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Shimotsuma T, Tomotaki S, Akita M, Araki R, Tomotaki H, Iwanaga K, Kobayashi A, Saitoh A, Fushimi Y, Takita J, Kawai M. Severe Bronchopulmonary Dysplasia Adversely Affects Brain Growth in Preterm Infants. Neonatology 2024:1-9. [PMID: 38648742 DOI: 10.1159/000538527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/19/2024] [Indexed: 04/25/2024]
Abstract
INTRODUCTION Bronchopulmonary dysplasia (BPD) is associated with neurodevelopmental outcomes of preterm infants, but its effect on brain growth in preterm infants after the neonatal period is unknown. This study aimed to evaluate the effect of severe BPD on brain growth of preterm infants from term to 18 months of corrected age (CA). METHODS Sixty-three preterm infants (42 with severe BPD and 21 without severe BPD) who underwent magnetic resonance imaging at term equivalent age (TEA) and 18 months of CA were studied by using the Infant Brain Extraction and Analysis Toolbox (iBEAT). We measured segmented brain volumes and compared brain volume and brain growth velocity between the severe BPD group and the non-severe BPD group. RESULTS There was no significant difference in brain volumes at TEA between the groups. However, the brain volumes of the total brain and cerebral white matter in the severe BPD group were significantly smaller than those in the non-severe BPD group at 18 months of CA. The brain growth velocities from TEA to 18 months of CA in the total brain, cerebral cortex, and cerebral white matter in the severe BPD group were lower than those in the non-severe BPD group. CONCLUSION Brain growth in preterm infants with severe BPD from TEA age to 18 months of CA is less than that in preterm infants without severe BPD.
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Affiliation(s)
- Taiki Shimotsuma
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Department of Pediatrics, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Seiichi Tomotaki
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mitsuyo Akita
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Ryosuke Araki
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroko Tomotaki
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kougoro Iwanaga
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akira Kobayashi
- Department of Pediatrics, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Akihiko Saitoh
- Department of Pediatrics, Graduate School of Medicine and Dental Sciences, Niigata University, Niigata, Japan
| | - Yasutaka Fushimi
- Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Junko Takita
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masahiko Kawai
- Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Kohe SE, Gowing EK, Seo S, Oorschot DE. A Novel Rat Model of ADHD-like Hyperactivity/Impulsivity after Delayed Reward Has Selective Loss of Dopaminergic Neurons in the Right Ventral Tegmental Area. Int J Mol Sci 2023; 24:11252. [PMID: 37511013 PMCID: PMC10379272 DOI: 10.3390/ijms241411252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/01/2023] [Accepted: 07/04/2023] [Indexed: 07/30/2023] Open
Abstract
In attention deficit hyperactivity disorder (ADHD), hyperactivity and impulsivity occur in response to delayed reward. Herein we report a novel animal model in which male Sprague-Dawley rats exposed to repeated hypoxic brain injury during the equivalent of extreme prematurity were ADHD-like hyperactive/impulsive in response to delayed reward and attentive at 3 months of age. Thus, a unique animal model of one of the presentations/subtypes of ADHD was discovered. An additional finding is that the repeated hypoxia rats were not hyperactive in the widely used open field test, which is not ADHD specific. Hence, it is recommended that ADHD-like hyperactivity and ADHD-like impulsivity, specifically in response to delayed reward, be a primary component in the design of future experiments that characterize potential animal models of ADHD, replacing open field testing of hyperactivity. Unknown is whether death and/or activity of midbrain dopaminergic neurons contributed to the ADHD-like hyperactivity/impulsivity detected after delayed reward. Hence, we stereologically measured the absolute number of dopaminergic neurons in four midbrain subregions and the average somal/nuclear volume of those neurons. Repeated hypoxia rats had a significant specific loss of dopaminergic neurons in the right ventral tegmental area (VTA) at 2 weeks of age and 18 months of age, providing new evidence of a site of pathology. No dopaminergic neuronal loss occurred in three other midbrain regions. Fewer VTA dopaminergic neurons correlated with increased ADHD-like hyperactivity and impulsivity. Novel early intervention therapies to rescue VTA dopaminergic neurons and potentially prevent ADHD-like hyperactivity/impulsivity can now be investigated.
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Affiliation(s)
- Sarah E Kohe
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
| | - Emma K Gowing
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
| | - Steve Seo
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
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Leroux S, Rodriguez-Duboc A, Arabo A, Basille-Dugay M, Vaudry D, Burel D. Intermittent hypoxia in a mouse model of apnea of prematurity leads to a retardation of cerebellar development and long-term functional deficits. Cell Biosci 2022; 12:148. [PMID: 36068642 PMCID: PMC9450451 DOI: 10.1186/s13578-022-00869-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/02/2022] [Indexed: 11/30/2022] Open
Abstract
Background Apnea of prematurity (AOP) is caused by respiratory control immaturity and affects nearly 50% of premature newborns. This pathology induces perinatal intermittent hypoxia (IH), which leads to neurodevelopmental disorders. The impact on the brain has been well investigated. However, despite its functional importance and immaturity at birth, the involvement of the cerebellum remains poorly understood. Therefore, this study aims to identify the effects of IH on cerebellar development using a mouse model of AOP consisting of repeated 2-min cycles of hypoxia and reoxygenation over 6 h and for 10 days starting on postnatal day 2 (P2). Results At P12, IH-mice cerebella present higher oxidative stress associated with delayed maturation of the cerebellar cortex and decreased dendritic arborization of Purkinje cells. Moreover, mice present with growth retardation and motor disorders. In response to hypoxia, the developing cerebellum triggers compensatory mechanisms resulting in the unaltered organization of the cortical layers from P21 onwards. Nevertheless, some abnormalities remain in adult Purkinje cells, such as the dendritic densification, the increase in afferent innervation, and axon hypomyelination. Moreover, this compensation seems insufficient to allow locomotor recovery because adult mice still show motor impairment and significant disorders in spatial learning. Conclusions All these findings indicate that the cerebellum is a target of intermittent hypoxia through alterations of developmental mechanisms leading to long-term functional deficits. Thus, the cerebellum could contribute, like others brain structures, to explaining the pathophysiology of AOP. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00869-5.
