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Lipp HP, Krackow S, Turkes E, Benner S, Endo T, Russig H. IntelliCage: the development and perspectives of a mouse- and user-friendly automated behavioral test system. Front Behav Neurosci 2024; 17:1270538. [PMID: 38235003 PMCID: PMC10793385 DOI: 10.3389/fnbeh.2023.1270538] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/18/2023] [Indexed: 01/19/2024] Open
Abstract
IntelliCage for mice is a rodent home-cage equipped with four corner structures harboring symmetrical double panels for operant conditioning at each of the two sides, either by reward (access to water) or by aversion (non-painful stimuli: air-puffs, LED lights). Corner visits, nose-pokes and actual licks at bottle-nipples are recorded individually using subcutaneously implanted transponders for RFID identification of up to 16 adult mice housed in the same home-cage. This allows for recording individual in-cage activity of mice and applying reward/punishment operant conditioning schemes in corners using workflows designed on a versatile graphic user interface. IntelliCage development had four roots: (i) dissatisfaction with standard approaches for analyzing mouse behavior, including standardization and reproducibility issues, (ii) response to handling and housing animal welfare issues, (iii) the increasing number of mouse models had produced a high work burden on classic manual behavioral phenotyping of single mice. and (iv), studies of transponder-chipped mice in outdoor settings revealed clear genetic behavioral differences in mouse models corresponding to those observed by classic testing in the laboratory. The latter observations were important for the development of home-cage testing in social groups, because they contradicted the traditional belief that animals must be tested under social isolation to prevent disturbance by other group members. The use of IntelliCages reduced indeed the amount of classic testing remarkably, while its flexibility was proved in a wide range of applications worldwide including transcontinental parallel testing. Essentially, two lines of testing emerged: sophisticated analysis of spontaneous behavior in the IntelliCage for screening of new genetic models, and hypothesis testing in many fields of behavioral neuroscience. Upcoming developments of the IntelliCage aim at improved stimulus presentation in the learning corners and videotracking of social interactions within the IntelliCage. Its main advantages are (i) that mice live in social context and are not stressfully handled for experiments, (ii) that studies are not restricted in time and can run in absence of humans, (iii) that it increases reproducibility of behavioral phenotyping worldwide, and (iv) that the industrial standardization of the cage permits retrospective data analysis with new statistical tools even after many years.
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Affiliation(s)
- Hans-Peter Lipp
- Faculty of Medicine, Institute of Evolutionary Medicine, University of Zürich, Zürich, Switzerland
| | - Sven Krackow
- Institute of Pathology and Molecular Pathology, University Hospital Zürich, Zürich, Switzerland
| | - Emir Turkes
- Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Seico Benner
- Center for Health and Environmental Risk Research, National Institute for Environmental Studies, Ibaraki, Japan
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2
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Minocycline treatment improves cognitive and functional plasticity in a preclinical mouse model of major depressive disorder. Behav Brain Res 2023; 441:114295. [PMID: 36641083 DOI: 10.1016/j.bbr.2023.114295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/06/2022] [Accepted: 01/10/2023] [Indexed: 01/13/2023]
Abstract
Major depressive disorder (MDD) is a chronic, recurring, and potentially life-threatening illness, which affects over 300 million people worldwide. MDD affects not only the emotional and social domains but also cognition. However, the currently available treatments targeting cognitive deficits in MDD are limited. Minocycline, an antibiotic with anti-inflammatory properties recently identified as a potential antidepressant, has been shown to attenuate learning and memory deficits in animal models of cognitive impairment. Here, we explored whether minocycline recovers the deficits in cognition in a mouse model of depression. C57BL6/J adult male mice were exposed to two weeks of chronic unpredictable mild stress to induce a depressive-like phenotype. Immediately afterward, mice received either vehicle or minocycline for three weeks in standard housing conditions. We measured anhedonia as a depressive-like response, and place learning to assess cognitive abilities. We also recorded long-term potentiation (LTP) as an index of hippocampal functional plasticity and ran immunohistochemical assays to assess microglial proportion and morphology. After one week of treatment, cognitive performance in the place learning test was significantly improved by minocycline, as treated mice displayed a higher number of correct responses when learning novel spatial configurations. Accordingly, minocycline-treated mice displayed higher LTP compared to controls. However, after three weeks of treatment, no difference between treated and control animals was found for behavior, neural plasticity, and microglial properties, suggesting that minocycline has a fast but short effect on cognition, without lasting effects on microglia. These findings together support the usefulness of minocycline as a potential treatment for cognitive impairment associated with MDD.
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3
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Petković A, Chaudhury D. Encore: Behavioural animal models of stress, depression and mood disorders. Front Behav Neurosci 2022; 16:931964. [PMID: 36004305 PMCID: PMC9395206 DOI: 10.3389/fnbeh.2022.931964] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022] Open
Abstract
Animal studies over the past two decades have led to extensive advances in our understanding of pathogenesis of depressive and mood disorders. Among these, rodent behavioural models proved to be of highest informative value. Here, we present a comprehensive overview of the most popular behavioural models with respect to physiological, circuit, and molecular biological correlates. Behavioural stress paradigms and behavioural tests are assessed in terms of outcomes, strengths, weaknesses, and translational value, especially in the domain of pharmacological studies.
