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Makowiecki K, Stevens N, Cullen CL, Zarghami A, Nguyen PT, Johnson L, Rodger J, Hinder MR, Barnett M, Young KM, Taylor BV. Safety of low-intensity repetitive transcranial magneTic brAin stimUlation foR people living with mUltiple Sclerosis (TAURUS): study protocol for a randomised controlled trial. Trials 2022; 23:626. [PMID: 35922816 PMCID: PMC9347125 DOI: 10.1186/s13063-022-06526-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 07/06/2022] [Indexed: 11/30/2022] Open
Abstract
Background Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease, characterised by oligodendrocyte death and demyelination. Oligodendrocyte progenitor cells can differentiate into new replacement oligodendrocytes; however, remyelination is insufficient to protect neurons from degeneration in people with MS. We previously reported that 4 weeks of daily low-intensity repetitive transcranial magnetic stimulation (rTMS) in an intermittent theta-burst stimulation (iTBS) pattern increased the number of new myelinating oligodendrocytes in healthy adult mice. This study translates this rTMS protocol and aims to determine its safety and tolerability for people living with MS. We will also perform magnetic resonance imaging (MRI) and symptom assessments as preliminary indicators of myelin addition following rTMS. Methods Participants (N = 30, aged 18–65 years) will have a diagnosis of relapsing-remitting or secondary progressive MS. ≤2 weeks before the intervention, eligible, consenting participants will complete a physical exam, baseline brain MRI scan and participant-reported MS symptom assessments [questionnaires: Fatigue Severity Scale, Quality of Life (AQoL-8D), Hospital Anxiety and Depression Scale; and smartphone-based measures of cognition (electronic symbol digit modalities test), manual dexterity (pinching test, draw a shape test) and gait (U-Turn test)]. Participants will be pseudo-randomly allocated to rTMS (n=20) or sham (placebo; n=10), stratified by sex. rTMS or sham will be delivered 5 days per week for 4 consecutive weeks (20 sessions, 6 min per day). rTMS will be applied using a 90-mm circular coil at low-intensity (25% maximum stimulator output) in an iTBS pattern. For sham, the coil will be oriented 90° to the scalp, preventing the magnetic field from stimulating the brain. Adverse events will be recorded daily. We will evaluate participant blinding after the first, 10th and final session. After the final session, participants will repeat symptom assessments and brain MRI, for comparison with baseline. Participant-reported assessments will be repeated at 4-month post-allocation follow-up. Discussion This study will determine whether this rTMS protocol is safe and tolerable for people with MS. MRI and participant-reported symptom assessments will serve as preliminary indications of rTMS efficacy for myelin addition to inform further studies. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12619001196134. Registered on 27 August 2019
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Affiliation(s)
- Kalina Makowiecki
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia.
| | - Natasha Stevens
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Amin Zarghami
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Phuong Tram Nguyen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Lewis Johnson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Jennifer Rodger
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Mark R Hinder
- Sensorimotor Neuroscience and Ageing Research Lab, School of Psychological Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Michael Barnett
- Sydney Neuroimaging Analysis Centre (SNAC), Sydney, NSW, Australia.,Brain & Mind Centre, University of Sydney, Sydney, NSW, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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Ferreira S, Pitman KA, Summers BS, Wang S, Young KM, Cullen CL. Oligodendrogenesis increases in hippocampal grey and white matter prior to locomotor or memory impairment in an adult mouse model of tauopathy. Eur J Neurosci 2021; 54:5762-5784. [PMID: 32181929 PMCID: PMC8451881 DOI: 10.1111/ejn.14726] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 12/12/2022]
Abstract
Myelin and axon losses are associated with cognitive decline in healthy ageing but are worse in people diagnosed with tauopathy. To determine whether tauopathy is also associated with enhanced myelin plasticity, we evaluated the behaviour of OPCs in mice that expressed a human pathological variant of microtubule-associated protein tau (MAPTP301S ). By 6 months of age (P180), MAPTP301S mice overexpressed hyperphosphorylated tau and had developed reactive gliosis in the hippocampus but had not developed overt locomotor or memory impairment. By performing cre-lox lineage tracing of adult OPCs, we determined that the number of newborn oligodendrocytes added to the hippocampus, entorhinal cortex and fimbria was equivalent in control and MAPTP301S mice prior to P150. However, between P150 and P180, significantly more new oligodendrocytes were added to these regions in the MAPTP301S mouse brain. This large increase in new oligodendrocyte number was not the result of increased OPC proliferation, nor did it alter oligodendrocyte density in the hippocampus, entorhinal cortex or fimbria, which was equivalent in P180 wild-type and MAPTP301S mice. Furthermore, the proportion of hippocampal and fimbria axons with myelin was unaffected by tauopathy. However, the proportion of myelinated axons that were ensheathed by immature myelin internodes was significantly increased in the hippocampus and fimbria of P180 MAPTP301S mice, when compared with their wild-type littermates. These data suggest that MAPTP301S transgenic mice experience significant oligodendrocyte turnover, with newborn oligodendrocytes compensating for myelin loss early in the development of tauopathy.
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Affiliation(s)
- Solène Ferreira
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Kimberley A. Pitman
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Benjamin S. Summers
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Shiwei Wang
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Kaylene M. Young
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
| | - Carlie L. Cullen
- Menzies Institute for Medical ResearchUniversity of TasmaniaHobartTasmaniaAustralia
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3
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Fletcher JL, Makowiecki K, Cullen CL, Young KM. Oligodendrogenesis and myelination regulate cortical development, plasticity and circuit function. Semin Cell Dev Biol 2021; 118:14-23. [PMID: 33863642 DOI: 10.1016/j.semcdb.2021.03.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 12/17/2022]
Abstract
During cortical development and throughout adulthood, oligodendrocytes add myelin internodes to glutamatergic projection neurons and GABAergic inhibitory neurons. In addition to directing node of Ranvier formation, to enable saltatory conduction and influence action potential transit time, oligodendrocytes support axon health by communicating with axons via the periaxonal space and providing metabolic support that is particularly critical for healthy ageing. In this review we outline the timing of oligodendrogenesis in the developing mouse and human cortex and describe the important role that oligodendrocytes play in sustaining and modulating neuronal function. We also provide insight into the known and speculative impact that myelination has on cortical axons and their associated circuits during the developmental critical periods and throughout life, particularly highlighting their life-long role in learning and remembering.