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Characterization of a mGluR5 Knockout Rat Model with Hallmarks of Fragile X Syndrome. Life (Basel) 2022; 12:life12091308. [PMID: 36143345 PMCID: PMC9504063 DOI: 10.3390/life12091308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022] Open
Abstract
The number of reported cases of neurodevelopmental disorders has increased significantly in the last few decades, but the etiology of these diseases remains poorly understood. There is evidence of a fundamental link between genetic abnormalities and symptoms of autism spectrum disorders (ASDs), and the most common monogenetic inheritable form of ASDs is Fragile X Syndrome (FXS). Previous studies indicate that FXS is linked to glutamate signaling regulation by the G-protein-coupled metabotropic glutamate receptor 5 (mGluR5), which has been shown to have a regulatory role in neuroinflammation. We characterized the effect of knocking out mGluR5 in an organism known to have complex cognitive functions—the rat. The heterozygous phenotype is the most clinically relevant; therefore, we performed analysis in heterozygous pups. We showed developmental abnormalities in heterozygous mGluR5 knockout rats, as well as a significant increase in chemokine (C-X-C motif) ligand 1 (CXCL) expression, a hallmark indicator of early onset inflammation. We quantified an increase in microglial density in the knockout pups and quantified morphological phenotypes representative of greater reactivity in the male vs. female and postnatal day 28 heterozygous pups compared to postnatal day 14 heterozygous pups. In response to injury, reactive microglia release matrix metalloproteases, contribute to extracellular matrix (ECM) breakdown, and are responsible for eradicating cellular and molecular debris. In our study, the changes in microglial density and reactivity correlated with abnormalities in the mRNA expression levels of ECM proteins and with the density of perineuronal nets. We saw atypical neuropsychiatric behavior in open field and elevated plus tests in heterozygous pups compared to wild-type litter and age-matched controls. These results demonstrate the pathological potential of the mGluR5 knockout in rats and further support the presence of neuroinflammatory roots in ASDs.
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Pharmacodynamic Effects of Standard versus High Caffeine Doses in the Developing Brain of Neonatal Rats Exposed to Intermittent Hypoxia. Int J Mol Sci 2021; 22:ijms22073473. [PMID: 33801707 PMCID: PMC8037517 DOI: 10.3390/ijms22073473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/11/2021] [Accepted: 03/23/2021] [Indexed: 02/06/2023] Open
Abstract
(1) Background: Caffeine citrate, at standard doses, is effective for reducing the incidence of apnea of prematurity (AOP) and may confer neuroprotection and decrease neonatal morbidities in extremely low gestational age neonates (ELGANs) requiring oxygen therapy. We tested the hypothesis that high-dose caffeine (HiC) has no adverse effects on the neonatal brain. (2) Methods: Newborn rat pups were randomized to room air (RA), hyperoxia (Hx) or neonatal intermittent hypoxia (IH), from birth (P0) to P14 during which they received intraperitoneal injections of LoC (20 mg/kg on P0; 5 mg/kg/day on P1-P14), HiC (80 mg/kg; 20 mg/kg), or equivalent volume saline. Blood gases, histopathology, myelin and neuronal integrity, and adenosine receptor reactivity were assessed. (3) Results: Caffeine treatment in Hx influenced blood gases more than treatment in neonatal IH. Exposure to neonatal IH resulted in hemorrhage and higher brain width, particularly in layer 2 of the cerebral cortex. Both caffeine doses increased brain width in RA, but layer 2 was increased only with HiC. HiC decreased oxidative stress more effectively than LoC, and both doses reduced apoptosis biomarkers. In RA, both caffeine doses improved myelination, but the effect was abolished in Hx and neonatal IH. Similarly, both doses inhibited adenosine 1A receptor in all oxygen environments, but adenosine 2A receptor was inhibited only in RA and Hx. (4) Conclusions: Caffeine, even at high doses, when administered in normoxia, can confer neuroprotection, evidenced by reductions in oxidative stress, hypermyelination, and increased Golgi bodies. However, varying oxygen environments, such as Hx or neonatal IH, may alter and modify pharmacodynamic actions of caffeine and may even override the benefits caffeine.
