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Vodjerek L, Erixon F, Mendes Ferreira C, Fickel J, Eccard JA. The role of male quality in sequential mate choice: pregnancy replacement in small mammals? ROYAL SOCIETY OPEN SCIENCE 2024; 11:240189. [PMID: 39076357 PMCID: PMC11285816 DOI: 10.1098/rsos.240189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 03/26/2024] [Accepted: 06/06/2024] [Indexed: 07/31/2024]
Abstract
Females mainly increase their reproductive success by improving the quality of their mates and need to be discriminative in their mate choices. Here, we investigate whether female mammals can trade up sire quality in sequential mate choice during already progressed pregnancies. A male-induced pregnancy termination (functional 'Bruce effect') could thus have an adaptive function in mate choice as a functional part of a pregnancy replacement. We used bank voles (Myodes glareolus) as a model system and exchanged the breeding male in the early second trimester of a potential pregnancy. Male quality was determined using urine marking values. Females were offered a sequence of either high- then low-quality male (HL) or a low- then high-quality male (LH). The majority of females bred with high-quality males independent of their position in the sequence, which may indicate a pregnancy replacement in LH but not in HL. The body size of the second male, which could have been related to the coercion of females by males into remating, did not explain late pregnancies. Thus, pregnancy replacement, often discussed as a counterstrategy to infanticide, may constitute adaptive mate choice in female mammals, and female choice may induce pregnancy replacement in mammals.
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Affiliation(s)
- Lea Vodjerek
- Animal Ecology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Filippa Erixon
- Animal Ecology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Clara Mendes Ferreira
- Animal Ecology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Jörns Fickel
- Molecular Ecology and Evolution, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Jana A. Eccard
- Animal Ecology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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Winkler GA, Grahame NJ. Home cage voluntary alcohol consumption increases binge drinking without affecting abstinence-related depressive-like behaviors or operant responding in crossed high alcohol-preferring mice (cHAPs). Alcohol 2024; 116:9-19. [PMID: 37838352 PMCID: PMC10947980 DOI: 10.1016/j.alcohol.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/29/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023]
Abstract
Chronic alcohol consumption can lead to tolerance and escalation of drinking in humans and animals, but mechanisms underlying these changes are not fully characterized. Preclinical models can delineate which mechanisms are involved. The chronic intermittent ethanol exposure (CIE) procedure uses forced exposure to vaporized alcohol that elicits withdrawal and increased responding for alcohol in operant tasks in C57BL/6J inbred mice. Chronic two-bottle choice (2BC) drinking in the same strain elicits abstinent-related depression-like behavior, suggestive of allostatic changes. Selected lines such as crossed High Alcohol Preferring (cHAP) mice voluntarily drink to blood alcohol concentrations comparable to those attained in CIE and could be used to assess how alcohol affects these same endpoints without the confounds of involuntary vapor inhalation. In three experiments, we assess how 2BC drinking in cHAP mice affects abstinence-related depressive- and anxiety-like behavior, operant responding for alcohol, and binge consumption using drinking-in-the-dark (DID). We hypothesized that cHAPs with home-cage drinking experience would exhibit more depressive behavior after abstinence, increased responding for alcohol in the operant box, and increased DID intake. Of these, a drinking history increased DID intake in female cHAPs only and increased sucrose preference and intake following abstinence, but had no effects on operant responding or NSFT latency and FST immobility following forced abstinence. These results are consistent with recent findings using slice electrophysiology showing tolerance to alcohol's actions on the dorsolateral striatum following 2BC drinking in female, but not male cHAP mice. Overall, these data suggest that cHAPs may require procedures allowing rapid intoxication, such as DID, to demonstrate changes in alcohol's rewarding effects.
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Affiliation(s)
- Garrett A Winkler
- Addiction Neuroscience, Department of Psychology and Indiana Alcohol Research Center, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, United States
| | - Nicholas J Grahame
- Addiction Neuroscience, Department of Psychology and Indiana Alcohol Research Center, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, United States.
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Schonkeren SL, Thijssen MS, Idris M, Wouters K, de Vaan J, Teubner A, Gijbels MJ, Boesmans W, Melotte V. Differences in enteric neuronal density in the NSE-Noggin mouse model across institutes. Sci Rep 2024; 14:3686. [PMID: 38355947 PMCID: PMC10866904 DOI: 10.1038/s41598-024-54337-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/12/2024] [Indexed: 02/16/2024] Open
Abstract
The enteric nervous system (ENS) is a large and complex part of the peripheral nervous system, and it is vital for gut homeostasis. To study the ENS, different hyper- and hypo-innervated model systems have been developed. The NSE-Noggin mouse model was described as one of the few models with a higher enteric neuronal density in the colon. However, in our hands NSE-Noggin mice did not present with a hyperganglionic phenotype. NSE-Noggin mice were phenotyped based on fur appearance, genotyped and DNA sequenced to demonstrate transgene and intact NSE-Noggin-IRES-EGFP construct presence, and RNA expression of Noggin was shown to be upregulated. Positive EGFP staining in the plexus of NSE-Noggin mice also confirmed Noggin protein expression. Myenteric plexus preparations of the colon were examined to quantify both the overall density of enteric neurons and the proportions of enteric neurons expressing specific subtype markers. The total number of enteric neurons in the colonic myenteric plexus of transgenic mice did not differ significantly from wild types, nor did the proportion of calbindin, calretinin, or serotonin immunoreactive myenteric neurons. Possible reasons as to why the hyperinnervated phenotype could not be observed in contrast with original studies using this mouse model are discussed, including study design, influence of microbiota, and other environmental variables.