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Affiliation(s)
- Jessica L Fletcher
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kalina Makowiecki
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
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4
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Cullen CL, Pepper RE, Clutterbuck MT, Pitman KA, Oorschot V, Auderset L, Tang AD, Ramm G, Emery B, Rodger J, Jolivet RB, Young KM. Periaxonal and nodal plasticities modulate action potential conduction in the adult mouse brain. Cell Rep 2021; 34:108641. [PMID: 33472075 DOI: 10.1016/j.celrep.2020.108641] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 11/18/2020] [Accepted: 12/21/2020] [Indexed: 12/25/2022] Open
Abstract
Central nervous system myelination increases action potential conduction velocity. However, it is unclear how myelination is coordinated to ensure the temporally precise arrival of action potentials and facilitate information processing within cortical and associative circuits. Here, we show that myelin sheaths, supported by mature oligodendrocytes, remain plastic in the adult mouse brain and undergo subtle structural modifications to influence action potential conduction velocity. Repetitive transcranial magnetic stimulation and spatial learning, two stimuli that modify neuronal activity, alter the length of the nodes of Ranvier and the size of the periaxonal space within active brain regions. This change in the axon-glial configuration is independent of oligodendrogenesis and robustly alters action potential conduction velocity. Because aptitude in the spatial learning task was found to correlate with action potential conduction velocity in the fimbria-fornix pathway, modifying the axon-glial configuration may be a mechanism that facilitates learning in the adult mouse brain.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | | | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Viola Oorschot
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Alexander D Tang
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Georg Ramm
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Melbourne, VIC 3800, Australia
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health and Science University, Portland, OR 97239-3098, USA
| | - Jennifer Rodger
- Experimental and Regenerative Neuroscience, School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia; Perron Institute for Neurological and Translational Research, Perth, WA 6009, Australia
| | - Renaud B Jolivet
- Département de Physique Nucléaire et Corpusculaire, University of Geneva, 1211 Geneva 4, Switzerland
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia.
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5
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Cullen CL, O'Rourke M, Beasley SJ, Auderset L, Zhen Y, Pepper RE, Gasperini R, Young KM. Kif3a deletion prevents primary cilia assembly on oligodendrocyte progenitor cells, reduces oligodendrogenesis and impairs fine motor function. Glia 2020; 69:1184-1203. [PMID: 33368703 PMCID: PMC7986221 DOI: 10.1002/glia.23957] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/06/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022]
Abstract
Primary cilia are small microtubule‐based organelles capable of transducing signals from growth factor receptors embedded in the cilia membrane. Developmentally, oligodendrocyte progenitor cells (OPCs) express genes associated with primary cilia assembly, disassembly, and signaling, however, the importance of primary cilia for adult myelination has not been explored. We show that OPCs are ciliated in vitro and in vivo, and that they disassemble their primary cilia as they progress through the cell cycle. OPC primary cilia are also disassembled as OPCs differentiate into oligodendrocytes. When kinesin family member 3a (Kif3a), a gene critical for primary cilium assembly, was conditionally deleted from adult OPCs in vivo (Pdgfrα‐CreER™:: Kif3afl/fl transgenic mice), OPCs failed to assemble primary cilia. Kif3a‐deletion was also associated with reduced OPC proliferation and oligodendrogenesis in the corpus callosum and motor cortex and a progressive impairment of fine motor coordination.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Megan O'Rourke
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Shannon J Beasley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Yilan Zhen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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6
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Auderset L, Pitman KA, Cullen CL, Pepper RE, Taylor BV, Foa L, Young KM. Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Is a Negative Regulator of Oligodendrocyte Progenitor Cell Differentiation in the Adult Mouse Brain. Front Cell Dev Biol 2020; 8:564351. [PMID: 33282858 PMCID: PMC7691426 DOI: 10.3389/fcell.2020.564351] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Low-density lipoprotein receptor-related protein 1 (LRP1) is a large, endocytic cell surface receptor that is highly expressed by oligodendrocyte progenitor cells (OPCs) and LRP1 expression is rapidly downregulated as OPCs differentiate into oligodendrocytes (OLs). We report that the conditional deletion of Lrp1 from adult mouse OPCs (Pdgfrα-CreER :: Lrp1fl/fl) increases the number of newborn, mature myelinating OLs added to the corpus callosum and motor cortex. As these additional OLs extend a normal number of internodes that are of a normal length, Lrp1-deletion increases adult myelination. OPC proliferation is also elevated following Lrp1 deletion in vivo, however, this may be a secondary, homeostatic response to increased OPC differentiation, as our in vitro experiments show that LRP1 is a direct negative regulator of OPC differentiation, not proliferation. Deleting Lrp1 from adult OPCs also increases the number of newborn mature OLs added to the corpus callosum in response to cuprizone-induced demyelination. These data suggest that the selective blockade of LRP1 function on adult OPCs may enhance myelin repair in demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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7
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Ferreira S, Pitman KA, Wang S, Summers BS, Bye N, Young KM, Cullen CL. Amyloidosis is associated with thicker myelin and increased oligodendrogenesis in the adult mouse brain. J Neurosci Res 2020; 98:1905-1932. [PMID: 32557778 PMCID: PMC7540704 DOI: 10.1002/jnr.24672] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/03/2020] [Accepted: 05/25/2020] [Indexed: 12/15/2022]
Abstract
In Alzheimer's disease, amyloid plaque formation is associated with the focal death of oligodendrocytes and soluble amyloid β impairs the survival of oligodendrocytes in vitro. However, the response of oligodendrocyte progenitor cells (OPCs) to early amyloid pathology remains unclear. To explore this, we performed a histological, electrophysiological, and behavioral characterization of transgenic mice expressing a pathological form of human amyloid precursor protein (APP), containing three single point mutations associated with the development of familial Alzheimer's disease (PDGFB‐APPSw.Ind, also known as J20 mice). PDGFB‐APPSw.Ind transgenic mice had impaired survival from weaning, were hyperactive by 2 months of age, and developed amyloid plaques by 6 months of age, however, their spatial memory remained intact over this time course. Hippocampal OPC density was normal in P60‐P180 PDGFB‐APPSw.Ind transgenic mice and, by performing whole‐cell patch‐clamp electrophysiology, we found that their membrane properties, including their response to kainate (100 µM), were largely normal. However, by P100, the response of hippocampal OPCs to GABA was elevated in PDGFB‐APPSw.Ind transgenic mice. We also found that the nodes of Ranvier were shorter, the paranodes longer, and the myelin thicker for hippocampal axons in young adult PDGFB‐APPSw.Ind transgenic mice compared with wildtype littermates. Additionally, oligodendrogenesis was normal in young adulthood, but increased in the hippocampus, entorhinal cortex, and fimbria of PDGFB‐APPSw.Ind transgenic mice as pathology developed. As the new oligodendrocytes were not associated with a change in total oligodendrocyte number, these cells are likely required for cell replacement.
