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Basavarajappa BS, Subbanna S. Synaptic Plasticity Abnormalities in Fetal Alcohol Spectrum Disorders. Cells 2023; 12:442. [PMID: 36766783 PMCID: PMC9913617 DOI: 10.3390/cells12030442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/10/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
The brain's ability to strengthen or weaken synaptic connections is often termed synaptic plasticity. It has been shown to function in brain remodeling following different types of brain damage (e.g., drugs of abuse, alcohol use disorders, neurodegenerative diseases, and inflammatory conditions). Although synaptic plasticity mechanisms have been extensively studied, how neural plasticity can influence neurobehavioral abnormalities in alcohol use disorders (AUDs) is far from being completely understood. Alcohol use during pregnancy and its harmful effects on the developing offspring are major public health, social, and economic challenges. The significant attribute of prenatal alcohol exposure on offspring is damage to the central nervous system (CNS), causing a range of synaptic structural, functional, and behavioral impairments, collectively called fetal alcohol spectrum disorder (FASD). Although the synaptic mechanisms in FASD are limited, emerging evidence suggests that FASD pathogenesis involves altering a set of molecules involved in neurotransmission, myelination, and neuroinflammation. These studies identify several immediate and long-lasting changes using many molecular approaches that are essential for synaptic plasticity and cognitive function. Therefore, they can offer potential synaptic targets for the many neurobehavioral abnormalities observed in FASD. In this review, we discuss the substantial research progress in different aspects of synaptic and molecular changes that can shed light on the mechanism of synaptic dysfunction in FASD. Increasing our understanding of the synaptic changes in FASD will significantly advance our knowledge and could provide a basis for finding novel therapeutic targets and innovative treatment strategies.
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Affiliation(s)
- Balapal S. Basavarajappa
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
- Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, NY 10032, USA
- Department of Psychiatry, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Psychiatry, New York University Langone Medical Center, New York, NY 10016, USA
| | - Shivakumar Subbanna
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
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Binge-like Prenatal Ethanol Exposure Causes Impaired Cellular Differentiation in the Embryonic Forebrain and Synaptic and Behavioral Defects in Adult Mice. Brain Sci 2022; 12:brainsci12060793. [PMID: 35741678 PMCID: PMC9220802 DOI: 10.3390/brainsci12060793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/10/2022] [Accepted: 06/15/2022] [Indexed: 11/30/2022] Open
Abstract
An embryo’s in-utero exposure to ethanol due to a mother’s alcohol drinking results in a range of deficits in the child that are collectively termed fetal alcohol spectrum disorders (FASDs). Prenatal ethanol exposure is one of the leading causes of preventable intellectual disability. Its neurobehavioral underpinnings warrant systematic research. We investigated the immediate effects on embryos of acute prenatal ethanol exposure during gestational days (GDs) and the influence of such exposure on persistent neurobehavioral deficits in adult offspring. We administered pregnant C57BL/6J mice with ethanol (1.75 g/kg) (GDE) or saline (GDS) intraperitoneally (i.p.) at 0 h and again at 2 h intervals on GD 8 and GD 12. Subsequently, we assessed apoptosis, differentiation, and signaling events in embryo forebrains (E13.5; GD13.5). Long-lasting effects of GDE were evaluated via a behavioral test battery. We also determined the long-term potentiation and synaptic plasticity-related protein expression in adult hippocampal tissue. GDE caused apoptosis, inhibited differentiation, and reduced pERK and pCREB signaling and the expression of transcription factors Pax6 and Lhx2. GDE caused persistent spatial and social investigation memory deficits compared with saline controls, regardless of sex. Interestingly, GDE adult mice exhibited enhanced repetitive and anxiety-like behavior, irrespective of sex. GDE reduced synaptic plasticity-related protein expression and caused hippocampal synaptic plasticity (LTP and LTD) deficits in adult offspring. These findings demonstrate that binge-like ethanol exposure at the GD8 and GD12 developmental stages causes defects in pERK–pCREB signaling and reduces the expression of Pax6 and Lhx2, leading to impaired cellular differentiation during the embryonic stage. In the adult stage, binge-like ethanol exposure caused persistent synaptic and behavioral abnormalities in adult mice. Furthermore, the findings suggest that combining ethanol exposure at two sensitive stages (GD8 and GD12) causes deficits in synaptic plasticity-associated proteins (Arc, Egr1, Fgf1, GluR1, and GluN1), leading to persistent FASD-like neurobehavioral deficits in mice.
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Miguel-Hidalgo JJ. Astroglia in the Vulnerability and Maintenance of Alcohol Use Disorders. ADVANCES IN NEUROBIOLOGY 2021; 26:255-279. [PMID: 34888838 DOI: 10.1007/978-3-030-77375-5_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Changes induced in the morphology and the multiplicity of functional roles played by astrocytes in brain regions critical to the establishment and maintenance of alcohol abuse suggest that they make an important contribution to the vulnerability to alcohol use disorders. The understanding of the relevant mechanisms accounting for that contribution is complicated by the fact that alcohol itself acts directly on astrocytes altering their metabolism, gene expression, and plasticity, so that the ultimate result is a complex interaction of various cellular pathways, including intracellular calcium regulation, neuroimmune responses, and regulation of neurotransmitter and gliotransmitter release and uptake. The recent years have seen a steady increase in the characterization of several of the relevant mechanisms, but much remains to be done for a full understanding of the astrocytes' contribution to the vulnerability to alcohol dependence and abuse and for using that knowledge in designing effective therapies for AUDs.
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Affiliation(s)
- José Javier Miguel-Hidalgo
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA.