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Affiliation(s)
- Simone L Schonkeren
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Meike S Thijssen
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
- Biomedical Research Institute (BIOMED), Hasselt University, Hasselt, Belgium
| | - Musa Idris
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Kim Wouters
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Joëlle de Vaan
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Andreas Teubner
- Central Animal Facility, Faculty of Health, Medicine & Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Marion J Gijbels
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences: Atherosclerosis & Ischemic Syndrome, Amsterdam Infection and Immunity: Inflammatory Diseases, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
| | - Werend Boesmans
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands
- Biomedical Research Institute (BIOMED), Hasselt University, Hasselt, Belgium
| | - Veerle Melotte
- Department of Pathology, GROW-Research Institute for Oncology and Reproduction, Maastricht University Medical Center, Maastricht, The Netherlands.
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands.
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von Kortzfleisch VT, Richter SH. Systematic heterogenization revisited: Increasing variation in animal experiments to improve reproducibility? J Neurosci Methods 2024; 401:109992. [PMID: 37884081 DOI: 10.1016/j.jneumeth.2023.109992] [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: 05/16/2023] [Revised: 10/10/2023] [Accepted: 10/22/2023] [Indexed: 10/28/2023]
Abstract
Life sciences are currently facing a reproducibility crisis. Originally, the crisis was born out of single alarming failures to reproduce findings at different times and locations. Nowadays, systematic studies indicate that the prevalence of irreproducible research does in fact exceed 50%. Viewed from a rather cynical perspective, Fett's law of the lab "Never replicate a successful experiment" has thus taken on a completely new meaning. In this respect, animal research has come under particular scrutiny, as the stakes are high in terms of both research ethics and societal impact. To counteract this, it is essential to identify sources of poor reproducibility as well as to iron out these failures. We here review the current debate, briefly discuss potential reasons, and summarize steps that have already been undertaken to improve reproducibility in animal research. By the example of classical behavioural phenotyping studies, we particularly highlight the role strict standardization plays in exacerbating the crisis, and review the concept of systematic heterogenization as an alternative strategy to deal with variation in animal studies. Briefly, we argue that systematic variation rather than strict homogenization of experimental conditions benefits the robustness of research findings, and hence their reproducibility. To this end, we will present concrete examples for systematically heterogenized experiments and provide a practical guide on how to apply systematic heterogenization in experimental practice.
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Affiliation(s)
| | - S Helene Richter
- Department of Behavioural Biology, University of Münster, Badestraße 13, 48149 Münster, Germany.
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Jaric I, Voelkl B, Amrein I, Wolfer DP, Novak J, Detotto C, Weber-Stadlbauer U, Meyer U, Manuella F, Mansuy IM, Würbel H. Using mice from different breeding sites fails to improve replicability of results from single-laboratory studies. Lab Anim (NY) 2024; 53:18-22. [PMID: 38151528 PMCID: PMC10766513 DOI: 10.1038/s41684-023-01307-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 11/20/2023] [Indexed: 12/29/2023]
Abstract
Theoretical and empirical evidence indicates that low external validity due to rigorous standardization of study populations is a cause of poor replicability in animal research. Here we report a multi-laboratory study aimed at investigating whether heterogenization of study populations by using animals from different breeding sites increases the replicability of results from single-laboratory studies. We used male C57BL/6J mice from six different breeding sites to test a standardized against a heterogenized (HET) study design in six independent replicate test laboratories. For the standardized design, each laboratory ordered mice from a single breeding site (each laboratory from a different one), while for the HET design, each laboratory ordered proportionate numbers of mice from the five remaining breeding sites. To test our hypothesis, we assessed 14 outcome variables, including body weight, behavioral measures obtained from a single session on an elevated plus maze, and clinical blood parameters. Both breeding site and test laboratory affected variation in outcome variables, but the effect of test laboratory was more pronounced for most outcome variables. Moreover, heterogenization of study populations by breeding site (HET) did not reduce variation in outcome variables between test laboratories, which was most likely due to the fact that breeding site had only little effect on variation in outcome variables, thereby limiting the scope for HET to reduce between-lab variation. We conclude that heterogenization of study populations by breeding site has limited capacity for improving the replicability of results from single-laboratory animal studies.