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Affiliation(s)
- Solène Ferreira
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Shiwei Wang
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Benjamin S Summers
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Nicole Bye
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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8
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Cullen CL, Senesi M, Tang AD, Clutterbuck MT, Auderset L, O'Rourke ME, Rodger J, Young KM. Low-intensity transcranial magnetic stimulation promotes the survival and maturation of newborn oligodendrocytes in the adult mouse brain. Glia 2019; 67:1462-1477. [PMID: 30989733 PMCID: PMC6790715 DOI: 10.1002/glia.23620] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 03/05/2019] [Accepted: 03/25/2019] [Indexed: 11/23/2022]
Abstract
Neuronal activity is a potent extrinsic regulator of oligodendrocyte generation and central nervous system myelination. Clinically, repetitive transcranial magnetic stimulation (rTMS) is delivered to noninvasively modulate neuronal activity; however, the ability of rTMS to facilitate adaptive myelination has not been explored. By performing cre‐lox lineage tracing, to follow the fate of oligodendrocyte progenitor cells in the adult mouse brain, we determined that low intensity rTMS (LI‐rTMS), administered as an intermittent theta burst stimulation, but not as a continuous theta burst or 10 Hz stimulation, increased the number of newborn oligodendrocytes in the adult mouse cortex. LI‐rTMS did not alter oligodendrogenesis per se, but instead increased cell survival and enhanced myelination. These data suggest that LI‐rTMS can be used to noninvasively promote myelin addition to the brain, which has potential implications for the treatment of demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Matteo Senesi
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Alexander D Tang
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Perth, Western Australia, Australia
| | | | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Megan E O'Rourke
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neurosciences, School of Biological Sciences, University of Western Australia, Perth, Western Australia, Australia.,Brain Plasticity Lab, Perron Institute for Neurological and Translational Science, Perth, Western Australia, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
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9
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Lucia D, Burgess D, Cullen CL, Dorey ES, Rawashdeh O, Moritz KM. Periconceptional maternal alcohol consumption leads to behavioural changes in adult and aged offspring and alters the expression of hippocampal genes associated with learning and memory and regulators of the epigenome. Behav Brain Res 2019; 362:249-257. [PMID: 30633938 DOI: 10.1016/j.bbr.2019.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 02/07/2023]
Abstract
Maternal alcohol consumption throughout pregnancy can result in long term behavioural deficits in offspring. However, less is known about the impact of alcohol during the periconceptional period (PC). The aim of this study was to examine the effect of PC ethanol (PC:EtOH) exposure on long term cognitive function; including memory and anxiety. Rats were exposed to a liquid diet containing ethanol (EtOH) (12.5% vol;vol) or a control diet from 4 days prior to mating until day 4 of pregnancy. Separate cohorts of animals were tested at 6 months (adult) or 15-18 months of age (aged). Offspring underwent a series of behavioural tests to assess anxiety, spatial and recognition memory. The hippocampus was collected, and mRNA expression of epigenetic modifiers and genes implicated in learning and memory were examined. PC:EtOH exposure resulted in a subtle anxiety like behaviour in adult female offspring with a significant reduction in directed exploring/head dipping behaviour during holeboard testing. In aged male offspring, PC:EtOH exposure resulted in a tendency for increased directed exploring/head dipping behaviour during holeboard testing. No differences between treatments were observed in the elevated plus maze. Aged female offspring exposed to PC:EtOH demonstrated short term spatial memory impairment (P < 0.05). PC:EtOH resulted in an upregulation of hippocampal mRNA expression of bdnf, grin2a and grin2b at 18 months of age along with increased expression of epigenetic modifiers (dnmt1, dnmt3a and hdac2). In conclusion, PC:EtOH can lead to sex specific anxiety-like behaviour and impairments in spatial memory and altered hippocampal gene expression.
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Affiliation(s)
- D Lucia
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - D Burgess
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - C L Cullen
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - E S Dorey
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - O Rawashdeh
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - K M Moritz
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Child Health Research Centre, The University of Queensland, 4072, Australia.
