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Wang J, Akbari A, Chardahcherik M, Wu J. Ginger (Zingiber Officinale Roscoe) ameliorates ethanol-induced cognitive impairment by modulating NMDA and GABA-A receptors in rat hippocampus. Metab Brain Dis 2024; 39:67-76. [PMID: 37966694 DOI: 10.1007/s11011-023-01301-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 09/24/2023] [Indexed: 11/16/2023]
Abstract
Brain damage caused by ethanol abuse may lead to permanent damage, including severe dementia. The aim of this study was to investigate the effects of ginger powder on ethanol-induced cognitive disorders by examining oxidative damage and inflammation status, and the gene expression of N-methyl-D-aspartate (NMDA) and γ-Aminobutyric acid (GABA)-A receptors in the hippocampus of male rats. 24 adult male Sprague-Dawley rats were allocated randomly to four groups as follows control, ethanol (4g/kg/day, by gavage), ginger (1g/kg/day, by gavage), and ginger-ethanol. At the end of the study, memory and learning were evaluated by the shuttle box test. Moreover, to explore mechanisms involved in ethanol-induced cognitive impairment and the protective effect of ginger, the expression of Nuclear factor kappa B (NF-κB), nuclear factor erythroid 2-related factor 2 (Nrf2), NMDA receptor, and GABA-A receptor was measured along with inflammatory and oxidative biomarkers in the hippocampus tissue. The results showed that ethanol could induce cognitive impairment in the ethanol group, while pretreatment with ginger could reverse it. The gene expression of the NF-κB/ Tumor necrosis factor (TNF)-α/Interleukin (IL)-1β pathway and NMDA and GABA-A receptors significantly increased in the ethanol group compared to the control group. While pretreatment with ginger could significantly improve ethanol-induced cognitive impairment through these pathways in the ginger-ethanol group compared to the ethanol group (P < 0.05). It can be concluded that ginger powder could ameliorate ethanol-induced cognitive impairment by modulating the expression of NMDA and GABA-A receptors and inhibiting oxidative damage and the NF-κB/TNF-α/IL-1β pathway in the rat hippocampus.
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Affiliation(s)
- Jiaojiao Wang
- Department of Neurology, General Hospital of Ningxia Medical University, Yinchuan, 750000, China
| | - Abolfazl Akbari
- Department of Physiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Marjan Chardahcherik
- Department of Biochemistry, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | - Jun Wu
- Department of Internal Medicine, Xi'an Yanta Qiangsen Meilin Hospital, Xi'an, 710000, China.
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2
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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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3
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Stanton ME, Murawski NJ, Jablonski SA, Robinson-Drummer PA, Heroux NA. Mechanisms of context conditioning in the developing rat. Neurobiol Learn Mem 2021; 179:107388. [PMID: 33482320 DOI: 10.1016/j.nlm.2021.107388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/04/2021] [Accepted: 01/12/2021] [Indexed: 12/14/2022]
Abstract
The article reviews our studies of contextual fear conditioning (CFC) in rats during a period of development---Postnatal Day (PND) 17-33---that represents the late-infant, juvenile, and early-adolescent stages. These studies seek to acquire 'systems level' knowledge of brain and memory development and apply it to a rodent model of Fetal Alcohol Spectrum Disorder (FASD). This rodent model focuses on alcohol exposure from PND4-9, a period of brain development equivalent to the human third trimester, when neocortex, hippocampus, and cerebellum are especially vulnerable to adverse effects of alcohol. Our research emphasizes a variant of CFC, termed the Context Preexposure Facilitation Effect (CPFE, Fanselow, 1990), in which context representations incidentally learned on one occasion are retrieved and associated with immediate shock on a subsequent occasion. These representations can be encoded at the earliest developmental stage but seem not to be retained or retrieved until the juvenile period. This is associated with developmental differences in context-elicited expression, in prefrontal cortex, hippocampus, and amygdala, of immediate early genes (IEGs) that are implicated in long-term memory. Loss-of-function studies establish a functional role for these regions as soon as the CPFE emerges during ontogeny. In our rodent model of FASD, the CPFE is much more sensitive to alcohol dose than other commonly used cognitive tasks. This impairment can be reversed by acute administration during behavioral testing of drugs that enhance cholinergic function. This effect is associated with normalized IEG expression in prefrontal cortex during incidental context learning. In summary, our findings suggest that long-term memory of incidentally-learned context representations depends on prefrontal-hippocampal circuitry that is important both for the normative development of context conditioning and for its disruption by developmental alcohol exposure.
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Affiliation(s)
- Mark E Stanton
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States.
| | - Nathen J Murawski
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - Sarah A Jablonski
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | | | - Nicholas A Heroux
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
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4
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Sawchuk SD, Reid HMO, Neale KJ, Shin J, Christie BR. Effects of Ethanol on Synaptic Plasticity and NMDA Currents in the Juvenile Rat Dentate Gyrus. Brain Plast 2020; 6:123-136. [PMID: 33680851 PMCID: PMC7903019 DOI: 10.3233/bpl-200110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background and Objectives: We examined how acute ethanol (EtOH) exposure affects long term depression (LTD) in the dentate gyrus (DG) of the hippocampus in juvenile rats. EtOH is thought to directly modulate n-methyl-D-aspartate receptor (NMDAr) currents, which are believed important for LTD induction. LTD in turn is believed to play an important developmental role in the hippocampus by facilitating synaptic pruning. Methods: Hippocampal slices (350μm) were obtained at post-natal day (PND) 14, 21, or 28. Field EPSPs (excitatory post-synaptic potential) or whole-cell EPSCs (excitatory post-synaptic conductance) were recorded from the DG (dentate gyrus) in response to medial perforant path activation. Low-frequency stimulation (LFS; 900 pulses; 120 s pulse) was used to induce LTD. Results: Whole-cell recordings indicated that EtOH exposure at 50mM did not significantly impact ensemble NMDAr EPSCs in slices obtained from animals in the PND14 or 21 groups, but it reliably produced a modest inhibition in the PND28 group. Increasing the concentration to 100 mM resulted in a modest inhibition of NMDAr EPSCs in all three groups. LTD induction and maintenance was equivalent in magnitude in all three age groups in control conditions, however, and surprisingly, NMDA antagonist AP5 only reliably blocked LTD in the PND21 and 28 age groups. The application of 50 mM EtOH attenuated LTD in all three age groups, however increasing the concentration to 100 mM did not reliably inhibit LTD. Conclusions: These results indicate that the effect of EtOH on NMDAr-EPSCs recorded from DGCs is both age and concentration dependent in juveniles. Low concentrations of EtOH can attenuate, but did not block LTD in the DG. The effects of EtOH on LTD do not align well with it’s effects on NNMDA receptors.
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Affiliation(s)
- Scott D Sawchuk
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Hannah M O Reid
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Katie J Neale
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - James Shin
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Brian R Christie
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Psychology, University of British Columbia, Vancouver, BC, Canada.,Island Medical Program and Department of Cellular and Physiological Sciences, University of British Columbia, Victoria, BC, Canada
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5
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Alcohol as an early life stressor: Epigenetics, metabolic, neuroendocrine and neurobehavioral implications. Neurosci Biobehav Rev 2020; 118:654-668. [PMID: 32976915 DOI: 10.1016/j.neubiorev.2020.08.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/18/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
Ethanol exposure during gestation is an early life stressor that profoundly dysregulates structure and functions of the embryonal nervous system, altering the cognitive and behavioral development. Such dysregulation is also achieved by epigenetic mechanisms, which, altering the chromatin structure, redraw the entire pattern of gene expression. In parallel, an oxidative stress response at the cellular level and a global upregulation of neuroendocrine stress response, regulated by the HPA axis, exist and persist in adulthood. This neurobehavioral framework matches those observed in other psychiatric diseases such as mood diseases, depression, autism; those early life stressing events, although probably triggered by specific and different epigenetic mechanisms, give rise to largely overlapping neurobehavioral phenotypes. An early diagnosis of prenatal alcohol exposure, using reliable markers of ethanol intake, together with a deeper understanding of the pathogenic mechanisms, some of them reversible by their nature, can offer a temporal "window" of intervention. Supplementing a mother's diet with protective and antioxidant substances in addition to supportive psychological therapies can protect newborns from being affected.
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6
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Post-exposure environment modulates long-term developmental ethanol effects on behavior, neuroanatomy, and cortical oscillations. Brain Res 2020; 1748:147128. [PMID: 32950485 DOI: 10.1016/j.brainres.2020.147128] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/25/2020] [Accepted: 09/12/2020] [Indexed: 11/23/2022]
Abstract
Developmental exposure to ethanol has a wide range of anatomical, cellular, physiological and behavioral impacts that can last throughout life. In humans, this cluster of effects is termed fetal alcohol spectrum disorder and is highly prevalent in western cultures. The ultimate expression of the effects of developmental ethanol exposure however can be influenced by post-exposure experience. Here we examined the effects of developmental binge exposure to ethanol (postnatal day 7) in C57BL/6By mice on a specific cohort of inter-related long-term outcomes including contextual memory, hippocampal parvalbumin-expressing neuron density, frontal cortex oscillations related to sleep-wake cycling including delta oscillation amplitude and sleep spindle density, and home-cage behavioral activity. When assessed in adults that were raised in standard housing, all of these factors were altered by early ethanol exposure compared to saline controls except home-cage activity. However, exposure to an enriched environment and exercise from weaning to postnatal day 90 reversed most of these ethanol-induced impairments including memory, CA1 but not dentate gyrus PV+ cell density, delta oscillations and sleep spindles, and enhanced home-cage behavioral activity in Saline- but not EtOH-treated mice. The results are discussed in terms of the inter-dependence of diverse developmental ethanol outcomes and potential mechanisms of post-exposure experiences to regulate those outcomes.