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Affiliation(s)
- Ivana Jaric
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
| | - Bernhard Voelkl
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Irmgard Amrein
- Institute of Anatomy, Division of Functional Neuroanatomy, University of Zürich, Zürich, Switzerland
| | - David P Wolfer
- Institute of Anatomy, Division of Functional Neuroanatomy, University of Zürich, Zürich, Switzerland
- Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Janja Novak
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Carlotta Detotto
- Central Animal Facilities, Experimental Animal Center, University of Bern, Bern, Switzerland
| | - Ulrike Weber-Stadlbauer
- Institute of Pharmacology and Toxicology, Vetsuisse Faculty and Center of Neuroscience Zürich, University of Zürich, Zürich, Switzerland
| | - Urs Meyer
- Institute of Pharmacology and Toxicology, Vetsuisse Faculty and Center of Neuroscience Zürich, University of Zürich, Zürich, Switzerland
| | - Francesca Manuella
- Laboratory of Neuroepigenetics, Brain Research Institute, Medical Faculty, University of Zürich, Zürich, Switzerland
- Institute for Neuroscience, Department of Health Science and Technology, Swiss Federal Institute of Technology Zürich (ETHZ), Zurich, Switzerland
- Center for Neuroscience Zürich, University Zürich and ETHZ, Zürich, Switzerland
| | - Isabelle M Mansuy
- Laboratory of Neuroepigenetics, Brain Research Institute, Medical Faculty, University of Zürich, Zürich, Switzerland
- Institute for Neuroscience, Department of Health Science and Technology, Swiss Federal Institute of Technology Zürich (ETHZ), Zurich, Switzerland
- Center for Neuroscience Zürich, University Zürich and ETHZ, Zürich, Switzerland
| | - Hanno Würbel
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
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Lim CJM, Platt B, Janhunen SK, Riedel G. Comparison of automated video tracking systems in the open field test: ANY-Maze versus EthoVision XT. J Neurosci Methods 2023; 397:109940. [PMID: 37544382 DOI: 10.1016/j.jneumeth.2023.109940] [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: 06/11/2023] [Revised: 07/26/2023] [Accepted: 08/03/2023] [Indexed: 08/08/2023]
Abstract
BACKGROUND ANY-Maze and EthoVision XT are two commonly used automated animal tracking systems employed to produce reliable and consistent results in behavioural paradigms. Data obtained with both tracking systems have presented differences, particularly when varying laboratory lighting conditions and contrasts of mice coat colour against the arena background in both water maze and tunnel maze. METHOD In this study, two fluorescent lighting conditions (58 and 295 lux), local to our laboratory, and different coat-coloured mouse lines (C57BL/6 J - black; CD1 - agouti; C3H/HeN - white) were used to compare reproducibility in measures of tracking systems (ANY-Maze versus EthoVision) in the open field test. RESULTS Differences between systems were reliant on the contrasts between coat and background colours. Surprisingly, black animals presented the greatest differences in read-outs between tracking systems, regardless of lighting conditions. Data from both video observation tools differed mainly in exploration-related parameters (distance travelled), but less in more static proxies (time in thigmotaxis zone). Overall, EthoVision XT returned higher values for most parameters analysed relative to ANY-Maze. More inconsistencies in recording and analysis can be expected from other video recording systems. CONCLUSION Data analysis software provides an additional source of variation in need of consideration when reproducibility in behavioural neuroscience is required.
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Affiliation(s)
- Charmaine J M Lim
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Bettina Platt
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Gernot Riedel
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom.
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Carneiro CFD, Drude N, Hülsemann M, Collazo A, Toelch U. Mapping strategies towards improved external validity in preclinical translational research. Expert Opin Drug Discov 2023; 18:1273-1285. [PMID: 37691294 DOI: 10.1080/17460441.2023.2251886] [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: 02/24/2023] [Accepted: 08/22/2023] [Indexed: 09/12/2023]
Abstract
INTRODUCTION Translation is about successfully bringing findings from preclinical contexts into the clinic. This transfer is challenging as clinical trials frequently fail despite positive preclinical results. Limited robustness of preclinical research has been marked as one of the drivers of such failures. One suggested solution is to improve the external validity of in vitro and in vivo experiments via a suite of complementary strategies. AREAS COVERED In this review, the authors summarize the literature available on different strategies to improve external validity in in vivo, in vitro, or ex vivo experiments; systematic heterogenization; generalizability tests; and multi-batch and multicenter experiments. Articles that tested or discussed sources of variability in systematically heterogenized experiments were identified, and the most prevalent sources of variability are reviewed further. Special considerations in sample size planning, analysis options, and practical feasibility associated with each strategy are also reviewed. EXPERT OPINION The strategies reviewed differentially influence variation in experiments. Different research projects, with their unique goals, can leverage the strengths and limitations of each strategy. Applying a combination of these approaches in confirmatory stages of preclinical research putatively increases the chances of success in clinical studies.