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Affiliation(s)
| | - Dipesh Chaudhury
- Laboratory of Neural Systems and Behaviour, Department of Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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4
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Abstract
Until recently laboratory tasks for studying behavior were highly artificial, simplified, and designed without consideration for the environmental or social context. Although such an approach offers good control over behavior, it does not allow for researching either voluntary responses or individual differences. Importantly for neuroscience studies, the activity of the neural circuits involved in producing unnatural, artificial behavior is variable and hard to predict. In addition, different ensembles may be activated depending on the strategy the animal adopts to deal with the spurious problem. Thus, artificial and simplified tasks based on responses, which do not occur spontaneously entail problems with modeling behavioral impairments and underlying brain deficits. To develop valid models of human disorders we need to test spontaneous behaviors consistently engaging well-defined, evolutionarily conserved neuronal circuits. Such research focuses on behavioral patterns relevant for surviving and thriving under varying environmental conditions, which also enable high reproducibility across different testing settings.
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Affiliation(s)
- Alicja Puścian
- Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders – BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Pasteur 3 Street, 02-093 Warsaw, Poland
| | - Ewelina Knapska
- Nencki-EMBL Partnership for Neural Plasticity and Brain Disorders – BRAINCITY, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Pasteur 3 Street, 02-093 Warsaw, Poland
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5
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Nigri M, Åhlgren J, Wolfer DP, Voikar V. Role of Environment and Experimenter in Reproducibility of Behavioral Studies With Laboratory Mice. Front Behav Neurosci 2022; 16:835444. [PMID: 35250504 PMCID: PMC8895324 DOI: 10.3389/fnbeh.2022.835444] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/26/2022] [Indexed: 11/13/2022] Open
Abstract
Behavioral phenotyping of mice has received a great deal of attention during the past three decades. However, there is still a pressing need to understand the variability caused by environmental and biological factors, human interference, and poorly standardized experimental protocols. The inconsistency of results is often attributed to the inter-individual difference between the experimenters and environmental conditions. The present work aims to dissect the combined influence of the experimenter and the environment on the detection of behavioral traits in two inbred strains most commonly used in behavioral genetics due to their contrasting phenotypes, the C57BL/6J and DBA/2J mice. To this purpose, the elevated O-maze, the open field with object, the accelerating rotarod and the Barnes maze tests were performed by two experimenters in two diverse laboratory environments. Our findings confirm the well-characterized behavioral differences between these strains in exploratory behavior, motor performance, learning and memory. Moreover, the results demonstrate how the experimenter and the environment influence the behavioral tests with a variable-dependent effect, often with mutually exclusive contributions. In this context, our study highlights how both the experimenter and the environment can have an impact on the strain effect size without altering the direction of the conclusions. Importantly, the general agreement on the results is reached by converging evidence from multiple measures addressing the same trait. In conclusion, the present work elucidates the contribution of both the experimenter and the laboratory environment in the intricate field of reproducibility in mouse behavioral phenotyping.
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Affiliation(s)
- Martina Nigri
- Faculty of Medicine, Institute of Anatomy, University of Zurich, Zurich, Switzerland
- Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zürich, Zurich, Switzerland
- *Correspondence: Martina Nigri,
| | - Johanna Åhlgren
- Laboratory Animal Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - David P. Wolfer
- Faculty of Medicine, Institute of Anatomy, University of Zurich, Zurich, Switzerland
- Department of Health Sciences and Technology, Institute of Human Movement Sciences and Sport, ETH Zürich, Zurich, Switzerland
| | - Vootele Voikar
- Laboratory Animal Center, HiLIFE, University of Helsinki, Helsinki, Finland
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
- Vootele Voikar,
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6
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Selecting antidepressants according to a drug-by-environment interaction: A comparison of fluoxetine and minocycline effects in mice living either in enriched or stressful conditions. Behav Brain Res 2021; 408:113256. [PMID: 33775780 DOI: 10.1016/j.bbr.2021.113256] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/18/2021] [Accepted: 03/18/2021] [Indexed: 11/23/2022]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for major depressive disorder. It has been recently proposed that these drugs, by enhancing neural plasticity, amplify the influences of the living conditions on mood. Consequently, SSRI outcome depends on the quality of the environment, improving symptomatology mainly in individuals living in favorable conditions. In adverse conditions, drugs with a different mechanism of action might have higher efficacy. The antibiotic minocycline, with neuroprotective and anti-inflammatory properties, has been recently proposed as a novel potential antidepressant treatment. To explore the drug-by-environment interaction, we compared the effects on depressive-like behavior and neural plasticity of the SSRI fluoxetine and minocycline in enriched and stressful conditions. We first exposed C57BL/6 adult female mice to 14 days of chronic unpredictable mild stress to induce a depressive-like profile. Afterward, mice received vehicle, fluoxetine, or minocycline for 21 days, while exposed to either enriched or stressful conditions. During the first five days, fluoxetine led to an improvement in enrichment but not in stress. By contrast, minocycline led to an improvement in both conditions. After 21 days, all groups showed a significant improvement in enrichment while fluoxetine worsened the depressive like behavior in stress. The effects of the drugs on neural plasticity, measured as long-term potentiation, were also environment-dependent. Overall, we show that the environment affects fluoxetine but not minocycline outcome, indicating that the latter represents a potential alternative to SSRIs to treat depressed patients living in adverse conditions. From a translation perspective, our finding call for considering the drug-by-environment interaction to select the most effective pharmacological treatment.