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Delatour LC, Yeh PWL, Yeh HH. Prenatal Exposure to Ethanol Alters Synaptic Activity in Layer V/VI Pyramidal Neurons of the Somatosensory Cortex. Cereb Cortex 2020; 30:1735-1751. [PMID: 31647550 PMCID: PMC7132917 DOI: 10.1093/cercor/bhz199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/04/2019] [Accepted: 08/04/2019] [Indexed: 12/31/2022] Open
Abstract
Fetal alcohol spectrum disorder (FASD) encompasses a range of cognitive and behavioral deficits, with aberrances in the function of cerebral cortical pyramidal neurons implicated in its pathology. However, the mechanisms underlying these aberrances, including whether they persist well beyond ethanol exposure in utero, remain to be explored. We addressed these issues by employing a mouse model of FASD in which pregnant mice were exposed to binge-type ethanol from embryonic day 13.5 through 16.5. In both male and female offspring (postnatal day 28-32), whole-cell patch clamp recording of layer V/VI somatosensory cortex pyramidal neurons revealed increases in the frequency of excitatory and inhibitory postsynaptic currents. Furthermore, expressing channelrhodopsin in either GABAergic interneurons (Nkx2.1Cre-Ai32) or glutamatergic pyramidal neurons (Emx1IRES Cre-Ai32) revealed a shift in optically evoked paired-pulse ratio. These findings are consistent with an excitatory-inhibitory imbalance with prenatal ethanol exposure due to diminished inhibitory but enhanced excitatory synaptic strength. Prenatal ethanol exposure also altered the density and morphology of spines along the apical dendrites of pyramidal neurons. Thus, while both presynaptic and postsynaptic mechanisms are affected following prenatal exposure to ethanol, there is a prominent presynaptic component that contributes to altered inhibitory and excitatory synaptic transmission in the somatosensory cortex.
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Affiliation(s)
- Laurie C Delatour
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Pamela W L Yeh
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Hermes H Yeh
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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Thorpe HHA, Hamidullah S, Jenkins BW, Khokhar JY. Adolescent neurodevelopment and substance use: Receptor expression and behavioral consequences. Pharmacol Ther 2019; 206:107431. [PMID: 31706976 DOI: 10.1016/j.pharmthera.2019.107431] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2019] [Indexed: 12/18/2022]
Abstract
Adolescence is the transitional period between childhood and adulthood, during which extensive brain development occurs. Since this period also overlaps with the initiation of drug use, it is important to consider how substance use during this time might produce long-term neurobiological alterations, especially against the backdrop of developmental changes in neurotransmission. Alcohol, cannabis, nicotine, and opioids all produce marked changes in the expression and function of the neurotransmitter and receptor systems with which they interact. These acute and chronic alterations also contribute to behavioral consequences ranging from increased addiction risk to cognitive or neuropsychiatric behavioral dysfunctions. The current review provides an in-depth overview and update of the developmental changes in neurotransmission during adolescence, as well as the impact of drug exposure during this neurodevelopmental window. While most of these factors have been studied in animal models, which are the focus of this review, future longitudinal studies in humans that assess neural function and behavior will help to confirm pre-clinical findings. Furthermore, the neural changes induced by each drug should also be considered in the context of other contributing factors, such as sex. Further understanding of these consequences can help in the identification of novel approaches for preventing and reversing the neurobiological effects of adolescent substance use.
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Affiliation(s)
- Hayley H A Thorpe
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Shahnaza Hamidullah
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Bryan W Jenkins
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Jibran Y Khokhar
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada.
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Fontaine CJ, Pinar C, Yang W, Pang AF, Suesser KE, Choi JSJ, Christie BR. Impaired Bidirectional Synaptic Plasticity in Juvenile Offspring Following Prenatal Ethanol Exposure. Alcohol Clin Exp Res 2019; 43:2153-2166. [PMID: 31386206 DOI: 10.1111/acer.14170] [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: 05/27/2019] [Accepted: 07/24/2019] [Indexed: 01/08/2023]
Abstract
BACKGROUND The hippocampus is particularly vulnerable to the teratogenic effects of prenatal ethanol exposure (PNEE), and hippocampal structural and functional deficits are thought to contribute to the learning and memory deficits that are a hallmark feature of fetal alcohol spectrum disorders. METHODS Sprague Dawley dams were exposed to a liquid diet that contained EtOH (35.5% EtOH-derived calories) throughout gestation, and then, PNEE juvenile (P21-28) male and female offspring were used for in vitro electrophysiological recordings. We examined long-term potentiation (LTP), long-term depression (LTD), and depotentiation in the medial perforant path input to the dentate gyrus (DG) to determine the impact of PNEE on the dynamic range of bidirectional synaptic plasticity in both sexes. RESULTS PNEE reduced the responsiveness of the DGs of male but not in female offspring, and this effect was no longer apparent when GABAergic signaling was inhibited. There was also a sex-specific LTD impairment in males, but increasing the duration of the conditioning stimulus could overcome this deficit. The magnitude of LTP was also reduced, but in both sexes following PNEE. This appears to be an increase in the threshold for induction, not in capacity, as the level of LTP induced in PNEE animals was increased to control levels when additional conditioning stimuli were administered. CONCLUSIONS These data are the first to describe, in a single study, the impact of PNEE on the dynamic range of bidirectional synaptic plasticity in the juvenile DG in both males and in females. The data suggest that PNEE increases the threshold for LTP in the DG in both sexes, but produces a sex-specific increase in the threshold for LTD in males These alterations reduce the dynamic range for synaptic plasticity in both sexes.
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Affiliation(s)
| | - Cristina Pinar
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Waisley Yang
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Angela F Pang
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Konrad E Suesser
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - James S J Choi
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Brian R Christie
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Island Medical Program, Department of Cellular and Physiological Sciences, University of British Columbia, Victoria, BC, Canada
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Elibol B, Beker M, Sahbaz CD, Kilic U, Jakubowska-Doğru E. Prenatal ethanol intoxication and maternal intubation stress alter cell survival and apoptosis in the postnatal development of rat hippocampus. Acta Neurobiol Exp (Wars) 2019. [DOI: 10.21307/ane-2019-012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Naassila M, Pierrefiche O. GluN2B Subunit of the NMDA Receptor: The Keystone of the Effects of Alcohol During Neurodevelopment. Neurochem Res 2018; 44:78-88. [DOI: 10.1007/s11064-017-2462-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/18/2017] [Accepted: 12/26/2017] [Indexed: 12/18/2022]
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Effects of pre-natal alcohol exposure on hippocampal synaptic plasticity: Sex, age and methodological considerations. Neurosci Biobehav Rev 2016; 64:12-34. [PMID: 26906760 DOI: 10.1016/j.neubiorev.2016.02.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/14/2016] [Accepted: 02/18/2016] [Indexed: 12/28/2022]
Abstract
The consumption of alcohol during gestation is detrimental to the developing central nervous system (CNS). The severity of structural and functional brain alterations associated with alcohol intake depends on many factors including the timing and duration of alcohol consumption. The hippocampal formation, a brain region implicated in learning and memory, is highly susceptible to the effects of developmental alcohol exposure. Some of the observed effects of alcohol on learning and memory may be due to changes at the synaptic level, as this teratogen has been repeatedly shown to interfere with hippocampal synaptic plasticity. At the molecular level alcohol interferes with receptor proteins and can disrupt hormones that are important for neuronal signaling and synaptic plasticity. In this review we examine the consequences of prenatal and early postnatal alcohol exposure on hippocampal synaptic plasticity and highlight the numerous factors that can modulate the effects of alcohol. We also discuss some potential mechanisms responsible for these changes as well as emerging therapeutic avenues that are beginning to be explored.
