged on P11 and P21. On P68 (1 h after Morris water maze testing) MA-treated offspring showed a trend toward higher levels of BDNF in the hippocampus than saline-treated animals. MA treatment increased NGF levels in the hippocampus but only on P20. No effect of MA treatment was observed in the elevated zero maze. MA-treated offspring had increased latencies, cumulative distances, path lengths, and first bearings in the Morris water maze. The findings indicate that early MA exposure induces hippocampal BDNF increases that precede the later emergence of spatial learning deficits.
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Affiliation(s)
| | | | | | - Charles V. Vorhees
- Corresponding author. Tel.: +1 513 636 8622; fax: +1 513 636 3912. (C.V. Vorhees)
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20
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Mohtasham L, Auais A, Piedimonte G. Nerve growth factor mediates steroid-resistant inflammation in respiratory syncytial virus infection. Pediatr Pulmonol 2007; 42:496-504. [PMID: 17469147 DOI: 10.1002/ppul.20607] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neurotrophic factors and receptors are upregulated in the respiratory tract of humans and rodents infected by the respiratory syncytial virus, leading to airway inflammation and hyperreactivity. The contribution of neurotrophic pathways to the recruitment of immuno-inflammatory cells and their response to anti-inflammatory therapy remains unclear. We sought to determine whether selective nerve growth factor inhibition prevents the immuno-inflammatory response against infection, and explored the effect of inhaled corticosteroids on virus-induced neurotrophic upregulation and the consequent recruitment of immuno-inflammatory cells into the airways. We tried to inhibit the recruitment of lymphocytes and monocytes into the airways of infected weanling rats using immunologic inhibition of nerve growth factor with a specific blocking antibody, or chemical inhibition of receptor tyrosine kinase with K252a. The anti-inflammatory activity of inhaled corticosteroids was studied in infected rats treated with budesonide, fluticasone, or vehicle. Immunological or chemical inhibition of nerve growth factor or its high-affinity receptor tyrosine kinase pathway inhibited the recruitment of inflammatory cells triggered by nociceptive irritation of infected rat airways, thereby reducing local and systemic immuno-inflammatory responses against the virus. Neurotrophic upregulation in infected airways was not affected by inhaled corticosteroids. As a logical consequence, these commonly used drugs were also unable to stop the recruitment of immune and inflammatory effector cells into infected airways. Overexpression of neurotrophic factors and receptors in airways infected by respiratory syncytial virus is critical for the development of airway inflammation and hyperreactivity, which is resistant to the anti-inflammatory effect of inhaled corticosteroids.
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Affiliation(s)
- Lida Mohtasham
- Department of Pediatrics, West Virginia University School of Medicine, Morgantown, West Virginia 26506-9214, USA
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21
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Faure J, Uys JDK, Marais L, Stein DJ, Daniels WMU. Early maternal separation alters the response to traumatization: resulting in increased levels of hippocampal neurotrophic factors. Metab Brain Dis 2007; 22:183-95. [PMID: 17468977 DOI: 10.1007/s11011-007-9048-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2007] [Accepted: 02/14/2007] [Indexed: 12/13/2022]
Abstract
Early life adversity predisposes individuals to the development of psychopathology in later life, especially depression and anxiety disorders. Prior history of stressors may also be a vulnerability factor for developing posttraumatic stress disorder (PTSD) in response to trauma. We examined the mechanisms underlying this phenomenon by employing two animal stress models, early maternal separation followed by later time-dependent sensitization (TDS). In animals exposed to adult TDS, those with prior early adversity did not differ from controls on tests of anxiety (elevated plus maze, open field), or HPA function (ACTH and corticosterone levels). However, those with prior early adversity had increased levels of neurotrophic factors (BDNF, NGF and NT-3) in both the dorsal and ventral hippocampus. Although early adversity is known to be associated with negative effects on neuronal function, it may also be associated with an increased ability to respond to subsequent stressors with compensatory mechanisms such as increased neurotrophic factor release.
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Affiliation(s)
- Jacqueline Faure
- Department of Medical Physiology, University of Stellenbosch, Tygerberg, Western Cape, South Africa.