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7
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Voikar V, Gaburro S. Three Pillars of Automated Home-Cage Phenotyping of Mice: Novel Findings, Refinement, and Reproducibility Based on Literature and Experience. Front Behav Neurosci 2020; 14:575434. [PMID: 33192366 PMCID: PMC7662686 DOI: 10.3389/fnbeh.2020.575434] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/05/2020] [Indexed: 12/12/2022] Open
Abstract
Animal models of neurodegenerative and neuropsychiatric disorders require extensive behavioral phenotyping. Currently, this presents several caveats and the most important are: (i) rodents are nocturnal animals, but mostly tested during the light period; (ii) the conventional behavioral experiments take into consideration only a snapshot of a rich behavioral repertoire; and (iii) environmental factors, as well as experimenter influence, are often underestimated. Consequently, serious concerns have been expressed regarding the reproducibility of research findings on the one hand, and appropriate welfare of the animals (based on the principle of 3Rs-reduce, refine and replace) on the other hand. To address these problems and improve behavioral phenotyping in general, several solutions have been proposed and developed. Undisturbed, 24/7 home-cage monitoring (HCM) is gaining increased attention and popularity as demonstrating the potential to substitute or complement the conventional phenotyping methods by providing valuable data for identifying the behavioral patterns that may have been missed otherwise. In this review, we will briefly describe the different technologies used for HCM systems. Thereafter, based on our experience, we will focus on two systems, IntelliCage (NewBehavior AG and TSE-systems) and Digital Ventilated Cage (DVC®, Tecniplast)-how they have been developed and applied during recent years. Additionally, we will touch upon the importance of the environmental/experimenter artifacts and propose alternative suggestions for performing phenotyping experiments based on the published evidence. We will discuss how the integration of telemetry systems for deriving certain physiological parameters can help to complement the description of the animal model to offer better translation to human studies. Ultimately, we will discuss how such HCM data can be statistically interpreted and analyzed.
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Affiliation(s)
- Vootele Voikar
- Neuroscience Center, University of Helsinki, Helsinki, Finland
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8
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Kiryk A, Janusz A, Zglinicki B, Turkes E, Knapska E, Konopka W, Lipp HP, Kaczmarek L. IntelliCage as a tool for measuring mouse behavior - 20 years perspective. Behav Brain Res 2020; 388:112620. [PMID: 32302617 DOI: 10.1016/j.bbr.2020.112620] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 03/23/2020] [Indexed: 12/21/2022]
Abstract
Since the 1980s, we have witnessed the rapid development of genetically modified mouse models of human diseases. A large number of transgenic and knockout mice have been utilized in basic and applied research, including models of neurodegenerative and neuropsychiatric disorders. To assess the biological function of mutated genes, modern techniques are critical to detect changes in behavioral phenotypes. We review the IntelliCage, a high-throughput system that is used for behavioral screening and detailed analyses of complex behaviors in mice. The IntelliCage was introduced almost two decades ago and has been used in over 150 studies to assess both spontaneous and cognitive behaviors. We present a critical analysis of experimental data that have been generated using this device.
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Affiliation(s)
- Anna Kiryk
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Artur Janusz
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Bartosz Zglinicki
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Emir Turkes
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, Irving Medical Center, New York, NY, USA
| | - Ewelina Knapska
- BRAINCITY, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Witold Konopka
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Hans-Peter Lipp
- Institute of Anatomy, University of Zurich, Zurich, Switzerland; Institute of Evolutionary Medicine, University of Zurich, Zurich, Switzerland
| | - Leszek Kaczmarek
- BRAINCITY, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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9
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Martínez de Lagrán M. Mapping behavioral landscapes in Down syndrome animal models. PROGRESS IN BRAIN RESEARCH 2020; 251:145-179. [DOI: 10.1016/bs.pbr.2020.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Umemori J, Winkel F, Didio G, Llach Pou M, Castrén E. iPlasticity: Induced juvenile-like plasticity in the adult brain as a mechanism of antidepressants. Psychiatry Clin Neurosci 2018; 72:633-653. [PMID: 29802758 PMCID: PMC6174980 DOI: 10.1111/pcn.12683] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
Abstract
The network hypothesis of depression proposes that mood disorders reflect problems in information processing within particular neural networks. Antidepressants (AD), including selective serotonin reuptake inhibitors (SSRI), function by gradually improving information processing within these networks. AD have been shown to induce a state of juvenile-like plasticity comparable to that observed during developmental critical periods: Such critical-period-like plasticity allows brain networks to better adapt to extrinsic and intrinsic signals. We have coined this drug-induced state of juvenile-like plasticity 'iPlasticity.' A combination of iPlasticity induced by chronic SSRI treatment together with training, rehabilitation, or psychotherapy improves symptoms of neuropsychiatric disorders and issues underlying the developmentally or genetically malfunctioning networks. We have proposed that iPlasticity might be a critical component of AD action. We have demonstrated that iPlasticity occurs in the visual cortex, fear erasure network, extinction of aggression caused by social isolation, and spatial reversal memory in rodent models. Chronic SSRI treatment is known to promote neurogenesis and to cause dematuration of granule cells in the dentate gyrus and of interneurons, especially parvalbumin interneurons enwrapped by perineuronal nets in the prefrontal cortex, visual cortex, and amygdala. Brain-derived neurotrophic factor (BDNF), via its receptor tropomyosin kinase receptor B, is involved in the processes of synaptic plasticity, including neurogenesis, neuronal differentiation, weight of synapses, and gene regulation of synaptic formation. BDNF can be activated by both chronic SSRI treatment and neuronal activity. Accordingly, the BDNF/tropomyosin kinase receptor B pathway is critical for iPlasticity, but further analyses will be needed to provide mechanical insight into the processes of iPlasticity.