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Affiliation(s)
- Clarissa F D Carneiro
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
| | - Natascha Drude
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
| | - Maren Hülsemann
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
| | - Anja Collazo
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
| | - Ulf Toelch
- QUEST Center for Responsible Research, Berlin Institute of Health at Charité, Berlin, Germany
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Examining litter specific variability in mice and its impact on neurodevelopmental studies. Neuroimage 2023; 269:119888. [PMID: 36681136 DOI: 10.1016/j.neuroimage.2023.119888] [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: 09/27/2022] [Revised: 01/07/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Our current understanding of litter variability in neurodevelopmental studies using mice may limit translation of neuroscientific findings. Higher variance of measures across litters than within, often termed intra-litter likeness, may be attributable to both pre- and postnatal environment. This study aimed to assess the litter-effect within behavioral assessments (2 timepoints) and anatomy using T1-weighted magnetic resonance images across 72 brain region volumes (4 timepoints) (36 C57bl/6J inbred mice; 7 litters: 19F/17M). Between-litter comparisons of brain and behavioral measures and their associations were evaluated using univariate and multivariate techniques. A power analysis using simulation methods was then performed on modeled neurodevelopment and to evaluate trade-offs between number-of-litters, number-of-mice-per-litter, and sample size. Our results show litter-specific developmental effects, from the adolescent period to adulthood for brain structure volumes and behaviors, and for their associations in adulthood. Our power simulation analysis suggests increasing the number-of-litters in experimental designs to achieve the smallest total sample size necessary for detecting different rates of change in specific brain regions. Our results demonstrate how litter-specific effects may influence development and that increasing the litters to the total sample size ratio should be strongly considered when designing neurodevelopmental studies.
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SEVELJEVIC-JARAN DASA, ANTOLIC MAJA, OGNJENOVIC ANJA, KALLIOKOSKI OTTO, ABELSON KLASS, HAU JANN. Effects of Multimodal Therapy, Blinding, and Multi-laboratory Protocol Conduct on the Robustness of the Rat Model of Adjuvant Induced Arthritis. In Vivo 2023; 37:115-123. [PMID: 36593032 PMCID: PMC9843802 DOI: 10.21873/invivo.13060] [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: 11/08/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 01/03/2023]
Abstract
BACKGROUND/AIM The aim of this study was to investigate the effects of multimodal therapy comprising buprenorphine (BUP) and indomethacin (IND) on key translational parameters in the rat adjuvant induced arthritis (AIA) model. Furthermore, we investigated the difference between visual assessment scores and histology scores generated by blinded and non-blinded assessors and the robustness and generalizability of results by conducting a multi-laboratory study. MATERIALS AND METHODS The experiment was terminated on day 26 after 11 days (days 15-25) of voluntarily ingested buprenorphine and 7 days of gavage delivered indomethacin treatment (days 19-25). The treatment effects were assessed on the last day of the study, relying on body weight assessment, serum concentrations of α1- acid glycoprotein, and assessment of affected hind paws swelling, in-life and post mortem. RESULTS Across two laboratories, the combined analgesic treatments had minimal effects on the measured model parameters indicating that multimodal treatment did not affect the translatability of the model. We found an improvement in clinical scores (a negative change in scores) in nearly all medicated animals when scored informed, whereas it was essentially 50:50 for the blinded scorings and no difference between the blinded and informed histological scoring. CONCLUSION The present results support the use of more effective analgesic treatment regimens and the good practice recommendations advocating blinding as a mandatory practice in conduct of preclinical in vivo efficacy studies. In spite of minor differences between results obtained at the two sites, there was good agreement between them indicating robustness of the AIA model.