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22
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Rossi C, Angelucci A, Costantin L, Braschi C, Mazzantini M, Babbini F, Fabbri ME, Tessarollo L, Maffei L, Berardi N, Caleo M. Brain-derived neurotrophic factor (BDNF) is required for the enhancement of hippocampal neurogenesis following environmental enrichment. Eur J Neurosci 2006; 24:1850-6. [PMID: 17040481 DOI: 10.1111/j.1460-9568.2006.05059.x] [Citation(s) in RCA: 449] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Neurogenesis continues to occur in the adult mammalian hippocampus and is regulated by both genetic and environmental factors. It is known that exposure to an enriched environment enhances the number of newly generated neurons in the dentate gyrus. However, the mechanisms by which enriched housing produces these effects are poorly understood. To test a role for neurotrophins, we used heterozygous knockout mice for brain-derived neurotrophic factor (BDNF+/-) and mice lacking neurotrophin-4 (NT-4-/-) together with their wild-type littermates. Mice were either reared in standard laboratory conditions or placed in an enriched environment for 8 weeks. Animals received injections of the mitotic marker bromodeoxyuridine (BrdU) to label newborn cells. Enriched wild-type and enriched NT-4-/- mice showed a two-fold increase in hippocampal neurogenesis as assessed by stereological counting of BrdU-positive cells in the dentate gyrus and double labelling for BrdU and the neuronal marker NeuN. Remarkably, this enhancement of hippocampal neurogenesis was not seen in enriched BDNF+/- mice. Failure to up-regulate BDNF accompanied the lack of a neurogenic response in enriched BDNF heterozygous mice. We conclude that BDNF but not NT-4 is required for the environmental induction of neurogenesis.
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Affiliation(s)
- Chiara Rossi
- Istituto di Neuroscienze C.N.R., via G. Moruzzi 1, 56100 Pisa, Italy
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23
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Francia N, Cirulli F, Chiarotti F, Antonelli A, Aloe L, Alleva E. Spatial memory deficits in middle-aged mice correlate with lower exploratory activity and a subordinate status: role of hippocampal neurotrophins. Eur J Neurosci 2006; 23:711-28. [PMID: 16487153 DOI: 10.1111/j.1460-9568.2006.04585.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of the present work was to relate age-related individual differences in cognitive function with behavioural strategies employed in social and non-social challenges. To this purpose, the behaviour of adult (5-month-old) and middle-aged (13-month-old) CD-1 mice was scored in the social interaction, plus-maze, Morris water maze (MWM) and open-field tests. In addition, brain levels of nerve growth factor and brain-derived neurotrophic factor (BDNF) were analysed and correlated with the behaviours scored. Compared to adults, middle-aged mice showed greater anxiety in both non-social and social situations, spending less time in the open arms of the plus-maze and performing more freezing behaviour in response to aggression. Based upon their behaviour in the social interaction test, adult and middle-aged subjects were classified as dominant or subordinate and their behaviour in the open field, plus-maze and MWM tests subjected to factor analysis, taking into account age and social status. Results highlighted meaningful differences in exploratory strategies as a function of social status only in middle-aged subjects. In particular, middle-aged dominants were, overall, more explorative than same-aged subordinates, spending less time in peripheral areas and approaching more readily a novel object. Interestingly, in middle-aged mice, superior performance in the MWM task was associated with exploratory strategies exploited by dominants. At adulthood, BDNF hippocampal levels, but not specific behaviours, were positively correlated with the ability to learn a spatial task. Overall, data indicate that, in middle-aged subjects individual differences in exploratory strategies, rather than neurotrophin levels, are able to predict the degree of impairment in a spatial learning task.
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Affiliation(s)
- N Francia
- Section of Behavioural Neurosciences, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Viale Regina Elena 299, I-00161 Rome, Italy
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24
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Guijarro C, Rutz S, Rothmaier K, Turiault M, Zhi Q, Naumann T, Frotscher M, Tronche F, Jackisch R, Kretz O. Maturation and maintenance of cholinergic medial septum neurons require glucocorticoid receptor signaling. J Neurochem 2006; 97:747-58. [PMID: 16573657 DOI: 10.1111/j.1471-4159.2006.03728.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glucocorticoids have been shown to influence trophic processes in the nervous system. In particular, they seem to be important for the development of cholinergic neurons in various brain regions. Here, we applied a genetic approach to investigate the role of the glucocorticoid receptor (GR) on the maturation and maintenance of cholinergic medial septal neurons between P15 and one year of age by using a mouse model carrying a CNS-specific conditional inactivation of the GR gene (GRNesCre). The number of choline acetyltransferase and p75NTR immuno-positive neurons in the medial septum (MS) was analyzed by stereology in controls versus mutants. In addition, cholinergic fiber density, acetylcholine release and cholinergic key enzyme activity of these neurons were determined in the hippocampus. We found that in GRNesCre animals the number of medial septal cholinergic neurons was significantly reduced during development. In addition, cholinergic cell number further decreased with aging in these mutants. The functional GR gene is therefore required for the proper maturation and maintenance of medial septal cholinergic neurons. However, the loss of cholinergic neurons in the medial septum is not accompanied by a loss of functional cholinergic parameters of these neurons in their target region, the hippocampus. This pinpoints to plasticity of the septo-hippocampal system, that seems to compensate for the septal cell loss by sprouting of the remaining neurons.