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10
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Pepper RE, Pitman KA, Cullen CL, Young KM. How Do Cells of the Oligodendrocyte Lineage Affect Neuronal Circuits to Influence Motor Function, Memory and Mood? Front Cell Neurosci 2018; 12:399. [PMID: 30524235 PMCID: PMC6262292 DOI: 10.3389/fncel.2018.00399] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/17/2018] [Indexed: 12/11/2022] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) are immature cells in the central nervous system (CNS) that can rapidly respond to changes within their environment by modulating their proliferation, motility and differentiation. OPCs differentiate into myelinating oligodendrocytes throughout life, and both cell types have been implicated in maintaining and modulating neuronal function to affect motor performance, cognition and emotional state. However, questions remain about the mechanisms employed by OPCs and oligodendrocytes to regulate circuit function, including whether OPCs can only influence circuits through their generation of new oligodendrocytes, or can play other regulatory roles within the CNS. In this review, we detail the molecular and cellular mechanisms that allow OPCs, newborn oligodendrocytes and pre-existing oligodendrocytes to regulate circuit function and ultimately influence behavioral outcomes.
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Affiliation(s)
- Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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11
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Cullen CL, Young KM. Can Thyroid Hormone Analogues Be Used to Overcome Hypomyelination and Demyelination of the Central Nervous System? EBioMedicine 2017; 26:15-16. [PMID: 29128443 PMCID: PMC5832563 DOI: 10.1016/j.ebiom.2017.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 11/27/2022] Open
Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool St, Hobart 7000, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, 17 Liverpool St, Hobart 7000, Australia.
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12
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Schlegel RN, Spiers JG, Moritz KM, Cullen CL, Björkman ST, Paravicini TM. Maternal hypomagnesemia alters hippocampal NMDAR subunit expression and programs anxiety-like behaviour in adult offspring. Behav Brain Res 2017; 328:39-47. [PMID: 28389335 DOI: 10.1016/j.bbr.2017.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/24/2017] [Accepted: 04/03/2017] [Indexed: 02/05/2023]
Abstract
It is well established that maternal undernutrition and micronutrient deficiencies can lead to altered development and behaviour in offspring. However, few studies have explored the implications of maternal Mg deficiency and programmed behavioural and neurological outcomes in offspring. We used a model of Mg deficiency (prior to and during pregnancy and lactation) in CD1 mice to investigate if maternal Mg deficiency programmed changes in behaviour and NMDAR subunit expression in offspring. Hippocampal tissue was collected at postnatal day 2 (PN2), PN8, PN21 and 6 months, and protein expression of NMDAR subunits GluN1, GluN2A and GluN2B was determined. At 6 months of age, offspring were subject to behavioural tasks testing aspects of anxiety-like behaviour, memory, and neophobia. Maternal hypomagnesemia was associated with increased GluN1, GluN2A and GluN2B subunit expression in female offspring at 6 months, but decreased GluN1 and GluN2A expression in males. The GluN2B:GluN2A expression ratio was increased in both sexes. Male (but not female) offspring from Mg-deficient dams showed anxiety-like behaviour, with reduced head dips (Suok test), and reduced exploration of open arms (elevated plus maze). Both male and female offspring from Mg-deficient dams also showed impaired recognition memory (novel object test). These findings suggest that maternal Mg deficiency can result in behavioural deficits in adult life, and that these changes may be related to alterations in hippocampal NMDA receptor expression.
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Affiliation(s)
- R N Schlegel
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - J G Spiers
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - K M Moritz
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - C L Cullen
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia; Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - S T Björkman
- University of Queensland Centre for Clinical Research, Brisbane, Australia
| | - T M Paravicini
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia; School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.
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Wang S, Bolós M, Clark R, Cullen CL, Southam KA, Foa L, Dickson TC, Young KM. Amyloid β precursor protein regulates neuron survival and maturation in the adult mouse brain. Mol Cell Neurosci 2016; 77:21-33. [DOI: 10.1016/j.mcn.2016.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 08/12/2016] [Accepted: 09/19/2016] [Indexed: 01/08/2023] Open
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O’Rourke M, Cullen CL, Auderset L, Pitman KA, Achatz D, Gasperini R, Young KM. Evaluating Tissue-Specific Recombination in a Pdgfrα-CreERT2 Transgenic Mouse Line. PLoS One 2016; 11:e0162858. [PMID: 27626928 PMCID: PMC5023134 DOI: 10.1371/journal.pone.0162858] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/30/2016] [Indexed: 11/18/2022] Open
Abstract
In the central nervous system (CNS) platelet derived growth factor receptor alpha (PDGFRα) is expressed exclusively by oligodendrocyte progenitor cells (OPCs), making the Pdgfrα promoter an ideal tool for directing transgene expression in this cell type. Two Pdgfrα-CreERT2 mouse lines have been generated for this purpose which, when crossed with cre-sensitive reporter mice, allow the temporally restricted labelling of OPCs for lineage-tracing studies. These mice have also been used to achieve the deletion of CNS-specific genes from OPCs. However the ability of Pdgfrα-CreERT2 mice to induce cre-mediated recombination in PDGFRα+ cell populations located outside of the CNS has not been examined. Herein we quantify the proportion of PDGFRα+ cells that become YFP-labelled following Tamoxifen administration to adult Pdgfrα-CreERT2::Rosa26-YFP transgenic mice. We report that the vast majority (>90%) of PDGFRα+ OPCs in the CNS, and a significant proportion of PDGFRα+ stromal cells within the bone marrow (~38%) undergo recombination and become YFP-labelled. However, only a small proportion of the PDGFRα+ cell populations found in the sciatic nerve, adrenal gland, pituitary gland, heart, gastrocnemius muscle, kidney, lung, liver or intestine become YFP-labelled. These data suggest that Pdgfrα-CreERT2 transgenic mice can be used to achieve robust recombination in OPCs, while having a minimal effect on most PDGFRα+ cell populations outside of the CNS.