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7
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Gruol DL, Hernandez RV, Roberts A. Alcohol Enhances Responses to High Frequency Stimulation in Hippocampus from Transgenic Mice with Increased Astrocyte Expression of IL-6. Cell Mol Neurobiol 2020; 41:1299-1310. [PMID: 32562098 DOI: 10.1007/s10571-020-00902-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/09/2020] [Indexed: 12/29/2022]
Abstract
Recent studies show that alcohol exposure can induce glial production of neuroimmune factors in the CNS. Of these, IL-6 has gained attention because it is involved in a number of important physiological and pathophysiological processes that could be affected by alcohol-induced CNS production of IL-6, particularly under conditions of excessive alcohol use. For example, IL-6 has been shown to play a role in hippocampal behaviors and synaptic plasticity (long-term potentiation; LTP) associated with memory and learning. Surprisingly, in our in vitro studies of LTP at the Schaffer collateral to CA1 pyramidal neuron synapse in hippocampus from transgenic mice that express elevated levels of astrocyte produced IL-6 (TG), LTP was not altered by the increased levels of IL-6. However, exposure to acute alcohol revealed neuroadaptive changes that served to protect LTP against the alcohol-induced reduction of LTP observed in hippocampus from non-transgenic control mice (WT). Here we examined the induction phase of LTP to assess if presynaptic neuroadaptive changes occurred in the hippocampus of TG mice that contributed to the resistance of LTP to alcohol. Results are consistent with a role for IL-6-induced neuroadaptive effects on presynaptic mechanisms involved in transmitter release in the resistance of LTP to alcohol in hippocampus from the TG mice. These actions are important with respect to a role for IL-6 in physiological and pathophysiological processes in the CNS and in CNS actions of alcohol, especially when excessive alcohol used is comorbid with conditions associated with elevated levels of IL-6 in the CNS.
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Affiliation(s)
- Donna L Gruol
- Neuroscience Department, SR301, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
| | - Ruben V Hernandez
- Neuroscience Department, SR301, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Amanda Roberts
- Animal Models Core Facility, The Scripps Research Institute, La Jolla, CA, 92037, USA
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8
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Waltes R, Freitag CM, Herlt T, Lempp T, Seitz C, Palmason H, Meyer J, Chiocchetti AG. Impact of autism-associated genetic variants in interaction with environmental factors on ADHD comorbidities: an exploratory pilot study. J Neural Transm (Vienna) 2019; 126:1679-1693. [PMID: 31707462 DOI: 10.1007/s00702-019-02101-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 10/29/2019] [Indexed: 02/07/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is determined by genetic and environmental factors, and shares genetic risk with ASD. Functional single-nucleotide polymorphisms of the metabotropic glutamatergic signaling pathway are reported to increase the risk for ASD. The aim of this pilot study was to explore the main effects of respective ASD variants as well as their interaction effects with well-replicated ADHD environmental risk factors on the risk for ADHD, ADHD symptom severities, and comorbidities. We included 318 children with ADHD, aged 5-13 years, and their parents (N = 164 trios, N = 113 duos, N = 41 singletons). Interaction of ASD risk variants CYFIP1-rs7170637, CYFIP1-rs3693, CAMK4-rs25925, and GRM1-rs6923492 with prenatal biological and lifetime psychosocial risk factors was explored in a subsample with complete environmental risk factors (N = 139 trios, N = 83 duos, two singletons) by transmission disequilibrium test and stepwise regression analyses. We identified nominally significant (alpha < 0.05) GxE interactions of acute life events with CYFIP1-rs3693 on ADHD diagnosis (p = 0.004; fdr = 0.096) but no significant association of any single marker. Further results suggest that the risk for comorbid disruptive disorders was significantly modulated by GxE interactions between familial risk factors and CAMK4-rs25925 (p = 0.001; fdr = 0.018) and prenatal alcohol exposure with CYFIP1-rs3693 (p = 0.003; fdr = 0.027); both findings survived correction for multiple testing (fdr value < 0.05). Nominal significant GxE interactions moderating the risk for anxiety disorders have also been identified, but did not pass multiple testing corrections. This pilot study suggests that common ASD variants of the glutamatergic system interact with prenatal and lifetime psychosocial risk factors influencing the risk for ADHD common comorbidities and thus warrants replication in larger samples.
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Affiliation(s)
- Regina Waltes
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, JW Goethe University, Deutschordenstr. 50, 60528, Frankfurt am Main, Germany
| | - Christine M Freitag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, JW Goethe University, Deutschordenstr. 50, 60528, Frankfurt am Main, Germany
| | - Timo Herlt
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, JW Goethe University, Deutschordenstr. 50, 60528, Frankfurt am Main, Germany
| | - Thomas Lempp
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, JW Goethe University, Deutschordenstr. 50, 60528, Frankfurt am Main, Germany
| | - Christiane Seitz
- Department of Child and Adolescent Psychiatry and Psychotherapy, Saarland University Hospital, 66421, Homburg, Germany
| | - Haukur Palmason
- Department of Neurobehavioral Genetics, Institute of Psychobiology, University of Trier, 54290, Trier, Germany
| | - Jobst Meyer
- Department of Neurobehavioral Genetics, Institute of Psychobiology, University of Trier, 54290, Trier, Germany
| | - Andreas G Chiocchetti
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Frankfurt, JW Goethe University, Deutschordenstr. 50, 60528, Frankfurt am Main, Germany.
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9
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Bird CW, Barber MJ, Post HR, Jacquez B, Chavez GJ, Faturos NG, Valenzuela CF. Neonatal ethanol exposure triggers apoptosis in the murine retrosplenial cortex: Role of inhibition of NMDA receptor-driven action potential firing. Neuropharmacology 2019; 162:107837. [PMID: 31689422 DOI: 10.1016/j.neuropharm.2019.107837] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/07/2019] [Accepted: 10/30/2019] [Indexed: 02/07/2023]
Abstract
Exposure to ethanol during the last trimester equivalent of human pregnancy causes apoptotic neurodegeneration in the developing brain, an effect that is thought to be mediated, in part, by inhibition of NMDA receptors. However, NMDA receptors can rapidly adapt to the acute effects of ethanol and are ethanol resistant in some populations of developing neurons. Here, we characterized the effect of ethanol on NMDA and non-NMDA receptor-mediated synaptic transmission in the retrosplenial cortex (RSC), a brain region involved in the integration of different modalities of spatial information that is among the most sensitive regions to ethanol-induced neurodegeneration. A single 4-h exposure to ethanol vapor of 7-day-old transgenic mice that express the Venus fluorescent protein in interneurons triggered extensive apoptosis in the RSC. Slice electrophysiological recordings showed that bath-applied ethanol inhibits NMDA and non-NMDA receptor excitatory postsynaptic currents (EPSCs) in pyramidal neurons and interneurons; however, we found no evidence of acute tolerance development to this effect after the 4-h in-vivo ethanol vapor exposure. Acute bath application of ethanol reduced action potential firing evoked by synaptic stimulation to a greater extent in pyramidal neurons than interneurons. Submaximal inhibition of NMDA EPSCs, but not non-NMDA EPSCs, mimicked the acute effect of ethanol on synaptically-evoked action potential firing. These findings indicate that partial inhibition of NMDA receptors by ethanol has sizable effects on the excitability of glutamatergic and GABAergic neurons in the developing RSC, and suggest that positive allosteric modulators of these receptors could ameliorate ethanol intoxication-induced neurodegeneration during late stages of fetal development.
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Affiliation(s)
- Clark W Bird
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Megan J Barber
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Hilary R Post
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Belkis Jacquez
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Glenna J Chavez
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - Nicholas G Faturos
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA
| | - C Fernando Valenzuela
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA.
