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Stea SG, Grisel JE. β-Endorphin influences sedative and ataxic effects of alcohol. Alcohol 2024; 115:69-77. [PMID: 37741556 DOI: 10.1016/j.alcohol.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023]
Abstract
Beta-endorphin (β-E) is an opioid peptide linked to the behavioral effects of ethanol. For example, β-E provides negative feedback to inhibit the hypothalamic-pituitary-adrenal (HPA) stress axis, and neuroadaptation of this system to ethanol may facilitate sex differences in disordered drinking. Locomotor sensitivity to ethanol may also influence the risk for addiction; however, the role of β-E in psychomotor effects of ethanol is not fully understood. We examined the role of β-E and sex on locomotor effects of ethanol using adult male and female wild-type C57BL/6J and β-E deficient B6.129S2-Pomctm1Low/J mice in a parallel rod floor apparatus following 0.75 or 2.0 g/kg ethanol. Beginning 15 min after intraperitoneal injection, we recorded foot slips, distance traveled, slips per meter, first instance of immobility, and total time spent off-balance (lying on the floor) over 15 min, and collected blood for analysis of ethanol concentration 60 min after injection. Overall, β-E deficient mice were more sedated and ataxic following ethanol; at the lower dose they slipped more frequently and had a higher rate of slips per meter traveled. At the higher dose, β-E deficient mice were predominantly sedated, slipping less frequently, and traveling less, as well as spending more time off-balance and becoming immobile sooner. Genotype interacted with sex in that male β-E deficient mice slipped more frequently than their female counterparts, suggesting that β-E may elicit sex-dependent effects of ethanol-induced ataxia. Blood ethanol concentration did not differ between any group, suggesting that behavioral differences result from altered sensitivity to ethanol. Our data support the contention that β-E modulates the locomotor effects of ethanol and may influence ataxia in a sex-dependent manner. These findings help elucidate the role of β-E in diverging behavioral responses to ethanol and may aid the development of targeted treatments for alcohol use disorders.
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Affiliation(s)
- Samuel G Stea
- Department of Psychology & Neuroscience Program, Bucknell University, Lewisburg, PA 17837, United States
| | - Judith E Grisel
- Department of Psychology & Neuroscience Program, Bucknell University, Lewisburg, PA 17837, United States.
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2
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Bumgarner JR, McCray EW, Nelson RJ. The disruptive relationship among circadian rhythms, pain, and opioids. Front Neurosci 2023; 17:1109480. [PMID: 36875657 PMCID: PMC9975345 DOI: 10.3389/fnins.2023.1109480] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 01/26/2023] [Indexed: 02/17/2023] Open
Abstract
Pain behavior and the systems that mediate opioid analgesia and opioid reward processing display circadian rhythms. Moreover, the pain system and opioid processing systems, including the mesolimbic reward circuitry, reciprocally interact with the circadian system. Recent work has demonstrated the disruptive relationship among these three systems. Disruption of circadian rhythms can exacerbate pain behavior and modulate opioid processing, and pain and opioids can influence circadian rhythms. This review highlights evidence demonstrating the relationship among the circadian, pain, and opioid systems. Evidence of how disruption of one of these systems can lead to reciprocal disruptions of the other is then reviewed. Finally, we discuss the interconnected nature of these systems to emphasize the importance of their interactions in therapeutic contexts.
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Affiliation(s)
- Jacob R Bumgarner
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, United States
| | - Evan W McCray
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, United States
| | - Randy J Nelson
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, United States
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3
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Jordan CJ, Xi ZX. Identification of the Risk Genes Associated With Vulnerability to Addiction: Major Findings From Transgenic Animals. Front Neurosci 2022; 15:811192. [PMID: 35095405 PMCID: PMC8789752 DOI: 10.3389/fnins.2021.811192] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 12/14/2021] [Indexed: 12/21/2022] Open
Abstract
Understanding risk factors for substance use disorders (SUD) can facilitate medication development for SUD treatment. While a rich literature exists discussing environmental factors that influence SUD, fewer articles have focused on genetic factors that convey vulnerability to drug use. Methods to identify SUD risk genes include Genome-Wide Association Studies (GWAS) and transgenic approaches. GWAS have identified hundreds of gene variants or single nucleotide polymorphisms (SNPs). However, few genes identified by GWAS have been verified by clinical or preclinical studies. In contrast, significant progress has been made in transgenic approaches to identify risk genes for SUD. In this article, we review recent progress in identifying candidate genes contributing to drug use and addiction using transgenic approaches. A central hypothesis is if a particular gene variant (e.g., resulting in reduction or deletion of a protein) is associated with increases in drug self-administration or relapse to drug seeking, this gene variant may be considered a risk factor for drug use and addiction. Accordingly, we identified several candidate genes such as those that encode dopamine D2 and D3 receptors, mGluR2, M4 muscarinic acetylcholine receptors, and α5 nicotinic acetylcholine receptors, which appear to meet the risk-gene criteria when their expression is decreased. Here, we describe the role of these receptors in drug reward and addiction, and then summarize major findings from the gene-knockout mice or rats in animal models of addiction. Lastly, we briefly discuss future research directions in identifying addiction-related risk genes and in risk gene-based medication development for the treatment of addiction.
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Affiliation(s)
- Chloe J. Jordan
- Division of Alcohol, Drugs and Addiction, Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
- *Correspondence: Chloe J. Jordan,
| | - Zheng-Xiong Xi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD, United States
- Zheng-Xiong Xi,
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4
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Nelson RJ, Bumgarner JR, Walker WH, DeVries AC. Time-of-day as a critical biological variable. Neurosci Biobehav Rev 2021; 127:740-746. [PMID: 34052279 PMCID: PMC8504485 DOI: 10.1016/j.neubiorev.2021.05.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/20/2021] [Accepted: 05/17/2021] [Indexed: 12/13/2022]
Abstract
Time-of-day is a crucial, yet often overlooked, biological variable in biomedical research. We examined the top 25 most cited papers in several domains of behavioral neuroscience to determine whether time-of-day information was reported. The majority of studies report behavioral testing conducted during the day, which does not coincide with the optimal time to perform the testing from an functional perspective of the animals being tested. The majority of animal models used in biomedical research are nocturnal rodents; thus, testing during the light phase (i.e. animals' rest period) may alter the results and introduce variability across studies. Time-of-day is rarely considered in analyses or reported in publications; the majority of publications fail to include temporal details when describing their experimental methods, and those few that report testing during the dark rarely report whether measures are in place to protect from exposure to extraneous light. We propose that failing to account for time-of-day may compromise replication of findings across behavioral studies and reduce their value when extrapolating results to diurnal humans.
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Affiliation(s)
- Randy J Nelson
- Department of Neuroscience, Rockefeller Neuroscience Institute, Morgantown, WV, 26506, USA; West Virginia Clinical and Translational Science Institute, West Virginia University, Morgantown, WV, 26506, USA.
| | - Jacob R Bumgarner
- Department of Neuroscience, Rockefeller Neuroscience Institute, Morgantown, WV, 26506, USA
| | - William H Walker
- Department of Neuroscience, Rockefeller Neuroscience Institute, Morgantown, WV, 26506, USA; West Virginia Clinical and Translational Science Institute, West Virginia University, Morgantown, WV, 26506, USA
| | - A Courtney DeVries
- Department of Neuroscience, Rockefeller Neuroscience Institute, Morgantown, WV, 26506, USA; Department of Medicine, Division of Hematology and Oncology, Morgantown, WV, 26506, USA; WVU Cancer Institute, Morgantown, WV, 26506, USA; West Virginia Clinical and Translational Science Institute, West Virginia University, Morgantown, WV, 26506, USA
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5
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Role of the Serotonin Receptor 7 in Brain Plasticity: From Development to Disease. Int J Mol Sci 2020; 21:ijms21020505. [PMID: 31941109 PMCID: PMC7013427 DOI: 10.3390/ijms21020505] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 12/18/2022] Open
Abstract
Our knowledge on the plastic functions of the serotonin (5-HT) receptor subtype 7 (5-HT7R) in the brain physiology and pathology have advanced considerably in recent years. A wealth of data show that 5-HT7R is a key player in the establishment and remodeling of neuronal cytoarchitecture during development and in the mature brain, and its dysfunction is linked to neuropsychiatric and neurodevelopmental diseases. The involvement of this receptor in synaptic plasticity is further demonstrated by data showing that its activation allows the rescue of long-term potentiation (LTP) and long-term depression (LTD) deficits in various animal models of neurodevelopmental diseases. In addition, it is becoming clear that the 5-HT7R is involved in inflammatory intestinal diseases, modulates the function of immune cells, and is likely to play a role in the gut-brain axis. In this review, we will mainly focus on recent findings on this receptor’s role in the structural and synaptic plasticity of the mammalian brain, although we will also illustrate novel aspects highlighted in gastrointestinal (GI) tract and immune system.