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Affiliation(s)
- Juzoh Umemori
- Neuroscience Center, HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Frederike Winkel
- Neuroscience Center, HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Giuliano Didio
- Neuroscience Center, HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Maria Llach Pou
- Neuroscience Center, HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Eero Castrén
- Neuroscience Center, HiLIFEUniversity of HelsinkiHelsinkiFinland
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11
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Dzik JM, Puścian A, Mijakowska Z, Radwanska K, Łęski S. PyMICE: APython library for analysis of IntelliCage data. Behav Res Methods 2018; 50:804-815. [PMID: 28643159 PMCID: PMC5880855 DOI: 10.3758/s13428-017-0907-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
IntelliCage is an automated system for recording the behavior of a group of mice housed together. It produces rich, detailed behavioral data calling for new methods and software for their analysis. Here we present PyMICE, a free and open-source library for analysis of IntelliCage data in the Python programming language. We describe the design and demonstrate the use of the library through a series of examples. PyMICE provides easy and intuitive access to IntelliCage data, and thus facilitates the possibility of using numerous other Python scientific libraries to form a complete data analysis workflow.
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Affiliation(s)
- Jakub M Dzik
- Department of Neurophysiology Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Poland 3 Pasteur Str., Warsaw, 02-093, Poland
| | - Alicja Puścian
- Department of Neurophysiology Laboratory of Emotions Neurobiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Poland 3 Pasteur Str., Warsaw, 02-093, Poland
| | - Zofia Mijakowska
- Department of Molecular and Cellular Neurobiology Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Poland 3 Pasteur Str., Warsaw, 02-093, Poland
| | - Kasia Radwanska
- Department of Molecular and Cellular Neurobiology Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Poland 3 Pasteur Str., Warsaw, 02-093, Poland
| | - Szymon Łęski
- Department of Neurophysiology Laboratory of Neuroinformatics, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Poland 3 Pasteur Str., Warsaw, 02-093, Poland.
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12
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Marwari S, Dawe GS. (R)-fluoxetine enhances cognitive flexibility and hippocampal cell proliferation in mice. J Psychopharmacol 2018; 32:441-457. [PMID: 29458297 DOI: 10.1177/0269881118754733] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fluoxetine is a clinically successful antidepressant. It is a racemic mixture of (R) and (S) stereoisomers. In preclinical studies, chronic treatment with fluoxetine (10 mg/kg) had antidepressant effects correlated with increased hippocampal cell proliferation in adult rodents. However, the contribution of the enantiomers of fluoxetine is largely unknown. We investigated the effects of treatment with (R)- and (S)-fluoxetine on cognitive behavioral paradigms and examined cell proliferation in the hippocampus of C57BL/6J female mice. In a behavioral sequencing task using the IntelliCage system in which discriminated spatial patterns of rewarded and never-rewarded corners were reversed serially, (R)-fluoxetine-treated mice showed rapid acquisition of behavioral sequencing (compared with S-fluoxetine) and cognitive flexibility in subsequent reversal stages in intra- and inter-session analysis. (R)-fluoxetine also increased cell proliferation in the hippocampus, in particular in the suprapyramidal blade of the dentate gyrus. (R)-fluoxetine had superior effects to (S)-fluoxetine in elevated plus maze, forced-swim and tail-suspension tests. These results suggest that (R)-fluoxetine, which has been reported to have a shorter half-life than (S)-fluoxetine, has superior antidepressant effects and more consistently improves spatial learning and memory. This profile offers advantages in depression treatment and may also aid management of the neurocognitive impairments associated with depression.
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Affiliation(s)
- Subhi Marwari
- 1 Department of Pharmacology, National University of Singapore, Singapore
| | - Gavin S Dawe
- 1 Department of Pharmacology, National University of Singapore, Singapore.,2 Neurobiology and Ageing Programme, Life Sciences Institute, University of Singapore, Singapore
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13
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Heinla I, Åhlgren J, Vasar E, Voikar V. Behavioural characterization of C57BL/6N and BALB/c female mice in social home cage - Effect of mixed housing in complex environment. Physiol Behav 2018; 188:32-41. [PMID: 29382562 DOI: 10.1016/j.physbeh.2018.01.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 12/13/2022]
Abstract
Developing reliable mouse models for social behaviour is challenging. Different tests have been proposed, but most of them consist of rather artificial confrontations of unfamiliar mice in novel arenas or are relying on social stress induced by aggressive conspecifics. Natural social interaction in home cage in laboratory has not been investigated well. IntelliCage is a fully automated home-cage system, where activity of the group-housed mice can be monitored along with various cognitive tasks. Here we report the behavioural profile of C57BL/6N (B6) and BALB/c (BALB) female mice in IntelliCage when separated by strain, followed by monitoring of activity and formation of 'home-base' after mixing two strains. For that purpose, 3 cages were connected. Significant differences between the strains were established in baseline behaviour in conventional tests and in IntelliCage. The B6 mice showed reduced anxiety-like behaviour in open field and light-dark box, slightly enhanced exploratory activity in IntelliCage during initial adaptation and clearly distinct circadian activity. Mixing of two strains resulted in reduction of body weight and anhedonia in B6 mice. In addition, the B6 mice showed clear preference to previous home-cage, and formed a new home-base faster than BALB mice. In contrast, BALB mice showed enhanced activity and moving between the cages without showing any preference to previous home-cage. It could be argued that social challenge caused changes in both strains and different coping styles are responsible for behavioural manifestations. Altogether, this approach could be useful in modelling and validating mouse models for disorders with disturbed social behaviour.