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Goodfellow MJ, Abdulla KA, Lindquist DH. Neonatal Ethanol Exposure Impairs Trace Fear Conditioning and Alters NMDA Receptor Subunit Expression in Adult Male and Female Rats. Alcohol Clin Exp Res 2016; 40:309-18. [DOI: 10.1111/acer.12958] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 11/04/2015] [Indexed: 01/10/2023]
Affiliation(s)
| | - Khalid A. Abdulla
- Department of Psychology; The Ohio State University; Columbus Ohio
- Department of Neuroscience; The Ohio State University; Columbus Ohio
| | - Derick H. Lindquist
- Department of Psychology; The Ohio State University; Columbus Ohio
- Department of Neuroscience; The Ohio State University; Columbus Ohio
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11
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Bird CW, Candelaria-Cook FT, Magcalas CM, Davies S, Valenzuela CF, Savage DD, Hamilton DA. Moderate prenatal alcohol exposure enhances GluN2B containing NMDA receptor binding and ifenprodil sensitivity in rat agranular insular cortex. PLoS One 2015; 10:e0118721. [PMID: 25747876 PMCID: PMC4351952 DOI: 10.1371/journal.pone.0118721] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/06/2015] [Indexed: 12/31/2022] Open
Abstract
Prenatal exposure to alcohol affects the expression and function of glutamatergic neurotransmitter receptors in diverse brain regions. The present study was undertaken to fill a current gap in knowledge regarding the regional specificity of ethanol-related alterations in glutamatergic receptors in the frontal cortex. We quantified subregional expression and function of glutamatergic neurotransmitter receptors (AMPARs, NMDARs, GluN2B-containing NMDARs, mGluR1s, and mGluR5s) by radioligand binding in the agranular insular cortex (AID), lateral orbital area (LO), prelimbic cortex (PrL) and primary motor cortex (M1) of adult rats exposed to moderate levels of ethanol during prenatal development. Increased expression of GluN2B-containing NMDARs was observed in AID of ethanol-exposed rats compared to modest reductions in other regions. We subsequently performed slice electrophysiology measurements in a whole-cell patch-clamp preparation to quantify the sensitivity of evoked NMDAR-mediated excitatory postsynaptic currents (EPSCs) in layer II/III pyramidal neurons of AID to the GluN2B negative allosteric modulator ifenprodil. Consistent with increased GluN2B expression, ifenprodil caused a greater reduction in NMDAR-mediated EPSCs from prenatal alcohol-exposed rats than saccharin-exposed control animals. No alterations in AMPAR-mediated EPSCs or the ratio of AMPARs/NMDARs were observed. Together, these data indicate that moderate prenatal alcohol exposure has a significant and lasting impact on GluN2B-containing receptors in AID, which could help to explain ethanol-related alterations in learning and behaviors that depend on this region.
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Affiliation(s)
- Clark W. Bird
- Department of Psychology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | | | - Christy M. Magcalas
- Department of Psychology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Suzy Davies
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - C. Fernando Valenzuela
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Daniel D. Savage
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Derek A. Hamilton
- Department of Psychology, University of New Mexico, Albuquerque, New Mexico, United States of America
- Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico, United States of America
- * E-mail:
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Moderate prenatal alcohol exposure alters behavior and neuroglial parameters in adolescent rats. Behav Brain Res 2014; 269:175-84. [DOI: 10.1016/j.bbr.2014.04.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/18/2014] [Accepted: 04/14/2014] [Indexed: 11/21/2022]
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Goodfellow MJ, Lindquist DH. Significant long-term, but not short-term, hippocampal-dependent memory impairment in adult rats exposed to alcohol in early postnatal life. Dev Psychobiol 2014; 56:1316-26. [PMID: 24691725 DOI: 10.1002/dev.21210] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 01/27/2014] [Indexed: 12/14/2022]
Abstract
In rodents, ethanol exposure in early postnatal life is known to induce structural and functional impairments throughout the brain, including the hippocampus. Herein, rat pups were administered one of three ethanol doses over postnatal days (PD) 4-9, a period of brain development comparable to the third trimester of human pregnancy. As adults, control and ethanol rats were trained and tested in a variant of hippocampal-dependent one-trial context fear conditioning. In Experiment 1, subjects were placed into a novel context and presented with an immediate footshock (i.e., within ∼8 sec). When re-exposed to the same context 24 hr later low levels of conditioned freezing were observed. Context pre-exposure 24 hr prior to the immediate shock reversed the deficit in sham-intubated and unintubated control rats, enhancing freezing behavior during the context retention test. Even with context pre-exposure, however, significant dose-dependent reductions in contextual freezing were seen in ethanol rats. In Experiment 2, the interval between context pre-exposure and the immediate shock was shortened to 2 hr, in addition to the standard 24 hr. Ethanol rats trained with the 2 hr, but not 24 hr, interval displayed retention test freezing levels roughly equal to controls. Results suggest the ethanol rats can encode a short-term context memory and associate it with the aversive footshock 2 hr later. In the 24 hr ethanol rats the short-term context memory is poorly transferred or consolidated into long-term memory, we propose, impeding the memory's subsequent retrieval and association with shock.