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Affiliation(s)
- DASA SEVELJEVIC-JARAN
- In Vivo Pharmacology and Toxicology Department and Toxicology and Laboratory Animal Science Department, Selvita Ltd., Zagreb, Croatia,Department of Experimental Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - MAJA ANTOLIC
- In Vivo Pharmacology and Toxicology Department and Toxicology and Laboratory Animal Science Department, Selvita Ltd., Zagreb, Croatia
| | - ANJA OGNJENOVIC
- In Vivo Pharmacology and Toxicology Department and Toxicology and Laboratory Animal Science Department, Selvita Ltd., Zagreb, Croatia
| | - OTTO KALLIOKOSKI
- Department of Experimental Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - KLAS S.P. ABELSON
- Department of Experimental Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - JANN HAU
- Department of Experimental Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Mañas‐Padilla MC, Tezanos P, Cintado E, Vicente L, Sánchez‐Salido L, Gil‐Rodríguez S, Trejo JL, Santín LJ, Castilla‐Ortega E. Environmental enrichment alleviates cognitive and psychomotor alterations and increases adult hippocampal neurogenesis in cocaine withdrawn mice. Addict Biol 2023; 28:e13244. [PMID: 36577726 PMCID: PMC9786803 DOI: 10.1111/adb.13244] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/07/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022]
Abstract
Cocaine is a widely used psychostimulant drug whose repeated exposure induces persistent cognitive/emotional dysregulation, which could be a predictor of relapse in users. However, there is scarce evidence on effective treatments to alleviate these symptoms. Environmental enrichment (EE) has been shown to be associated with improved synaptic function and cellular plasticity changes related to adult hippocampal neurogenesis (AHN), resulting in cognitive enhancement. Therefore, EE could mitigate the negative impact of chronic administration of cocaine in mice and reduce the emotional and cognitive symptoms present during cocaine abstinence. In this study, mice were chronically administered with cocaine for 14 days, and control mice received saline. After the last cocaine or saline dose, mice were submitted to control or EE housing conditions, and they stayed undisturbed for 28 days. Subsequently, mice were evaluated with a battery of behavioural tests for exploratory activity, emotional behaviour, and cognitive performance. EE attenuated hyperlocomotion, induced anxiolytic-like behaviour and alleviated cognitive impairment in spatial memory in the cocaine-abstinent mice. The EE protocol notably upregulated AHN in both control and cocaine-treated mice, though cocaine slightly reduced the number of immature neurons. Altogether, these results demonstrate that EE could enhance hippocampal neuroplasticity ameliorating the behavioural and cognitive consequences of repeated administration of cocaine. Therefore, environmental stimulation may be a useful strategy in the treatment cocaine addiction.
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Affiliation(s)
- M. Carmen Mañas‐Padilla
- Instituto de Investigación Biomédica de Málaga‐IBIMAMálagaSpain,Departamento de Psicobiología y Metodología de las Ciencias del ComportamientoUniversidad de MálagaMálagaSpain
| | - Patricia Tezanos
- Department of Translational NeuroscienceCajal Institute, Spanish National Research CouncilMadridSpain
| | - Elisa Cintado
- Department of Translational NeuroscienceCajal Institute, Spanish National Research CouncilMadridSpain
| | - Lucía Vicente
- Centro de Experimentación AnimalUniversidad de MálagaMálagaSpain,Departamento de PsicologíaUniversidad de DeustoBilbaoSpain
| | - Lourdes Sánchez‐Salido
- Instituto de Investigación Biomédica de Málaga‐IBIMAMálagaSpain,Unidad de Gestión Clínica de Salud MentalHospital Regional Universitario de MálagaMálagaSpain
| | - Sara Gil‐Rodríguez
- Instituto de Investigación Biomédica de Málaga‐IBIMAMálagaSpain,Departamento de Psicobiología y Metodología de las Ciencias del ComportamientoUniversidad de MálagaMálagaSpain
| | - José L. Trejo
- Department of Translational NeuroscienceCajal Institute, Spanish National Research CouncilMadridSpain
| | - Luis J. Santín
- Instituto de Investigación Biomédica de Málaga‐IBIMAMálagaSpain,Departamento de Psicobiología y Metodología de las Ciencias del ComportamientoUniversidad de MálagaMálagaSpain
| | - Estela Castilla‐Ortega
- Instituto de Investigación Biomédica de Málaga‐IBIMAMálagaSpain,Departamento de Psicobiología y Metodología de las Ciencias del ComportamientoUniversidad de MálagaMálagaSpain
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11
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Urbi B, Lee Y, Hughes I, Thorning S, Broadley SA, Sabet A, Heshmat S. Effects of cannabinoids in Parkinson's disease animal models: a systematic review and meta-analysis. BMJ OPEN SCIENCE 2022; 6:e100302. [PMID: 36618606 PMCID: PMC9812814 DOI: 10.1136/bmjos-2022-100302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Objectives Cannabis has been proposed as a potential treatment for Parkinson's disease (PD) due to its neuroprotective benefits. However, there has been no rigorous review of preclinical studies to evaluate any potential treatment effect. This systematic review was undertaken to provide evidence in support or against a treatment effect of cannabinoids in animal models of PD. Methods Databases were searched for any controlled comparative studies that assessed the effects of any cannabinoid, cannabinoid-based treatment or endocannabinoid transport blocker on behavioural symptoms in PD animal models. Results A total of 41 studies were identified to have met the criteria for this review. 14 of these studies were included in meta-analyses of rotarod, pole and open field tests. Meta-analysis of rotarod tests showed a weighted mean difference of 31.63 s for cannabinoid-treated group compared with control. Meta-analysis of pole tests also showed a positive treatment effect, evidenced by a weighted mean difference of -1.51 s for cannabinoid treat group compared with control. However, meta-analysis of open field test demonstrated a standardised mean difference of only 0.36 indicating no benefit. Conclusion This review demonstrates cannabinoid treatment effects in alleviating motor symptoms of PD animal models and supports the conduct of clinical trials of cannabis in PD population. However, there is no guarantee of successful clinical translation of this outcome because of the many variables that might have affected the results, such as the prevalent unclear and high risk of bias, the different study methods, PD animal models and cannabinoids used.