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Affiliation(s)
- Megan O’Rourke
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Carlie L. Cullen
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Kimberley A. Pitman
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Daniela Achatz
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
- School of Medicine, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Liverpool Street, Hobart, Tasmania 7000, Australia
- * E-mail:
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Auderset L, Cullen CL, Young KM. Low Density Lipoprotein-Receptor Related Protein 1 Is Differentially Expressed by Neuronal and Glial Populations in the Developing and Mature Mouse Central Nervous System. PLoS One 2016; 11:e0155878. [PMID: 27280679 PMCID: PMC4900551 DOI: 10.1371/journal.pone.0155878] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/05/2016] [Indexed: 11/19/2022] Open
Abstract
The low density lipoprotein-receptor related protein 1 (LRP1) is a large endocytic cell surface receptor that is known to interact with a variety of ligands, intracellular adaptor proteins and other cell surface receptors to regulate cellular behaviours ranging from proliferation to cell fate specification, migration, axon guidance, and lipid metabolism. A number of studies have demonstrated that LRP1 is expressed in the brain, yet it is unclear which central nervous system cell types express LRP1 during development and in adulthood. Herein we undertake a detailed study of LRP1 expression within the mouse brain and spinal cord, examining a number of developmental stages ranging from embryonic day 13.5 to postnatal day 60. We report that LRP1 expression in the brain peaks during postnatal development. On a cellular level, LRP1 is expressed by radial glia, neuroblasts, microglia, oligodendrocyte progenitor cells (OPCs), astrocytes and neurons, with the exception of parvalbumin+ interneurons in the cortex. Most cell populations exhibit stable expression of LRP1 throughout development; however, the proportion of OPCs that express LRP1 increases significantly from ~69% at E15.5 to ~99% in adulthood. We also report that LRP1 expression is rapidly lost as OPCs differentiate, and is absent from all oligodendrocytes, including newborn oligodendrocytes. While LRP1 function has been primarily examined in mature neurons, these expression data suggest it plays a more critical role in glial cell regulation-where expression levels are much higher.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Carlie L. Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7000, Australia
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Cullen CL, Young KM. How Does Transcranial Magnetic Stimulation Influence Glial Cells in the Central Nervous System? Front Neural Circuits 2016; 10:26. [PMID: 27092058 PMCID: PMC4820444 DOI: 10.3389/fncir.2016.00026] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is widely used in the clinic, and while it has a direct effect on neuronal excitability, the beneficial effects experienced by patients are likely to include the indirect activation of other cell types. Research conducted over the past two decades has made it increasingly clear that a population of non-neuronal cells, collectively known as glia, respond to and facilitate neuronal signaling. Each glial cell type has the ability to respond to electrical activity directly or indirectly, making them likely cellular effectors of TMS. TMS has been shown to enhance adult neural stem and progenitor cell (NSPC) proliferation, but the effect on cell survival and differentiation is less certain. Furthermore there is limited information regarding the response of astrocytes and microglia to TMS, and a complete paucity of data relating to the response of oligodendrocyte-lineage cells to this treatment. However, due to the critical and yet multifaceted role of glial cells in the central nervous system (CNS), the influence that TMS has on glial cells is certainly an area that warrants careful examination.
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Affiliation(s)
- Carlie L. Cullen
- Menzies Institute for Medical Research, University of TasmaniaHobart, TAS, Australia
| | - Kaylene M. Young
- Menzies Institute for Medical Research, University of TasmaniaHobart, TAS, Australia
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Cullen CL, Burne THJ, Lavidis NA, Moritz KM. Low dose prenatal alcohol exposure does not impair spatial learning and memory in two tests in adult and aged rats. PLoS One 2014; 9:e101482. [PMID: 24978807 PMCID: PMC4076304 DOI: 10.1371/journal.pone.0101482] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 06/06/2014] [Indexed: 11/18/2022] Open
Abstract
Consumption of alcohol during pregnancy can have detrimental impacts on the developing hippocampus, which can lead to deficits in learning and memory function. Although high levels of alcohol exposure can lead to severe deficits, there is a lack of research examining the effects of low levels of exposure. This study used a rat model to determine if prenatal exposure to chronic low dose ethanol would result in deficits in learning and memory performance and if this was associated with morphological changes within the hippocampus. Sprague Dawley rats were fed a liquid diet containing 6% (vol/vol) ethanol (EtOH) or an isocaloric control diet throughout gestation. Male and Female offspring underwent behavioural testing at 8 (Adult) or 15 months (Aged) of age. Brains from these animals were collected for stereological analysis of pyramidal neuron number and dendritic morphology within the CA1 and CA3 regions of the dorsal hippocampus. Prenatal ethanol exposed animals did not differ in spatial learning or memory performance in the Morris water maze or Y maze tasks compared to Control offspring. There was no effect of prenatal ethanol exposure on pyramidal cell number or density within the dorsal hippocampus. Overall, this study indicates that chronic low dose prenatal ethanol exposure in this model does not have long term detrimental effects on pyramidal cells within the dorsal hippocampus or impair spatial learning and memory performance.