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Affiliation(s)
- Molly J Goodfellow
- Department of Psychology, The Ohio State University, Columbus, OH, 43210
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Idrus NM, McGough NNH, Riley EP, Thomas JD. Administration of memantine during withdrawal mitigates overactivity and spatial learning impairments associated with neonatal alcohol exposure in rats. Alcohol Clin Exp Res 2014; 38:529-37. [PMID: 24428701 DOI: 10.1111/acer.12259] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Accepted: 07/02/2013] [Indexed: 12/24/2022]
Abstract
BACKGROUND Prenatal alcohol exposure can disrupt central nervous system development, manifesting as behavioral deficits that include motor, emotional, and cognitive dysfunction. Both clinical and animal studies have reported binge drinking during development to be highly correlated with an increased risk of fetal alcohol spectrum disorders (FASD). We hypothesized that binge drinking may be especially damaging because it is associated with episodes of alcohol withdrawal. Specifically, we have been investigating the possibility that NMDA receptor-mediated excitotoxicity occurs during alcohol withdrawal and contributes to developmental alcohol-related neuropathology. Consistent with this hypothesis, administration of the NMDA receptor antagonists MK-801 or eliprodil during withdrawal attenuates behavioral alterations associated with early alcohol exposure. In this study, we investigated the effects of memantine, a clinically used NMDA receptor antagonist, on minimizing ethanol-induced overactivity and spatial learning deficits. METHODS Sprague-Dawley pups were exposed to 6.0 g/kg ethanol via intubation on postnatal day (PD) 6, a period of brain development that models late gestation in humans. Controls were intubated with a calorically matched maltose solution. During withdrawal, 24 and 36 hours after ethanol exposure, subjects were injected with a total of either 0, 20, or 30 mg/kg memantine. The subjects' locomotor levels were recorded in open field activity monitors on PDs 18 to 21 and on a serial spatial discrimination reversal learning task on PDs 40 to 43. RESULTS Alcohol exposure induced overactivity and impaired performance in spatial learning. Memantine administration significantly attenuated the ethanol-associated behavioral alterations in a dose-dependent manner. Thus, memantine may be neuroprotective when administered during ethanol withdrawal. CONCLUSIONS These data have important implications for the treatment of EtOH's neurotoxic effects and provide further support that ethanol withdrawal significantly contributes to FASD.
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Affiliation(s)
- Nirelia M Idrus
- Center for Behavioral Teratology, Department of Psychology, San Diego State University, San Diego, California
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Diaz MR, Jotty K, Locke JL, Jones SR, Valenzuela CF. Moderate Alcohol Exposure during the Rat Equivalent to the Third Trimester of Human Pregnancy Alters Regulation of GABAA Receptor-Mediated Synaptic Transmission by Dopamine in the Basolateral Amygdala. Front Pediatr 2014; 2:46. [PMID: 24904907 PMCID: PMC4035091 DOI: 10.3389/fped.2014.00046] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/10/2014] [Indexed: 01/22/2023] Open
Abstract
Fetal ethanol (EtOH) exposure leads to a range of neurobehavioral alterations, including deficits in emotional processing. The basolateral amygdala (BLA) plays a critical role in modulating emotional processing, in part, via dopamine (DA) regulation of GABA transmission. This BLA modulatory system is acquired during the first 2 weeks of postnatal life in rodents (equivalent to the third trimester of human pregnancy) and we hypothesized that it could be altered by EtOH exposure during this period. We found that exposure of rats to moderate levels of EtOH vapor during the third trimester-equivalent [postnatal days (P) 2-12] alters DA modulation of GABAergic transmission in BLA pyramidal neurons during periadolescence. Specifically, D1R-mediated potentiation of spontaneous inhibitory postsynaptic currents (IPSCs) was significantly attenuated in EtOH-exposed animals. However, this was associated with a compensatory decrease in D3R-mediated suppression of miniature IPSCs. Western blot analysis revealed that these effects were not a result of altered D1R or D3R levels. BLA samples from EtOH-exposed animals also had significantly lower levels of the DA precursor (L-3,4-dihydroxyphenylalanine) but DA levels were not affected. This is likely a consequence of reduced catabolism of DA, as indicated by reduced levels of 3,4-dihydroxyphenylacetic acid and homovanillic acid in the BLA samples. Anxiety-like behavior was not altered in EtOH-exposed animals. This is the first study to demonstrate that the modulatory actions of DA in the BLA are altered by developmental EtOH exposure. Although compensatory adaptations were engaged in our moderate EtOH exposure paradigm, it is possible that these are not able to restore homeostasis and correct anxiety-like behaviors under conditions of heavier EtOH exposure. Therefore, future studies should investigate the potential role of alterations in the modulatory actions of DA in the pathophysiology of fetal alcohol spectrum disorders.
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Affiliation(s)
- Marvin Rafael Diaz
- Department of Neurosciences, University of New Mexico Health Sciences Center , Albuquerque, NM , USA
| | - Karick Jotty
- Department of Neurosciences, University of New Mexico Health Sciences Center , Albuquerque, NM , USA
| | - Jason L Locke
- Department of Physiology and Pharmacology, Wake Forest School of Medicine , Winston-Salem, NC , USA
| | - Sara R Jones
- Department of Physiology and Pharmacology, Wake Forest School of Medicine , Winston-Salem, NC , USA
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Sickmann HM, Patten AR, Morch K, Sawchuk S, Zhang C, Parton R, Szlavik L, Christie BR. Prenatal ethanol exposure has sex-specific effects on hippocampal long-term potentiation. Hippocampus 2013; 24:54-64. [PMID: 23996604 DOI: 10.1002/hipo.22203] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2013] [Indexed: 11/09/2022]
Abstract
Alcohol consumption during pregnancy is deleterious to the developing brain of the fetus and leads to persistent deficits in adulthood. Long-term potentiation (LTP) is a biological model for learning and memory processes and previous evidence has shown that prenatal ethanol exposure (PNEE) affects LTP in a sex specific manner during adolescence. The objective of this study was to determine if there are sex specific differences in adult animals and to elucidate the underlying molecular mechanisms that contribute to these differences. Pregnant Sprague-Dawley dams were assigned to either; liquid ethanol, pair-fed or standard chow diet. In vivo electrophysiology was performed in the hippocampal dentate gyrus (DG) of adult offspring. LTP was induced by administering 400 Hz stimuli. Western blot analysis for glutamine synthetase (GS) and glutamate decarboxylase from tissue of the DG indicated that GS expression was increased following PNEE. Surprisingly, adult females did not show any deficit in N-methyl-D-aspartate (NMDA)-dependent LTP after PNEE. In contrast, males showed a 40% reduction in LTP. It was indicated that glutamine synthetase expression was increased in PNEE females, suggesting that altered excitatory neurotransmitter replenishment may serve as a compensatory mechanism. Ovariectomizing females did not influence LTP in control or PNEE animals, suggesting that circulating estradiol levels do not play a major role in maintaining LTP levels in PNEE females. These results demonstrate the sexually dimorphic effects of PNEE on the ability for the adult brain to elicit LTP in the DG. The mechanisms for these effects are not fully understood, but an increase in glutamine synthetase in females may underlie this phenomenon.