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Affiliation(s)
- Berzenn Urbi
- Office for Research Governance and Development, Gold Coast University Hospital, Southport, Queensland, Australia,Medicine, Griffith University Faculty of Health, Gold Coast, Queensland, Australia
| | - Yunjoo Lee
- Medicine, Griffith University Faculty of Health, Gold Coast, Queensland, Australia
| | - Ian Hughes
- Office for Research Governance and Development, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Sarah Thorning
- Office for Research Governance and Development, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Simon A Broadley
- Medicine, Griffith University Faculty of Health, Gold Coast, Queensland, Australia,Department of Neurology, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Arman Sabet
- Medicine, Griffith University Faculty of Health, Gold Coast, Queensland, Australia,Department of Neurology, Gold Coast University Hospital, Southport, Queensland, Australia
| | - Saman Heshmat
- Department of Neurology, Gold Coast University Hospital, Southport, Queensland, Australia
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12
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How Well Do Rodent Models of Parkinson's Disease Recapitulate Early Non-Motor Phenotypes? A Systematic Review. Biomedicines 2022; 10:biomedicines10123026. [PMID: 36551782 PMCID: PMC9775565 DOI: 10.3390/biomedicines10123026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
The prodromal phase of Parkinson's disease (PD) is characterised by many non-motor symptoms, and these have recently been posited to be predictive of later diagnosis. Genetic rodent models can develop non-motor phenotypes, providing tools to identify mechanisms underlying the early development of PD. However, it is not yet clear how reproducible non-motor phenotypes are amongst genetic PD rodent models, whether phenotypes are age-dependent, and the translatability of these phenotypes has yet to be explored. A systematic literature search was conducted on studies using genetic PD rodent models to investigate non-motor phenotypes; cognition, anxiety/depressive-like behaviour, gastrointestinal (GI) function, olfaction, circadian rhythm, cardiovascular and urinary function. In total, 51 genetic models of PD across 150 studies were identified. We found outcomes of most phenotypes were inconclusive due to inadequate studies, assessment at different ages, or variation in experimental and environmental factors. GI dysfunction was the most reproducible phenotype across all genetic rodent models. The mouse model harbouring mutant A53T, and the wild-type hα-syn overexpression (OE) model recapitulated the majority of phenotypes, albeit did not reliably produce concurrent motor deficits and nigral cell loss. Furthermore, animal models displayed different phenotypic profiles, reflecting the distinct genetic risk factors and heterogeneity of disease mechanisms. Currently, the inconsistent phenotypes within rodent models pose a challenge in the translatability and usefulness for further biomechanistic investigations. This review highlights opportunities to improve phenotype reproducibility with an emphasis on phenotypic assay choice and robust experimental design.
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13
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Kempermann G, Lopes JB, Zocher S, Schilling S, Ehret F, Garthe A, Karasinsky A, Brandmaier AM, Lindenberger U, Winter Y, Overall RW. The individuality paradigm: Automated longitudinal activity tracking of large cohorts of genetically identical mice in an enriched environment. Neurobiol Dis 2022; 175:105916. [DOI: 10.1016/j.nbd.2022.105916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022] Open
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14
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Jaric I, Voelkl B, Clerc M, Schmid MW, Novak J, Rosso M, Rufener R, von Kortzfleisch VT, Richter SH, Buettner M, Bleich A, Amrein I, Wolfer DP, Touma C, Sunagawa S, Würbel H. The rearing environment persistently modulates mouse phenotypes from the molecular to the behavioural level. PLoS Biol 2022; 20:e3001837. [PMID: 36269766 PMCID: PMC9629646 DOI: 10.1371/journal.pbio.3001837] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 11/02/2022] [Accepted: 09/20/2022] [Indexed: 11/07/2022] Open
Abstract
The phenotype of an organism results from its genotype and the influence of the environment throughout development. Even when using animals of the same genotype, independent studies may test animals of different phenotypes, resulting in poor replicability due to genotype-by-environment interactions. Thus, genetically defined strains of mice may respond differently to experimental treatments depending on their rearing environment. However, the extent of such phenotypic plasticity and its implications for the replicability of research findings have remained unknown. Here, we examined the extent to which common environmental differences between animal facilities modulate the phenotype of genetically homogeneous (inbred) mice. We conducted a comprehensive multicentre study, whereby inbred C57BL/6J mice from a single breeding cohort were allocated to and reared in 5 different animal facilities throughout early life and adolescence, before being transported to a single test laboratory. We found persistent effects of the rearing facility on the composition and heterogeneity of the gut microbial community. These effects were paralleled by persistent differences in body weight and in the behavioural phenotype of the mice. Furthermore, we show that environmental variation among animal facilities is strong enough to influence epigenetic patterns in neurons at the level of chromatin organisation. We detected changes in chromatin organisation in the regulatory regions of genes involved in nucleosome assembly, neuronal differentiation, synaptic plasticity, and regulation of behaviour. Our findings demonstrate that common environmental differences between animal facilities may produce facility-specific phenotypes, from the molecular to the behavioural level. Furthermore, they highlight an important limitation of inferences from single-laboratory studies and thus argue that study designs should take environmental background into account to increase the robustness and replicability of findings. The phenotype of an organism results not only from its genotype but also the influence of its environment throughout development. This study shows that common environmental differences between animal facilities can induce substantial variation in the phenotype of mice, thereby highlighting an important limitation of inferences from single-laboratory studies in animal research.