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Yun H, Park ES, Choi S, Shin B, Yu J, Yu J, Amarasekara DS, Kim S, Lee N, Choi JS, Choi Y, Rho J. TDAG51 is a crucial regulator of maternal care and depressive-like behavior after parturition. PLoS Genet 2019; 15:e1008214. [PMID: 31251738 PMCID: PMC6599150 DOI: 10.1371/journal.pgen.1008214] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 05/27/2019] [Indexed: 12/11/2022] Open
Abstract
Postpartum depression is a severe emotional and mental disorder that involves maternal care defects and psychiatric illness. Postpartum depression is closely associated with a combination of physical changes and physiological stress during pregnancy or after parturition in stress-sensitive women. Although postpartum depression is relatively well known to have deleterious effects on the developing fetus, the influence of genetic risk factors on the development of postpartum depression remains unclear. In this study, we discovered a novel function of T cell death-associated gene 51 (TDAG51/PHLDA1) in the regulation of maternal and depressive-like behavior. After parturition, TDAG51-deficient dams showed impaired maternal behavior in pup retrieving, nursing and nest building tests. In contrast to the normal dams, the TDAG51-deficient dams also exhibited more sensitive depressive-like behaviors after parturition. Furthermore, changes in the expression levels of various maternal and depressive-like behavior-associated genes regulating neuroendocrine factor and monoamine neurotransmitter levels were observed in TDAG51-deficient postpartum brain tissues. These findings indicate that TDAG51 plays a protective role against maternal care defects and depressive-like behavior after parturition. Thus, TDAG51 is a maternal care-associated gene that functions as a crucial regulator of maternal and depressive-like behavior after parturition. Postpartum depression is a severe emotional and mental disease that can affect women typically after parturition. However, the genetic risk factors associated with the development of postpartum depression are still largely unknown. We discovered a novel function of T cell death-associated gene 51 (TDAG51) in the regulation of maternal behavior and postpartum depression. We report that TDAG51 deficiency induces depressive-like and abnormal maternal behavior after parturition. The loss of TDAG51 in postpartum brain tissues induces changes in the expression levels of various maternal and depressive-like behavior-associated genes that regulate the levels of neuroendocrine factors and monoamine neurotransmitters. TDAG51 is a maternal care-associated gene that functions as a crucial regulator of maternal and depressive-like behavior after parturition.
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Affiliation(s)
- Hyeongseok Yun
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Eui-Soon Park
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Seunga Choi
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Bongjin Shin
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Jungeun Yu
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Jiyeon Yu
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | | | - Sumi Kim
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Nari Lee
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
| | - Jong-Soon Choi
- Division of Life Science, Korea Basic Science Institute, Daejeon, Korea
| | - Yongwon Choi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jaerang Rho
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon, Korea
- * E-mail:
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7
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Sano K, Kawashima M, Imada T, Suzuki T, Nakamura S, Mimura M, Tanaka KF, Tsubota K. Enriched environment alleviates stress-induced dry-eye through the BDNF axis. Sci Rep 2019; 9:3422. [PMID: 30833600 PMCID: PMC6399317 DOI: 10.1038/s41598-019-39467-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/24/2019] [Indexed: 01/20/2023] Open
Abstract
The number of patients with dry eye disease (DED) is increasing, and DED has become an urgent public health problem. A comorbidity of mental disorders has been reported in DED patients. We hypothesized that physical and psychological stressors impair tear secretion. To examine the relationship between stress loading and decreased tear secretion, we established a stress-induced DED mouse model, which permitted us to address the underlying mechanism of pathogenesis and resilience. Enriched environment (EE) was an effective intervention to prevent and alleviate stress-induced decreased tear secretion. Because stress loading resulted in decreased brain-derived neurotrophic factor (BDNF) expression while EE resulted in increased expression, we focused on the role of BDNF in tear secretion. Using two distinct Bdnf gene knockdown mice, we evaluated whether BDNF was a deterministic factor in regulating tear secretion in healthy and stressed conditions. Bdnf knockdown mice showed decreased basal tear secretion and loss of stress tolerance by EE for tear secretion. These results suggest that BDNF expression is related to tear secretion and to the pathology of DED.
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Affiliation(s)
- Kokoro Sano
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Motoko Kawashima
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Toshihiro Imada
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Toru Suzuki
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Shigeru Nakamura
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, 160-8582, Japan.
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
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8
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Evaluation of 5-HT7 receptor antagonism for the treatment of anxiety, depression, and schizophrenia through the use of receptor-deficient mice. Behav Brain Res 2019; 360:270-278. [DOI: 10.1016/j.bbr.2018.12.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 12/09/2018] [Accepted: 12/09/2018] [Indexed: 11/21/2022]
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9
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Maxwell J, Gleason SD, Falcone J, Svensson K, Balcer OM, Li X, Witkin JM. Effects of 5-HT 7 receptor antagonists on behaviors of mice that detect drugs used in the treatment of anxiety, depression, or schizophrenia. Behav Brain Res 2018; 359:467-473. [PMID: 30471311 DOI: 10.1016/j.bbr.2018.11.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
Abstract
5-HT7 receptors have been suggested to play a role in the regulation of psychiatric disorders. The experimental literature however is not fully consistent on this possibility. Two selective 5-HT7 receptor antagonists, DR-4004 and SB-269970, were evaluated in mouse models used to detect drugs used to treat anxiety, depression, or schizophrenia. A 5-HT-induced hypothermia assay was used to define the doses of DR-4004 and SB-269970 predicted to impact 5-HT7 receptors in the brain in vivo. 5-HT produced hypothermia in wildtype mice by either i.p. or i.c.v. routes but did not in 5-HT7 receptor knockout mice. 5-HT-induced hypothermia was not attenuated by drugs selectively blocking alpha1 or 5-HT1A receptors. Doses of DR-4004 and SB-269970 that blocked 5-HT-induced hypothermia, did not display significant anxiolytic-like (elevated plus maze; vogel conflict) or antidepressant-like efficacy (tail-suspension test) in mouse models. These compounds did demonstrate some antipsychotic-like properties in the PCP-induced hyperactivity assay and anxiolytic/anti-stress effects in the stress-induced cGMP assay. Negative findings were substantiated by positive control drugs that were active in each assay system. We conclude that 5-HT-induced hypothermia can be used to estimate blockade of central 5-HT7 receptors. Effects of DR-4004 and SB-269970 in animal models are generally consistent with the experimental literature that the evidence is mixed or not robust regarding the potential efficacy of 5-HT7 receptor antagonism in the treatment of anxiety, depression, or schizophrenia.
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Affiliation(s)
- Julia Maxwell
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Scott D Gleason
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Julie Falcone
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Kjell Svensson
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Olivia M Balcer
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Xia Li
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Jeffrey M Witkin
- Neuroscience Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA.
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10
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Abstract
Nonhuman animals have been major contributors to the science of the genetics of addiction. Given the explosion of interest in genetics, it is fair to ask, are we making reasonable progress toward our goals with animal models? I will argue that our goals are changing and that overall progress has been steady and seems likely to continue apace. Genetics tools have developed almost incredibly rapidly, enabling both more reductionist and more synthetic or integrative approaches. I believe that these approaches to making progress have been unbalanced in biomedical science, favoring reductionism, particularly in animal genetics. I argue that substantial, novel progress is also likely to come in the other direction, toward synthesis and abstraction. Another area in which future progress with genetic animal models seems poised to contribute more is the reconciliation of human and animal phenotypes, or consilience. The inherent power of the genetic animal models could be more profitably exploited. In the end, animal research has continued to provide novel insights about how genes influence individual differences in addiction risk and consequences. The rules of the genetics game are changing so fast that it is hard to remember how comparatively little we knew even a generation ago. Rather than worry about whether we have been wasting time and resources asking the questions we have been, we should look to the future and see if we can come up with some new ones. The valuable findings from the past will endure, and the sidetracks will be forgotten.
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Affiliation(s)
- John C Crabbe
- Department of Behavioral Neuroscience, Oregon Health & Science University, Veterans Affairs Portland Health Care System Portland, Oregon
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11
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Robinson S, Adelman JS. A Method for Remotely Silencing Neural Activity in Rodents During Discrete Phases of Learning. J Vis Exp 2015:e52859. [PMID: 26131591 DOI: 10.3791/52859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This protocol describes how to temporarily and remotely silence neuronal activity in discrete brain regions while animals are engaged in learning and memory tasks. The approach combines pharmacogenetics (Designer-Receptors-Exclusively-Activated-by-Designer-Drugs) with a behavioral paradigm (sensory preconditioning) that is designed to distinguish between different forms of learning. Specifically, viral-mediated delivery is used to express a genetically modified inhibitory G-protein coupled receptor (the Designer Receptor) into a discrete brain region in the rodent. Three weeks later, when designer receptor expression levels are high, a pharmacological agent (the Designer Drug) is administered systemically 30 min prior to a specific behavioral session. The drug has affinity for the designer receptor and thus results in inhibition of neurons that express the designer receptor, but is otherwise biologically inert. The brain region remains silenced for 2-5 hr (depending on the dose and route of administration). Upon completion of the behavioral paradigm, brain tissue is assessed for correct placement and receptor expression. This approach is particularly useful for determining the contribution of individual brain regions to specific components of behavior and can be used across any number of behavioral paradigms.
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12
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Dopamine D3 receptor is necessary for ethanol consumption: an approach with buspirone. Neuropsychopharmacology 2014; 39:2017-28. [PMID: 24584330 PMCID: PMC4059912 DOI: 10.1038/npp.2014.51] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/12/2014] [Accepted: 02/24/2014] [Indexed: 11/09/2022]
Abstract
Mesolimbic dopamine (DA) controls drug- and alcohol-seeking behavior, but the role of specific DA receptor subtypes is unclear. We tested the hypothesis that D3R gene deletion or the D3R pharmacological blockade inhibits ethanol preference in mice. D3R-deficient mice (D3R(-/-)) and their wild-type (WT) littermates, treated or not with the D3R antagonists SB277011A and U99194A, were tested in a long-term free choice ethanol-drinking (two-bottle choice) and in a binge-like ethanol-drinking paradigm (drinking in the dark, DID). The selectivity of the D3R antagonists was further assessed by molecular modeling. Ethanol intake was negligible in D3R(-/-) and robust in WT both in the two-bottle choice and DID paradigms. Treatment with D3R antagonists inhibited ethanol intake in WT but was ineffective in D3R(-/-) mice. Ethanol intake increased the expression of RACK1 and brain-derived neurotrophic factor (BDNF) in both WT and D3R(-/-); in WT there was also a robust overexpression of D3R. Thus, increased expression of D3R associated with activation of RACK1/BDNF seems to operate as a reinforcing mechanism in voluntary ethanol intake. Indeed, blockade of the BDNF pathway by the TrkB selective antagonist ANA-12 reversed chronic stable ethanol intake and strongly decreased the striatal expression of D3R. Finally, we evaluated buspirone, an approved drug for anxiety disorders endowed with D3R antagonist activity (confirmed by molecular modeling analysis), that resulted effective in inhibiting ethanol intake. Thus, DA signaling via D3R is essential for ethanol-related reward and consumption and may represent a novel therapeutic target for weaning.