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Affiliation(s)
- H M Sickmann
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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Hippocampal-dependent Pavlovian conditioning in adult rats exposed to binge-like doses of ethanol as neonates. Behav Brain Res 2012; 242:191-9. [PMID: 23274841 DOI: 10.1016/j.bbr.2012.12.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 01/13/2023]
Abstract
Binge-like postnatal ethanol exposure produces significant damage throughout the brain in rats, including the cerebellum and hippocampus. In the current study, cue- and context-mediated Pavlovian conditioning were assessed in adult rats exposed to moderately low (3E; 3g/kg/day) or high (5E; 5g/kg/day) doses of ethanol across postnatal days 4-9. Ethanol-exposed and control groups were presented with 8 sessions of trace eyeblink conditioning followed by another 8 sessions of delay eyeblink conditioning, with an altered context presented over the last two sessions. Both forms of conditioning rely on the brainstem and cerebellum, while the more difficult trace conditioning also requires the hippocampus. The hippocampus is also needed to gate or modulate expression of the eyeblink conditioned response (CR) based on contextual cues. Results indicate that the ethanol-exposed rats were not significantly impaired in trace EBC relative to control subjects. In terms of CR topography, peak amplitude was significantly reduced by both doses of alcohol, whereas onset latency but not peak latency was significantly lengthened in the 5E rats across the latter half of delay EBC in the original training context. Neither dosage resulted in significant impairment in the contextual gating of the behavioral response, as revealed by similar decreases in CR production across all four treatment groups following introduction of the novel context. Results suggest ethanol-induced brainstem-cerebellar damage can account for the present results, independent of the putative disruption in hippocampal development and function proposed to occur following postnatal ethanol exposure.
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Helfer JL, White ER, Christie BR. Enhanced deficits in long-term potentiation in the adult dentate gyrus with 2nd trimester ethanol consumption. PLoS One 2012; 7:e51344. [PMID: 23227262 PMCID: PMC3515437 DOI: 10.1371/journal.pone.0051344] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 11/05/2012] [Indexed: 12/05/2022] Open
Abstract
Ethanol exposure during pregnancy can cause structural and functional changes in the brain that can impair cognitive capacity. The hippocampal formation, an area of the brain strongly linked with learning and memory, is particularly vulnerable to the teratogenic effects of ethanol. In the present experiments we sought to determine if the functional effects of developmental ethanol exposure could be linked to ethanol exposure during any single trimester-equivalent. Ethanol exposure during the 1st or 3rd trimester-equivalent produced only minor changes in synaptic plasticity in adult offspring. In contrast, ethanol exposure during the 2nd trimester equivalent resulted in a pronounced decrease in long-term potentiation, indicating that the timing of exposure influences the severity of the deficit. Together, the results from these experiments demonstrate long-lasting alterations in synaptic plasticity as the result of developmental ethanol exposure and dependent on the timing of exposure. Furthermore, these results allude to neural circuit malfunction within the hippocampal formation, perhaps relating to the learning and memory deficits observed in individuals with fetal alcohol spectrum disorders.
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Affiliation(s)
- Jennifer L. Helfer
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Emily R. White
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Graduate Program in Neuroscience, University of Victoria, Victoria, British Columbia, Canada
| | - Brian R. Christie
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- Graduate Program in Neuroscience, University of Victoria, Victoria, British Columbia, Canada
- Graduate Program in Neuroscience and the Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- The Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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Ali SF, Onaivi ES, Dodd PR, Cadet JL, Schenk S, Kuhar MJ, Koob GF. Understanding the Global Problem of Drug Addiction is a Challenge for IDARS Scientists. Curr Neuropharmacol 2011; 9:2-7. [PMID: 21886551 PMCID: PMC3137181 DOI: 10.2174/157015911795017245] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 04/17/2010] [Accepted: 05/26/2010] [Indexed: 11/22/2022] Open
Abstract
IDARS is an acronym for the International Drug Abuse Research Society. Apart from our scientific and educational purposes, we communicate information to the general and scientific community about substance abuse and addiction science and treatment potential. Members of IDARS are research scientists and clinicians from around the world, with scheduled meetings across the globe. IDARS is developing a vibrant and exciting international mechanism not only for scientific interactions in the domain of addiction between countries but also ultimately as a resource for informing public policy across nations. Nonetheless, a lot more research needs to be done to better understand the neurobiological basis of drug addiction - A challenge for IDARS scientists.