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Affiliation(s)
- Ivana Jaric
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- * E-mail: (IJ); (HW)
| | - Bernhard Voelkl
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Melanie Clerc
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | | | - Janja Novak
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Marianna Rosso
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Reto Rufener
- Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | | | - S. Helene Richter
- Department of Behavioural Biology, University of Münster, Münster, Germany
| | - Manuela Buettner
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Germany
| | - André Bleich
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Germany
| | - Irmgard Amrein
- Institute of Anatomy, Division of Functional Neuroanatomy, University of Zürich, Zürich, Switzerland; Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - David P. Wolfer
- Institute of Anatomy, Division of Functional Neuroanatomy, University of Zürich, Zürich, Switzerland; Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Chadi Touma
- Department of Behavioural Biology, Osnabrück University, Osnabrück, Germany
| | - Shinichi Sunagawa
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Hanno Würbel
- Animal Welfare Division, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- * E-mail: (IJ); (HW)
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15
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Questionable Research Practices, Low Statistical Power, and Other Obstacles to Replicability: Why Preclinical Neuroscience Research Would Benefit from Registered Reports. eNeuro 2022; 9:9/4/ENEURO.0017-22.2022. [PMID: 35922130 PMCID: PMC9351632 DOI: 10.1523/eneuro.0017-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 05/22/2022] [Accepted: 05/31/2022] [Indexed: 02/03/2023] Open
Abstract
Replicability, the degree to which a previous scientific finding can be repeated in a distinct set of data, has been considered an integral component of institutionalized scientific practice since its inception several hundred years ago. In the past decade, large-scale replication studies have demonstrated that replicability is far from favorable, across multiple scientific fields. Here, I evaluate this literature and describe contributing factors including the prevalence of questionable research practices (QRPs), misunderstanding of p-values, and low statistical power. I subsequently discuss how these issues manifest specifically in preclinical neuroscience research. I conclude that these problems are multifaceted and difficult to solve, relying on the actions of early and late career researchers, funding sources, academic publishers, and others. I assert that any viable solution to the problem of substandard replicability must include changing academic incentives, with adoption of registered reports being the most immediately impactful and pragmatic strategy. For animal research in particular, comprehensive reporting guidelines that document potential sources of sensitivity for experimental outcomes is an essential addition.
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16
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Suman PR, Lino de Oliveira C. Systematic heterogenisation to improve reproducibility in animal studies. PLoS Biol 2022; 20:e3001629. [PMID: 35522652 PMCID: PMC9075638 DOI: 10.1371/journal.pbio.3001629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A recent study published in PLoS Biology investigated whether the systematic use of multiple experimenters boosts the reproducibility of behavioural assays in mice. This Primer explores study designs to investigate systematic heterogenization in single-or multi-laboratory settings.