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Affiliation(s)
- Christian Guijarro
- Department of Anatomy and Cell Biology, University of Freiburg, D-79104 Freiburg, Germany
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25
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Kreider ML, Tate CA, Cousins MM, Oliver CA, Seidler FJ, Slotkin TA. Lasting effects of developmental dexamethasone treatment on neural cell number and size, synaptic activity, and cell signaling: critical periods of vulnerability, dose-effect relationships, regional targets, and sex selectivity. Neuropsychopharmacology 2006; 31:12-35. [PMID: 15920497 DOI: 10.1038/sj.npp.1300783] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glucocorticoids administered to prevent respiratory distress in preterm infants are associated with neurodevelopmental disorders. To evaluate the long-term effects on forebrain development, we treated developing rats with dexamethasone (Dex) at 0.05, 0.2, or 0.8 mg/kg, doses below or spanning the range in clinical use, testing the effects of administration during three different stages: gestational days 17-19, postnatal days 1-3, or postnatal days 7-9. In adulthood, we assessed biomarkers of neural cell number and size, cholinergic presynaptic activity, neurotransmitter receptor expression, and synaptic signaling mediated through adenylyl cyclase (AC), in the cerebral cortex, hippocampus, and striatum. Even at doses that were devoid of lasting effects on somatic growth, Dex elicited deficits in the number and size of neural cells, with the largest effect in the cerebral cortex. Indices of cholinergic synaptic function (choline acetyltransferase, hemicholinium-3 binding) indicated substantial hyperactivity in males, especially in the hippocampus, effectively eliminating the normal sex differences for these parameters. However, the largest effects were seen for cerebrocortical cell signaling mediated by AC, where Dex treatment markedly elevated overall activity while obtunding the function of G-protein-coupled catecholaminergic or cholinergic receptors that stimulate or inhibit AC; uncoupling was noted despite receptor upregulation. Again, the effects on signaling were larger in males and offset the normal sex differences in AC. These results indicate that, during critical developmental periods, Dex administration evokes lasting alterations in neural cell numbers and synaptic function in forebrain regions, even at doses below those used in preterm infants.
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Affiliation(s)
- Marisa L Kreider
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, USA
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26
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Roskoden T, Linke R, Schwegler H. Transient early postnatal corticosterone treatment of rats leads to accelerated aquisition of a spatial radial maze task and morphological changes in the septohippocampal region. Behav Brain Res 2005; 157:45-53. [PMID: 15617770 DOI: 10.1016/j.bbr.2004.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Revised: 06/04/2004] [Accepted: 06/09/2004] [Indexed: 01/05/2023]
Abstract
In the present study new-born rats were treated with corticosterone (CORT) between postnatal days 1 and 12. At the age of 16-20 weeks, these animals were tested for spatial learning capacity using an eight-arm radial maze. After behavioral testing, density of cholinergic fibers and sizes of the mossy fiber terminal fields in the hippocampus and number of cholinergic and GABAergic neurons in the septal area were quantified. In the radial arm maze CORT-treated animals initially showed better working memory performance than controls. However, control animals showed a significant improvement of spatial working memory in the last trials and reached similar working memory scores as compared to treated animals. At neither day of training differences in reference memory errors were found between groups. In the diagonal band of Broca, both numbers of cholinergic and GABAergic neurons were increased after corticosterone treatment. The fiber systems in hippocampus showed no significant differences between groups. In conclusion, early postnatal stress induced by CORT administration in neonatal rats results in mild, yet significant morphological and behavioral changes in later life.
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Affiliation(s)
- Thomas Roskoden
- Institut of Anatomy, Otto-von-Guericke-University, Leipziger Street 44, D-39120 Magdeburg, Germany.