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Somkuwar SS, Villalpando EG, Quach LW, Head BP, McKenna BS, Scadeng M, Mandyam CD. Abstinence from ethanol dependence produces concomitant cortical gray matter abnormalities, microstructural deficits and cognitive dysfunction. Eur Neuropsychopharmacol 2021; 42:22-34. [PMID: 33279357 PMCID: PMC7797163 DOI: 10.1016/j.euroneuro.2020.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/12/2020] [Accepted: 11/07/2020] [Indexed: 12/20/2022]
Abstract
Previous studies demonstrate that ethanol dependence induced by repeating cycles of chronic intermittent ethanol vapor exposure (CIE) followed by protracted abstinence (CIE-PA) produces significant alterations in oligodendrogenesis in the rodent medial prefrontal cortex (mPFC). Specifically, CIE-PA produced an unprecedented increase in premyelinating oligodendroglial progenitor cells and myelin, which have been associated with persistent elevated drinking behaviors during abstinence. The current study used neuroimaging and electron microscopy to evaluate the integrity of enhanced myelin and microstructural deficits underlying enhanced myelination in the mPFC in male rats experiencing forced abstinence for 1 day (D), 7D, 21D and 42D following seven weeks of CIE. In vivo diffusion tensor imaging (DTI) detected altered microstructural integrity in the mPFC and corpus callosum (CC). Altered integrity was characterized as reduced fractional anisotropy (FA) in the CC, and enhanced mean diffusivity (MD) in the mPFC in 7D abstinent rats. Increased MD occurred concomitantly with increases in myelin associated proteins, flayed myelin and enhanced mitochondrial stress in the mPFC in 7D abstinent rats, suggesting that the increases in myelination during abstinence was aberrant. Evaluation of cognitive performance via Pavlovian conditioning in 7D abstinent rats revealed reduced retrieval and recall of fear memories dependent on the mPFC. These findings indicate that forced abstinence from moderate to severe alcohol use disorder produces gray matter damage via myelin dysfunction in the mPFC and that these microstructural changes were associated with deficits in PFC dependent behaviors.
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Affiliation(s)
| | | | - Leon W Quach
- VA San Diego Healthcare System, San Diego, CA 92161, USA
| | - Brian P Head
- VA San Diego Healthcare System, San Diego, CA 92161, USA; Departments of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
| | - Benjamin S McKenna
- Departments of Psychiatry, University of California San Diego, San Diego, CA 92161, USA
| | - Miriam Scadeng
- Departments of Radiology, University of California San Diego, San Diego, CA 92161, USA
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA 92161, USA; Departments of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA.
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Niatsetskaya Z, Sosunov S, Stepanova A, Goldman J, Galkin A, Neginskaya M, Pavlov E, Ten V. Cyclophilin D-dependent oligodendrocyte mitochondrial ion leak contributes to neonatal white matter injury. J Clin Invest 2020; 130:5536-5550. [PMID: 32925170 PMCID: PMC7524474 DOI: 10.1172/jci133082] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
Postnatal failure of oligodendrocyte maturation has been proposed as a cellular mechanism of diffuse white matter injury (WMI) in premature infants. However, the molecular mechanisms for oligodendrocyte maturational failure remain unclear. In neonatal mice and cultured differentiating oligodendrocytes, sublethal intermittent hypoxic (IH) stress activated cyclophilin D-dependent mitochondrial proton leak and uncoupled mitochondrial respiration, leading to transient bioenergetic stress. This was associated with development of diffuse WMI: poor oligodendrocyte maturation, diffuse axonal hypomyelination, and permanent sensorimotor deficit. In normoxic mice and oligodendrocytes, exposure to a mitochondrial uncoupler recapitulated the phenotype of WMI, supporting the detrimental role of mitochondrial uncoupling in the pathogenesis of WMI. Compared with WT mice, cyclophilin D-knockout littermates did not develop bioenergetic stress in response to IH challenge and fully preserved oligodendrocyte maturation, axonal myelination, and neurofunction. Our study identified the cyclophilin D-dependent mitochondrial proton leak and uncoupling as a potentially novel subcellular mechanism for the maturational failure of oligodendrocytes and offers a potential therapeutic target for prevention of diffuse WMI in premature infants experiencing chronic IH stress.
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Affiliation(s)
| | | | | | - James Goldman
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | | | - Maria Neginskaya
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, USA
| | - Evgeny Pavlov
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, USA
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Aghoghovwia BE, Goddard L, Oorschot DE. Long-Term Fine Motor Capability on the Staircase Test Correlates with the Absolute Number, but Not the Density, of DARPP-Positive Neurons in the Caudate-Putamen. Anat Rec (Hoboken) 2019; 302:2040-2048. [PMID: 31177619 DOI: 10.1002/ar.24196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 12/03/2018] [Accepted: 01/07/2019] [Indexed: 11/08/2022]
Abstract
Measurement of long-term functional and anatomical outcomes in the same animal is considered a powerful strategy for correlating structure with function. In a neonatal animal model of hypoxic-ischemic brain injury that is relevant to cerebral palsy, long-term functional deficits on the staircase test and long-term anatomical deficits in the absolute number of medium-spiny projection neurons in the caudate-putamen were reported in different animals due to logistical constraints. Here, we investigated if these functional and anatomical measures were correlated when measured in the same animals. The medium-spiny projection neurons were investigated because (1) they comprise the vast majority (>97%) of all neurons in the caudate-putamen and (2) motor deficits observed during staircase testing are likely to involve these striatal medium-spiny projection neurons through their connections. We found that long-term skilled forepaw capability on the staircase test was correlated with the absolute number of DARPP-32-positive medium-spiny projection neurons in the caudate-putamen. Specifically, deficits in skilled forepaw ability for the number of sugar pellets eaten and retrieved, and for the maximum staircase level reached, were significantly correlated with a lower absolute neuronal number. We also found that skilled forepaw ability on the staircase test was not correlated with the neuronal density (i.e., number per unit volume) of DARPP-32-positive medium-spiny projection neurons. Since neuronal density is an indirect measure of neuronal survival that is used in the literature, and absolute neuronal number is a direct measure, the results also highlight the scientific value of measuring absolute neuronal number. Anat Rec, 302:2040-2048, 2019. © 2019 American Association for Anatomy.