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13
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Canugovi C, Misiak M, Ferrarelli LK, Croteau DL, Bohr VA. The role of DNA repair in brain related disease pathology. DNA Repair (Amst) 2013; 12:578-87. [PMID: 23721970 DOI: 10.1016/j.dnarep.2013.04.010] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Oxidative DNA damage is implicated in brain aging, neurodegeneration and neurological diseases. Damage can be created by normal cellular metabolism, which accumulates with age, or by acute cellular stress conditions which create bursts of oxidative damage. Brain cells have a particularly high basal level of metabolic activity and use distinct oxidative damage repair mechanisms to remove oxidative damage from DNA and dNTP pools. Accumulation of this damage in the background of a functional DNA repair response is associated with normal aging, but defective repair in brain cells can contribute to neurological dysfunction. Emerging research strongly associates three common neurodegenerative conditions, Alzheimer's, Parkinson's and stroke, with defects in the ability to repair chronic or acute oxidative damage in neurons. This review explores the current knowledge of the role of oxidative damage repair in preserving brain function and highlights the emerging models and methods being used to advance our knowledge of the pathology of neurodegenerative disease.
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Affiliation(s)
- Chandrika Canugovi
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, Baltimore, MD 21224, USA
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14
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Kuroda KO, Tachikawa K, Yoshida S, Tsuneoka Y, Numan M. Neuromolecular basis of parental behavior in laboratory mice and rats: with special emphasis on technical issues of using mouse genetics. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:1205-31. [PMID: 21338647 DOI: 10.1016/j.pnpbp.2011.02.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 02/14/2011] [Accepted: 02/14/2011] [Indexed: 01/07/2023]
Abstract
To support the well-being of the parent-infant relationship, the neuromolecular mechanisms of parental behaviors should be clarified. From neuroanatomical analyses in laboratory rats, the medial preoptic area (MPOA) has been shown to be of critical importance in parental retrieving behavior. More recently, various gene-targeted mouse strains have been found to be defective in different aspects of parental behaviors, contributing to the identification of molecules and signaling pathways required for the behavior. Therefore, the neuromolecular basis of "mother love" is now a fully approachable research field in modern molecular neuroscience. In this review, we will provide a summary of the required brain areas and gene for parental behavior in laboratory mice (Mus musculus) and rats (Rattus norvegicus). Basic protocols and technical considerations on studying the mechanism of parental behavior using genetically-engineered mouse strains will also be presented.
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Affiliation(s)
- Kumi O Kuroda
- Unit for Affiliative Social Behavior, RIKEN Brain Science Institute, Saitama 351-0198, Japan.
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15
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Fragel-Madeira L, Meletti T, Mariante RM, Monteiro RQ, Einicker-Lamas M, Bernardo RR, Lopes AH, Linden R. Platelet activating factor blocks interkinetic nuclear migration in retinal progenitors through an arrest of the cell cycle at the S/G2 transition. PLoS One 2011; 6:e16058. [PMID: 21298035 PMCID: PMC3029264 DOI: 10.1371/journal.pone.0016058] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023] Open
Abstract
Nuclear migration is regulated by the LIS1 protein, which is the regulatory subunit of platelet activating factor (PAF) acetyl-hydrolase, an enzyme complex that inactivates the lipid mediator PAF. Among other functions, PAF modulates cell proliferation, but its effects upon mechanisms of the cell cycle are unknown. Here we show that PAF inhibited interkinetic nuclear migration (IKNM) in retinal proliferating progenitors. The lipid did not, however, affect the velocity of nuclear migration in cells that escaped IKNM blockade. The effect depended on the PAF receptor, Erk and p38 pathways and Chk1. PAF induced no cell death, nor a reduction in nucleotide incorporation, which rules out an intra-S checkpoint. Notwithstanding, the expected increase in cyclin B1 content during G2-phase was prevented in the proliferating cells. We conclude that PAF blocks interkinetic nuclear migration in retinal progenitor cells through an unusual arrest of the cell cycle at the transition from S to G2 phases. These data suggest the operation, in the developing retina, of a checkpoint that monitors the transition from S to G2 phases of the cell cycle.
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Affiliation(s)
| | - Tamara Meletti
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael M. Mariante
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robson Q. Monteiro
- Institute of Medical Biochemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Robson R. Bernardo
- Institute of Chemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Angela H. Lopes
- Institute of Microbiology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Linden
- Institute of Biophysics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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Mathiasen LS, Mirza NR, Rodgers RJ. Strain- and model-dependent effects of chlordiazepoxide, L-838,417 and zolpidem on anxiety-like behaviours in laboratory mice. Pharmacol Biochem Behav 2008; 90:19-36. [PMID: 18321566 DOI: 10.1016/j.pbb.2008.01.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Revised: 01/10/2008] [Accepted: 01/22/2008] [Indexed: 01/23/2023]
Abstract
The promise of subtype-selective GABA(A) receptor drugs with anxiolytic properties but with a much reduced side-effect burden (compared to benzodiazepines) is an attainable goal. However, its achievement necessitates the availability of in vivo preclinical assays capable of demonstrating differences as well as similarities between subtype-selective agents and non-selective benzodiazepines. In this study, we have compared three mouse strains (NMRI, C57BL/6J and DBA/2) in four models of anxiety-like behaviour (plus-maze, zero-maze, light-dark, and Vogel conflict). Furthermore, in each model, we have contrasted in detail the behavioural responses of each strain to the non-selective benzodiazepine chlordiazepoxide (CDP; 5-20 mg/kg), and the subtype-selective agents L-838,417 (GABA(A)-alpha(2/3/5); 3-30 mg/kg) and zolpidem (GABA(A)-alpha1; 0.3-3.0 mg/kg). The data show a complex mouse strainxmodelxpharmacological agent interaction. Most importantly, not all mouse strainxmodel test systems showed a positive response to CDP or predicted the response to L-838,417. This dissociation between CDP and L-838,417 opens up opportunities for preclinical test systems that differentiate subtype-selective and non-selective GABA(A) receptor agents, an attribute that might well be important in providing the necessary confidence for further drug development. Present findings suggest the need for a much greater focus on defining test systems appropriate for screening novel chemical entities, rather than self-selection of models or genotypes based on responses to known pharmacological agents. For example, if current data with L-838,417 are confirmed with compounds showing similar selectivity profiles, such agents may in future be best identified and characterised using test systems comprising NMRI mice in the zero-maze and/or C57 mice in the Vogel conflict and/or light-dark tests.
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Affiliation(s)
- L S Mathiasen
- Behavioural Neuroscience Laboratory, Institute of Psychological Sciences, Leeds University, Leeds LS2 9JT, Leeds, UK
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Abstract
While the cause of autism remains unknown, the high concordance between monozygotic twins supports a strong genetic component. The importance of genetic factors in autism encourages the development of mutant mouse models, to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (i) face validity (resemblance to the human symptoms) (ii) construct validity (similarity to the underlying causes of the disease) and (iii) predictive validity (expected responses to treatments that are effective in the human disease). There is a growing need for mouse behavioral tasks with all three types of validity, to define robust phenotypes in mouse models of autism. Ideal mouse models will incorporate analogies to the three diagnostic symptoms of autism: abnormal social interactions, deficits in communication and high levels of repetitive behaviors. Social approach is tested in an automated three chambered apparatus that offers the subject a choice between spending time with another mouse, with a novel object, or remaining in an empty familiar environment. Reciprocal social interaction is scored from videotapes of interactions between pairs of unfamiliar mice. Communication is evaluated by measuring emission and responses to vocalizations and olfactory cues. Repetitive behaviors are scored for measures of grooming, jumping, or stereotyped sniffing of one location or object. Insistence on sameness is modeled by scoring a change in habit, for example, reversal of the spatial location of a reinforcer in the Morris water maze or T-maze. Associated features of autism, for example, mouse phenotypes relevant to anxiety, seizures, sleep disturbances and sensory hypersensitivity, may be useful to include in a mouse model that meets some of the core diagnostic criteria. Applications of these assays include (i) behavioral phenotyping of transgenic and knockout mice with mutations in genes relevant to autism; (ii) characterization of inbred strains of mice; (iii) evaluation of environmental toxins; (iv) comparison of behavioral phenotypes with genetic factors, such as unusual expression patterns of genes or unusual single nucleotide polymorphisms; and (v) evaluation of proposed therapeutics for the treatment of autism.
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Affiliation(s)
- Jacqueline N Crawley
- Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute of Mental Health, Bethesda, MD 20892-3730. USA.
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Wilson RB, Kunchithapautham K, Rohrer B. Paradoxical role of BDNF: BDNF+/- retinas are protected against light damage-mediated stress. Invest Ophthalmol Vis Sci 2007; 48:2877-86. [PMID: 17525224 PMCID: PMC1964504 DOI: 10.1167/iovs.06-1079] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Photoreceptors can be prevented from undergoing apoptosis in response to constant light by the application of exogenous neuroprotective agents, including brain-derived neurotrophic factor (BDNF). BDNF, however, cannot exert its effect directly on photoreceptors because they do not express receptors for BDNF. It has been proposed that BDNF released from Müller cells provides a feed-forward loop, increasing ciliary neurotrophic factor (CNTF) and basic fibroblast growth factor (bFGF) production in Müller cells, which may enhance photoreceptor survival. The authors hypothesized that retinas with reduced BDNF levels in which the BDNF-mediated release of neuroprotective signals is dampened are more susceptible to light-induced photoreceptor degeneration. METHODS Young adult BDNF+/+ and BDNF+/- littermates (B6.129-BDNF(tm1-LT)) were analyzed. Retinal neurotrophin and growth factor mRNA levels were determined by quantitative RT-PCR, photoreceptor function was assessed through electroretinography, and survival was documented in morphologic sections and in TUNEL assays. Oxidative stress was assayed by measuring glutathione peroxidase activity. RESULTS At baseline, BDNF+/- animals had significantly increased levels of glial-derived neurotrophic factor (GDNF) mRNA compared with their wild-type littermates. After light damage GDNF, CNTF, and BDNF mRNA levels dropped 14- to 16-fold in the BDNF+/+ mice but remained almost unchanged compared with baseline levels in the BDNF+/- mice. Preservation of neurotrophin levels in BDNF+/- mice correlated with photoreceptor cell survival, preservation of function, and reduced oxidative stress. CONCLUSIONS Contrary to the hypothesis, reducing BDNF levels resulted in photoreceptor protection against light damage. Survival was paralleled by a reduction in oxidative stress and the preservation of neurotrophin levels, suggesting that chronic reduction of BDNF in the retina provides a level of preconditioning against stress.