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Affiliation(s)
- Carlie L. Cullen
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Thomas H. J. Burne
- Queensland Brain Institute, The University of Queensland, St. Lucia, Australia
| | - Nickolas A. Lavidis
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Karen M. Moritz
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
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Cullen CL, Burne THJ, Lavidis NA, Moritz KM. Low dose prenatal ethanol exposure induces anxiety-like behaviour and alters dendritic morphology in the basolateral amygdala of rat offspring. PLoS One 2013; 8:e54924. [PMID: 23383000 PMCID: PMC3559882 DOI: 10.1371/journal.pone.0054924] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/19/2012] [Indexed: 11/19/2022] Open
Abstract
Prenatal exposure to high levels of alcohol is strongly associated with poor cognitive outcomes particularly in relation to learning and memory. It is also becoming more evident that anxiety disorders and anxiety-like behaviour can be associated with prenatal alcohol exposure. This study used a rat model to determine if prenatal exposure to a relatively small amount of alcohol would result in anxiety-like behaviour and to determine if this was associated with morphological changes in the basolateral amygdala. Pregnant Sprague Dawley rats were fed a liquid diet containing either no alcohol (Control) or 6% (vol/vol) ethanol (EtOH) throughout gestation. Male and Female offspring underwent behavioural testing at 8 months (Adult) or 15 months (Aged) of age. Rats were perfusion fixed and brains were collected at the end of behavioural testing for morphological analysis of pyramidal neuron number and dendritic morphology within the basolateral amygdala. EtOH exposed offspring displayed anxiety-like behaviour in the elevated plus maze, holeboard and emergence tests. Although sexually dimorphic behaviour was apparent, sex did not impact anxiety-like behaviour induced by prenatal alcohol exposure. This increase in anxiety – like behaviour could not be attributed to a change in pyramidal cell number within the BLA but rather was associated with an increase in dendritic spines along the apical dendrite which is indicative of an increase in synaptic connectivity and activity within these neurons. This study is the first to link increases in anxiety like behaviour to structural changes within the basolateral amygdala in a model of prenatal ethanol exposure. In addition, this study has shown that exposure to even a relatively small amount of alcohol during development leads to long term alterations in anxiety-like behaviour.
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Affiliation(s)
- Carlie L. Cullen
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Thomas H. J. Burne
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland, Australia
| | - Nickolas A. Lavidis
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Karen M. Moritz
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
- * E-mail:
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Abstract
OBJECTIVE The aim of the study was to assess the ocular features, normal conjunctival bacterial and fungal flora, and intraocular pressure (IOP) in the Canadian beaver (Castor canadensis). SAMPLE POPULATION Sixteen, apparently healthy beavers with no evidence of ocular disease, and live-trapped in regions throughout Prince Edward Island. PROCEDURES The beavers were sedated with intramuscular ketamine (12-15 mg/kg). Two culture specimens were obtained from the ventral conjunctival sac of both eyes of 10/16 beavers for aerobic and anaerobic bacterial and fungal identifications. The anterior ocular structures of all beavers were evaluated using a transilluminator and slit lamp biomicroscope. Palpebral fissure length (11/16 beavers), and horizontal and vertical corneal diameters (10/16 beavers) were measured. IOPs were measured in both eyes of 11/16 beavers using applanation tonometry. Both eyes of 3/16 beavers and one eye of 1/16 beavers were dilated using topical tropicamide prior to sedation to effect timely maximal dilation. Culture specimens and IOPs were not evaluated in these four animals. Indirect ophthalmoscopy was performed on 7/8 eyes of these four beavers. RESULTS Conjunctival specimens from all eyes cultured positively for one or more isolates of aerobic bacteria. The most common isolate was Micrococcus spp. (five beavers; 9/20 eyes). Other isolates included a Gram-positive coccobacilli-like organism (four beavers; 7/20 eyes), Aeromonas hydrophila (three beavers; 4/20 eyes), Staphylococcus spp. (three beavers; 4/20 eyes), Gram positive bacilli (one beaver; 2/20 eyes), Enterobacter spp. (two beavers; 2/20 eyes), Streptococcus spp. (two beavers; 2/20 eyes), aerobic diphtheroids (one beaver; 1/20 eyes), and Pseudomonas spp. (one beaver; 1/20 eyes). Clostridium sordellii (one beaver; 1/20 eyes) and Peptostreptococcus spp. (one beaver; 1/20 eyes) were the sole anaerobic bacteria isolated. All conjunctival specimens were negative for growth of fungi. Ophthalmic examinations revealed the normal beaver eye and ocular adnexa included dorsal and ventral puncta, a vestigial third eyelid, and a circular pupil. Average palpebral fissure length was 9.36 mm (SD = 1.00) for both eyes. Mean horizontal and vertical corneal diameters of both eyes were 9.05 mm (SD = 0.64) and 8.45 mm (SD = 0.69), respectively. Mean IOP for the right and left eyes were 17.11 mmHg (SD = 6.39) and 18.79 mmHg (SD = 5.63), respectively. Indirect ophthalmoscopic examinations revealed normal anangiotic retinas. CONCLUSIONS Gram-positive aerobes were most commonly cultured from the conjunctival sac of normal beavers, with Micrococcus spp. predominating. The overall mean IOP in ketamine-sedated beavers was 17.95 mmHg. The beaver, an amphibious rodent, has an anangiotic retina.
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Affiliation(s)
- C L Cullen
- Department of Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3 Canada.
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Grahn BH, Cullen CL. Diagnostic ophthalmology. Can Vet J 2001; 42:735-6. [PMID: 11565376 PMCID: PMC1476607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- B H Grahn
- Department of Small Animal Clinical Studies, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
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Abstract
OBJECTIVE Investigation of the pathogenesis of Great Pyrenees retinopathy. ANIMALS One male and two female puppies of parents who were affected with Great Pyrenees retinopathy and one 4-year-old affected adult male Great Pyrenees dog. PROCEDURE The puppies were examined daily from 7 weeks of age by indirect ophthalmoscopy and their fundi were photographed until the lesions were static. Fluorescein angiography was completed at 7 weeks of age, within 24 h of detection of ophthalmoscopic lesions, and then weekly. The eyes of a 4-year-old and two 20-week-old puppies were examined with light microscopy, and transmitting and scanning electron microscopy. RESULTS Blocked choroidal fluorescence was detected at 7 weeks of age. The blocked fluorescence enlarged, when the characteristic serous retinal detachments developed at 11 weeks of age. The detachments enlarged in size and number until the puppies were approximately 20 weeks old. Fluorescein pooling confirmed the presence of transient retinal pigment epithelial detachments. Leakage of dye into serous retinal detachments was not detected in this study. Light microscopy and transmitting and scanning electron microscopy confirmed the presence of multifocal serous retinal detachments with focal retinal degeneration that extended to the inner nuclear layer in a 4-year-old dog. The retinal detachments were accompanied by hypertrophy, hyperplasia, increased pigmentation, and vacuolation of the retinal pigment epithelium. CONCLUSIONS AND CLINICAL RELEVANCE Great Pyrenees retinopathy is manifested by multifocal serous retinal and retinal pigment epithelial detachments. These detachments are similar to those noted with central serous retinopathy of humans. The sudden development of multifocal retinal and retinal pigment epithelial detachments, and the serous nature of these detachments, supports a theory that they develop secondary to focal secretion and absorption defects in retinal pigment epithelial cells. Given the age of the puppies when the blocked choroidal fluorescence was noted and maturation of the dog retina at 8 weeks postpartum, this retinopathy is considered to be a retinal pigment epithelial dysplasia. This unique inherited retinopathy offers an opportunity to study retinal pigment epithelial secretion.