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10
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Neonatal ethanol exposure impairs long-term context memory formation and prefrontal immediate early gene expression in adolescent rats. Behav Brain Res 2018; 359:386-395. [PMID: 30447241 DOI: 10.1016/j.bbr.2018.11.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/19/2018] [Accepted: 11/13/2018] [Indexed: 11/21/2022]
Abstract
Fetal alcohol exposure leads to severe disruptions in learning and memory involving the hippocampus and prefrontal cortex in humans. Animal model research on FASD has documented impairment of hippocampal neuroanatomy and function but animal studies of cognition involving the prefrontal cortex are sparse. We have found that a variant of contextual fear conditioning in which both the hippocampus and prefrontal cortex is required, the Context Preexposure Facilitation Effect (CPFE), is particularly sensitive to neurobehavioral disruption caused by neonatal ethanol exposure during the third trimester equivalent of human pregnancy in the rat (i.e., PD4-9). In the CPFE, learning about the context, acquiring a context-shock association, and retrieving contextual fear are temporally separated across three days. The current study asked whether neonatal alcohol exposure impairs context learning, consolidation, or retrieval and examined prefrontal and hippocampal molecular signaling as correlates of this impairment. Long-Evans rats that received oral intubation of ethanol (AE; 5.25 g/kg/day, split into two doses) or underwent sham-intubation (SI) from PND4-9 were tested on the CPFE on PD31-33. Extending our previous reports, ethanol abolished both post-shock and retention test freezing in the CPFE. Assays (qPCR) of immediate early gene expression revealed that ethanol disrupted prefrontal but not hippocampal expression of c-Fos, Arc, Egr-1, and Npas4 during context learning. Finally, ethanol-exposed animals were unimpaired in a standard contextual fear conditioning procedure in which learning about the context and acquiring a context-shock association occurs concurrently. These findings implicate impaired prefrontal function in cognitive deficits arising from 3rd-trimester equivalent alcohol exposure in the rat.
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11
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Jablonski SA, Robinson-Drummer PA, Schreiber WB, Asok A, Rosen JB, Stanton ME. Impairment of the context preexposure facilitation effect in juvenile rats by neonatal alcohol exposure is associated with decreased Egr-1 mRNA expression in the prefrontal cortex. Behav Neurosci 2018; 132:497-511. [PMID: 30346189 DOI: 10.1037/bne0000272] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The context preexposure facilitation effect (CPFE) is a variant of contextual fear conditioning in which learning about the context (preexposure) and associating the context with a shock (training) occur on separate occasions. The CPFE is sensitive to a range of neonatal alcohol doses (Murawski & Stanton, 2011). The current study examined the impact of neonatal alcohol on Egr-1 mRNA expression in the infralimbic (IL) and prelimbic (PL) subregions of the mPFC, the CA1 of dorsal hippocampus (dHPC), and the lateral nucleus of the amygdala (LA), following the preexposure and training phases of the CPFE. Rat pups were exposed to a 5.25 g/kg/day single binge-like dose of alcohol (Group EtOH) or were sham intubated (SI; Group SI) over postnatal days (PD) 7-9. In behaviorally tested rats, alcohol administration disrupted freezing. Following context preexposure, Egr-1 mRNA was elevated in both EtOH and SI groups compared with baseline control animals in all regions analyzed. Following both preexposure and training, Group EtOH displayed a significant decrease in mPFC Egr-1 mRNA expression compared with Group SI. However, this decrease was greatest after training. Training day decreases in Egr-1 expression were not found in LA or CA1 in Group EtOH compared with Group SI. A second experiment confirmed that the EtOH-induced training-day deficits in mPFC Egr-1 mRNA expression were specific to groups which learned contextual fear (vs. nonassociative controls). Thus, memory processes that engage the mPFC during the context-shock association may be most susceptible to the teratogenic effects of neonatal alcohol. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Affiliation(s)
| | | | | | - Arun Asok
- Department of Psychological and Brain Sciences
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12
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Lovinger DM, Abrahao KP. Synaptic plasticity mechanisms common to learning and alcohol use disorder. ACTA ACUST UNITED AC 2018; 25:425-434. [PMID: 30115764 PMCID: PMC6097767 DOI: 10.1101/lm.046722.117] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/21/2018] [Indexed: 11/24/2022]
Abstract
Alcohol use disorders include drinking problems that span a range from binge drinking to alcohol abuse and dependence. Plastic changes in synaptic efficacy, such as long-term depression and long-term potentiation are widely recognized as mechanisms involved in learning and memory, responses to drugs of abuse, and addiction. In this review, we focus on the effects of chronic ethanol (EtOH) exposure on the induction of synaptic plasticity in different brain regions. We also review findings indicating that synaptic plasticity occurs in vivo during EtOH exposure, with a focus on ex vivo electrophysiological indices of plasticity. Evidence for effects of EtOH-induced or altered synaptic plasticity on learning and memory and EtOH-related behaviors is also reviewed. As this review indicates, there is much work needed to provide more information about the molecular, cellular, circuit, and behavioral consequences of EtOH interactions with synaptic plasticity mechanisms.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
| | - Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
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13
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Wong EL, Stowell RD, Majewska AK. What the Spectrum of Microglial Functions Can Teach us About Fetal Alcohol Spectrum Disorder. Front Synaptic Neurosci 2017; 9:11. [PMID: 28674490 PMCID: PMC5474469 DOI: 10.3389/fnsyn.2017.00011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/29/2017] [Indexed: 12/18/2022] Open
Abstract
Alcohol exposure during gestation can lead to severe defects in brain development and lifelong physical, behavioral and learning deficits that are classified under the umbrella term fetal alcohol spectrum disorder (FASD). Sadly, FASD is diagnosed at an alarmingly high rate, affecting 2%–5% of live births in the United States, making it the most common non-heritable cause of mental disability. Currently, no standard therapies exist that are effective at battling FASD symptoms, highlighting a pressing need to better understand the underlying mechanisms by which alcohol affects the developing brain. While it is clear that sensory and cognitive deficits are driven by inappropriate development and remodeling of the neural circuits that mediate these processes, alcohol’s actions acutely and long-term on the brain milieu are diverse and complex. Microglia, the brain’s immune cells, have been thought to be a target for alcohol during development because of their exquisite ability to rapidly detect and respond to perturbations affecting the brain. Additionally, our view of these immune cells is rapidly changing, and recent studies have revealed a myriad of microglial physiological functions critical for normal brain development and long-term function. A clear and complete understanding of how microglial roles on this end of the spectrum may be altered in FASD is currently lacking. Such information could provide important insights toward novel therapeutic targets for FASD treatment. Here we review the literature that links microglia to neural circuit remodeling and provide a discussion of the current understanding of how developmental alcohol exposure affects microglial behavior in the context of developing brain circuits.
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Affiliation(s)
- Elissa L Wong
- Department of Environmental Medicine, University of Rochester Medical CenterRochester, NY, United States
| | - Rianne D Stowell
- Department of Neuroscience, University of Rochester Medical CenterRochester, NY, United States
| | - Ania K Majewska
- Department of Neuroscience, University of Rochester Medical CenterRochester, NY, United States
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Jakubowska‐Dogru E, Elibol B, Dursun I, Yürüker S. Effects of prenatal binge‐like ethanol exposure and maternal stress on postnatal morphological development of hippocampal neurons in rats. Int J Dev Neurosci 2017. [DOI: 10.1016/j.ijdevneu.2017.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Ewa Jakubowska‐Dogru
- Middle East Technical UniversityFaculty of Science and Arts, Department of Biological SciencesAnkaraTurkey
| | - Birsen Elibol
- Bezmialem Vakif University, Faculty of MedicineDepartment of Medical BiologyIstanbulTurkey
| | - Ilknur Dursun
- Istanbul Kemerburgaz University, Faculty of MedicineDepartment of PhysiologyIstanbulTurkey
| | - Sinan Yürüker
- Hacettepe University, Faculty of MedicineDepartment of Histology and EmbryologyAnkaraTurkey
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15
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Harrison NL, Skelly MJ, Grosserode EK, Lowes DC, Zeric T, Phister S, Salling MC. Effects of acute alcohol on excitability in the CNS. Neuropharmacology 2017; 122:36-45. [PMID: 28479395 DOI: 10.1016/j.neuropharm.2017.04.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/04/2017] [Accepted: 04/06/2017] [Indexed: 01/23/2023]
Abstract
Alcohol has many effects on brain function and hence on human behavior, ranging from anxiolytic and mild disinhibitory effects, sedation and motor incoordination, amnesia, emesis, hypnosis and eventually unconsciousness. In recent years a variety of studies have shown that acute and chronic exposure to alcohol can modulate ion channels that regulate excitability. Modulation of intrinsic excitability provides another way in which alcohol can influence neuronal network activity, in addition to its actions on synaptic inputs. In this review, we review "low dose" effects [between 2 and 20 mM EtOH], and "medium dose"; effects [between 20 and 50 mM], by considering in turn each of the many networks and brain regions affected by alcohol, and thereby attempt to integrate in vitro physiological studies in specific brain regions (e.g. amygdala, ventral tegmental area, prefrontal cortex, thalamus, cerebellum etc.) within the context of alcohol's behavioral actions in vivo (e.g. anxiolysis, euphoria, sedation, motor incoordination). This article is part of the Special Issue entitled "Alcoholism".