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Affiliation(s)
- R. Brooks Wilson
- Neurosciences Division of Research, Medical University of South Carolina, Charleston, South Carolina
| | - Kannan Kunchithapautham
- Neurosciences Division of Research, Medical University of South Carolina, Charleston, South Carolina
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
- Neurosciences Division of Research, Medical University of South Carolina, Charleston, South Carolina
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Olsson IAS, Westlund K. More than numbers matter: The effect of social factors on behaviour and welfare of laboratory rodents and non-human primates. Appl Anim Behav Sci 2007. [DOI: 10.1016/j.applanim.2006.05.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Schmitt U, Hiemke C, Fahrenholz F, Schroeder A. Over-expression of two different forms of the α-secretase ADAM10 affects learning and memory in mice. Behav Brain Res 2006; 175:278-84. [PMID: 17014917 DOI: 10.1016/j.bbr.2006.08.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 08/24/2006] [Accepted: 08/25/2006] [Indexed: 01/31/2023]
Abstract
Members of the ADAM family (adisintegrin and metalloprotease) are the main candidates for physiologically relevant alpha-secretases. The alpha-secretase cleaves in the non-amyloidogenic pathway the amyloid precursor protein within the region of the Abeta peptides preventing their aggregation in the brain. The increase of alpha-secretase activity in the brain provides a plausible strategy to prevent Abeta formation. Concerning this possibility two transgenic mouse lines (FVB/N) have been created: mice over-expressing the bovine form of the alpha-secretase (ADAM10) and mice over-expressing an inactive form of the alpha-secretase (ADAM10-E348A-HA; ADAM10-dn). For behavioral examination a F1 generation of transgenic mice (C57Bl/6 x FVB/N (tg)) was generated and compared to wild type F1 generation (C57Bl/6 x FVB/N). Behavior was characterized in the following tasks: standard open field, enriched open field, elevated plus-maze, and the Morris water maze hidden platform task. Concerning basal activity, exploration, and anxiety, transgenic mice behaved similar to controls. With respect to learning and memory both transgenic lines showed a significant deficit compared to controls. ADAM10 mice however, showed thigmotaxis with passive floating behavior in the Morris water maze indicating differences in motivation, whereas, ADAM10-dn mice displayed an inconspicuous but limited goal-directed search pattern. Thus variation of the enzymatic activity of alpha-secretase ADAM10 alters learning and memory differentially. Nevertheless, it could be concluded that both, ADAM10 and ADAM10-dn mice are suitable control mice for the assessment of alpha-secretase-related effects in animal models of Alzheimer's disease.
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Affiliation(s)
- Ulrich Schmitt
- Department of Psychiatry, Johannes Gutenberg University, 55101 Mainz, Germany.
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Abstract
Cholecystokinin (CCK) inhibits food intake in adults. This paper describes research examining the ability of CCK to affect feeding in infant rats and the role of CCK in the developmentally emerging ability of the rat pup to inhibit ingestion in response to sensory characteristics of food. First, data will be described from studies that asked if the CCK system is functional in preweanling rats. Specifically, these studies examined whether exogenous and endogenous CCK can decrease intake of the infant rat during independent ingestion (of a milk diet, away from the dam). In addition, the ability of exogenous CCK to activate central feeding-control areas in the brain stem and hypothalamus in infant rats was examined by C-FOS staining. Next, experiments examining which specific intake-inhibitory sensory aspects of food are mediated by CCK will be described. The volume, hypertonicity, fat, carbohydrate and protein content of a preload were separately manipulated in different studies, followed closely by a 30-min test meal. The selective CCK(1) receptor antagonist devazepide was used to assess CCK mediation of the control of intake produced by particular sensory aspects of food, at the earliest age in which this ability to control intake appears. Finally, the pattern of independent ingestion in infant OLETF rats lacking CCK(1) receptors was examined. The results suggest that the CCK intake-inhibitory mechanism is potentially available to the young, suckling pup even before it starts to feed on its own. However, it appears to mediate only a portion of the controls of intake during nursing and early stages of weaning. Some aspects of the CCK system (e.g., forebrain-hindbrain connections) and CCK's role in mediating the effects of other stimulus aspects of food apparently undergo a post-weaning maturational process.
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Affiliation(s)
- Aron Weller
- Department of Psychology, and the Gonda Goldschmied Brain Research Center, Bar Ilan University, Ramat Gan, Israel.
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Schimmelmann BG, Friedel S, Christiansen H, Dempfle A, Hinney A, Hebebrand J. Genetische Befunde bei der Aufmerksamkeitsdefizit- und Hyperaktivitätsstörung (ADHS). ZEITSCHRIFT FUR KINDER-UND JUGENDPSYCHIATRIE UND PSYCHOTHERAPIE 2006; 34:425-33. [PMID: 17094061 DOI: 10.1024/1422-4917.34.6.425] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Zusammenfassung: Die Aufmerksamkeitsdefizit- und Hyperaktivitätsstörung (ADHS) ist mit einer Prävalenz von 3-7% eine häufige kinder- und jugendpsychiatrische Störung. Auf der Basis formalgenetischer Studien ergibt sich eine Heritabilitätsschätzung von 60-80% für ADHS mit einem ca. 5-fach erhöhten Risiko für erstgradige Verwandte von Betroffenen. Bislang vier Genomscans lieferten potentiell relevante chromosomale Regionen, insbesondere den einheitlichen Kopplungsbefund auf 5p13. Aus einer Vielzahl von Assoziationsstudien zu Kandidatengenen deuten aktuelle Metaanalysen auf die Relevanz der Gene der dopaminergen Rezeptoren DRD4 und DRD5 sowie des serotonergen Rezeptors HTR1B und des Synaptosomal Assoziierten Proteins (SNAP-25). In Tiermodellen liegen vorwiegend Paradigmen für Hyperaktivität vor; diese sind in knockout- und Quantitative Trait Loci (QTL) Designs mit viel versprechenden Ergebnissen zum dopaminergen System untersucht worden. Es ist davon auszugehen, dass erst das Zusammenwirken verschiedener Gen-Varianten mit jeweils moderatem bis hin zu kleinem Effekt den Phänotyp ADHS bedingen (Oligo-/ Polygenie) und bei verschiedenen Betroffenen unterschiedliche Kombinationen von prädisponierenden Gen-Polymorphismen zu ADHS führen können. Entsprechend sind für molekulargenetische Studien große Fallzahlen notwendig und die bisherigen Befunde als vorläufig zu interpretieren. Zukunftsweisend für die molekulargenetische Aufklärung von ADHS sind SNP-basierte Genomscans, mit denen 10 000-1 000 000 einzelne Polymorphismen (SNPs) gleichzeitig untersucht werden können. Tiermodelle liefern Hinweise auf die Funktion relevanter Kandidatengene und tragen zur Erweiterung der bislang teilweise widersprüchlichen Kenntnisse zur Neurobiologie des ADHS bei.
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Affiliation(s)
- Benno Graf Schimmelmann
- Klinik für Psychiatrie und Psychotherapie des Kindes- und Jugendalters, Universität Duisburg-Essen, Rheinische Kliniken Essen, Virchowstrasse 174, DE-45147 Essen.
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Rodgers RJ, Augar R, Berryman N, Hansom CJ, O'Mahony ML, Palmer RM, Stevens A, Tallett AJ. Atypical anxiolytic-like response to naloxone in benzodiazepine-resistant 129S2/SvHsd mice: role of opioid receptor subtypes. Psychopharmacology (Berl) 2006; 187:345-55. [PMID: 16802164 DOI: 10.1007/s00213-006-0435-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 04/26/2006] [Indexed: 11/28/2022]
Abstract
RATIONALE Mice of many 129 substrains respond to environmental novelty with behavioural suppression and high levels of anxiety-like behaviour. Although resistant to conventional anxiolytics, this behavioural phenotype may involve stress-induced release of endogenous opioids. OBJECTIVES To assess the effects of opioid receptor blockade on behavioural reactions to novelty stress in a chlordiazepoxide-resistant 129 substrain. MATERIALS AND METHODS Experiment 1 contrasted the effects of the broad-spectrum opioid receptor antagonist naloxone (1.0-10.0 mg/kg) in C57BL/6JOlaHsd and 129S2/SvHsd mice exposed to the elevated plus-maze. Experiments 2-4 examined the responses of 129S2/SvHsd mice to the mu-selective opioid receptor antagonist beta-funaltrexamine (2.5-10.0 mg/kg), the delta-selective antagonist naltrindole (2.5-10.0 mg/kg) and the kappa-selective antagonist nor-binaltorphimine (2.5-5.0 mg/kg). RESULTS 129 mice displayed higher levels of anxiety-like behaviour and lower levels of general exploration relative to their C57 counterparts. Although naloxone failed to alter the behaviour of C57 mice, both doses of this antagonist produced behaviourally selective reductions in open-arm avoidance in 129 mice. Surprisingly, none of the more selective opioid receptor antagonists replicated this effect of naloxone: beta-funaltrexamine was devoid of behavioural activity, naltrindole suppressed rearing (all doses) and increased immobility (10 mg/kg), while nor-binaltorphimine (5 mg/kg) nonspecifically increased percent open arm entries. CONCLUSIONS Recent evidence suggests differential involvement of opioid receptor subtypes in the anxiolytic efficacy of diverse compounds including conventional benzodiazepines. The insensitivity of 129 mice to the anxiolytic action of chlordiazepoxide, coupled with their atypical anxiolytic response to naloxone (but not more selective opioid receptor antagonists), suggests an abnormality in anxiety-related neurocircuitry involving opioid-GABA interactions.