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Affiliation(s)
- Indrek Heinla
- Institute of Biomedicine and Translational Medicine, Department of Physiology, University of Tartu, Estonia
| | - Johanna Åhlgren
- Laboratory Animal Center, HiLIFE, University of Helsinki, Finland
| | - Eero Vasar
- Institute of Biomedicine and Translational Medicine, Department of Physiology, University of Tartu, Estonia
| | - Vootele Voikar
- Laboratory Animal Center, HiLIFE, University of Helsinki, Finland; Neuroscience Center, HiLIFE, University of Helsinki, Finland.
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14
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Voikar V, Krackow S, Lipp HP, Rau A, Colacicco G, Wolfer DP. Automated dissection of permanent effects of hippocampal or prefrontal lesions on performance at spatial, working memory and circadian timing tasks of C57BL/6 mice in IntelliCage. Behav Brain Res 2017; 352:8-22. [PMID: 28927717 PMCID: PMC6102415 DOI: 10.1016/j.bbr.2017.08.048] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 12/23/2022]
Abstract
To evaluate permanent effects of hippocampal and prefrontal cortex lesion on spatial tasks, lesioned and sham-operated female C57BL/6 mice were exposed to a series of conditioning schemes in IntelliCages housing 8–10 transponder-tagged mice from each treatment group. Sequential testing started at 51–172 days after bilateral lesions and lasted for 154 and 218 days in two batches of mice, respectively. Spontaneous undisturbed behavioral patterns clearly separated the three groups, hippocampals being characterized by more erratic hyperactivity, and strongly impaired circadian synchronization ability. Hippocampal lesions led to deficits in spatial passive avoidance, as well as in spatial reference and working memory tasks. Impairment was minimal in rewarded preference/reversal schemes, but prominent if behavioral responses required precise circadian timing or included punishment of wrong spatial choices. No differences between sham-operated and prefrontally lesioned subjects in conditioning success were discernible. These results corroborate the view that hippocampal dysfunction spares simple spatial learning tasks but impairs the ability to cope with conflicting task-inherent spatial, temporal or emotional cues. Methodologically, the results show that automated testing and data analysis of socially kept mice is a powerful, efficient and animal-friendly tool for dissecting complex features and behavioral profiles of hippocampal dysfunction characterizing many transgenic or pharmacological mouse models.
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Affiliation(s)
- Vootele Voikar
- Institute of Anatomy, University of Zürich, Switzerland; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Finland
| | - Sven Krackow
- Institute of Anatomy, University of Zürich, Switzerland; XBehavior GmbH, Bänk, Dägerlen, Switzerland
| | - Hans-Peter Lipp
- Institute of Anatomy, University of Zürich, Switzerland; Institute of Evolutionary Medicine, University of Zürich, Switzerland; School of Laboratory Medicine and Medical Sciences, University of Kwazulu-Natal, South Africa
| | - Anton Rau
- Institute of Anatomy, University of Zürich, Switzerland; Chair of Entrepreneurial Risks, Department of Management, Technology, and Economics, ETH Zürich, Zürich, Switzerland
| | | | - David P Wolfer
- Institute of Anatomy, University of Zürich, Switzerland; Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.