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Affiliation(s)
- Neil L Harrison
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States.
| | - Mary Jane Skelly
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
| | - Emma K Grosserode
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
| | - Daniel C Lowes
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
| | - Tamara Zeric
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
| | - Sara Phister
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
| | - Michael C Salling
- Departments of Anesthesiology and Pharmacology, College of Physicians and Surgeons, Columbia University, New York, N.Y., 10032, United States
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Boschen KE, Klintsova AY. Neurotrophins in the Brain: Interaction With Alcohol Exposure During Development. VITAMINS AND HORMONES 2016; 104:197-242. [PMID: 28215296 PMCID: PMC5997461 DOI: 10.1016/bs.vh.2016.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fetal alcohol spectrum disorders (FASDs) are a result of the teratogenic effects of alcohol on the developing fetus. Decades of research examining both individuals with FASDs and animal models of developmental alcohol exposure have revealed the devastating effects of alcohol on brain structure, function, behavior, and cognition. Neurotrophic factors have an important role in guiding normal brain development and cellular plasticity in the adult brain. This chapter reviews the current literature showing that alcohol exposure during the developmental period impacts neurotrophin production and proposes avenues through which alcohol exposure and neurotrophin action might interact. These areas of overlap include formation of long-term potentiation, oxidative stress processes, neuroinflammation, apoptosis and cell loss, hippocampal adult neurogenesis, dendritic morphology and spine density, vasculogenesis and angiogenesis, and behaviors related to spatial memory, anxiety, and depression. Finally, we discuss how neurotrophins have the potential to act in a compensatory manner as neuroprotective molecules that can combat the deleterious effects of in utero alcohol exposure.
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Affiliation(s)
- K E Boschen
- University of Delaware, Newark, DE, United States
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17
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Boschen KE, McKeown SE, Roth TL, Klintsova AY. Impact of exercise and a complex environment on hippocampal dendritic morphology, Bdnf gene expression, and DNA methylation in male rat pups neonatally exposed to alcohol. Dev Neurobiol 2016; 77:708-725. [PMID: 27597545 DOI: 10.1002/dneu.22448] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 08/23/2016] [Accepted: 09/01/2016] [Indexed: 12/14/2022]
Abstract
Alcohol exposure in utero can result in Fetal Alcohol Spectrums Disorders (FASD). Measures of hippocampal neuroplasticity, including long-term potentiation, synaptic and dendritic organization, and adult neurogenesis, are consistently disrupted in rodent models of FASD. The current study investigated whether third trimester-equivalent binge-like alcohol exposure (AE) [postnatal days (PD) 4-9] affects dendritic morphology of immature dentate gyrus granule cells, and brain-derived neurotrophic factor (Bdnf) gene expression and DNA methylation in hippocampal tissue in adult male rats. To understand immediate impact of alcohol, DNA methylation was measured in the PD10 hippocampus. In addition, two behavioral interventions, wheel running (WR) and environmental complexity (EC), were utilized as rehabilitative therapies for alcohol-induced deficits. AE significantly decreased dendritic complexity of the immature neurons, demonstrating the long-lasting impact of neonatal alcohol exposure on dendritic morphology of immature neurons in the hippocampus. Both housing conditions robustly enhanced dendritic complexity in the AE animals. While Bdnf exon I DNA methylation was lower in the AE and sham-intubated animals compared with suckle controls on PD10, alterations to Bdnf DNA methylation and gene expression levels were not present at PD72. In control animals, exercise, but not exercise followed by housing in EC, resulted in higher levels of hippocampal Bdnf gene expression and lower DNA methylation. These studies demonstrate the long-lasting negative impact of developmental alcohol exposure on hippocampal dendritic morphology and support the implementation of exercise and complex environments as therapeutic interventions for individuals with FASD. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 708-725, 2017.
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Affiliation(s)
- K E Boschen
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware, 19716
| | - S E McKeown
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware, 19716
| | - T L Roth
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware, 19716
| | - A Y Klintsova
- Department of Psychological and Brain Sciences, University of Delaware, Newark, Delaware, 19716
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18
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Boschen KE, Ruggiero MJ, Klintsova AY. Neonatal binge alcohol exposure increases microglial activation in the developing rat hippocampus. Neuroscience 2016; 324:355-66. [PMID: 26996510 DOI: 10.1016/j.neuroscience.2016.03.033] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 01/05/2023]
Abstract
Aberrant activation of the developing immune system can have long-term negative consequences on cognition and behavior. Teratogens, such as alcohol, activate microglia, the brain's resident immune cells, which could contribute to the lifelong deficits in learning and memory observed in humans with Fetal Alcohol Spectrum Disorders (FASD) and in rodent models of FASD. The current study investigates the microglial response of the brain 24 h following neonatal alcohol exposure (postnatal days (PDs) 4-9, 5.25 g/kg/day). On PD10, microglial cell counts and area of cell territory were assessed using unbiased stereology in the hippocampal subfields CA1, CA3 and dentate gyrus (DG), and hippocampal expression of pro- and anti-inflammatory genes was analyzed. A significant decrease in microglial cell counts in CA1 and DG was found in alcohol-exposed and sham-intubated (SI) animals compared to undisturbed suckle controls (SCs), suggesting overlapping effects of alcohol exposure and intubation alone on the neuroimmune response. Cell territory was decreased in alcohol-exposed animals in CA1, CA3, and DG compared to controls, suggesting the microglia have shifted to a more activated state following alcohol treatment. Furthermore, both alcohol-exposed and SI animals had increased levels of pro-inflammatory cytokines IL-1β, TNF-α, CD11b, and CCL4; in addition, CCL4 was significantly increased in alcohol-exposed animals compared to SI as well. Alcohol-exposed animals also showed increased levels of anti-inflammatory cytokine TGF-β compared to both SI and SCs. In summary, the number and activation of microglia in the neonatal hippocampus are both affected in a rat model of FASD, along with increased gene expression of pro- and anti-inflammatory cytokines. This study shows that alcohol exposure during development induces a neuroimmune response, potentially contributing to long-term alcohol-related changes to cognition, behavior and immune function.
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Affiliation(s)
- K E Boschen
- University of Delaware, Department of Psychological and Brain Sciences, 108 Wolf Hall, Newark, DE 19716, USA.
| | - M J Ruggiero
- University of Delaware, Department of Psychological and Brain Sciences, 108 Wolf Hall, Newark, DE 19716, USA.
| | - A Y Klintsova
- University of Delaware, Department of Psychological and Brain Sciences, 108 Wolf Hall, Newark, DE 19716, USA.
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19
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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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20
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Morton RA, Valenzuela CF. Further characterization of the effect of ethanol on voltage-gated Ca(2+) channel function in developing CA3 hippocampal pyramidal neurons. Brain Res 2015; 1633:19-26. [PMID: 26711851 DOI: 10.1016/j.brainres.2015.12.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/16/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
Abstract
Developmental ethanol exposure damages the hippocampus, a brain region involved in learning and memory. Alterations in synaptic transmission and plasticity may play a role in this effect of ethanol. We previously reported that acute and repeated exposure to ethanol during the third trimester-equivalent inhibits long-term potentiation of GABAA receptor-dependent synaptic currents in CA3 pyramidal neurons through a mechanism that depends on retrograde release of brain-derived neurotrophic factor driven by activation of voltage-gated Ca(2+) channels (Zucca and Valenzuela, 2010). We found evidence indicating that voltage-gated Ca(2+) channels are inhibited in the presence of ethanol, an effect that may play a role in its mechanism of action. Here, we further investigated the acute effect of ethanol on the function of voltage-gated Ca(2+) channels in CA3 pyramidal neurons using Ca(2+) imaging techniques. These experiments revealed that acute ethanol exposure inhibits voltage-gated Ca(2+) channels both in somatic and proximal dendritic compartments. To investigate the long-term consequences of ethanol on voltage-gated Ca(2+) channels, we used patch-clamp electrophysiological techniques to assess the function of L-type voltage-gated Ca(2+) channels during and following ten days of vapor ethanol exposure. During ethanol withdrawal periods, the function of these channels was not significantly affected by vapor chamber exposure. Taken together with our previous findings, our results suggest that 3(rd) trimester-equivalent ethanol exposure transiently inhibits L-type voltage-gated Ca(2+) channel function in CA3 pyramidal neurons and that compensatory mechanisms restore their function during ethanol withdrawal. Transient inhibition of these channels by ethanol may be, in part, responsible for the hippocampal abnormalities associated with developmental exposure to this agent.
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Affiliation(s)
- Russell A Morton
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - C Fernando Valenzuela
- Department of Neurosciences, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
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21
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Patten AR, Sawchuk S, Wortman RC, Brocardo PS, Gil-Mohapel J, Christie BR. Prenatal ethanol exposure impairs temporal ordering behaviours in young adult rats. Behav Brain Res 2015; 299:81-9. [PMID: 26632335 DOI: 10.1016/j.bbr.2015.11.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 02/03/2023]
Abstract
Prenatal ethanol exposure (PNEE) causes significant deficits in functional (i.e., synaptic) plasticity in the dentate gyrus (DG) and cornu ammonis (CA) hippocampal sub-regions of young adult male rats. Previous research has shown that in the DG, these deficits are not apparent in age-matched PNEE females. This study aimed to expand these findings and determine if PNEE induces deficits in hippocampal-dependent behaviours in both male and female young adult rats (PND 60). The metric change behavioural test examines DG-dependent deficits by determining whether an animal can detect a metric change between two identical objects. The temporal order behavioural test is thought to rely in part on the CA sub-region of the hippocampus and determines whether an animal will spend more time exploring an object that it has not seen for a larger temporal window as compared to an object that it has seen more recently. Using the liquid diet model of FASD (where 6.6% (v/v) ethanol is provided through a liquid diet consumed ad libitum throughout the entire gestation), we found that PNEE causes a significant impairment in the temporal order task, while no deficits in the DG-dependent metric change task were observed. There were no significant differences between males and females for either task. These results indicate that behaviours relying partially on the CA-region may be more affected by PNEE than those that rely on the DG.