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Affiliation(s)
- Benjamin E Aghoghovwia
- Department of Anatomy, School of Biomedical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Liping Goddard
- Department of Anatomy, School of Biomedical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, School of Biomedical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
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Goussakov I, Synowiec S, Yarnykh V, Drobyshevsky A. Immediate and delayed decrease of long term potentiation and memory deficits after neonatal intermittent hypoxia. Int J Dev Neurosci 2019; 74:27-37. [PMID: 30858028 PMCID: PMC6461389 DOI: 10.1016/j.ijdevneu.2019.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/07/2019] [Accepted: 03/07/2019] [Indexed: 11/25/2022] Open
Abstract
Apnea of prematurity is a common clinical condition that occurs in premature infants and results in intermittent hypoxia (IH) to brain and other organs. While short episodes of apnea are considered of no clinical significance, prolonged apnea with bradycardia and large oxygen desaturation is associated with adverse neurological and cognitive outcome. The mechanisms of cognitive deficits in IH are poorly understood. We hypothesized that brief but multiple episodes of severe oxygen desaturation accompanied by bradycardia may affect early and late synaptic plasticity and produce long-term cognitive deficits. C57BL/6 mouse pups were exposed to IH paradigm consisting of alternating cycles of 5% oxygen for 2.5 min and room air for 5-10 min, 2 h a day from P3 to P7. Long term potentiation (LTP) of synaptic strength in response to high frequency stimulation in hippocampal slices were examined 3 days and 6 weeks after IH. LTP was decreased in IH group relative to controls at both time points. That decrease was associated with deficits in spatial memory on Morris water maze and context fear conditioning test. Hypomyelination was observed in multiple gray and white matter areas on in vivo MRI using micromolecule proton fraction and ex vivo diffusion tensor imaging. No difference in caspase labeling was found between control and IH groups. We conclude that early changes in synaptic plasticity occurring during severe episodes of neonatal IH and persisting to adulthood may represent functional and structural substrate for long term cognitive deficits.
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Affiliation(s)
- Ivan Goussakov
- Department of Pediatrics, NorthShore University HealthSystem Research Institute, 2650 Ridge Ave 60201, Evanston, IL, USA
| | - Sylvia Synowiec
- Department of Pediatrics, NorthShore University HealthSystem Research Institute, 2650 Ridge Ave 60201, Evanston, IL, USA
| | - Vasily Yarnykh
- Department of Radiology, University of Washington, 850 Republican St., Room 255 Seattle, WA, USA
| | - Alexander Drobyshevsky
- Department of Pediatrics, NorthShore University HealthSystem Research Institute, 2650 Ridge Ave 60201, Evanston, IL, USA.
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Miguel PM, Deniz BF, Deckmann I, Confortim HD, Diaz R, Laureano DP, Silveira PP, Pereira LO. Prefrontal cortex dysfunction in hypoxic-ischaemic encephalopathy contributes to executive function impairments in rats: Potential contribution for attention-deficit/hyperactivity disorder. World J Biol Psychiatry 2018; 19:547-560. [PMID: 28105895 DOI: 10.1080/15622975.2016.1273551] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES The attention-deficit/hyperactivity disorder (ADHD) compromises the quality of life of individuals including adaptation to the social environment. ADHD aetiology includes perinatal conditions such as hypoxic-ischaemic events; preclinical studies have demonstrated attentional deficits and impulsive-hyperactive outcomes after neonatal hypoxic and/or ischaemic intervention, but data are missing to understand this relationship. Thus, the aim of this study was to evaluate executive function (EF) and impulsivity, and tissue integrity and dopaminergic function in the prefrontal cortex (PFC) of rats submitted to hypoxia-ischaemia (HI). METHODS At postnatal day (PND) 7, male Wistar rats were divided into control (n = 10) and HI groups (n = 11) and the HI procedure was conducted. At PND60, the animals were tested in the attentional set-shifting (ASS) task to EF and in the tolerance to delay of reward for assessment of impulsivity. After, morphological analysis and the dopaminergic system were evaluated in the PFC. RESULTS Animals subjected to HI had impairments in EF evidenced by a behavioural inflexibility that was correlated to PFC atrophy. Moreover, HI animals presented reduced D2 receptors in the ipsilateral side of ischaemia in the PFC. CONCLUSIONS Animals submitted to HI presented impaired EF associated with tissue atrophy and dopaminergic disturbance in the PFC.