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Affiliation(s)
- R J Rodgers
- Behavioural Neuroscience Laboratory, Institute of Psychological Sciences, University of Leeds, Leeds, LS2 9JT, UK,
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Egerton A, Allison C, Brett RR, Pratt JA. Cannabinoids and prefrontal cortical function: Insights from preclinical studies. Neurosci Biobehav Rev 2006; 30:680-95. [PMID: 16574226 DOI: 10.1016/j.neubiorev.2005.12.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 11/18/2005] [Accepted: 12/19/2005] [Indexed: 10/24/2022]
Abstract
Marijuana use has been associated with disordered cognition across several domains influenced by the prefrontal cortex (PFC). Here, we review the contribution of preclinical research to understanding the effects of cannabinoids on cognitive ability, and the mechanisms by which cannabinoids may affect the neurochemical processes in the PFC that are associated with these impairments. In rodents, acute administration of cannabinoid agonists produces deficits in working memory, attentional function and reversal learning. These effects appear to be largely dependent on CB1 cannabinoid receptor activation. Preclinical studies also indicate that the endogenous cannabinoid system may tonically regulate some mnemonic processes. Effects of cannabinoids on cognition may be mediated via interaction with neurochemical processes in the PFC and hippocampus. In the PFC, cannabinoids may alter dopaminergic, cholinergic and serotonergic transmission. These mechanisms may underlie cognitive impairments observed following marijuana intake in humans, and may also be relevant to other disorders of cognition. Preclinical research will further enhance our understanding of the interactions between the cannabinoid system and cognitive functioning.
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Affiliation(s)
- Alice Egerton
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, UK
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Valverde O, Karsak M, Zimmer A. Analysis of the endocannabinoid system by using CB1 cannabinoid receptor knockout mice. Handb Exp Pharmacol 2005:117-45. [PMID: 16596773 DOI: 10.1007/3-540-26573-2_4] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The endocannabinoid system has been involved in the control of several neurophysiological and behavioural responses. To date, three lines of CB1 knockout mice have been established independently in different laboratories. This chapter reviews the main results obtained with these lines of CB1 knockout mice in several physiological responses that have been previously related to the activity of the endocannabinoid system. Studies using CB1 knockout mice have demonstrated that this receptor participates in the control of several behavioural responses including locomotion, anxiety- and depressive-like states, cognitive functions such as memory and learning processes, cardiovascular responses and feeding. Furthermore, the CB1 cannabinoid receptor is involved in the control of pain by acting at peripheral, spinal and supraspinal levels. The involvement of the CB1 cannabinoid receptor in the behavioural and biochemical processes underlying drug addiction has also been investigated. These CB1 knockouts have provided new findings to clarify the interactions between cannabinoids and the other drugs of abuse such as opioids, psychostimulants, nicotine and ethanol. Recent studies have demonstrated that endocannabinoids can function as retrograde messengers, modulating the release of different neurotransmitters, including opioids, gamma-aminobutyric acid (GABA), and cholecystokinin (CCK), which could explain some of the responses observed after the stimulation of the CB1 cannabinoid receptor. This review provides an update of the apparently controversial data reported in the literature using the three different lines of CB1 knockout mice, which seem to be mainly due to the use of different experimental procedures rather than any constitutive alteration in these lines of knockouts.
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Affiliation(s)
- O Valverde
- Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Carrer Dr. Aiguader, 80, 08003 Barcelona, Spain
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Abumrad NA, Ajmal M, Pothakos K, Robinson JK. CD36 expression and brain function: does CD36 deficiency impact learning ability? Prostaglandins Other Lipid Mediat 2005; 77:77-83. [PMID: 16099393 DOI: 10.1016/j.prostaglandins.2004.09.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2004] [Accepted: 09/14/2004] [Indexed: 11/29/2022]
Abstract
This article first presents an overview of published literature documenting the role of the scavenger receptor CD36 in activation of brain microglia with reference to brain pathologies such as Alzheimer's and malaria. Second, the possibility that CD36 may play a role in brain FA metabolism is discussed. Long-chain polyunsaturated fatty acids (PUFAs) are important for brain function and are mostly derived from the plasma. Based on its role in facilitating FA uptake in several tissues and cell types, CD36 expressed on microvascular endothelial cells in the brain may facilitate local uptake of PUFAs. Alternatively, CD36 may influence brain FA supply indirectly via impacting utilization of dietary FA or their metabolism in tissues such as the liver. We examined the possibility that CD36 expression impacts brain function by evaluating the behavior of CD36 null mice using a battery of standard tests. Our data indicate that CD36 deficient mice have normal patterns of activity, anxiety and exploration of novel environments. However they appear to have a significant impairment in learning ability. These findings could provide a new perspective regarding the regulation of brain lipid metabolism.
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Affiliation(s)
- Nada A Abumrad
- Department of Physiology, Biophysics and Psychology, Stony Brook University, NY 11794, USA.
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Varvel SA, Anum E, Niyuhire F, Wise LE, Lichtman AH. Delta(9)-THC-induced cognitive deficits in mice are reversed by the GABA(A) antagonist bicuculline. Psychopharmacology (Berl) 2005; 178:317-27. [PMID: 15322725 DOI: 10.1007/s00213-004-1988-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Accepted: 07/07/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE The results of recent in vitro studies have underscored the important role that activation of CB(1) receptors has on GABAergic activity in brain areas associated with memory. OBJECTIVES The primary purpose of this study was to test the hypothesis that the memory disruptive effects of Delta(9)-tetrahydrocannabinol (Delta(9)-THC) in vivo are mediated through GABAergic systems. Conversely, we also evaluated whether blocking CB(1) receptor signaling would alter memory deficits elicited by GABA agonists. METHODS The GABA(A) antagonist bicuculline and GABA(B) antagonist CGP 36742 were evaluated for their ability to ameliorate Delta(9)-THC-induced deficits in a mouse working memory Morris water maze task. Mice were also assessed in a T-maze task, as well as non-cognitive behavioral assays. Additionally, the effects of GABA(A) and GABA(B) agonists were assessed in either CB(1) (-/-) mice or wild type mice treated with the CB(1) antagonist SR 141716. RESULTS Memory deficits resulting from 10 mg/kg Delta(9)-THC in the Morris water maze were completely reversed by bicuculline, though unaffected by CGP 36742. Bicuculline also blocked the disruptive effects of Delta(9)-THC in the T-maze, but failed to alter non-mnemonic effects of Delta(9)-THC. Although CB(1) (-/-) mice exhibited supersensitivity to muscimol-induced water maze deficits compared with wild type control mice, muscimol elicited virtually identical effects in SR 141716-treated and vehicle-treated wild type mice. CONCLUSIONS This is the first demonstration of which we are aware showing that GABA(A) receptors may play a necessary role in Delta(9)-THC-induced memory impairment in whole animals.
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Affiliation(s)
- S A Varvel
- Department of Pharmacology, VCU, PO Box 980613, Richmond, VA 23298, USA.
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Abstract
The importance of genetic factors in autism has prompted the development of mutant mouse models to advance our understanding of biological mechanisms underlying autistic behaviors. Mouse models of human neuropsychiatric diseases are designed to optimize (1) face validity, i.e., resemblance to the human symptoms; (2) construct validity, i.e., similarity to the underlying causes of the disease; and (3) predictive validity, i.e., expected responses to treatments that are effective in the human disease. There is a growing need for mouse behavioral tasks with all three types of validity for modeling the symptoms of autism. We are in the process of designing a set of tasks with face validity for the defining features of autism: deficits in appropriate reciprocal social interactions, deficits in verbal social communication, and high levels of ritualistic repetitive behaviors. Social approach is tested in an automated three-chambered apparatus that offers the subject a choice between a familiar environment, a novel environment, and a novel environment containing a stranger mouse. Preference for social novelty is tested in the same apparatus, with a choice between the start chamber, the chamber containing a familiar mouse, and the chamber containing a stranger mouse. Social communication is evaluated by measuring the ultrasonic distress vocalizations emitted by infant mouse pups and the parental response of retrieving the pup to the nest. Resistance to change in ritualistic repetitive behaviors is modeled by forcing a change in habit, including reversal of the spatial location of a reinforcer in a T-maze task and in the Morris water maze. Mouse behavioral tasks that may model additional features of autism are discussed, including tasks relevant to anxiety, seizures, sleep disturbances, and sensory hypersensitivity. Applications of these tests include (1) behavioral phenotyping of transgenic and knockout mice with mutations in genes relevant to autism, (2) characterization of mutant mice derived from random chemical mutagenesis, (3) DNA microarray analyses of genes in inbred strains of mice that differ in social interaction, social communication and resistance to change in habit, and (4) evaluation of proposed therapeutics for the treatment of autism.
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Affiliation(s)
- Jacqueline N Crawley
- Mouse Behavioral Phenotyping Laboratory, Neurodevelopmental Disorders Research Center, University of North Carolina, Chapel Hill, North Carolina, USA.
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Crews D, Fuller T, Mirasol EG, Pfaff DW, Ogawa S. Postnatal environment affects behavior of adult transgenic mice. Exp Biol Med (Maywood) 2004; 229:935-9. [PMID: 15388889 DOI: 10.1177/153537020422900910] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Behavioral phenotypes of knockout mice are often interpreted as the effects of the absence of the gene product on adult behavior, yet behavioral differences among genotypes may be exaggerated or blurred by the postnatal environment. For example, mice develop in litters of varying sex ratios and genotypes, and it is possible that some of these behavioral differences may result from the composition of the litter. To determine whether these factors might play a role in the development of the behavioral characteristics that have become diagnostic of the knockout, offspring of parents heterozygous for a null mutation of estrogen receptor alpha (ERKO) were sexed and genotyped within 2 days of birth. Litters were then reconstituted, forming same-sex litters of equal numbers of ERKO and wild-type (WT) individuals that were tested in a standard resident-intruder paradigm. In this manner the effect of genotype would be evident without the potential confound of the presence of the opposite sex in the litter. Behavioral differences between the genotypes were more sharply defined than reported previously. ERKO females displayed only aggressive behavior whereas their WT littermates displayed only mounting behavior; both aggression and mounting behavior were greatly reduced in ERKO males. These data suggest that the postnatal environment such as litter composition may influence the development of sociosexual behaviors in ERKO mice.