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Affiliation(s)
- Anna R Patten
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada.
| | - Scott Sawchuk
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada
| | - Ryan C Wortman
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada
| | - Patricia S Brocardo
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada
| | - Brian R Christie
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, British Columbia, Canada; Brain Research Centre and Program in Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada; Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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22
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Xiang Y, Kim KY, Gelernter J, Park IH, Zhang H. Ethanol upregulates NMDA receptor subunit gene expression in human embryonic stem cell-derived cortical neurons. PLoS One 2015; 10:e0134907. [PMID: 26266540 PMCID: PMC4534442 DOI: 10.1371/journal.pone.0134907] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/16/2015] [Indexed: 01/16/2023] Open
Abstract
Chronic alcohol consumption may result in sustained gene expression alterations in the brain, leading to alcohol abuse or dependence. Because of ethical concerns of using live human brain cells in research, this hypothesis cannot be tested directly in live human brains. In the present study, we used human embryonic stem cell (hESC)-derived cortical neurons as in vitro cellular models to investigate alcohol-induced expression changes of genes involved in alcohol metabolism (ALDH2), anti-apoptosis (BCL2 and CCND2), neurotransmission (NMDA receptor subunit genes: GRIN1, GRIN2A, GRIN2B, and GRIN2D), calcium channel activity (ITPR2), or transcriptional repression (JARID2). hESCs were differentiated into cortical neurons, which were characterized by immunostaining using antibodies against cortical neuron-specific biomarkers. Ethanol-induced gene expression changes were determined by reverse-transcription quantitative polymerase chain reaction (RT-qPCR). After a 7-day ethanol (50 mM) exposure followed by a 24-hour ethanol withdrawal treatment, five of the above nine genes (including all four NMDA receptor subunit genes) were highly upregulated (GRIN1: 1.93-fold, P = 0.003; GRIN2A: 1.40-fold, P = 0.003; GRIN2B: 1.75-fold, P = 0.002; GRIN2D: 1.86-fold, P = 0.048; BCL2: 1.34-fold, P = 0.031), and the results of GRIN1, GRIN2A, and GRIN2B survived multiple comparison correction. Our findings suggest that alcohol responsive genes, particularly NMDA receptor genes, play an important role in regulating neuronal function and mediating chronic alcohol consumption-induced neuroadaptations.
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Affiliation(s)
- Yangfei Xiang
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States of America
| | - Kun-Yong Kim
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States of America
| | - Joel Gelernter
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States of America
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT, United States of America
- VA Medical Center, VA Connecticut Healthcare System, West Haven, CT, United States of America
| | - In-Hyun Park
- Department of Genetics, Yale University School of Medicine, New Haven, CT, United States of America
- * E-mail: (HZ); (IHP)
| | - Huiping Zhang
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States of America
- VA Medical Center, VA Connecticut Healthcare System, West Haven, CT, United States of America
- * E-mail: (HZ); (IHP)
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Lantz CL, Sipe GO, Wong EL, Majewska AK, Medina AE. Effects of Developmental Alcohol Exposure on Potentiation and Depression of Visual Cortex Responses. Alcohol Clin Exp Res 2015; 39:1434-42. [PMID: 26108422 PMCID: PMC4515209 DOI: 10.1111/acer.12775] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/07/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Neuronal plasticity deficits are thought to underlie abnormal neurodevelopment in fetal alcohol spectrum disorders and in animal models of this condition. Previously, we found that alcohol exposure during a period that is similar to the last months of gestation in humans disrupts ocular dominance plasticity (ODP), as measured in superficial cortical layers. We hypothesize that exposure to alcohol can differentially affect the potentiation and depression of responses that are necessary for activity-dependent sprouting and pruning of neuronal networks. ODP is an established paradigm that allows the assessment of activity-dependent depression and potentiation of responses in vivo. METHODS Mouse pups were exposed to 3.6 to 5 g/kg of ethanol in saline daily or every other day between postnatal days 4 and 9. Visual cortex plasticity was then assessed during the critical period for ODP using 2 techniques that separately record in layers 4 (visually evoked potentials [VEPs]) and 2/3 (optical imaging of intrinsic signals [OI]). RESULTS We discovered a layer-specific effect of early alcohol exposure. Recording of VEPs from layer 4 showed that while the potentiation component of ODP was disrupted in animals treated with alcohol when compared with saline controls, the depression component of ODP (Dc-ODP) was unaltered. In contrast, OI from layers 2/3 showed that Dc-ODP was markedly disrupted in alcohol-treated animals when compared with controls. CONCLUSIONS Combined with our previous work, these findings strongly suggest that developmental alcohol exposure has a distinct and layer-specific effect on the potentiation and depression of cortical responses after monocular deprivation.
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Affiliation(s)
- Crystal L Lantz
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
- Department of Biology, University of Maryland, College Park, Maryland
| | - Grayson O Sipe
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, Rochester, New York
| | - Elissa L Wong
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York
| | - Ania K Majewska
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, Rochester, New York
| | - Alexandre E Medina
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
- Department of Pediatrics, School of Medicine, University of Maryland, Baltimore, Maryland
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Boschen KE, Criss KJ, Palamarchouk V, Roth TL, Klintsova AY. Effects of developmental alcohol exposure vs. intubation stress on BDNF and TrkB expression in the hippocampus and frontal cortex of neonatal rats. Int J Dev Neurosci 2015; 43:16-24. [PMID: 25805052 PMCID: PMC4442714 DOI: 10.1016/j.ijdevneu.2015.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 03/13/2015] [Accepted: 03/14/2015] [Indexed: 12/16/2022] Open
Abstract
Third trimester-equivalent alcohol exposure causes significant deficits in hippocampal and cortical neuroplasticity, resulting in alterations to dendritic arborization, hippocampal adult neurogenesis, and performance on learning tasks. The current study investigated the impact of neonatal alcohol exposure (postnatal days 4-9, 5.25 g/kg/day) on expression of brain-derived neurotrophic factor (BDNF) and the tropomyosin-related kinase B (TrkB) receptor in the hippocampal and frontal cortex of infant Long-Evans rats. Levels of BDNF protein were increased in the hippocampus, but not frontal cortex, of alcohol-exposed rats 24h after the last dose, when compared with undisturbed (but not sham-intubated) control animals. BDNF protein levels showed a trend toward increase in hippocampus of sham-intubated animals as well, suggesting an effect of the intubation procedure. TrkB protein was increased in the hippocampus of alcohol-exposed animals compared to sham-intubated pups, indicating an alcohol-specific effect on receptor expression. In addition, expression of bdnf total mRNA in alcohol-exposed and sham-intubated pups was enhanced in the hippocampus; however, there was a differential effect of alcohol and intubation stress on exon I- and IV-specific mRNA transcripts. Further, plasma corticosterone was found to be increased in both alcohol-exposed and sham-intubated pups compared to undisturbed animals. Upregulation of BDNF could potentially represent a neuroprotective mechanism activated following alcohol exposure or stress. The results suggest that alcohol exposure and stress have both overlapping and unique effects on BDNF, and highlight the need for the stress of intubation to be taken into consideration in studies that implement this route of drug delivery.
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Affiliation(s)
- K E Boschen
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - K J Criss
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - V Palamarchouk
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - T L Roth
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States
| | - A Y Klintsova
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE 19716, United States.
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25
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Boschen KE, Hamilton GF, Delorme JE, Klintsova AY. Activity and social behavior in a complex environment in rats neonatally exposed to alcohol. Alcohol 2014; 48:533-41. [PMID: 25150044 DOI: 10.1016/j.alcohol.2014.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Environmental complexity (EC) is a powerful, stimulating paradigm that engages animals through a variety of sensory and motor pathways. Exposure to EC (30 days) following 12 days of wheel running preserves hippocampal neuroplasticity in male rats neonatally exposed to alcohol during the third-trimester equivalent (binge-like exposure on postnatal days [PD] 4-9). The current experiment investigates the importance of various components of EC (physical activity, exploration, social interaction, novelty) and examines whether neonatal alcohol exposure affects how male rats interact with their environment and other male rats. Male pups were assigned to 1 of 3 neonatal conditions from PD 4-9: suckle control (SC), sham-intubated (SI), or alcohol-exposed (AE, 5.25 g/kg/day). From PD 30-42 animals were housed with 24-h access to a voluntary running wheel. The animals were then placed in EC from PD 42-72 (9 animals/cage, counterbalanced by neonatal condition). During EC, the animals were filmed for five 30-min sessions (PD 42, 48, 56, 64, 68). For the first experiment, the videos were coded for distance traveled in the cage, overall locomotor activity, time spent near other animals, and interaction with toys. For the second experiment, the videos were analyzed for wrestling, mounting, boxing, grooming, sniffing, and crawling over/under. AE animals were found to be less active and exploratory and engaged in fewer mounting behaviors compared to control animals. Results suggest that after exposure to wheel running, AE animals still have deficits in activity and social behaviors while housed in EC compared to control animals with the same experience.