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Affiliation(s)
- S F Ali
- Neurochemistry Laboratory, NCTR/FDA, Jefferson, AR, USA
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Zink M, Ferbert T, Frank ST, Seufert P, Gebicke-Haerter PJ, Spanagel R. Perinatal exposure to alcohol disturbs spatial learning and glutamate transmission-related gene expression in the adult hippocampus. Eur J Neurosci 2011; 34:457-68. [DOI: 10.1111/j.1460-9568.2011.07776.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Pian JP, Criado JR, Milner R, Ehlers CL. N-methyl-D-aspartate receptor subunit expression in adult and adolescent brain following chronic ethanol exposure. Neuroscience 2010; 170:645-54. [PMID: 20603193 DOI: 10.1016/j.neuroscience.2010.06.065] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 06/16/2010] [Accepted: 06/25/2010] [Indexed: 11/17/2022]
Abstract
Substantial evidence suggests that glutamatergic neurotransmission is a critical mediator of the experience-dependent synaptic plasticity that may underlie alcohol dependence. Substance abuse typically begins in adolescence; therefore, the impact of alcohol on glutamatergic systems during this critical time in brain development is of particular importance. The N-methyl-d-aspartate receptor (NMDAR) is involved in developmental mechanisms underlying neuronal differentiation and synaptogenesis and as such may be a target system for alcohol effects during adolescence. In the present study quantitative biochemical determinations were made of the relative abundance of different protein expressions of NMDAR subunits in adolescents and adults after 2 weeks of ethanol vapor exposure, and 24 h and 2 weeks following withdrawal. After 2 weeks of ethanol vapor exposure N-methyl-d-aspartate receptor NR1 subunit (NR1), N-methyl-d-aspartate receptor NR2A subunit (NR2A), and N-methyl-d-aspartate receptor NR2B subunit (NR2B) subunit expression was found to be increased in hippocampus of the adults. In contrast, 2 weeks of ethanol exposure resulted in no significant changes in NR1 and NR2B subunits and a reduction NR2A subunit expression in hippocampus in adolescents. Twenty-four h and 2 weeks following withdrawal from ethanol vapor NR1 and NR2A subunit expression in hippocampus was decreased in adolescents, whereas in adults it had returned to control levels. In frontal cortex, 2 weeks of chronic ethanol exposure produced decreases in NR1 subunit expression in both adults and adolescents but also produced decreases in NR2A and NR2B subunit expression in adults that returned or exceeded control levels by 2 weeks following withdrawal from ethanol vapor. These results demonstrate that NMDAR subunit composition can be modulated differentially between adolescents and adults by chronic ethanol exposure and withdrawal. These developmental differences in NMDAR subunits composition may also be associated with the enhanced vulnerability of the adolescent brain to ethanol dependence.
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Affiliation(s)
- J P Pian
- Department of Molecular and Integrative Neurosciences, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Nixon K, Morris SA, Liput DJ, Kelso ML. Roles of neural stem cells and adult neurogenesis in adolescent alcohol use disorders. Alcohol 2010; 44:39-56. [PMID: 20113873 DOI: 10.1016/j.alcohol.2009.11.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 10/24/2009] [Accepted: 11/07/2009] [Indexed: 01/19/2023]
Abstract
This review discusses the contributions of a newly considered form of plasticity, the ongoing production of new neurons from neural stem cells, or adult neurogenesis, within the context of neuropathologies that occur with excessive alcohol intake in the adolescents. Neural stem cells and adult neurogenesis are now thought to contribute to the structural integrity of the hippocampus, a limbic system region involved in learning, memory, behavioral control, and mood. In adolescents with alcohol use disorders (AUDs), the hippocampus appears to be particularly vulnerable to the neurodegenerative effects of alcohol, but the role of neural stem cells and adult neurogenesis in alcoholic neuropathology has only recently been considered. This review encompasses a brief overview of neural stem cells and the processes involved in adult neurogenesis, how neural stem cells are affected by alcohol, and possible differences in the neurogenic niche between adults and adolescents. Specifically, what is known about developmental differences in adult neurogenesis between the adult and adolescent is gleaned from the literature, as well as how alcohol affects this process differently among the age groups. Finally, this review suggests differences that may exist in the neurogenic niche between adults and adolescents and how these differences may contribute to the susceptibility of the adolescent hippocampus to damage. However, many more studies are needed to discern whether these developmental differences contribute to the vulnerability of the adolescent to developing an AUD.
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Samudio-Ruiz SL, Allan AM, Sheema S, Caldwell KK. Hippocampal N-methyl-D-aspartate receptor subunit expression profiles in a mouse model of prenatal alcohol exposure. Alcohol Clin Exp Res 2009; 34:342-53. [PMID: 19951292 DOI: 10.1111/j.1530-0277.2009.01096.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Although several reports have been published showing prenatal ethanol exposure is associated with alterations in N-methyl-D-aspartate (NMDA) receptor subunit levels and, in a few cases, subcellular distribution, results of these studies are conflicting. METHODS We used semi-quantitative immunoblotting techniques to analyze NMDA receptor NR1, NR2A, and NR2B subunit levels in the adult mouse hippocampal formation isolated from offspring of dams who consumed moderate amounts of ethanol throughout pregnancy. We employed subcellular fractionation and immunoprecipitation techniques to isolate synaptosomal membrane- and postsynaptic density protein-95 (PSD-95)-associated pools of receptor subunits. RESULTS We found that, compared to control animals, fetal alcohol-exposed (FAE) adult mice had: (i) increased synaptosomal membrane NR1 levels with no change in association of this subunit with PSD-95 and no difference in total NR1 expression in tissue homogenates; (ii) decreased NR2A subunit levels in hippocampal homogenates, but no alterations in synaptosomal membrane NR2A levels and no change in NR2A-PSD-95 association; and (iii) no change in tissue homogenate or synaptosomal membrane NR2B levels but a reduction in PSD-95-associated NR2B subunits. No alterations were found in mRNA levels of NMDA receptor subunits suggesting that prenatal alcohol-associated differences in subunit protein levels are the result of differences in post-transcriptional regulation of subunit localization. CONCLUSIONS Our results demonstrate that prenatal alcohol exposure induces selective changes in NMDA receptor subunit levels in specific subcellular locations in the adult mouse hippocampal formation. Of particular interest is the finding of decreased PSD-95-associated NR2B levels, suggesting that synaptic NR2B-containing NMDA receptor concentrations are reduced in FAE animals. This result is consistent with various biochemical, physiological, and behavioral findings that have been linked with prenatal alcohol exposure.
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Affiliation(s)
- Sabrina L Samudio-Ruiz
- Department of Neurosciences, School of Medicine, University of New Mexico, Albuquerque, New Mexico, USA
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Ridge JP, Ho AMC, Dodd PR. Sex differences in NMDA receptor expression in human alcoholics. Alcohol Alcohol 2009; 44:594-601. [PMID: 19736238 DOI: 10.1093/alcalc/agp052] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIM The aim of this study was to assess whether chronic alcohol misuse affects N-methyl-d-aspartate (NMDA) receptor subunit concentrations in human cases, and whether male and female subjects respond differently. METHODS Real-time RT-PCR normalized to GAPDH was used to assay NR1, NR2A and NR2B subunit mRNA in superior frontal (SFC) and primary motor (PMC) cortex tissue obtained at autopsy from chronic alcoholics with and without comorbid cirrhosis of the liver, and from matched controls. RESULTS The expression of all three subunits was significantly lower in both areas of cirrhotic alcoholics than in either controls or alcoholics without comorbid disease, who did not differ significantly. Values were also influenced by the subject's sex and genotype. The mu-opiate receptor C1031G polymorphism selectively modulated NMDA transcript expression in cirrhotic-alcoholic SFC, an effect that was more marked for NR1 and NR2A than for NR2B subunit transcripts. Contrasting 5HT1B genotypes affected NMDA mRNA expression differently in male and female SFC, but not PMC, in cirrhotic alcoholics. CONCLUSION NMDA receptor subunit expression may differentially influence male and female cirrhotic alcoholics' susceptibility to brain damage.