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15
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Puścian A, Łęski S, Kasprowicz G, Winiarski M, Borowska J, Nikolaev T, Boguszewski PM, Lipp HP, Knapska E. Eco-HAB as a fully automated and ecologically relevant assessment of social impairments in mouse models of autism. eLife 2016; 5. [PMID: 27731798 PMCID: PMC5092044 DOI: 10.7554/elife.19532] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/11/2016] [Indexed: 12/21/2022] Open
Abstract
Eco-HAB is an open source, RFID-based system for automated measurement and analysis of social preference and in-cohort sociability in mice. The system closely follows murine ethology. It requires no contact between a human experimenter and tested animals, overcoming the confounding factors that lead to irreproducible assessment of murine social behavior between laboratories. In Eco-HAB, group-housed animals live in a spacious, four-compartment apparatus with shadowed areas and narrow tunnels, resembling natural burrows. Eco-HAB allows for assessment of the tendency of mice to voluntarily spend time together in ethologically relevant mouse group sizes. Custom-made software for automated tracking, data extraction, and analysis enables quick evaluation of social impairments. The developed protocols and standardized behavioral measures demonstrate high replicability. Unlike classic three-chambered sociability tests, Eco-HAB provides measurements of spontaneous, ecologically relevant social behaviors in group-housed animals. Results are obtained faster, with less manpower, and without confounding factors. DOI:http://dx.doi.org/10.7554/eLife.19532.001
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Affiliation(s)
- Alicja Puścian
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Szymon Łęski
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Grzegorz Kasprowicz
- Center for Theoretical Physics, Polish Academy of Sciences, Warsaw, Poland.,Institute of Electronic Systems, Warsaw University of Technology, Warsaw, Poland
| | - Maciej Winiarski
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Joanna Borowska
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz Nikolaev
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Paweł M Boguszewski
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Hans-Peter Lipp
- Institute of Anatomy, University of Zurich, Zurich, Switzerland.,School of Laboratory Medicine, Kwazulu-Natal University Durban, Durban, Republic of South Africa
| | - Ewelina Knapska
- Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
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16
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Koskela M, Bäck S, Võikar V, Richie CT, Domanskyi A, Harvey BK, Airavaara M. Update of neurotrophic factors in neurobiology of addiction and future directions. Neurobiol Dis 2016; 97:189-200. [PMID: 27189755 DOI: 10.1016/j.nbd.2016.05.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/09/2016] [Accepted: 05/13/2016] [Indexed: 02/07/2023] Open
Abstract
Drug addiction is a chronic brain disease and drugs of abuse cause long lasting neuroadaptations. Addiction is characterized by the loss of control over drug use despite harmful consequences, and high rates of relapse even after long periods of abstinence. Neurotrophic factors (NTFs) are well known for their actions on neuronal survival in the peripheral nervous system. Moreover, NTFs have been shown to be involved in synaptic plasticity in the brain. Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) are two of the most studied NTFs and both of them have been reported to increase craving when administered into the mesocorticolimbic dopaminergic system after drug self-administration. Here we review recent data on BDNF and GDNF functions in addiction-related behavior and discuss them in relation to previous findings. Finally, we give an insight into how new technologies could aid in further elucidating the role of these factors in drug addiction.
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Affiliation(s)
- Maryna Koskela
- Institute of Biotechnology, P.O. Box 56, 00014, University of Helsinki, Finland
| | - Susanne Bäck
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA
| | - Vootele Võikar
- Neuroscience Center, P.O. Box 56, 00014, University of Helsinki, Helsinki, Finland
| | - Christopher T Richie
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA
| | - Andrii Domanskyi
- Institute of Biotechnology, P.O. Box 56, 00014, University of Helsinki, Finland
| | - Brandon K Harvey
- Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD, USA
| | - Mikko Airavaara
- Institute of Biotechnology, P.O. Box 56, 00014, University of Helsinki, Finland.
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17
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Vannoni E, Voikar V, Colacicco G, Sánchez MA, Lipp HP, Wolfer DP. Spontaneous behavior in the social homecage discriminates strains, lesions and mutations in mice. J Neurosci Methods 2014; 234:26-37. [PMID: 24792526 DOI: 10.1016/j.jneumeth.2014.04.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 04/20/2014] [Accepted: 04/22/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Modern molecular genetics create a rapidly growing number of mutant mouse lines, many of which need to be phenotyped behaviorally. Poor reliability and low efficiency of traditional behavioral tests have prompted the development of new approaches to behavioral phenotyping, such as fully automated analysis of behavior in the homecage. NEW METHOD We asked whether the analysis of spontaneous behavior during the first week in the social homecage system IntelliCage could provide useful prescreening information before specialized and time consuming test batteries are run. To determine how much behavioral variation is captured in this data, we performed principal component analysis on free adaptation data of 1552 mice tested in the IntelliCage during the past years. We then computed individual component scores to characterize and compare groups of mice. RESULT We found 11 uncorrelated components which accounted for 82% of total variance. They characterize frequency and properties of corner visits and nosepokes, drinking activity, spatial distribution, as well as diurnal time course of activity. Behavioral profiles created using individual component scores were highly characteristic for different inbred strains or different lesion models of the nervous system. They were also remarkably stable across labs and experiments. COMPARISON WITH EXISTING METHODS Monitoring of mutant mice with known deficits in hippocampus-dependent tests produced profiles very similar to those of hippocampally lesioned mice. CONCLUSIONS Taken together, our results suggest that already the monitoring of spontaneous behavior during a week of free adaptation in the IntelliCage can contribute significantly to high throughput prescreening of mutant mice.
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Affiliation(s)
| | | | | | - María Alvarez Sánchez
- Institute of Anatomy, University of Zürich, Switzerland; Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, Switzerland
| | - Hans-Peter Lipp
- Institute of Anatomy, University of Zürich, Switzerland; School of Laboratory Medicine, University of Kwazulu-Natal, Durban, South Africa
| | - David P Wolfer
- Institute of Anatomy, University of Zürich, Switzerland; Institute of Human Movement Sciences and Sport, ETH Zürich, Switzerland.