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Affiliation(s)
- Karen E Boschen
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, USA
| | - Gillian F Hamilton
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, USA
| | - James E Delorme
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, USA
| | - Anna Y Klintsova
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, USA.
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Kleiber ML, Diehl EJ, Laufer BI, Mantha K, Chokroborty-Hoque A, Alberry B, Singh SM. Long-term genomic and epigenomic dysregulation as a consequence of prenatal alcohol exposure: a model for fetal alcohol spectrum disorders. Front Genet 2014; 5:161. [PMID: 24917881 PMCID: PMC4040446 DOI: 10.3389/fgene.2014.00161] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/15/2014] [Indexed: 01/02/2023] Open
Abstract
There is abundant evidence that prenatal alcohol exposure leads to a range of behavioral and cognitive impairments, categorized under the term fetal alcohol spectrum disorders (FASDs). These disorders are pervasive in Western cultures and represent the most common preventable source of neurodevelopmental disabilities. The genetic and epigenetic etiology of these phenotypes, including those factors that may maintain these phenotypes throughout the lifetime of an affected individual, has become a recent topic of investigation. This review integrates recent data that has progressed our understanding FASD as a continuum of molecular events, beginning with cellular stress response and ending with a long-term “footprint” of epigenetic dysregulation across the genome. It reports on data from multiple ethanol-treatment paradigms in mouse models that identify changes in gene expression that occur with respect to neurodevelopmental timing of exposure and ethanol dose. These studies have identified patterns of genomic alteration that are dependent on the biological processes occurring at the time of ethanol exposure. This review also adds to evidence that epigenetic processes such as DNA methylation, histone modifications, and non-coding RNA regulation may underlie long-term changes to gene expression patterns. These may be initiated by ethanol-induced alterations to DNA and histone methylation, particularly in imprinted regions of the genome, affecting transcription which is further fine-tuned by altered microRNA expression. These processes are likely complex, genome-wide, and interrelated. The proposed model suggests a potential for intervention, given that epigenetic changes are malleable and may be altered by postnatal environment. This review accentuates the value of mouse models in deciphering the molecular etiology of FASD, including those processes that may provide a target for the ammelioration of this common yet entirely preventable disorder.
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Affiliation(s)
- Morgan L Kleiber
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
| | - Eric J Diehl
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
| | - Benjamin I Laufer
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
| | - Katarzyna Mantha
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
| | | | - Bonnie Alberry
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
| | - Shiva M Singh
- Molecular Genetics Unit, Department of Biology, University of Western Ontario , London, ON, Canada
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Korkotian E, Bombela T, Odegova T, Zubov P, Segal M. Ethanol affects network activity in cultured rat hippocampus: mediation by potassium channels. PLoS One 2013; 8:e75988. [PMID: 24260098 PMCID: PMC3829821 DOI: 10.1371/journal.pone.0075988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 08/19/2013] [Indexed: 11/21/2022] Open
Abstract
The effects of ethanol on neuronal network activity were studied in dissociated cultures of rat hippocampus. Exposure to low (0.25–0.5%) ethanol concentrations caused an increase in synchronized network spikes, and a decrease in the duration of individual spikes. Ethanol also caused an increase in rate of miniature spontaneous excitatory postsynaptic currents. Higher concentrations of ethanol eliminated network spikes. These effects were reversible upon wash. The effects of the high, but not the low ethanol were blocked by the GABA antagonist bicuculline. The enhancing action of low ethanol was blocked by apamin, an SK potassium channel antagonist, and mimicked by 1-EBIO, an SK channel opener. It is proposed that in cultured hippocampal networks low concentration of ethanol is associated with SK channel activity, rather than the GABAergic receptor.
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Affiliation(s)
- Eduard Korkotian
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
- * E-mail:
| | - Tatyana Bombela
- Department of Pharmacognosy, Perm State Pharmaceutical Academy, Perm, Russia
| | - Tatiana Odegova
- Department of Microbiology, Perm State Pharmaceutical Academy, Perm, Russia
| | - Petr Zubov
- Department of Microbiology, Perm State Pharmaceutical Academy, Perm, Russia
| | - Menahem Segal
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
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Jablonski SA, Schreiber WB, Westbrook SR, Brennan LE, Stanton ME. Determinants of novel object and location recognition during development. Behav Brain Res 2013; 256:140-50. [PMID: 23933466 DOI: 10.1016/j.bbr.2013.07.055] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 07/24/2013] [Accepted: 07/30/2013] [Indexed: 11/19/2022]
Abstract
In the novel object recognition (OR) paradigm, rats are placed in an arena where they encounter two sample objects during a familiarization phase. A few minutes later, they are returned to the same arena and are presented with a familiar object and a novel object. The object location recognition (OL) variant involves the same familiarization procedure but during testing one of the familiar objects is placed in a novel location. Normal adult rats are able to perform both the OR and OL tasks, as indicated by enhanced exploration of the novel vs. the familiar test item. Rats with hippocampal lesions perform the OR but not OL task indicating a role of spatial memory in OL. Recently, these tasks have been used to study the ontogeny of spatial memory but the literature has yielded conflicting results. The current experiments add to this literature by: (1) behaviorally characterizing these paradigms in postnatal day (PD) 21, 26 and 31-day-old rats; (2) examining the role of NMDA systems in OR vs. OL; and (3) investigating the effects of neonatal alcohol exposure on both tasks. Results indicate that normal-developing rats are able to perform OR and OL by PD21, with greater novelty exploration in the OR task at each age. Second, memory acquisition in the OL but not OR task requires NMDA receptor function in juvenile rats [corrected]. Lastly, neonatal alcohol exposure does not disrupt performance in either task. Implications for the ontogeny of incidental spatial learning and its disruption by developmental alcohol exposure are discussed.
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Affiliation(s)
- S A Jablonski
- Psychology Department, University of Delaware, Newark, DE 19716, USA.
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Neurodevelopmental alcohol exposure elicits long-term changes to gene expression that alter distinct molecular pathways dependent on timing of exposure. J Neurodev Disord 2013; 5:6. [PMID: 23497526 PMCID: PMC3621102 DOI: 10.1186/1866-1955-5-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 02/20/2013] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Maternal alcohol consumption is known to adversely affect fetal neurodevelopment. While it is known that alcohol dose and timing play a role in the cognitive and behavioral changes associated with prenatal alcohol exposure, it is unclear what developmental processes are disrupted that may lead to these phenotypes. METHODS Mice (n=6 per treatment per developmental time) were exposed to two acute doses of alcohol (5 g/kg) at neurodevelopmental times representing the human first, second, or third trimester equivalent. Mice were reared to adulthood and changes to their adult brain transcriptome were assessed using expression arrays. These were then categorized based on Gene Ontology annotations, canonical pathway associations, and relationships to interacting molecules. RESULTS The results suggest that ethanol disrupts biological processes that are actively occurring at the time of exposure. These include cell proliferation during trimester one, cell migration and differentiation during trimester two, and cellular communication and neurotransmission during trimester three. Further, although ethanol altered a distinct set of genes depending on developmental timing, many of these show interrelatedness and can be associated with one another via 'hub' molecules and pathways such as those related to huntingtin and brain-derived neurotrophic factor. CONCLUSIONS These changes to brain gene expression represent a 'molecular footprint' of neurodevelopmental alcohol exposure that is long-lasting and correlates with active processes disrupted at the time of exposure. This study provides further support that there is no neurodevelopmental time when alcohol cannot adversely affect the developing brain.
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An L, Yang Z, Zhang T. Imbalanced synaptic plasticity induced spatial cognition impairment in male offspring rats treated with chronic prenatal ethanol exposure. Alcohol Clin Exp Res 2012; 37:763-70. [PMID: 23240555 DOI: 10.1111/acer.12040] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 09/05/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND As chronic prenatal ethanol (EtOH) exposure (CPEE) may cause deficiencies in a variety of behavioral and cognitive functions, the aim of present study is to investigate the effects of CPEE on spatial learning and memory and examine the action of CPEE on synaptic plasticity balance in the hippocampus of adolescent male rats. METHODS The animal model was produced by EtOH exposure throughout gestational period with 4 g/kg bodyweight, while the male offspring rats were used in the study. Morris water maze (MWM) test was performed, and then, long-term potentiation (LTP) and depotentiation were recorded from Schaffer collaterals to CA1 region in the hippocampus. RESULTS It was shown that escape latencies in learning period and re-acquisition period were prolonged in CPEE-treated group compared with that in control group. Furthermore, LTP was drastically inhibited, and depotentiation was distinctly enhanced in CPEE-treated group compared with that in control group. CONCLUSIONS It is suggested that the balance between cognitive stability and flexibility was broken by the bidirectional effects of long-term synaptic plasticity. In addition, the spatial cognition was attenuated by the alteration of synaptic plasticity balance in CPEE-treated male adolescent rats.