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Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5B4
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Grahn BH, Cullen CL. Diagnostic ophthalmology. Melting corneal ulcer. Can Vet J 2001; 42:656-7. [PMID: 11519280 PMCID: PMC1476574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- B H Grahn
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
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Grahn BH, Cullen CL. Diagnostic ophthalmology. Bilateral idiopathic uveitis in a llama. Can Vet J 2001; 42:575-6. [PMID: 11467189 PMCID: PMC1476630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- B H Grahn
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4
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Cullen CL, Grahn BH. Diagnostic ophthalmology. Can Vet J 2001; 42:394-5. [PMID: 11360866 PMCID: PMC1476511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Affiliation(s)
- C L Cullen
- Department of Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, 550 University Drive, Charlottetown, Prince Edward Island C1A 4P3
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Cullen CL, Grahn BH. Diagnostic ophthalmology. Epithelial inclusion cyst of the right cornea. Can Vet J 2001; 42:230-1. [PMID: 11265196 PMCID: PMC1476466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- C L Cullen
- Department of Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3
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Cullen CL, Grahn BH. Diagnostic ophthalmology. Corneal ulcer with severe secondary anterior uveitis in a pony. Can Vet J 2000; 41:887-9. [PMID: 11126499 PMCID: PMC1476431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- C L Cullen
- Department of Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3
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Cullen CL, Grahn BH, Wolfer J. Diagnostic ophthalmology. Mesenchymal orbital tumor with adjacent bony invasion. Can Vet J 2000; 41:723-4. [PMID: 10992994 PMCID: PMC1476397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- C L Cullen
- Department of Small Animal Clinical Studies, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Cullen CL, Grahn BH, Wolfer J, Kerr M. Diagnostic ophthalmology. Primary glandular orbital epithelial neoplasm in a dog. Can Vet J 2000; 41:645-7. [PMID: 10945133 PMCID: PMC1476235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- C L Cullen
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, Saskatoon, Saskatchewan
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Abstract
A seven-year-old, spayed female boxer was presented for sudden blindness and red eyes of one week's duration. Ophthalmic examination revealed bilateral uveitis with complete bullous retinal detachments. Initial diagnostic testing failed to reveal evidence of systemic disease. Cytopathology of subretinal aspirates confirmed the presence of macrophages with intracytoplasmic retinal pigment, epithelial and choroidal pigment, and monocytes. Tentative diagnoses were idiopathic uveitis and retinal detachment. The dog was treated with immunosuppressive doses of prednisone. The retinas reattached and vision returned. By two months, the dog became blind and systemically ill. Postmortem and histopathological examinations revealed intravascular lymphoma in multiple organs, including the eyes.
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Affiliation(s)
- C L Cullen
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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Cullen CL, Grahn BH, Wolfer J. Diagnostic ophthalmology. Right superficial corneal ulcer with mild secondary anterior uveitis and osseous choristoma in a guinea pig. Can Vet J 2000; 41:502-3. [PMID: 10857039 PMCID: PMC1476210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- C L Cullen
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Cullen CL, Grahn BH. Equine glaucoma: a retrospective study of 13 cases presented at the Western College of Veterinary Medicine from 1992 to 1999. Can Vet J 2000; 41:470-80. [PMID: 10857031 PMCID: PMC1476223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The prevalence of equine glaucoma seen by the ophthalmology service at the Western College of Veterinary Medicine (WCVM) was 6.5%. The majority of cases (11/13) were associated with clinical manifestations of uveitis. Congenital glaucoma was documented in 1 case, and primary glaucoma was diagnosed in a 12-year-old quarter horse. There were no breed or sex predilections evident. Affected horses were middle-aged to old (average age = 9.5 years, ranging from 2 weeks to 23 years). The clinical manifestations of equine glaucoma included blindness, diffuse corneal edema, corneal vascularization, buphthalmia, corneal striae, recurrent secondary ulcerative keratitis, and less commonly, iris bombé, tapetal hyper-reflectivity, complete pupillary occlusion from posterior synechiae, and optic disc cupping. Elevated intraocular pressure confirmed the diagnosis (n = 10), while 3 cases were normotensive with signs of glaucoma including corneal striae and buphthalmia. Affected eyes were treated medically and/or surgically. Regardless of the therapy instituted, the visual outcome was poor. Most affected eyes were blind at presentation or became blind within a few weeks.