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Affiliation(s)
- David Crews
- Section of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA.
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Vekovischeva OY, Aitta-Aho T, Echenko O, Kankaanpää A, Seppälä T, Honkanen A, Sprengel R, Korpi ER. Reduced aggression in AMPA-type glutamate receptor GluR-A subunit-deficient mice. GENES BRAIN AND BEHAVIOR 2004; 3:253-65. [PMID: 15344919 DOI: 10.1111/j.1601-1848.2004.00075.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The importance of AMPA-type glutamate receptors has been demonstrated in neuronal plasticity and in adaptation to drugs of abuse. We studied the involvement of AMPA receptors in social interaction and anxiety and found that in several paradigms of agonistic behavior naïve male mice deficient for the GluR-A subunit- containing AMPA receptors are less aggressive than wild-type littermates. GluR-A deficient mice and wild-type littermates exhibited similar basic behavior and reflexes as monitored by observational Irwin's test, but they tended to be less anxious in elevated plus-maze and light-dark tests. Maternal aggression or male-female encounters were not affected which suggests that male hormones are involved in the expression of suppressed aggressiveness. However, testosterone levels and brain monoamines can be excluded and found to be similar between GluR-A deficient and wild-type littermates. The reduced AMPA receptor levels caused by the lack of the GluR-A subunit, and measured by a 30% reduction in hippocampal [3H]-S-AMPA binding, seem to be the reason for suppressed male aggressiveness. When we analyzed mice with reduced number of functional AMPA receptors mediated by the genomic introduced GluR-A(Q582R) channel mutation, we observed again male-specific suppressed aggression, providing additional evidence for GluR-A subunit-containing AMPA receptor involvement in aggression.
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Affiliation(s)
- O Y Vekovischeva
- Institute of Biomedicine/Pharmacology, Biomedicum Helsinki, University of Helsinki, Finland
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Morgan MA, Schulkin J, Pfaff DW. Estrogens and non-reproductive behaviors related to activity and fear. Neurosci Biobehav Rev 2004; 28:55-63. [PMID: 15036933 DOI: 10.1016/j.neubiorev.2003.11.017] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2002] [Revised: 09/30/2003] [Accepted: 11/07/2003] [Indexed: 11/22/2022]
Abstract
Estrogens affect a variety of behaviors in addition to sexual responses, some of them related to motor activity and emotional reactivity. This is true in experimental animals and in humans. The literatures on these subjects are confusing because not all of the experimental results point in the same direction. Here we propose the following theoretical suggestion, hoping to account for the variety of reports extant: following the generally arousing effects of estrogens, their hormonal actions on motor activity and fear depend on context. In a safe environment, estrogen treatment causes increased activity. But in a novel environment or in contexts otherwise perceived as threatening, activity is reduced by estrogen, due to the hormone's arousing action, which heightens fear. Many hormone-dependent neural circuits involving several neuropeptides could provide mechanisms for this dynamic. We suggest a causal route could involve the activation of corticotropin releasing hormone gene expression in the brain. In sum, estrogenic effects on arousal states, as manifest differently according to details of the environmental context during behavioral test, could account for some of the discrepancies in the literature.
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Affiliation(s)
- M A Morgan
- Department of Research, american College of Obstetricians and Gynecologists, Washington DC 20024, USA.
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Ethical decisions concerning animal biotechnology: what is the role of animal welfare science? Anim Welf 2004. [DOI: 10.1017/s0962728600014494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
AbstractScientists recently attracted considerable public attention when they presented a featherless chicken tailored for production in hot climates. Although this chicken was actually the result of traditional breeding, it is an example of what might be achieved if targeted gene manipulation techniques become widely applied in agriculture. Through interfering directly with an animal's genome, scientists hope to be able to create animals with exactly the desired characteristics, such as lean meat or temperature tolerance. Industry and geneticists may be enthusiastic about the possibility of producing pork with polyunsaturated fatty acids or high-yielding dairy cows to be kept in tropical climates, but the European public often reacts with alarm at these prospects. A consistent pattern of the surveys conducted among members of the European public is that, of all of the potential biotechnology applications, those involving animals are the ones that people find the least acceptable. People fear a development of techniques that may get out of control, and they also have ethical concerns about humans’ right to ‘play God’ and about the welfare of the animals involved. All of these aspects seem to be relevant for an ethical discussion about animal biotechnology. Animal welfare scientists can play an important role by providing information for an animal welfare risk assessment at an early stage of research projects that involve the genetic modification of animals, and also by helping to develop guidelines for the housing and husbandry of animals with special needs. On the other hand, ethical problems remain that lie outside the area of science. In this paper we discuss the role of animal welfare science in aiding ethics decisions about animal biotechnology. We give a summary of the different ethical concerns expressed by ethicists and by the general public. Focusing on one of them, animal welfare, we give an introduction to the animal welfare implications of recent developments in reproductive and gene technologies. The importance of animal welfare aspects is discussed in relation to other ethical concerns about animal biotechnology.
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Abstract
Behaviors are quantitative traits determined through actions of multiple genes and subject to genome-environment interactions. Early studies concentrated on analyzing the effects of single genes on behaviors, often generating views of simplified linear genetic pathways. The genome era has generated a profound paradigm shift enabling us to identify all the genes that contribute to expression of a behavioral phenotype, to investigate how they are organized as functional ensembles and to begin to identify polymorphisms that contribute to phenotypic variation and are targets for natural selection. Recent studies show that the genetic architecture of behavior is determined by dynamic and plastic modular networks of pleiotropic genes and that the behavioral phenotype manifests itself as an emergent property of such networks. Such networks are exquisitely sensitive to genetic background and sex effects. This review describes how Drosophila can serve as a model for uncovering fundamental principles of the genetic architecture of behavior.
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Affiliation(s)
- Robert R H Anholt
- WM Keck Center for Behavioral Biology and Departments of Zoology and Genetics, North Carolina State University, Raleigh, NC 27695-7617, USA.
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McQuade JA, Xu M, Woods SC, Seeley RJ, Benoit SC. Ethanol consumption in mice with a targeted disruption of the dopamine-3 receptor gene. Addict Biol 2003; 8:295-303. [PMID: 13129831 DOI: 10.1080/13556210310001602202] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Considerable evidence suggests that the mesolimbic dopaminergic system is an important substrate for the rewarding effects of ethanol consumption. Previous data have demonstrated that pharmacological agents that alter dopamine signaling also influence the self-administration of ethanol. The present experiments were designed to assess the role of the dopamine-3 receptor (D3-R) on voluntary ethanol consumption in C57BL/6 mice. Mice with targeted disruption of the D3-R gene (D3-R - /-) were compared to wild-type controls in an ethanol intake paradigm. In Experiment 1, mice had 24-hour access to ethanol each day in a two-bottle choice paradigm for a period of 7 days per concentration. The concentrations tested were 3, 6, 10 and 15%. In Experiment 2, mice had I hour of access to ethanol each day in a two-bottle paradigm for a period of 7 days per concentration. The same concentrations in Experiment I were compared in Experiment 2. In Experiment 3 we sought to test the development of a conditioned taste aversion (CTA) after receiving an intraperitoneal (ip.) injection of 2.0 g/kg ethanol. In Experiment 4, blood ethanol levels where assessed following a 2.0 g/kg ip.injection of ethanol. Experiment 5 assessed taste preference for saccharine and quinine in wild-type and D3-R -/- mice. Contrary to our predictions, both D3-R -/- and wild-types on a CS57BL/6 background had similar intakes of ethanol, at all concentrations tested, in the 24-hour and 1-hour intake paradigms. Wild-type and D3-R -/- mice respond to injected ethanol similarly by developing a conditioned taste aversion. Metabolic analysis revealed mutant mice are slower in metabolizing a bolus injection of ethanol. Lastly, wild-type and D3-R -/- mice showed similar consumption to increasing concentration of both sweet and bitter tastes. These data suggest that deletion of the D3-R gene does not increase ethanol consumption above that found on the C57BL/6 genetic background. Furthermore, the D3-R -/- mice adequately learn a CTA to ethanol and do not ham differing taste reactivity to saccharin or quinine. However, D3-R -/- mice do appear to have a slower rate of ethanol metabolism.
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Affiliation(s)
- John-Andrews McQuade
- Department of Psychiatry, University of Cincinnati, Cincinnati, OH 45267-0559, USA
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Rodgers RJ, Davies B, Shore R. Absence of anxiolytic response to chlordiazepoxide in two common background strains exposed to the elevated plus-maze: importance and implications of behavioural baseline. GENES, BRAIN, AND BEHAVIOR 2002; 1:242-51. [PMID: 12882369 DOI: 10.1034/j.1601-183x.2002.10406.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Although genetic background is acknowledged as a potentially important determinant of mutant phenotypes, publications on genetically modified mice far outnumber those on progenitor strains. We have recently reported major differences in basal anxiety levels (elevated plus-maze & light/dark exploration) among three strains (C57BL/6JOlaHsd, 129/SvEv and 129S2/SvHsd) employed as progenitor stock in European laboratories (Rodgers et al. in press). Furthermore, the phenotypes of these inbred strains differed significantly from that of an outbred strain (Swiss-Webster) commonly used in behavioural pharmacology. In view of these findings, the present study assessed possible differences in the anxiolytic efficacy of chlordiazepoxide (0, 7.5 & 15.0 mg/kg, IP) in three of these strains (Swiss-Webster (SW), C57BL/6JOIaHsd (C57) & 129S2/SvHsd (129)). Experimentally naive mice were exposed to the elevated plus-maze, sessions were videotaped and behaviour analysed using ethological software. The performance of control subjects confirmed significant strain differences in basal levels of activity (SW > C57 > 129) and anxiety-related behaviours (129 = SW > C57), with hypolocomotion dominating the 129 profile. SW mice displayed an anxioselective response to both doses of chlordiazepoxide (CDP), with significant reductions in open arm avoidance and risk assessment observed in the absence of any change in general activity. In direct contrast, the lower dose of CDP (7.5 mg/kg) was without effect in either inbred strain, whereas treatment with 15.0 mg/kg induced a profile indicative of muscle relaxation/mild sedation in C57 mice and virtually abolished all behavioural activity in 129 mice. Although the absence of an anxiolytic response to CDP in C57 mice may be attributed to their low basal anxiety levels, the profile of 129 mice strongly suggests an abnormality in benzodiazepine/GABAA receptor function. The implications of these findings for research on mutant mice are discussed.