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Affiliation(s)
- Lei An
- College of Life Sciences, Nankai University, Tianjin, China
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Mishra D, Zhang X, Chergui K. Ethanol disrupts the mechanisms of induction of long-term potentiation in the mouse nucleus accumbens. Alcohol Clin Exp Res 2012; 36:2117-25. [PMID: 22551245 DOI: 10.1111/j.1530-0277.2012.01824.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 03/06/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Long-term changes in the efficacy of glutamatergic synaptic transmission in reward-related brain regions such as the nucleus accumbens (NAc) are proposed to contribute to neuroadaptations that lead to drug addiction. Although alcohol is a widely used addictive substance, the cellular mechanisms by which it influences synaptic plasticity in the NAc are not elucidated. We therefore examined whether acute ethanol (EtOH) alters long-term potentiation (LTP) in the core region of the NAc and investigated the possible underlying mechanisms. METHODS We measured field excitatory postsynaptic potential/population spike (fEPSP/PS) amplitude in mouse brain slices containing the NAc. We also used amperometry to detect, with carbon fiber electrode, evoked dopamine release in brain slices. RESULTS In control slices, high-frequency stimulation (HFS) induced a stable LTP. LTP was reduced in slices perfused with EtOH (50 mM). Given that induction of LTP is dependent on glutamate acting on N-methyl-d-aspartate (NMDA) receptors and group I metabotropic glutamate receptors (mGluRs), we studied the ability of EtOH to modulate these 2 classes of receptors. NMDA (20 μM) depressed the amplitude of the fEPSP/PS, but this effect was not altered by EtOH in our experimental conditions. However, EtOH reversed the ability of the group I mGluR agonist (S)-3,5-Dihydroxyphenylglycine (DHPG) (50 μM) to potentiate the depressant action of NMDA on the fEPSP/PS. We also examined whether EtOH could modulate dopamine release given that dopamine plays important roles in mediating the reinforcing actions of abused drugs and in the induction of LTP in the NAc. We found that EtOH reversibly decreased action potential-dependent dopamine release evoked by single stimulation pulses and by HFS trains in NAc slices. CONCLUSIONS These results show that EtOH impairs the induction of LTP possibly through several mechanisms that include inhibition of group I mGluR-mediated potentiation of NMDA receptor function and of evoked dopamine release. This study provides additional support for a key role of glutamatergic and dopaminergic neurotransmission in the NAc in mediating the reinforcing effects of acute alcohol.
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Affiliation(s)
- Devesh Mishra
- Section of Molecular Neurophysiology , Department of Physiology and Pharmacology, The Karolinska Institute, Stockholm, Sweden
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Möykkynen T, Korpi ER. Acute effects of ethanol on glutamate receptors. Basic Clin Pharmacol Toxicol 2012; 111:4-13. [PMID: 22429661 DOI: 10.1111/j.1742-7843.2012.00879.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 03/08/2012] [Indexed: 01/30/2023]
Abstract
Several studies have revealed that acute ethanol inhibits the function of glutamate receptors. Glutamate receptor-mediated synaptic plasticity, such as N-methyl-D-aspartate-dependent long-term potentiation, is also inhibited by ethanol. However, the inhibition seems to be restricted to certain brain areas such as the hippocampus, amygdala and striatum. Ethanol inhibition of glutamate receptors generally requires relatively high concentrations and may therefore explain consequences of severe ethanol intoxication such as impairment of motor performance and memory. Effects of ethanol on glutamate system of developing nervous system may have a role in causing foetal alcohol syndrome. Newly found regulatory proteins of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid AMPA receptors seem to affect ethanol inhibition thus opening new lines of research.
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Affiliation(s)
- Tommi Möykkynen
- Institute of Biomedicine, Pharmacology, University of Helsinki, Finland.
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Lieberman R, Levine ES, Kranzler HR, Abreu C, Covault J. Pilot study of iPS-derived neural cells to examine biologic effects of alcohol on human neurons in vitro. Alcohol Clin Exp Res 2012; 36:1678-87. [PMID: 22486492 DOI: 10.1111/j.1530-0277.2012.01792.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 01/31/2012] [Indexed: 01/06/2023]
Abstract
BACKGROUND Studies of the effects of alcohol on N-methyl-d-aspartate (NMDA) receptor function and gene expression have depended on rodent or postmortem human brain models. Ideally, the effects of alcohol might better be examined in living neural tissue derived from human subjects. In this study, we used new technologies to reprogram human subject-specific tissue into pluripotent cell colonies and generate human neural cultures as a model system to examine the molecular actions of alcohol. METHODS Induced pluripotent stem (iPS) cells were generated from skin biopsies taken from 7 individuals, 4 alcohol-dependent subjects, and 3 social drinkers. We differentiated the iPS cells into neural cultures and characterized them by immunocytochemistry using antibodies for the neuronal marker beta-III tubulin, glial marker s100β, and synaptic marker synpasin-1. Electrophysiology was performed to characterize the iPS-derived neurons and to measure the effects of acute alcohol exposure on the NMDA receptor response in chronically alcohol exposed and nonexposed neural cultures from 1 nonalcoholic. Finally, we examined changes in mRNA expression of the NMDA receptor subunit genes GRIN1, GRIN2A, GRIN2B, and GRIN2D after 7 days of alcohol exposure and after 24-hour withdrawal from chronic alcohol exposure. RESULTS Immunocytochemistry revealed positive staining for neuronal, glial, and synaptic markers. iPS-derived neurons displayed spontaneous electrical properties and functional ionotropic receptors. Acute alcohol exposure significantly attenuated the NMDA response, an effect that was not observed after 7 days of chronic alcohol exposure. After 7 days of chronic alcohol exposure, there were significant increases in mRNA expression of GRIN1, GRIN2A, and GRIN2D in cultures derived from alcoholic subjects but not in cultures derived from nonalcoholics. CONCLUSIONS These findings support the potential utility of human iPS-derived neural cultures as in vitro models to examine the molecular actions of alcohol on human neural cells.
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Affiliation(s)
- Richard Lieberman
- Graduate Program in Neuroscience, University of Connecticut Health Center, Farmington, CT 06030-1410, USA
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Neonatal alcohol exposure and the hippocampus in developing male rats: effects on behaviorally induced CA1 c-Fos expression, CA1 pyramidal cell number, and contextual fear conditioning. Neuroscience 2012; 206:89-99. [PMID: 22285885 DOI: 10.1016/j.neuroscience.2012.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 11/30/2011] [Accepted: 01/04/2012] [Indexed: 12/13/2022]
Abstract
Rats exposed to a high binge-like dose of alcohol over postnatal days (PD) 4-9 show reductions in CA1 pyramidal cells and impairments on behavioral tasks that depend on the hippocampus. We first examined hippocampal c-Fos expression as a marker of neuronal activity in normally developing rats following different phases of the context preexposure facilitation effect (CPFE) paradigm (Experiment 1). During the CPFE, preexposure to the training context facilitates contextual conditioning to an immediate shock given on a subsequent occasion. We then examined the relationship between CPFE impairment, hippocampal cell loss, and c-Fos expression in rats exposed to alcohol over PD 4-9 (Experiment 2). Normally developing (Experiment 1), sham-intubated control (SI), and PD 4-9 alcohol-exposed (4.00 g and 5.25 g/kg/d; Experiment 2) juvenile male rats were trained on the CPFE. The CPFE occurs over three phases separated by 24 h. Starting on PD 31, rats were preexposed to Context A or Context B for 5 min. After 24 h, all rats received an immediate 1.5-mA foot shock in Context A. Finally, rats were tested for contextual conditioning in Context A on PD 33. Normally developing and SI rats preexposed to Context A showed enhanced contextual fear compared with those preexposed to Context B (Experiment 1) or alcohol-exposed rats preexposed to Context A (Experiment 2). Rats were sacrificed 2 h following different phases of the CPFE and processed for c-Fos immunohistochemistry (Experiments 1 and 2) and CA1 pyramidal cell quantification (Experiment 2). In Experiment 1, c-Fos positive (c-Fos+) cells in the dentate gyrus (DG) were consistently high among rats preexposed to Context A (Pre), Context B (No Pre), or sacrificed directly from their home cage (Home) and did not differ across CPFE phases. CA3 and CA1 c-Fos+ cells were highest during preexposure and decreased across training phases, with Group No Pre showing greater numbers of c-Fos+ cells during training than Group Pre and Controls. In Experiment 2, SI rats had greater numbers of CA1 c-Fos+ cells compared with alcohol-exposed rats, differing significantly from rats exposed to the high alcohol dose (5.25 g) over PD 4-9. Experiment 2 also revealed a linear decline in CA1 pyramidal cells across treatment groups, again with rats from the high-alcohol dose group showing significantly fewer CA1 pyramidal cells compared with SI. Our results reveal that context novelty may be a significant contributor to differential hippocampal c-Fos expression following different phases of the CPFE. In addition, lower levels of c-Fos+ cells in alcohol-exposed rats following preexposure may be related to general reductions in the number of CA1 pyramidal cells in these rats. The significant CPFE impairments in rats exposed to the lower alcohol dose (4.00 g), who show a 15% reduction in CA1 pyramidal cells compared with SI rats, highlight the sensitivity of the CPFE to hippocampal insult.