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Affiliation(s)
- Justin P Ridge
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Brisbane, Australia
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Samudio-Ruiz SL, Allan AM, Valenzuela CF, Perrone-Bizzozero NI, Caldwell KK. Prenatal ethanol exposure persistently impairs NMDA receptor-dependent activation of extracellular signal-regulated kinase in the mouse dentate gyrus. J Neurochem 2009; 109:1311-23. [PMID: 19317851 DOI: 10.1111/j.1471-4159.2009.06049.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dentate gyrus (DG) is the central input region to the hippocampus and is known to play an important role in learning and memory. Previous studies have shown that prenatal alcohol is associated with hippocampal-dependent learning deficits and a decreased ability to elicit long-term potentiation (LTP) in the DG in adult animals. Given that activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling cascade by NMDA receptors is required for various forms of learning and memory, as well as LTP, in hippocampal regions, including the DG, we hypothesized that fetal alcohol-exposed adult animals would have deficits in hippocampal NMDA receptor-dependent ERK1/2 activation. We used immunoblotting and immunohistochemistry techniques to detect NMDA-stimulated ERK1/2 activation in acute hippocampal slices prepared from adult fetal alcohol-exposed mice. We present the first evidence linking prenatal alcohol exposure to deficits in NMDA receptor-dependent ERK1/2 activation specifically in the DG of adult offspring. This deficit may account for the LTP deficits previously observed in the DG, as well as the life-long cognitive deficits, associated with prenatal alcohol exposure.
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Affiliation(s)
- Sabrina L Samudio-Ruiz
- Department of Neurosciences, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
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Wei X, Zhang Z, Zhao L, Si J. CCK-8S inhibited the NMDA-activated current of cultured hippocampal neuron under normal and ethanol exposure conditions. Neurosci Lett 2009; 449:34-7. [DOI: 10.1016/j.neulet.2008.10.078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 09/26/2008] [Accepted: 10/21/2008] [Indexed: 11/26/2022]
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Wijayawardhane N, Shonesy BC, Vaglenova J, Vaithianathan T, Carpenter M, Breese CR, Dityatev A, Suppiramaniam V. Postnatal aniracetam treatment improves prenatal ethanol induced attenuation of AMPA receptor-mediated synaptic transmission. Neurobiol Dis 2007; 26:696-706. [PMID: 17493826 DOI: 10.1016/j.nbd.2007.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 03/23/2007] [Accepted: 03/24/2007] [Indexed: 10/23/2022] Open
Abstract
Aniracetam is a nootropic compound and an allosteric modulator of AMPA receptors (AMPARs) which mediate synaptic mechanisms of learning and memory. Here we analyzed impairments in AMPAR-mediated synaptic transmission caused by moderate prenatal ethanol exposure and investigated the effects of postnatal aniracetam treatment on these abnormalities. Pregnant Sprague-Dawley rats were gavaged with ethanol or isocaloric sucrose throughout pregnancy, and subsequently the offspring were treated with aniracetam on postnatal days (PND) 18 to 27. Hippocampal slices prepared from these pups on PND 28 to 34 were used for the whole-cell patch-clamp recordings of AMPAR-mediated spontaneous and miniature excitatory postsynaptic currents in CA1 pyramidal cells. Our results indicate that moderate ethanol exposure during pregnancy results in impaired hippocampal AMPAR-mediated neurotransmission, and critically timed aniracetam treatment can abrogate this deficiency. These results highlight the possibility that aniracetam treatment can restore synaptic transmission and ameliorate cognitive deficits associated with the fetal alcohol syndrome.
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Affiliation(s)
- Nayana Wijayawardhane
- Department of Pharmacal Sciences, 401 Walker Building, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849, USA
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Mello CF, Rubin MA, Sultana R, Barron S, Littleton JM, Butterfield DA. Difluoromethylornithine decreases long-lasting protein oxidation induced by neonatal ethanol exposure in the hippocampus of adolescent rats. Alcohol Clin Exp Res 2007; 31:887-94. [PMID: 17386069 DOI: 10.1111/j.1530-0277.2007.00369.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Ethanol exposure and withdrawal during central nervous system development can cause oxidative stress and produce severe and long-lasting behavioral and morphological alterations in which polyamines seem to play an important role. However, it is not known if early ethanol exposure causes long-lasting protein oxidative damage and if polyamines play a role in such a deleterious effect of ethanol. METHODS In this study we investigated the effects of early ethanol exposure (6 g/kg/d, by gavage), from postnatal day (PND) 1 to 8, and of the administration of difluoromethylornithine (DFMO, 500 mg/kg, i.p., on PND 8), a polyamine biosynthesis inhibitor, on the extent of oxidative modification of proteins. Indices of oxidative modification of proteins included protein carbonyls, 3-nitrotyrosine (3-NT), and protein bound 4-hydroxynonenal (HNE) in the hippocampus, cerebellum, hypothalamus, striatum, and cerebral cortex of Sprague-Dawley rats at PND 40. RESULTS Both ethanol and DFMO administration alone increased protein carbonyl immunoreactivity in the hippocampus at PND 40, but the combination of DFMO and ethanol resulted in no effect on protein carbonyl levels. No alterations in the content of protein-bound HNE, 3-NT, or carbonyl were found in any other cerebral structure. CONCLUSIONS These results suggest that the hippocampus is selectively affected by early ethanol exposure and by polyamine synthesis inhibition. In addition, the results suggest a role for polyamines in the long-lasting increase of protein carbonyls induced by ethanol exposure and withdrawal.