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18
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Puścian A, Lęski S, Górkiewicz T, Meyza K, Lipp HP, Knapska E. A novel automated behavioral test battery assessing cognitive rigidity in two genetic mouse models of autism. Front Behav Neurosci 2014; 8:140. [PMID: 24808839 PMCID: PMC4010752 DOI: 10.3389/fnbeh.2014.00140] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/08/2014] [Indexed: 01/20/2023] Open
Abstract
Repetitive behaviors are a key feature of many pervasive developmental disorders, such as autism. As a heterogeneous group of symptoms, repetitive behaviors are conceptualized into two main subgroups: sensory/motor (lower-order) and cognitive rigidity (higher-order). Although lower-order repetitive behaviors are measured in mouse models in several paradigms, so far there have been no high-throughput tests directly measuring cognitive rigidity. We describe a novel approach for monitoring repetitive behaviors during reversal learning in mice in the automated IntelliCage system. During the reward-motivated place preference reversal learning, designed to assess cognitive abilities of mice, visits to the previously rewarded places were recorded to measure cognitive flexibility. Thereafter, emotional flexibility was assessed by measuring conditioned fear extinction. Additionally, to look for neuronal correlates of cognitive impairments, we measured CA3-CA1 hippocampal long term potentiation (LTP). To standardize the designed tests we used C57BL/6 and BALB/c mice, representing two genetic backgrounds, for induction of autism by prenatal exposure to the sodium valproate. We found impairments of place learning related to perseveration and no LTP impairments in C57BL/6 valproate-treated mice. In contrast, BALB/c valproate-treated mice displayed severe deficits of place learning not associated with perseverative behaviors and accompanied by hippocampal LTP impairments. Alterations of cognitive flexibility observed in C57BL/6 valproate-treated mice were related to neither restricted exploration pattern nor to emotional flexibility. Altogether, we showed that the designed tests of cognitive performance and perseverative behaviors are efficient and highly replicable. Moreover, the results suggest that genetic background is crucial for the behavioral effects of prenatal valproate treatment.
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Affiliation(s)
- Alicja Puścian
- Department of Neurophysiology, Nencki Institute of Experimental Biology Warsaw, Poland
| | - Szymon Lęski
- Department of Neurophysiology, Nencki Institute of Experimental Biology Warsaw, Poland
| | - Tomasz Górkiewicz
- Department of Neurophysiology, Nencki Institute of Experimental Biology Warsaw, Poland
| | - Ksenia Meyza
- Department of Neurophysiology, Nencki Institute of Experimental Biology Warsaw, Poland
| | - Hans-Peter Lipp
- Division of Functional Neuroanatomy, Institute of Anatomy, University of Zurich Zurich, Switzerland ; Department of Physiology, School of Laboratory Medicine, Kwazulu-Natal University Durban, South Africa
| | - Ewelina Knapska
- Department of Neurophysiology, Nencki Institute of Experimental Biology Warsaw, Poland
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19
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Too LK, Ball HJ, McGregor IS, Hunt NH. A novel automated test battery reveals enduring behavioural alterations and cognitive impairments in survivors of murine pneumococcal meningitis. Brain Behav Immun 2014; 35:107-24. [PMID: 24060586 DOI: 10.1016/j.bbi.2013.09.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 08/29/2013] [Accepted: 09/11/2013] [Indexed: 01/21/2023] Open
Abstract
Pneumococcal meningitis, caused by Streptococcus pneumoniae infection, is a major form of lethal bacterial meningitis. Survivors are predisposed to developing lifelong disabling sequelae, including cognitive impairment, psychological problems and motor deficits. In our experimental model, ventricular inoculation of 10(5) colony-forming units of S. pneumoniae type 3 caused 90% of mice to develop life-threatening meningitis within 48 h. Antibiotic treatment with ceftriaxone 20 h post infection reduced the incidence of severe meningitis to <10%. At the time of treatment, upregulation of pro-inflammatory cytokines was detected, including interleukin-1β, interleukin-6 and tumour necrosis factor. We evaluated the long-term behavioural and cognitive sequelae in control mice and those surviving meningitis using an automated system (the IntelliCage) in which mice perform a range of behavioural and spatial tasks to obtain water rewards from conditioning units in their home cage. Surviving mice showed a number of altered behaviours relative to controls, including (i) hypoexploration when first exposed to the IntelliCage, (ii) altered activity patterns (fewer visits to conditioning stations during the light phase and more in the dark phase), (iii) avoidance of light (a constant or flashing LED stimulus), (iv) impaired spatial learning (a complex patrolling task), and (v) impaired discrimination reversal learning. Overall these results suggest photophobia and weakened learning ability in post-meningitic mice, particularly on tasks engaging hippocampal and prefrontal neural substrates. This study also demonstrates a standardised and comprehensive battery of tests that can be readily used to investigate neurological sequelae in undisturbed mice residing in a complex home cage environment.
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Affiliation(s)
- L K Too
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, University of Sydney, Sydney, New South Wales 2006, Australia
| | - H J Ball
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, University of Sydney, Sydney, New South Wales 2006, Australia
| | - I S McGregor
- School of Psychology, University of Sydney, Sydney, New South Wales 2006, Australia
| | - N H Hunt
- Molecular Immunopathology Unit, Bosch Institute and School of Medical Sciences, University of Sydney, Sydney, New South Wales 2006, Australia.