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Affiliation(s)
- R J Rodgers
- Behavioural Pharmacology Laboratory, School of Psychology University of Leeds, Leeds, UK.
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Rodgers RJ, Boullier E, Chatzimichalaki P, Cooper GD, Shorten A. Contrasting phenotypes of C57BL/6JOlaHsd, 129S2/SvHsd and 129/SvEv mice in two exploration-based tests of anxiety-related behaviour. Physiol Behav 2002; 77:301-10. [PMID: 12419406 DOI: 10.1016/s0031-9384(02)00856-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Knockout mice are typically generated on a mixed genetic background and, as such, detailed behavioural characterisation of these background strains is essential to the valid interpretation of mutant phenotypes. In this context, recent research has revealed significant differences in anxiety-like behaviour among the most commonly used background strains (C57BL/6J and various 129 substrains), leading to the possibility that at least certain mutant phenotypes may not after all be due to the targeted mutation. However, these findings derive largely from behavioural test batteries in which there may well be an experiential confound, while the widely reported hypolocomotor profile of most 129 substrains may compromise the principal indices of anxiety-like behaviour. In the present study, we have compared the behavioural profiles of three commonly used background strains (C57BL/6JOlaHsd, 129/SvEv and 129S2/SvHsd) in two of the most popular animal models of anxiety-the elevated plus-maze (EPM) and light/dark exploration (LDE) tests. Naive animals were used for each procedure, ethological scoring methods were employed throughout, and the inbred phenotypes were also compared with that of an outbred strain (Swiss-Webster) widely employed in test validation and behavioural pharmacology. Our results show that, despite their hypolocomotor profile, both 129 substrains display higher levels of anxiety-like behaviour (conventional and/or ethological measures) relative to the C57BL/6JOlaHsd strain. Furthermore, all three inbred strains were less active in both tests when compared with the outbred Swiss-Webster strain. However, whereas C57BL/6JOlaHsd mice displayed lower levels of anxiety-like behaviour than their Swiss-Webster counterparts (both tests), 129S2/SvHsd (but not 129/SvEv) mice exhibited evidence of higher anxiety, particularly in the LDE test. The implications of these findings are discussed in relation to both the behavioural and pharmacological phenotyping of mutant mice.
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Affiliation(s)
- R J Rodgers
- Behavioural Pharmacology Laboratory, School of Psychology, University of Leeds, Leeds LS2 9JT, UK.
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Rodríguez-Manzo G, López-Rubalcava C, Hen R, Fernández-Guasti A. Participation of 5-HT(1B) receptors in the inhibitory actions of serotonin on masculine sexual behaviour of mice: pharmacological analysis in 5-HT(1B) receptor knockout mice. Br J Pharmacol 2002; 136:1127-34. [PMID: 12163345 PMCID: PMC1573454 DOI: 10.1038/sj.bjp.0704827] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1 The role of the 5-Hydroxytryptamine(1B) (5-HT(1B)) receptor subtype in masculine sexual behaviour in mice was analysed in both 5-HT(1B) receptor knockout (KO(1B)) and wild-type (WT) animals. 2 Comparison of male copulatory behaviour of WT and KO(1B) strains revealed that KO(1B) mice become interested earlier in sexual behaviour, but require more stimulation to achieve ejaculation than its corresponding WT strain. 3 The pharmacological manipulation of male sexual activity in the WT strain showed that the serotonin precursor 5-Hydroxytryptophan (5-HTP), the 5-HT(1B) agonist (1-(m-trifluoromethylphenyl) piperazine (TFMPP) and the 5-Hydroxytryptamine(1A) (5-HT(1A)) receptor agonist 8-hydroxy-2-di-n-propylamino-tetralin (8-OH-DPAT) all inhibited male copulatory behaviour in mice. 4 In KO(1B) mice, TFMPP lacked an effect, 5-HTP exerted a mild inhibitory effect while 8-OH-DPAT provoked only a tendency towards a reduction in the percentage of animals that achieved ejaculation. In general, KO(1B) mice were less sensitive to the inhibitory actions of 5-HTP and 8-OH-DPAT than the WT strain. 5 Based on these results, we can suggest that serotonin plays a general inhibitory role in the sexual behaviour of male mice and that both 5-HT(1B) and 5-HT(1A) receptor subtypes participate in the inhibitory actions of this neurotransmitter. 6 The absence of the 5-HT(1B) receptor subtype affected both components of mouse masculine sexual behaviour, motivation and execution, further confirming the involvement of this receptor subtype in the control of this behaviour. In addition, the diminished sensitivity to serotonergic stimulation exhibited by KO(1B) mice suggests the occurrence of compensatory changes as a consequence of the absence of the 5-HT(1B) receptor subtype.
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Affiliation(s)
- Gabriela Rodríguez-Manzo
- Departmento de Farmacobiología, CINVESTAV, IPN, Sede Sur, Calzada de los Tenorios 235, Col. Granjas Coapa, México D.F.14330, México.
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Abstract
Emx1 is a mammalian homolog of the Drosophila gap gene empty spiracles (ems). Although it has been implicated in the formation of the mouse forebrain, the neuronal functions of this homeobox gene remain unknown. The restricted expression of Emx1 to the cerebral cortex and hippocampus suggests that it might play a role in emotional and other behavioral processes. The present study examined the phenotypes of Emx1-deficient mice generated by gene targeting technology in a battery of behavioral tests with a fixed inter-trial interval of 7 days. Compared with their wild-type littermates, the Emx1 homozygous mutant mice displayed markedly lowered anxiety-like behaviors in the elevated plus maze and dark/light exploration tests. Moreover, they exhibited less depressive-like response as indicated by the reduced duration of immobility in the forced swimming paradigm. There was a trend toward reduction in prepulse inhibition of acoustic startle in the homozygotes. No significant alterations in locomotor activity and susceptibility to pentylenetetrazol-induced seizure were found. This behavioral profile indicates an involvement of Emx1 in the emotional responses of mice.
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Affiliation(s)
- Bo-Jin Cao
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Avenue, Urbana, IL 61801, USA
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Young KA, Berry ML, Mahaffey CL, Saionz JR, Hawes NL, Chang B, Zheng QY, Smith RS, Bronson RT, Nelson RJ, Simpson EM. Fierce: a new mouse deletion of Nr2e1; violent behaviour and ocular abnormalities are background-dependent. Behav Brain Res 2002; 132:145-58. [PMID: 11997145 PMCID: PMC2862907 DOI: 10.1016/s0166-4328(01)00413-2] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A new spontaneous mouse mutation named fierce (frc) is deleted for the nuclear receptor Nr2e1 gene (also known as Tlx, mouse homolog of Drosophila tailless). The fierce mutation is genetically and phenotypically similar to Nr2e1 targeted mutations previously studied on segregating genetic backgrounds. However, we have characterized the fierce brain, eye, and behavioural phenotypes on three defined genetic backgrounds (C57BL/6J, 129P3/JEms, and B6129F1). The data revealed many novel and background-dependent phenotypic characteristics. Whereas abnormalities in brain development, hypoplasia of cerebrum and olfactory lobes, were consistent on all three backgrounds, our novel finding of enlarged ventricles in 100% and overt hydrocephalus in up to 30% of fierce mice were unique to the C57BL/6J background. Developmental eye abnormalities were also background-dependent with B6129F1-frc mice having less severe thinning of optic layers and less affected electroretinogram responses. Impaired regression of hyaloid vessels was observed in all backgrounds. Furthermore, retinal vessels were deficient in size and number in 129P3/JEms-frc and B6129F1-frc mice but almost entirely absent in C57BL/6J-frc mice. We present the first standardized behavioural tests conducted on Nr2e1 mutant mice and show that C57BL/6J-frc and B6129F1-frc mice have deficits in sensorimotor assays and are hyperaggressive in both sexes and backgrounds. However, C57BL/6J-frc mice were significantly more aggressive than B6129F1-frc mice. Overall, this extensive characterization of the fierce mutation is essential to its application for the study of behavioural, and brain and eye developmental disorders. In addition, the background-dependent differences revealed will enable the identification of important genetic modifiers.