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Acute administration of vinpocetine, a phosphodiesterase type 1 inhibitor, ameliorates hyperactivity in a mice model of fetal alcohol spectrum disorder. Drug Alcohol Depend 2011; 119:81-7. [PMID: 21689896 DOI: 10.1016/j.drugalcdep.2011.05.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 01/28/2023]
Abstract
BACKGROUND Maternal alcohol use during pregnancy causes a continuum of long-lasting disabilities in the offspring, commonly referred to as fetal alcohol spectrum disorder (FASD). Attention-deficit/hyperactivity disorder (ADHD) is possibly the most common behavioral problem in children with FASD and devising strategies that ameliorate this condition has great clinical relevance. Studies in rodent models of ADHD and FASD suggest that impairments in the cAMP signaling cascade contribute to the hyperactivity phenotype. In this work, we investigated whether the cAMP levels are affected in a long-lasting manner by ethanol exposure during the third trimester equivalent period of human gestation and whether the acute administration of the PDE1 inhibitor vinpocetine ameliorates the ethanol-induced hyperactivity. METHODS From postnatal day (P) 2 to P8, Swiss mice either received ethanol (5g/kg i.p.) or saline every other day. At P30, the animals either received vinpocetine (20mg/kg or 10mg/kg i.p.) or vehicle 4h before being tested in the open field. After the test, frontal cerebral cortices and hippocampi were dissected and collected for assessment of cAMP levels. RESULTS Early alcohol exposure significantly increased locomotor activity in the open field and reduced cAMP levels in the hippocampus. The acute treatment of ethanol-exposed animals with 20mg/kg of vinpocetine restored both their locomotor activity and cAMP levels to control levels. CONCLUSIONS These data lend support to the idea that cAMP signaling system contribute to the hyperactivity induced by developmental alcohol exposure and provide evidence for the potential therapeutic use of vinpocetine in FASD.
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Kost S, Sun C, Xiong W, Graham K, Cass CE, Young JD, Albensi BC, Parkinson FE. Behavioral effects of elevated expression of human equilibrative nucleoside transporter 1 in mice. Behav Brain Res 2011; 224:44-9. [DOI: 10.1016/j.bbr.2011.05.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 05/16/2011] [Accepted: 05/22/2011] [Indexed: 10/18/2022]
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Murawski NJ, Stanton ME. Effects of dose and period of neonatal alcohol exposure on the context preexposure facilitation effect. Alcohol Clin Exp Res 2011; 35:1160-70. [PMID: 21352243 DOI: 10.1111/j.1530-0277.2011.01449.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alcohol exposure in the rat on postnatal days (PD) 4 to 9 is known to partially damage the hippocampus and to impair hippocampus-dependent behavioral tasks. We previously reported that PD4 to 9 alcohol exposure eliminated the context preexposure facilitation effect (CPFE) in juvenile rats, a hippocampus-dependent variant of contextual fear conditioning. In the CPFE, context exposure and immediate shock occur on successive occasions and this produces conditioned freezing relative to a control group that is not preexposed to the training context. Here, we extend our earlier findings by examining the effects of neonatal alcohol administered at multiple doses or over different neonatal exposure periods. METHOD Rat pups (male and female) were exposed to a single binge dose of alcohol at one of 3 doses (2.75, 4.00, or 5.25 g/kg/d) over PD4 to 9 (Experiment 1) or to 5.25 g over PD4 to 6 or PD7 to 9 (Experiment 2). Sham-intubated (SI) and undisturbed (UD) rats served as controls. On PD31, rats were preexposed to either the training context (Pre) or an alternate context (No-Pre). On PD32, rats received an immediate unsignaled footshock (1.5 mA, 2 seconds) in the training context. Finally, on PD33, all rats were returned to the training context and tested for contextual freezing over a 5-minute period. RESULTS Undisturbed- and SI-Pre rats showed the CPFE, i.e., context preexposure facilitated contextual conditioning, relative to their No-Pre counterparts. The immediate shock deficit was present in all No-Pre groups, regardless of previous alcohol exposure. In Experiment 1, blood alcohol level was negatively correlated with contextual freezing. Group 2.75 g-Pre did not differ from controls. Group 4.00 g-Pre froze significantly less than Groups UD- and SI-Pre but more than Group 5.25-Pre, which showed the immediate shock deficit. In Experiment 2, alcohol exposure limited to PD7 to 9, but not PD4 to 6, disrupted the CPFE. CONCLUSIONS This is the first demonstration of dose-related impairment on a hippocampus-dependent task produced by neonatal alcohol exposure in the rat. Exposure period effects support previous studies of alcohol and spatial learning. The CPFE is a more sensitive behavioral task that can be used to elucidate developmental alcohol-induced deficits over a range of alcohol doses that are more relevant to human exposure levels.
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Affiliation(s)
- Nathen J Murawski
- Department of Psychology, University of Delaware, Newark, DE 19716, USA.
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Focus on: neurotransmitter systems. ALCOHOL RESEARCH & HEALTH : THE JOURNAL OF THE NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM 2011; 34:106-20. [PMID: 23580048 PMCID: PMC3860557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Neurotransmitter systems have been long recognized as important targets of the developmental actions of alcohol (i.e., ethanol). Short- and long-term effects of ethanol on amino acid (e.g., γ-aminobutyric acid and glutamate) and biogenic amine (e.g., serotonin and dopamine) neurotransmitters have been demonstrated in animal models of fetal alcohol spectrum disorders (FASD). Researchers have detected ethanol effects after exposure during developmental periods equivalent to the first, second, and third trimesters of human pregnancy. Results support the recommendation that pregnant women should abstain from drinking-even small quantities-as effects of ethanol on neurotransmitter systems have been detected at low levels of exposure. Recent studies have elucidated new mechanisms and/or consequences of the actions of ethanol on amino acid and biogenic amine neuro-transmitter systems. Alterations in these neurotransmitter systems could, in part, be responsible for many of the conditions associated with FASD, including (1) learning, memory, and attention deficits; (2) motor coordination impairments; (3) abnormal responsiveness to stress; and (4) increased susceptibility to neuropsychiatric disorders, such as substance abuse and depression, and also neurological disorders, such as epilepsy and sudden infant death syndrome. However, future research is needed to conclusively establish a causal relationship between these conditions and developmental dysfunctions in neurotransmitter systems.
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Puglia MP, Valenzuela CF. Repeated third trimester-equivalent ethanol exposure inhibits long-term potentiation in the hippocampal CA1 region of neonatal rats. Alcohol 2010; 44:283-90. [PMID: 20488644 PMCID: PMC2916030 DOI: 10.1016/j.alcohol.2010.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 03/27/2010] [Accepted: 03/30/2010] [Indexed: 10/19/2022]
Abstract
Developmental ethanol exposure damages the hippocampus, causing long-lasting learning and memory deficits. Synaptic plasticity mechanisms (e.g., long-term potentiation [LTP]) contribute to synapse formation and refinement during development. We recently showed that acute ethanol exposure inhibits glutamatergic synaptic transmission and N-methyl-d-aspartate receptor (NMDAR)-dependent LTP in the CA1 hippocampal region of postnatal day (P)7-9 rats. The objective of this study was to further characterize the effect of ethanol on LTP in the developing CA1 hippocampus during the third trimester equivalent. To more closely model human ethanol exposure during this period, rat pups were exposed to ethanol vapor (2 or 4.5 g/dL in air, serum ethanol concentrations=96.6-147.2 or 322-395.6 mg/dL) from P2-9 (4h/d). Brain slices were prepared immediately after the end of the 4-h exposure on P7-9 and extracellular electrophysiological recordings were performed 1-7h later under ethanol-free conditions to model early withdrawal. LTP was not different than group-matched controls in the 96.6-147.2mg/dL group; however, it was impaired in the 322-395.6 mg/dL group. Neither alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR)/NMDAR function nor glutamate release were affected in the 322-395.6 mg/dL ethanol exposure group. These data suggest that repeated in vivo exposure to elevated ethanol doses during the third trimester-equivalent period impairs synaptic plasticity, which may alter maturation of hippocampal circuits and ultimately contribute to the long-lasting cognitive deficits associated with fetal alcohol spectrum disorders.
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Affiliation(s)
- Michael P Puglia
- Department of Neurosciences, University of New Mexico Health Sciences Center, Albuquerque, 87131, USA
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Valenzuela CF, Lindquist B, Zamudio-Bulcock PA. A Review of Synaptic Plasticity at Purkinje Neurons with a Focus on Ethanol-Induced Cerebellar Dysfunction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 91:339-72. [DOI: 10.1016/s0074-7742(10)91011-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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