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Affiliation(s)
- Patrícia Maidana Miguel
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Bruna Ferrary Deniz
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Iohanna Deckmann
- b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Heloísa Deola Confortim
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Ramiro Diaz
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Daniela Pereira Laureano
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
| | - Patrícia Pelufo Silveira
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,c Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,d Ludmer Centre for Neuroinformatics and Mental Health , Douglas Mental Health University Institute, McGill University , Montreal , QC , Canada
| | - Lenir Orlandi Pereira
- a Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS) , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil.,b Departamento de Ciências Morfológicas, ICBS , Universidade Federal do Rio Grande do Sul , Porto Alegre , RS , Brazil
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Arancibia-Cárcamo IL, Ford MC, Cossell L, Ishida K, Tohyama K, Attwell D. Node of Ranvier length as a potential regulator of myelinated axon conduction speed. eLife 2017; 6. [PMID: 28130923 PMCID: PMC5313058 DOI: 10.7554/elife.23329] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/24/2017] [Indexed: 12/30/2022] Open
Abstract
Myelination speeds conduction of the nerve impulse, enhancing cognitive power. Changes of white matter structure contribute to learning, and are often assumed to reflect an altered number of myelin wraps. We now show that, in rat optic nerve and cerebral cortical axons, the node of Ranvier length varies over a 4.4-fold and 8.7-fold range respectively and that variation of the node length is much less along axons than between axons. Modelling predicts that these node length differences will alter conduction speed by ~20%, similar to the changes produced by altering the number of myelin wraps or the internode length. For a given change of conduction speed, the membrane area change needed at the node is >270-fold less than that needed in the myelin sheath. Thus, axon-specific adjustment of node of Ranvier length is potentially an energy-efficient and rapid mechanism for tuning the arrival time of information in the CNS. DOI:http://dx.doi.org/10.7554/eLife.23329.001 Information is transmitted around the nervous system as electrical signals passing along nerve cells. A fatty substance called myelin, which is wrapped around the nerve cells, increases the speed with which the signals travel along the nerve cells. This allows us to think and move faster than we would otherwise be able to do. The electrical signals start at small “nodes” between areas of myelin wrapping. Originally it was thought that we learn things mainly as a result of changes in the strength of connections between nerve cells, but recently it has been proposed that changes in myelin wrapping could also contribute to learning. Arancibia-Cárcamo, Ford, Cossell et al. investigated how much node structure varies in rat nerve cells, and whether differences in the length of nodes can fine-tune the activity of the nervous system. The experiments show that rat nerve cells do indeed have nodes with a range of different lengths. Calculations show that this could result in electrical signals moving at different speeds through different nerve cells. These findings raise the possibility that nerve cells actively alter the length of their nodes in order to alter their signal speed. The next step is to try to show experimentally that this happens during learning in animals. DOI:http://dx.doi.org/10.7554/eLife.23329.002
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Affiliation(s)
- I Lorena Arancibia-Cárcamo
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Marc C Ford
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Lee Cossell
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Kinji Ishida
- The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Morioka, Japan
| | - Koujiro Tohyama
- The Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University, Morioka, Japan.,Department of Physiology, School of Dentistry, Iwate Medical University, Morioka, Japan
| | - David Attwell
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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12
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Steullet P, Cabungcal JH, Monin A, Dwir D, O'Donnell P, Cuenod M, Do KQ. Redox dysregulation, neuroinflammation, and NMDA receptor hypofunction: A "central hub" in schizophrenia pathophysiology? Schizophr Res 2016; 176:41-51. [PMID: 25000913 PMCID: PMC4282982 DOI: 10.1016/j.schres.2014.06.021] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 06/06/2014] [Accepted: 06/08/2014] [Indexed: 12/18/2022]
Abstract
Accumulating evidence points to altered GABAergic parvalbumin-expressing interneurons and impaired myelin/axonal integrity in schizophrenia. Both findings could be due to abnormal neurodevelopmental trajectories, affecting local neuronal networks and long-range synchrony and leading to cognitive deficits. In this review, we present data from animal models demonstrating that redox dysregulation, neuroinflammation and/or NMDAR hypofunction (as observed in patients) impairs the normal development of both parvalbumin interneurons and oligodendrocytes. These observations suggest that a dysregulation of the redox, neuroimmune, and glutamatergic systems due to genetic and early-life environmental risk factors could contribute to the anomalies of parvalbumin interneurons and white matter in schizophrenia, ultimately impacting cognition, social competence, and affective behavior via abnormal function of micro- and macrocircuits. Moreover, we propose that the redox, neuroimmune, and glutamatergic systems form a "central hub" where an imbalance within any of these "hub" systems leads to similar anomalies of parvalbumin interneurons and oligodendrocytes due to the tight and reciprocal interactions that exist among these systems. A combination of vulnerabilities for a dysregulation within more than one of these systems may be particularly deleterious. For these reasons, molecules, such as N-acetylcysteine, that possess antioxidant and anti-inflammatory properties and can also regulate glutamatergic transmission are promising tools for prevention in ultra-high risk patients or for early intervention therapy during the first stages of the disease.
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Affiliation(s)
- P Steullet
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - J H Cabungcal
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - A Monin
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - D Dwir
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - P O'Donnell
- Neuroscience Research Unit, Pfizer, Inc., 700 Main Street, Cambridge, MA 02139, USA
| | - M Cuenod
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland
| | - K Q Do
- Center for Psychiatric Neuroscience, Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Site de Cery, 1008 Prilly-Lausanne, Switzerland.