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Affiliation(s)
- Kelly A. Young
- Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health, Baltimore, MD 21205, USA
| | | | | | | | | | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | | | | | - Roderick T. Bronson
- USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
| | - Randy J. Nelson
- Departments of Psychology and Neuroscience and Biochemistry and Molecular Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Elizabeth M. Simpson
- Centre for Molecular Medicine and Therapeutics, British Columbia Research Institute for Children's and Women's Health, Department of Medical Genetics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada V5Z 4H4
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Abstract
Estrogen has been shown to affect nonreproductive behaviors in humans and rodents, including anxiety, fear, and activity levels. Rat studies have shown increases and decreases in these behaviors. Inconsistencies may be due to differences in testing conditions and the extent to which each test measures anxiety, fear, or activity. Few mouse studies have been performed. The present study was conducted to address these issues by examining the effect of estradiol benzoate (EB) in ovariectomized (OVX), C57BL/6 mice on a range of behavioral paradigms measuring anxiety [open field (OF), dark-light transition (DLT), elevated plus maze (EP)], activity [running wheel (RW)], and conditioned fear learning (FCon). In OF, vehicle (Veh) animals spent more time in the center than EB-treated animals and were more active overall. In DLT, Veh animals were more active than EB-treated animals in both the dark and light compartments and made more transitions between the two. In EP, Veh animals entered a greater number of arms. During FCon, EB animals froze more than Veh to the conditioned stimulus. In contrast, in the home cage RW, EB animals were more active than Veh. Factor analysis was used to characterize intertask correlations of females' behavior and to explore the possibility that estrogen may have an impact on a general arousal factor. In sum, estrogen treatment heightened fear responses in a range of fear and anxiety-provoking situations (OF, DLT, EP, and FCon), while increasing activity in the safer RW. We suggest that EB treatment may result in a generally more aroused animal.
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Affiliation(s)
- M A Morgan
- Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, New York 10021, USA
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Anagnostopoulos AV, Sharp JJ, Mobraaten LE, Eppig JT, Davisson MT. Availability and characterization of transgenic and knockout mice with behavioral manifestations: where to look and what to search for. Behav Brain Res 2001; 125:33-7. [PMID: 11682090 DOI: 10.1016/s0166-4328(01)00284-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mice altered by transgenesis or gene targeting ("knockouts") have increasingly been employed as alternative effective tools in elucidating the genetic basis of neurophysiology and behavior. Standardization of specific behavioral paradigms and phenotyping strategies will ensure that these behavioral mouse mutants offer robust models for evaluating the efficacy of novel therapeutics in the treatment of hereditary neurological disorders. The Induced Mutant Resource (IMR) at The Jackson Laboratory (Bar Harbor, Maine, USA) imports, cryopreserves, develops, maintains, and distributes to the research community biomedically valuable stocks of transgenic and targeted mutant mice. Information on behavioral and neurological strains-including a phenotypic synopsis, husbandry requirements, strain availability, and genetic typing protocols-is available through the IMR database (http://www.jax.org/resources/documents/imr/). A current catalog of available strains is readily accessible via the JAX Mice Web site at http://jaxmice.jax.org/index.shtml. In addition, The Jackson Laboratory is now home to TBASE (http://tbase.jax.org/), a comprehensive, community database whose primary focus is on mouse knockouts. TBASE accommodates an exhaustive bibliographical resource for transgenic and knockout mice and provides a detailed phenotypic characterization of numerous behavioral knockouts that is primarily extracted from the literature. Concerted efforts to merge the two resources into a new, schematically reformed database are underway.
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Contet C, Rawlins JN, Deacon RM. A comparison of 129S2/SvHsd and C57BL/6JOlaHsd mice on a test battery assessing sensorimotor, affective and cognitive behaviours: implications for the study of genetically modified mice. Behav Brain Res 2001; 124:33-46. [PMID: 11423164 DOI: 10.1016/s0166-4328(01)00231-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mice from the 129S2/SvHsd (129) and C57BL/6JOlaHsd (C57) strains were assessed for performance on a test battery including sensorimotor, affective and cognitive measures, using established as well as modified paradigms. Marked strain differences were observed in measures of locomotion, motor coordination and anxiety: the 129 mice were typically less active and more anxious. In contrast, the strains did not markedly differ in muscular strength, habituation to an open field or spatial working memory. The data provide baseline parameters of behaviour against which genetically modified lines derived from these particular parental strains can be assessed.
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Affiliation(s)
- C Contet
- Ecole Normale Supérieure, 45 rue d'Ulm, 75005 Paris, France
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Van der Meer M, Baumans V, Olivier B, Kruitwagen CL, Van Dijk JE, Van Zutphen LF. Behavioral and physiological effects of biotechnology procedures used for gene targeting in mice. Physiol Behav 2001; 73:719-30. [PMID: 11566206 DOI: 10.1016/s0031-9384(01)00529-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effects of gene-targeting procedures on the behavior and physiological development of (chimeric) mice have been investigated. We used six groups of mice, each of them undergoing specific aspects of the biotechnological procedure, including electroporation, microinjection, and/or blastocyst culture. Changes in behavior and physiological development of the progeny (age 4-30 weeks) were investigated. Besides increased body weights, no significant difference between the six treatment groups and untreated C57BL/6 controls could be attributed to the biotechnology procedures. Therefore, we conclude that these procedures per se do not induce significant discomfort for the offspring. Differences in behavior, observed for the two groups of chimeric mice [one derived from electroporated embryonic stem (ES) cells and the other from nonelectroporated ES cells] when compared to the other (nonchimeric) groups, are, at least partly, due to the genetic background of the 129/Ola strain from which the ES cells are derived rather than to the biotechnological manipulations of the ES cells and/or blastocysts. The occurrence of hermaphrodites (8%) and some other gross pathologies observed in both groups of chimeric animals seem to indicate that developmental problems may occur when cells from different origin are simultaneously contributing to the development of one individual. This implies that during the production of gene-targeted mice, health and welfare of chimeric animals must be carefully monitored.
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Affiliation(s)
- M Van der Meer
- Department of Laboratory Animal Science, Utrecht University, PO Box 80.166, 3508 TD Utrecht, The Netherlands.
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46
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Anagnostopoulos AV, Mobraaten LE, Sharp JJ, Davisson MT. Transgenic and knockout databases: behavioral profiles of mouse mutants. Physiol Behav 2001; 73:675-89. [PMID: 11566202 DOI: 10.1016/s0031-9384(01)00525-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Genetically engineered strains of mice, modified by transgenesis or gene targeting ("knockouts") are being generated at an impressive rate and used, among other areas, as premiere research tools in deciphering the genetic basis of behavior. As behavioral phenotyping strategies continue to evolve, characterization of these "designer" mice will provide models to evaluate the efficacy of new pharmacological and gene therapy treatments in human hereditary diseases. Reported behavioral profiles include aberrant social, reproductive, and parental behaviors, learning and memory deficits, feeding disorders, aggression, anxiety-related behaviors, pain/analgesia, and altered responses to antidepressants, antipsychotics, ethanol, and psychostimulant drugs of abuse. The Induced Mutant Resource (IMR) at The Jackson Laboratory (TJL, Bar Harbor, ME, USA) imports, cryopreserves, develops, maintains, and distributes biomedically important stocks of transgenic and targeted mutant mice to the research community. Information on neurological/behavioral strains--including behavioral performance, husbandry requirements, strain availability, and genetic typing protocols--is provided through the IMR database (http://www.jax.org/resources/documents/imr/). A catalog of available strains is readily accessible via the JAX Mice website at http://jaxmice.jax.org/index.shtml. In addition, TJL is now host to TBASE (http://tbase.jax.org/), a comprehensive, public-domain database with primary emphasis on mouse knockouts. TBASE contains an exhaustive list of knockout-related citations and provides an extensive phenotypic characterization of numerous behavioral mutants that is extracted directly from the literature. Present efforts to merge the two resources into a novel, schematically enhanced database, provisionally named Transgenic and Targeted Mutation Database (TTMD), will be briefly discussed.
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Brown RE, Stanford L, Schellinck HM. Developing standardized behavioral tests for knockout and mutant mice. ILAR J 2001; 41:163-74. [PMID: 11406708 DOI: 10.1093/ilar.41.3.163] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- R E Brown
- Department of Psychology and Neuroscience Institute, Dalhousie University, Nova Scotia, Canada
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48
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Affiliation(s)
- R J Nelson
- Departments of Psychology, Neuroscience, and Biochemistry and Molecular Biology, The Johns Hopkins University, Baltimore, Maryland, USA
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DeVries AC, Nelson RJ, Traystman RJ, Hurn PD. Cognitive and behavioral assessment in experimental stroke research: will it prove useful? Neurosci Biobehav Rev 2001; 25:325-42. [PMID: 11445138 DOI: 10.1016/s0149-7634(01)00017-3] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stroke in humans is associated with deficits in sensorimotor and cognitive function. Consequently, many stroke researchers recently have expanded their techniques to assess cognitive and behavioral correlates of histologically-determined stroke damage in animal models. Although the incorporation of functional outcome assessment represents an important step forward in stroke research, reports of middle cerebral artery occlusion (MCAO) induced behavioral deficits often conflict, and a significant correlation between post-stroke histology and behavior has been reported in few stroke studies. Discrepancies in behavioral outcomes among studies may be due to several factors, such as method of MCAO, duration of occlusion, strain, the timing and method of the behavioral testing and the laboratory environment. Furthermore, proper experimental and control groups, necessary to rule out potential confounding factors during cognitive testing, often are not incorporated. The goal of this review is: (1) to provide a description of the techniques most commonly employed to assess functional outcome after (MCAO) in rodents and (2) to identify potential confounding factors that may interfere with a clear interpretation of the behavioral data.
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Affiliation(s)
- A C DeVries
- Department of Psychology, The Ohio State University, Columbus, OH 43210, USA.
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Estill SJ, Fay K, Garcia JA. Statistical parameters in behavioral tasks and implications for sample size of C57BL/6J:129S6/SvEvTac mixed strain mice. Transgenic Res 2001; 10:157-75. [PMID: 11305362 DOI: 10.1023/a:1008955016170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Most mixed strain progeny from gene-knockout experiments typically originate from C57BL/6J and one of the 129 substrains, frequently 129S6/SvEvTac. The results of this behavioral survey suggest that C57BL/6J:129S6/SvEvTac mixed strain mice are amenable to behavioral testing. The variability in behavioral tasks for subjects arising from this mixed strain genetic background does not preclude screening with a battery of behavioral tests. With clues provided by a screen of mixed strain subjects, follow-up analyses with isogenic, congenic, or F1 hybrid animals may be targeted to specific behavioral themes.
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Affiliation(s)
- S J Estill
- Department of Biochemistry, UT Southwestern Medical Center at Dallas, TX 75390-8573, USA
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