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27
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Bilbo SD, Levkoff LH, Mahoney JH, Watkins LR, Rudy JW, Maier SF. Neonatal infection induces memory impairments following an immune challenge in adulthood. Behav Neurosci 2005; 119:293-301. [PMID: 15727533 DOI: 10.1037/0735-7044.119.1.293] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Exposure to infectious agents during early postnatal life often alters glucocorticoid responses to stress and immune outcomes in adulthood. The authors examined whether neonatal infection results in memory impairments in adult animals. Rats infected with Escherichia coli (E. coli) as neonates displayed impaired memory for a recently explored context in adulthood. This impairment, however, was only observed in rats that received a peripheral immune challenge (lipopolysaccharide; LPS) immediately following context exposure. Adult rats treated neonatally with E. coli also had decreased hippocampal astrocytes compared with phosphate-buffered saline-treated rats, but displayed increased astrocyte reactivity in the hippocampus and decreased brain interleukin-1beta following lipopolysaccharide. Infection during development appears to alter glia within the hippocampus, which may contribute to altered cytokine responses and memory impairment.
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Affiliation(s)
- Staci D Bilbo
- Department of Psychology, University of Colorado, Boulder, CO 80309-0345, USA.
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28
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Luo T, Wagner E, Crandall JE, Dräger UC. A retinoic-acid critical period in the early postnatal mouse brain. Biol Psychiatry 2004; 56:971-80. [PMID: 15601608 DOI: 10.1016/j.biopsych.2004.09.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Revised: 07/26/2004] [Accepted: 09/26/2004] [Indexed: 11/17/2022]
Abstract
BACKGROUND A normal supply of vitamin A, which regulates gene expression through its active form retinoic acid, is required by many organs; both excess and deficiency can be teratogenic. Very little is known about the role of retinoic acid in maturation of the mammalian forebrain. METHODS As retinoic acid cannot be visualized directly, we mapped its actions in the forebrain with indirect morphologic methods and by applying retinoic acid overdoses to early postnatal mice. RESULTS During this time, the morphologic indicators of retinoic acid actions are localized mainly in the limbic system and they undergo rapid changes. Retinoic acid overdoses can cause lasting behavioral abnormalities that point to disrupted limbic functions. In the anterior cingulate cortex, inhibitory interneurons are affected, and in the hippocampus, primarily the dentate gyrus is abnormal. CONCLUSIONS Retinoic acid is involved in functional maturation of limbic regions of the forebrain with a critical stage early postnatally in mice, when their brains are particularly vulnerable to vitamin A perturbations. This developmental time in mice compares with the second trimester of gestation in humans, a stage when in genetically predisposed individuals the corresponding brain regions are known to pass through a period of increased susceptibility to environmental disturbances.
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Affiliation(s)
- Tuanlian Luo
- E. Kennedy Shriver Center at the University of Massachusetts Medical School, Waltham, MA 02452, USA
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29
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Mousavi K, Parry DJ, Jasmin BJ. BDNF rescues myosin heavy chain IIB muscle fibers after neonatal nerve injury. Am J Physiol Cell Physiol 2004; 287:C22-9. [PMID: 14973145 DOI: 10.1152/ajpcell.00583.2003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neonatal sciatic nerve injury is known to result in an extensive loss of lumbar motor neurons as well as the disappearance of their respective muscle fibers in the hindlimb musculature. The loss of motor neurons and muscle fibers can be prevented by immediate administration of target-derived neurotrophic factors to the site of injury. In the present study, we investigated the role of ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) in the survival and maturation of a subset of motor neurons innervating the extensor digitorum longus (EDL) and tibialis anterior (TA) muscles. We have shown that combined administration of CNTF and BDNF prevented the loss of motor units after neonatal nerve injury and contributed to the maintenance of muscle mass. Importantly, this combined neurotrophin regimen also prevented the disappearance of muscle fibers that express myosin heavy chain IIB (MyHC IIB) in both EDL and TA muscles 3 mo after neonatal sciatic nerve crush. In parallel studies, we observed a higher level of BDNF in EDL muscle during the critical period of development when motor neurons are highly susceptible to target removal. Given our previous findings that combined administration of CNTF with neurotrophin-3 (NT-3) or neurotrophin-4/5 (NT-4/5) did not result in the rescue of MyHC IIB fibers in EDL, the present results show the importance of muscle-derived BDNF in the survival and maturation of a subpopulation of motor neurons and of MyHC IIB muscle fibers during neonatal development of the neuromuscular system.
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Affiliation(s)
- Kambiz Mousavi
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
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