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Affiliation(s)
- C L Cullen
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Grahn BH, Cullen CL. Equine phacoclastic uveitis: the clinical manifestations, light microscopic findings, and therapy of 7 cases. Can Vet J 2000; 41:376-82. [PMID: 10816830 PMCID: PMC1476266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
This retrospective clinical study describes the clinical manifestations, light microscopic findings, and diagnosis and treatment of acute and chronic lens rupture in the horse. Rupture of the lens capsule in the horse usually results in a chronic, blinding inflammation (phacoclastic uveitis) unless prompt surgical and medical therapies are implemented. The clinical manifestations of acute lens capsule rupture included: cataract; intralenticular displacement of iridal pigment; lens cortical fragments attached to the perforated lens capsule, iris, and corneal endothelium; miosis; aqueous flare; and usually a corneal or scleral perforation with ulceration or focal full thickness corneal edema and scarring. The clinical signs of chronic phacoclastic uveitis include blindness, phthisis bulbi, and generalized corneal opacification related to scarring, vascularization, pigmentation, and edema. In one horse, acute phacoclastic uveitis was successfully treated with phacoemulsification to remove the ruptured lens and medical therapy to control the accompanying inflammation. The affected eyes of the horses with chronic phacoclastic uveitis were enucleated because of persistent clinical signs of nonulcerative keratitis and uveitis, despite long-term medical management. The clinical manifestations and lack of improvement with medical therapy are similar in the horse, dog, cat, and rabbit. However, the histologic findings in equine phacoclastic uveitis differ significantly from those in the dog, and rabbit.
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Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Cullen CL, Wheler C, Grahn BH. Diagnostic ophthalmology. Bullous spectaculopathy++ in a king snake. Can Vet J 2000; 41:327-8. [PMID: 10769776 PMCID: PMC1476148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- C L Cullen
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Grahn BH, Cullen CL, Wolfer J. Diagnostic ophthalmology. Multifocal retinopathy of a Great Pyrenees. Can Vet J 1999; 40:893-4. [PMID: 10646071 PMCID: PMC1539889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Grahn BH, Cullen CL, Wolfer J. Diagnostic ophthalmology. Necrotic scleritis and uveitis. Can Vet J 1999; 40:679-80. [PMID: 10495915 PMCID: PMC1539845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Grahn BH, Cullen CL, Wolfer J. Diagnostic ophthalmology. Can Vet J 1999; 40:521-2. [PMID: 10416077 PMCID: PMC1539754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Grahn BH, Wolfer J, Cullen CL. What is your diagnosis and therapeutic plan? Congenital atresia of the left nasolacrimal duct. Can Vet J 1999; 40:71-2. [PMID: 9919372 PMCID: PMC1539647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- B H Grahn
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon
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Duke T, Cullen CL, Fowler JD. Anesthesia case of the month. Analgesia for fractures until surgery can take place. J Am Vet Med Assoc 1998; 212:649-50. [PMID: 9524634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- T Duke
- Department of Veterinary Anesthesiology, Radiology, and Surgery, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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Steiman HR, Cullen CL, Geist JR. Bilateral mandibular regional odontodysplasia with vascular nevus. Pediatr Dent 1991; 13:303-6. [PMID: 1667684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Odontodysplasia is a rare clinicopathologic condition that has a variety of expressions, including a range of tooth coloration, formation of hypoplastic enamel affecting one or multiple teeth, bizarre radiographic appearance, and delayed eruption of teeth. An unusual case is presented of bilateral regional odontodysplasia associated with a vascular nevus of the face and neck. A review of the etiology with emphasis on the "local circulatory disease" theory is presented.
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Affiliation(s)
- H R Steiman
- Department of Endodontics, School of Dentistry, University of Detroit
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Cullen CL. Erythroblastosis fetalis produced by Kell immunization: dental findings. Pediatr Dent 1990; 12:393-6. [PMID: 2087415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Erythroblastosis fetalis is a severe hemolytic disease in the newborn that originates in utero because of a maternal-fetal blood incompatibility. An unusual case of erythroblastosis fetalis caused by an irregular antibody of the Kell blood group is presented. The dental findings are compared to those found with Rh(D) incompatibility.
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Affiliation(s)
- C L Cullen
- University of Detroit School of Dentistry
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Cullen CL. Defining and assessing affective outcomes in undergraduate pediatric dentistry. J Dent Educ 1990; 54:184-7. [PMID: 2137834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- C L Cullen
- Department of Pediatric Dentistry, University of Detroit School of Dentistry, MI 48207
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Brossok CE, Cullen CL. Nursing caries syndrome: restorative options for primary anterior teeth. Compendium 1988; 9:495-8, 500, 502-4 passim. [PMID: 3248279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Cullen CL, Wesley RK. Russell-Silver syndrome: microdontia and other pertinent oral findings. ASDC J Dent Child 1987; 54:201-4. [PMID: 3473100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The pertinent clinical systemic and oral findings have been presented. Systemically, the patient presented with prenatal onset of growth retardation marked by an initial low birth weight, hemiatrophy, normal head size, frontal bossing, and triangular facies. Oral findings include an intact appearing primary dentition marked by microdontia, congenital absence of second premolars, blunted condyles, decreased anterior and posterior cranial base lengths, a mild hypoplastic mandible, and decreased facial height.
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Wesley RK, Cullen CL, Bloom WS. Gardner's syndrome with bilateral osteomas of coronoid process resulting in limited opening. Pediatr Dent 1987; 9:53-7. [PMID: 3472187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Abstract
The extraction of the geminated maxillary central incisors was selected as the preferred treatment in this case because of the impossibility of properly recontouring these teeth. Although the crowns could have been reshaped somewhat to conform to a more normal size and shape, the roots were so wide that approximation of the central and lateral incisor crowns would have been impaired. The use of normally shaped, large lateral incisors in place of abnormal central incisors gives a better occlusion and a more esthetic result at the end of the treatment.
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Cullen CL, Studen DA. Child's play: techniques to promote cooperation from the child dental patient. Dent Assist (1931) 1985; 54:14-6. [PMID: 3858111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Cullen CL. Endodontic therapy of deciduous teeth. Compend Contin Educ Dent (Lawrenceville) 1983; 4:302-6, 308. [PMID: 6576889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Cullen CL. Sickle cell anemia: dental management of the child patient. J Mich Dent Assoc 1982; 64:77-8. [PMID: 6210780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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