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13
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Aghoghovwia BE, Oorschot DE. Absolute number of parvicellular and magnocellular neurons in the red nucleus of the rat midbrain: a stereological study. J Anat 2016; 229:406-15. [PMID: 27257130 DOI: 10.1111/joa.12495] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2016] [Indexed: 12/22/2022] Open
Abstract
The absolute number of parvicellular and magnocellular neurons in the red nucleus was estimated using design-based stereological counting methods and systematic random sampling techniques. Six young adult male rats, and a complete set of serial 40-μm glycolmethacrylate sections for each rat, were used to quantify neuronal numbers. After a random start, a systematic subset (i.e. every third) of the serial sections was used to estimate the total volume of the red nucleus using Cavalieri's method. The same set of sampled sections was used to estimate the number of neurons in a known subvolume (i.e. the numerical density Nv ) by the optical disector method. Multiplication of the total volume by Nv yielded the absolute number of neurons. It was found that the right red nucleus consisted, on average, of 8400 parvicellular neurons (with a coefficient of variation of 0.16) and 7000 magnocellular neurons (0.12). These total neuronal numbers provide important data for the transfer of information through these nuclei and for species comparisons.
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Affiliation(s)
- Benjamin E Aghoghovwia
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
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14
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Ayers-Ringler JR, Jia YF, Qiu YY, Choi DS. Role of astrocytic glutamate transporter in alcohol use disorder. World J Psychiatry 2016; 6:31-42. [PMID: 27014596 PMCID: PMC4804266 DOI: 10.5498/wjp.v6.i1.31] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/18/2015] [Accepted: 01/11/2016] [Indexed: 02/05/2023] Open
Abstract
Alcohol use disorder (AUD) is one of the most widespread neuropsychiatric conditions, having a significant health and socioeconomic impact. According to the 2014 World Health Organization global status report on alcohol and health, the harmful use of alcohol is responsible for 5.9% of all deaths worldwide. Additionally, 5.1% of the global burden of disease and injury is ascribed to alcohol (measured in disability adjusted life years, or disability adjusted life years). Although the neurobiological basis of AUD is highly complex, the corticostriatal circuit contributes significantly to the development of addictive behaviors. In-depth investigation into the changes of the neurotransmitters in this circuit, dopamine, gamma-aminobutyricacid, and glutamate, and their corresponding neuronal receptors in AUD and other addictions enable us to understand the molecular basis of AUD. However, these discoveries have also revealed a dearth of knowledge regarding contributions from non-neuronal sources. Astrocytes, though intimately involved in synaptic function, had until recently been noticeably overlooked in their potential role in AUD. One major function of the astrocyte is protecting neurons from excitotoxicity by removing glutamate from the synapse via excitatory amino acid transporter type 2. The importance of this key transporter in addiction, as well as ethanol withdrawal, has recently become evident, though its regulation is still under investigation. Historically, pharmacotherapy for AUD has been focused on altering the activity of neuronal glutamate receptors. However, recent clinical evidence has supported the animal-based findings, showing that regulating glutamate homeostasis contributes to successful management of recovery from AUD.
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15
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Sizemore RJ, Zhang R, Lin N, Goddard L, Wastney T, Parr-Brownlie LC, Reynolds JNJ, Oorschot DE. Marked differences in the number and type of synapses innervating the somata and primary dendrites of midbrain dopaminergic neurons, striatal cholinergic interneurons, and striatal spiny projection neurons in the rat. J Comp Neurol 2015; 524:1062-80. [PMID: 26355230 DOI: 10.1002/cne.23891] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 08/17/2015] [Accepted: 09/02/2015] [Indexed: 12/24/2022]
Abstract
Elucidating the link between cellular activity and goal-directed behavior requires a fuller understanding of the mechanisms underlying burst firing in midbrain dopaminergic neurons and those that suppress activity during aversive or non-rewarding events. We have characterized the afferent synaptic connections onto these neurons in the rat substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA), and compared these findings with cholinergic interneurons and spiny projection neurons in the striatum. We found that the average absolute number of synapses was three to three and one-half times greater onto the somata of dorsal striatal spiny projection neurons than onto the somata of dopaminergic neurons in the SNpc or dorsal striatal cholinergic interneurons. A similar comparison between populations of dopamine neurons revealed a two times greater number of somatic synapses on VTA dopaminergic neurons than SNpc dopaminergic neurons. The percentage of symmetrical, presumably inhibitory, synaptic inputs on somata was significantly higher on spiny projection neurons and cholinergic interneurons compared with SNpc dopaminergic neurons. Synaptic data on the primary dendrites yielded similar significant differences for the percentage of symmetrical synapses for VTA dopaminergic vs. striatal neurons. No differences in the absolute number or type of somatic synapses were evident for dopaminergic neurons in the SNpc of Wistar vs. Sprague-Dawley rat strains. These data from identified neurons are pivotal for interpreting their electrophysiological responses to afferent activity and for generating realistic computer models of neuronal networks of striatal and midbrain dopaminergic function.