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Affiliation(s)
- Carlos Fernando Mello
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Santa Maria, Santa Maria, Brazil
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Rashotte ME. Abram Amsel (1922-2006) in memoriam. Learn Behav 2007; 35:1-10. [PMID: 17557386 DOI: 10.3758/bf03196068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
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Dubois C, Naassila M, Daoust M, Pierrefiche O. Early chronic ethanol exposure in rats disturbs respiratory network activity and increases sensitivity to ethanol. J Physiol 2006; 576:297-307. [PMID: 16857714 PMCID: PMC1995622 DOI: 10.1113/jphysiol.2006.111138] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Chronic ethanol exposure during the fetal period alters spontaneous neuronal discharge, excitatory and inhibitory amino acid neurotransmission and neuronal sensitivity to ethanol in the adult brain. However, nothing is known about the effects of such exposure on the central respiratory rhythmic network, which is highly dependent on ethanol-sensitive amino acid neurotransmission. In 3- to 4-week-old rats, we investigated (1) the effects of chronic ethanol exposure (10% v/v as only source of fluid) during gestation and lactation on phrenic (Phr) and hypoglossal (XII) nerve activity using an in situ preparation and on spontaneous breathing at rest in unanaesthetized animals using plethysmography; (2) the sensitivity of the respiratory system to ethanol re-exposure in situ; and (3) the phrenic nerve response to muscimol, a GABA(A) receptor agonist, applied systemically in an in situ preparation. In control rats, ethanol (10-80 mm) induced a concentration-dependent decrease in the amplitude of both XII and Phr motor outflows. At 80 mm ethanol, the amplitude of the activity of the two nerves displayed a difference in sensitivity to ethanol and respiratory frequency increased as a result of shortening of postinspiratory duration period. After chronic ethanol exposure, respiratory frequency was significantly reduced by 43% in situ and by 23% in unanaesthetized animals, as a result of a selective increase in expiratory duration. During Phr burst, the ramp was steeper, revealing modification of inspiratory patterning. Interestingly that re-exposure to ethanol in situ elicited a dramatic inhibitory effect. At 80 mm, ethanol abolished rhythmic XII nerve outflow in all cases and Phr nerve outflow in only 50% of cases. Furthermore, administration of 50 microm muscimol abolished Phr nerve activity in all control rats, but only in 50% of ethanol-exposed animals. Our results demonstrate that chronic ethanol exposure at an early stage of brain development depresses breathing in juvenile rats, and sensitizes the respiratory network to re-exposure to ethanol, which does not seem to involve GABAergic neurotransmission.
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Affiliation(s)
- C Dubois
- GRAP-JE 2462, Groupe de Recherche sur l'Alcool et les Pharmacodépendances, UFR de Pharmacie, 1, rue des Louvels, 80036 Amiens, France
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Abstract
This article summarizes a symposium on context and alcohol-related cognitions presented at the 2004 Annual Meeting of the Research Society on Alcoholism in Vancouver, British Columbia, Canada. The studies reported here examine how the manipulation of contextual variables influences the availability of alcohol outcome expectancies and implicit memories for alcohol associations. The symposium illustrates the range of context variables and shows some of the potential impact of retrieval on cognitions that predict alcohol use. Two of the studies explore naturalistic drinking contexts: one examines the impact of stress induction, and one assesses within survey question placement effects. A variety of measures of alcohol cognitions were used. The results demonstrate that alcohol cognitions are more accessible in alcohol-related contexts. Moreover, availability of alcohol associations and expectancies depended on individual differences. These results underscore the potential value of memory processes in the retrieval and measurement of alcohol cognitions. The findings have direct implications for improving methods of predicting alcohol use and in understanding the role of alcohol cognitions in various contexts associated with alcohol use.
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Affiliation(s)
- Marvin Krank
- Department of Psychology, Okanagan University College, Kelowna, British Columbia, Canada.
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Izumi Y, Kitabayashi R, Funatsu M, Izumi M, Yuede C, Hartman RE, Wozniak DF, Zorumski CF. A single day of ethanol exposure during development has persistent effects on bi-directional plasticity, N-methyl-d-aspartate receptor function and ethanol sensitivity. Neuroscience 2005; 136:269-79. [PMID: 16181739 DOI: 10.1016/j.neuroscience.2005.07.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Revised: 07/06/2005] [Accepted: 07/06/2005] [Indexed: 11/22/2022]
Abstract
To determine factors that contribute to the learning deficits observed in individuals with fetal alcohol syndrome, we examined the effects of early postnatal ethanol exposure on forms of synaptic plasticity thought to underlie memory. Treatment of rat pups with ethanol on postnatal day 7 impaired the induction of N-methyl-D-aspartate receptor-dependent long-term potentiation and abolished homosynaptic long-term depression in the CA1 region of hippocampal slices prepared at postnatal day 30. An N-methyl-D-aspartate receptor-independent form of long-term potentiation induced by very high frequency stimulation could be induced in slices from ethanol-treated rats. Defects in long-term depression correlated with a diminished contribution of ifenprodil-sensitive N-methyl-D-aspartate receptors to synaptic transmission and defects in a spontaneous alternation behavioral task. Rats exposed to ethanol on postnatal day 7 also exhibited diminished sensitivity of synaptic N-methyl-D-aspartate receptors to block by ethanol at postnatal day 30 and decreased behavioral sedation to systemic ethanol injections. These results indicate that changes in synaptic plasticity and N-methyl-D-aspartate receptor function are likely to provide a neural substrate for the cognitive and behavioral changes that follow developmental ethanol exposure.
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Affiliation(s)
- Y Izumi
- Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Abstract
AIMS To describe recent research focusing on the analysis of gene and protein expression relevant to understanding ethanol consumption, dependence and effects, in order to identify common themes. METHODS A selective literature search was used to collate the relevant data. RESULTS Over 160 genes have been individually assessed before or after ethanol administration, as well as in genetically selected lines. Techniques for studying gene expression include northern blots, differential display, real time reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization. More recently, high throughput functional genomic technology, such as DNA microarrays, has been used to examine gene expression. Recent gene expression analyses have dramatically increased the number of candidate genes (nine array papers have illuminated 600 novel gene transcripts that may contribute to alcohol abuse and alcoholism). CONCLUSIONS Although functional genomic experiments (transcriptome analysis) have failed to identify a single alcoholism gene, they have illuminated important pathways and gene products that may contribute to the risk of alcohol abuse and alcoholism.
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Affiliation(s)
- Travis J Worst
- Center for the Neurobehavioral Study of Alcohol, Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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