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20
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Albuquerque B, Häussler A, Vannoni E, Wolfer DP, Tegeder I. Learning and memory with neuropathic pain: impact of old age and progranulin deficiency. Front Behav Neurosci 2013; 7:174. [PMID: 24319417 PMCID: PMC3837228 DOI: 10.3389/fnbeh.2013.00174] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/06/2013] [Indexed: 11/15/2022] Open
Abstract
Persistent neuropathic pain is a frequent consequence of peripheral nerve injuries, particularly in the elderly. Using the IntelliCage we studied if sciatic nerve injury obstructed learning and memory in young and aged mice, each in wild type and progranulin deficient mice, which develop premature signs of brain aging. Both young and aged mice developed long-term nerve injury-evoked hyperalgesia and allodynia. In both genotypes, aged mice with neuropathic pain showed high error rates in place avoidance acquisition tasks. However, once learnt, these aged mice with neuropathic pain showed a significantly stronger maintenance of the aversive memory. Nerve injury did not affect place preference behavior in neither genotype, neither in young nor aged mice. However, nerve injury in progranulin deficient mice impaired the learning of spatial sequences of awarded places, particularly in the aged mice. This task required a discrimination of clockwise and anti-clockwise sequences. The chaining failure occurred only in progranulin deficient mice after nerve injury, but not in sham operated or wildtype mice, suggesting that progranulin was particularly important for compensatory adaptations after nerve injury. In contrast, all aged mice with neuropathic pain, irrespective of the genotype, had a long maintenance of aversive memory suggesting a negative alliance and possibly mutual aggravation of chronic neuropathic pain and aversive memory at old age.
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Affiliation(s)
- Boris Albuquerque
- Department of Clinical Pharmacology, pharmazentrum frankfurt, Goethe-University Hospital Frankfurt am Main Frankfurt am Main, Germany
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21
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van den Bos R, Davies W, Dellu-Hagedorn F, Goudriaan AE, Granon S, Homberg J, Rivalan M, Swendsen J, Adriani W. Cross-species approaches to pathological gambling: a review targeting sex differences, adolescent vulnerability and ecological validity of research tools. Neurosci Biobehav Rev 2013; 37:2454-71. [PMID: 23867802 DOI: 10.1016/j.neubiorev.2013.07.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/28/2013] [Accepted: 07/08/2013] [Indexed: 02/06/2023]
Abstract
Decision-making plays a pivotal role in daily life as impairments in processes underlying decision-making often lead to an inability to make profitable long-term decisions. As a case in point, pathological gamblers continue gambling despite the fact that this disrupts their personal, professional or financial life. The prevalence of pathological gambling will likely increase in the coming years due to expanding possibilities of on-line gambling through the Internet and increasing liberal attitudes towards gambling. It therefore represents a growing concern for society. Both human and animal studies rapidly advance our knowledge on brain-behaviour processes relevant for understanding normal and pathological gambling behaviour. Here, we review in humans and animals three features of pathological gambling which hitherto have received relatively little attention: (1) sex differences in (the development of) pathological gambling, (2) adolescence as a (putative) sensitive period for (developing) pathological gambling and (3) avenues for improving ecological validity of research tools. Based on these issues we also discuss how research in humans and animals may be brought in line to maximize translational research opportunities.
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Affiliation(s)
- Ruud van den Bos
- Department of Organismal Animal Physiology, Radboud University Nijmegen, Nijmegen, The Netherlands; Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, The Netherlands.
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22
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Voikar V, Kulesskaya N, Laakso T, Lauren J, Strittmatter SM, Airaksinen MS. LRRTM1-deficient mice show a rare phenotype of avoiding small enclosures--a tentative mouse model for claustrophobia-like behaviour. Behav Brain Res 2012; 238:69-78. [PMID: 23089646 DOI: 10.1016/j.bbr.2012.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 02/03/2023]
Abstract
The LRRTM family proteins have been shown to act as synaptogenic cell adhesion molecules via interaction with presynaptic neurexins and are associated with neuropsychiatric disorders. LRRTM1-knockout mice have subtle morphological deficits in excitatory hippocampal synapses and were suggested to have impaired cognitive function. Here we report that LRRTM1-knockout mice exhibit an extraordinary phenotype of avoiding small enclosures. In the light-dark box, the knockout mice escape to dark through a standard opening as quickly as wild-type littermates but avoid escaping through a small doorway. While all wild-type mice spontaneously enter a small tube, most knockout mice do not. This apparent aversion to enter narrow space may explain other abnormalities such as increased time in open arms in the elevated plus maze and less visits through a tunnel in the IntelliCage. Moreover, LRRTM1-knockout mice show increased social interaction, reduced nest building and MK801-induced locomotion, and slower swim speed but normal water maze learning. Since LRRTM1 is predominantly expressed in thalamus, hippocampus and limbic cortex, specific synaptic defects in those areas presumably cause these behavioural abnormalities.
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Affiliation(s)
- V Voikar
- Neuroscience Center, University of Helsinki, Finland.,Department of Biosciences, University of Helsinki, Finland
| | - N Kulesskaya
- Neuroscience Center, University of Helsinki, Finland.,Department of Biosciences, University of Helsinki, Finland
| | - T Laakso
- Neuroscience Center, University of Helsinki, Finland
| | - J Lauren
- Cellular Neuroscience, Neurodegeneration, and Repair Program, and Departments of Neurology and Neurobiology, Yale School of Medicine, New Haven, CT, USA
| | - S M Strittmatter
- Cellular Neuroscience, Neurodegeneration, and Repair Program, and Departments of Neurology and Neurobiology, Yale School of Medicine, New Haven, CT, USA
| | - M S Airaksinen
- Neuroscience Center, University of Helsinki, Finland.,Institute of Biomedicine, University of Helsinki, Finland
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