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Affiliation(s)
- Rachel J Sizemore
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Rong Zhang
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Naili Lin
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Liping Goddard
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Timothy Wastney
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Louise C Parr-Brownlie
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - John N J Reynolds
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, 9054, New Zealand
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16
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d’Anglemont de Tassigny X, Sirerol-Piquer MS, Gómez-Pinedo U, Pardal R, Bonilla S, Capilla-Gonzalez V, López-López I, De la Torre-Laviana FJ, García-Verdugo JM, López-Barneo J. Resistance of subventricular neural stem cells to chronic hypoxemia despite structural disorganization of the germinal center and impairment of neuronal and oligodendrocyte survival. HYPOXIA (AUCKLAND, N.Z.) 2015; 3:15-33. [PMID: 27774479 PMCID: PMC5045070 DOI: 10.2147/hp.s78248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Chronic hypoxemia, as evidenced in de-acclimatized high-altitude residents or in patients with chronic obstructive respiratory disorders, is a common medical condition that can produce serious neurological alterations. However, the pathogenesis of this phenomenon is unknown. We have found that adult rodents exposed for several days/weeks to hypoxia, with an arterial oxygen tension similar to that of chronically hypoxemic patients, manifest a partially irreversible structural disarrangement of the subventricular neurogenic niche (subventricular zone) characterized by displacement of neurons and myelinated axons, flattening of the ependymal cell layer, and thinning of capillary walls. Despite these abnormalities, the number of neuronal and oligodendrocyte progenitors, neuroblasts, and neurosphere-forming cells as well as the proliferative activity in subventricular zone was unchanged. These results suggest that neural stem cells and their undifferentiated progeny are resistant to hypoxia. However, in vivo and in vitro experiments indicate that severe chronic hypoxia decreases the survival of newly generated neurons and oligodendrocytes, with damage of myelin sheaths. These findings help explain the effects of hypoxia on adult neurogenesis and provide new perspectives on brain responsiveness to persistent hypoxemia.
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Affiliation(s)
- Xavier d’Anglemont de Tassigny
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
| | - M Salomé Sirerol-Piquer
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
- Network Center of Biomedical Research on Neurodegenerative Diseases (CIBERNED), Spain
| | - Ulises Gómez-Pinedo
- Laboratory of Regenerative Medicine, San Carlos Institute of Health Investigation, Madrid, Spain
| | - Ricardo Pardal
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
| | - Sonia Bonilla
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
| | - Vivian Capilla-Gonzalez
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | - Ivette López-López
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
| | - Francisco Javier De la Torre-Laviana
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
| | - José Manuel García-Verdugo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
- Network Center of Biomedical Research on Neurodegenerative Diseases (CIBERNED), Spain
| | - José López-Barneo
- Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
- Network Center of Biomedical Research on Neurodegenerative Diseases (CIBERNED), Spain
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17
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Cameron SH, Alwakeel AJ, Goddard L, Hobbs CE, Gowing EK, Barnett ER, Kohe SE, Sizemore RJ, Oorschot DE. Delayed post-treatment with bone marrow-derived mesenchymal stem cells is neurorestorative of striatal medium-spiny projection neurons and improves motor function after neonatal rat hypoxia-ischemia. Mol Cell Neurosci 2015; 68:56-72. [PMID: 25828540 DOI: 10.1016/j.mcn.2015.03.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 03/19/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023] Open
Abstract
Perinatal hypoxia-ischemia is a major cause of striatal injury and may lead to cerebral palsy. This study investigated whether delayed administration of bone marrow-derived mesenchymal stem cells (MSCs), at one week after neonatal rat hypoxia-ischemia, was neurorestorative of striatal medium-spiny projection neurons and improved motor function. The effect of a subcutaneous injection of a high-dose, or a low-dose, of MSCs was investigated in stereological studies. Postnatal day (PN) 7 pups were subjected to hypoxia-ischemia. At PN14, pups received treatment with either MSCs or diluent. A subset of high-dose pups, and their diluent control pups, were also injected intraperitoneally with bromodeoxyuridine (BrdU), every 24h, on PN15, PN16 and PN17. This permitted tracking of the migration and survival of neuroblasts originating from the subventricular zone into the adjacent injured striatum. Pups were euthanized on PN21 and the absolute number of striatal medium-spiny projection neurons was measured after immunostaining for DARPP-32 (dopamine- and cAMP-regulated phosphoprotein-32), double immunostaining for BrdU and DARPP-32, and after cresyl violet staining alone. The absolute number of striatal immunostained calretinin interneurons was also measured. There was a statistically significant increase in the absolute number of DARPP-32-positive, BrdU/DARPP-32-positive, and cresyl violet-stained striatal medium-spiny projection neurons, and fewer striatal calretinin interneurons, in the high-dose mesenchymal stem cell (MSC) group compared to their diluent counterparts. A high-dose of MSCs restored the absolute number of these neurons to normal uninjured levels, when compared with previous stereological data on the absolute number of cresyl violet-stained striatal medium-spiny projection neurons in the normal uninjured brain. For the low-dose experiment, in which cresyl violet-stained striatal medium-spiny neurons alone were measured, there was a lower statistically significant increase in their absolute number in the MSC group compared to their diluent controls. Investigation of behavior in another cohort of animals showed that delayed administration of a high-dose of bone marrow-derived MSCs, at one week after neonatal rat hypoxia-ischemia, improved motor function on the cylinder test. Thus, delayed therapy with a high- or low-dose of adult MSCs, at one week after injury, is effective in restoring the loss of striatal medium-spiny projection neurons after neonatal rat hypoxia-ischemia and a high-dose of MSCs improved motor function.
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Affiliation(s)
- Stella H Cameron
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Amr J Alwakeel
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Liping Goddard
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Catherine E Hobbs
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Emma K Gowing
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Elizabeth R Barnett
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Sarah E Kohe
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Rachel J Sizemore
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, Otago School of Medical Sciences, and the Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
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18
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Juliano C, Sosunov S, Niatsetskaya Z, Isler JA, Utkina-Sosunova I, Jang I, Ratner V, Ten V. Mild intermittent hypoxemia in neonatal mice causes permanent neurofunctional deficit and white matter hypomyelination. Exp Neurol 2014; 264:33-42. [PMID: 25476492 DOI: 10.1016/j.expneurol.2014.11.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 11/13/2014] [Accepted: 11/20/2014] [Indexed: 10/24/2022]
Abstract
Very low birth weight (VLBW) premature infants experience numerous, often self-limited non-bradycardic episodes of intermittent hypoxemia (IH). We hypothesized that these episodes of IH affect postnatal white matter (WM) development causing hypomyelination and neurological handicap in the absence of cellular degeneration. Based on clinical data from ten VLBW neonates; a severity, daily duration and frequency of non-bradycardic IH episodes were reproduced in neonatal mice. Changes in heart rate and cerebral blood flow during IH were recorded. A short-term and long-term neurofunctional performance, cerebral content of myelin basic protein (MBP), 2'3' cyclic-nucleotide 3-phosphodiesterase (CNPase), electron microscopy of axonal myelination and the extent of cellular degeneration were examined. Neonatal mice exposed to IH exhibited no signs of cellular degeneration, yet demonstrated significantly poorer olfactory discrimination, wire holding, beam and bridge crossing, and walking-initiation tests performance compared to controls. In adulthood, IH-mice demonstrated no alteration in navigational memory. However, sensorimotor performance on rota-rod, wire-holding and beam tests was significantly worse compared to naive littermates. Both short- and long-term neurofunctional deficits were coupled with decreased MBP, CNPase content and poorer axonal myelination compared to controls. In neonatal mice mild, non-ischemic IH stress, mimicking that in VLBW preterm infants, replicates a key phenotype of non-cystic WM injury: permanent hypomyelination and sensorimotor deficits. Because this phenotype has developed in the absence of cellular degeneration, our data suggest that cellular mechanisms of WM injury induced by mild IH differ from that of cystic periventricular leukomalacia where the loss of myelin-producing cells and axons is the major mechanism of injury.
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Affiliation(s)
- Courtney Juliano
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Sergey Sosunov
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Zoya Niatsetskaya
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Joseph A Isler
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Irina Utkina-Sosunova
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Isaac Jang
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Veniamin Ratner
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA
| | - Vadim Ten
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, USA.
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19
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Wang J, Qiao J, Zhang Y, Wang H, Zhu S, Zhang H, Hartle K, Guo H, Guo W, He J, Kong J, Huang Q, Li XM. Desvenlafaxine prevents white matter injury and improves the decreased phosphorylation of the rate-limiting enzyme of cholesterol synthesis in a chronic mouse model of depression. J Neurochem 2014; 131:229-38. [PMID: 24934403 DOI: 10.1111/jnc.12792] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 01/07/2023]
Abstract
Serotonin/norepinephrine reuptake inhibitors antidepressants exert their effects by increasing serotonin and norepinephrine in the synaptic cleft. Studies show it takes 2-3 weeks for the mood-enhancing effects, which indicate other mechanisms may underlie their treatment effects. Here, we investigated the role of white matter in treatment and pathogenesis of depression using an unpredictable chronic mild stress (UCMS) mouse model. Desvenlafaxine (DVS) was orally administrated to UCMS mice at the dose of 10 mg/kg/day 1 week before they went through a 7-week stress procedure and lasted for over 8 weeks before the mice were killed. No significant changes were found for protein markers of neurons and astrocytes in UCMS mice. However, myelin and oligodendrocyte-related proteins were significantly reduced in UCMS mice. DVS prevented the stress-induced injury to white matter and the decrease of phosphorylated 5'-AMP-activated protein kinase and 3-hydroxy-3-methyl-glutaryl-CoA reductase protein expression. DVS increased open arm entries in an elevated plus-maze test, sucrose consumption in the sucrose preference test and decreased immobility in tail suspension and forced swimming tests. These findings suggest that stress induces depression-like behaviors and white matter deficits in UCMS mice. DVS may ameliorate the oligodendrocyte dysfunction by affecting cholesterol synthesis, alleviating the depression-like phenotypes in these mice. We examined the possible role of oligodendrocyte and myelin in the pathological changes of depression with an unpredictable chronic mild stress (UCMS) mouse model. Oligodendrocyte-related proteins in the mouse brain were specifically changed during the stress period. The depressive-like behaviors and oligodendrocyte deficits could be prevented by the administration of desvenlafaxine. Oligodendrocyte and myelin may be an essential target of desvenlafaxine for the treatment of depression.
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Affiliation(s)
- Junhui Wang
- Mental Health Center, Shantou University, Shantou, Guangdong, China.,Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jinping Qiao
- Mental Health Center, Shantou University, Shantou, Guangdong, China.,Clinical Laboratory, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yanbo Zhang
- Department of Psychiatry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Hongxing Wang
- Department of Clinical Psychiatry, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Shenghua Zhu
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Handi Zhang
- Mental Health Center, Shantou University, Shantou, Guangdong, China
| | - Kelly Hartle
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Huining Guo
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Wei Guo
- Department of Clinical Psychiatry, Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Jue He
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jiming Kong
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Qingjun Huang
- Mental Health Center, Shantou University, Shantou, Guangdong, China
| | - Xin-Min Li
- Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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