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Affiliation(s)
- Patrick Remus Suman
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, RJ, Brazil
| | - Cilene Lino de Oliveira
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina–UFSC, Florianópolis–SC, Brazil
- * E-mail:
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17
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Do multiple experimenters improve the reproducibility of animal studies? PLoS Biol 2022; 20:e3001564. [PMID: 35511779 PMCID: PMC9070896 DOI: 10.1371/journal.pbio.3001564] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 02/02/2022] [Indexed: 12/02/2022] Open
Abstract
The credibility of scientific research has been seriously questioned by the widely claimed “reproducibility crisis”. In light of this crisis, there is a growing awareness that the rigorous standardisation of experimental conditions may contribute to poor reproducibility of animal studies. Instead, systematic heterogenisation has been proposed as a tool to enhance reproducibility, but a real-life test across multiple independent laboratories is still pending. The aim of this study was therefore to test whether heterogenisation of experimental conditions by using multiple experimenters improves the reproducibility of research findings compared to standardised conditions with only one experimenter. To this end, we replicated the same animal experiment in 3 independent laboratories, each employing both a heterogenised and a standardised design. Whereas in the standardised design, all animals were tested by a single experimenter; in the heterogenised design, 3 different experimenters were involved in testing the animals. In contrast to our expectation, the inclusion of multiple experimenters in the heterogenised design did not improve the reproducibility of the results across the 3 laboratories. Interestingly, however, a variance component analysis indicated that the variation introduced by the different experimenters was not as high as the variation introduced by the laboratories, probably explaining why this heterogenisation strategy did not bring the anticipated success. Even more interestingly, for the majority of outcome measures, the remaining residual variation was identified as an important source of variance accounting for 41% (CI95 [34%, 49%]) to 72% (CI95 [58%, 88%]) of the observed total variance. Despite some uncertainty surrounding the estimated numbers, these findings argue for systematically including biological variation rather than eliminating it in animal studies and call for future research on effective improvement strategies. An experimenter heterogenisation was not sufficient to prevent idiosyncratic results in a multi-laboratory setting. Astonishingly, neither the experimenter nor the laboratory accounted for the main portion of the observed variation, but a high amount of residual variation in fact remained unexplained despite strict standardisation regimes.
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18
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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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19
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Ratuski AS, Weary DM. Environmental Enrichment for Rats and Mice Housed in Laboratories: A Metareview. Animals (Basel) 2022; 12:ani12040414. [PMID: 35203123 PMCID: PMC8868396 DOI: 10.3390/ani12040414] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/28/2022] [Accepted: 01/30/2022] [Indexed: 11/10/2022] Open
Abstract
Simple Summary Environmental enrichment has been widely studied with laboratory rodents, but there is no consensus regarding what counts as enrichment or what it should achieve. Inconsistent use of the term “enrichment” creates challenges in drawing conclusions about the quality of an environment. We conducted a metareview to better understand the definitions and goals of enrichment, perceived risks or requirements of enrichment, and what forms of enrichment have previously been endorsed for use with rodents housed in laboratories. This may help researchers and animal care staff to better define their chosen approach and intended outcomes when providing environmental enrichment. Abstract Environmental enrichment has been widely studied in rodents, but there is no consensus on what enrichment should look like or what it should achieve. Inconsistent use of the term “enrichment” creates challenges in drawing conclusions about the quality of an environment, which may slow housing improvements for laboratory animals. Many review articles have addressed environmental enrichment for laboratory rats and mice (Rattus norvegicus and Mus musculus). We conducted a metareview of 29 review articles to assess how enrichment has been defined and what are commonly described as its goals or requirements. Recommendations from each article were summarised to illustrate the conditions generally considered suitable for laboratory rodents. While there is no consensus on alternative terminology, many articles acknowledged that the blanket use of the terms “enriched” and “enrichment” should be avoided. Environmental enrichment was most often conceptualised as a method to increase natural behaviour and improve animal welfare. Authors also commonly outlined perceived risks and requirements of environmental enrichment. We discuss these perceptions, make suggestions for future research, and advocate for the adoption of more specific and value-neutral terminology.
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20
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Loss CM, Melleu FF, Domingues K, Lino-de-Oliveira C, Viola GG. Combining Animal Welfare With Experimental Rigor to Improve Reproducibility in Behavioral Neuroscience. Front Behav Neurosci 2021; 15:763428. [PMID: 34916915 PMCID: PMC8671008 DOI: 10.3389/fnbeh.2021.763428] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/18/2021] [Indexed: 02/05/2023] Open
Affiliation(s)
- Cássio Morais Loss
- Molecular and Behavioral Neuroscience Laboratory, Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, Brazil
- National Institute for Translational Medicine (INCT-TM), National Council for Scientific and Technological Development (CNPq/CAPES/FAPESP), Ribeirão Preto, Brazil
| | | | - Karolina Domingues
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Cilene Lino-de-Oliveira
- Departamento de Ciências Fisiológicas do Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Brazil
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21
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Freschet GT, Pagès L, Iversen CM, Comas LH, Rewald B, Roumet C, Klimešová J, Zadworny M, Poorter H, Postma JA, Adams TS, Bagniewska‐Zadworna A, Bengough AG, Blancaflor EB, Brunner I, Cornelissen JHC, Garnier E, Gessler A, Hobbie SE, Meier IC, Mommer L, Picon‐Cochard C, Rose L, Ryser P, Scherer‐Lorenzen M, Soudzilovskaia NA, Stokes A, Sun T, Valverde‐Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Batterman SA, Gomes de Moraes M, Janeček Š, Lambers H, Salmon V, Tharayil N, McCormack ML. A starting guide to root ecology: strengthening ecological concepts and standardising root classification, sampling, processing and trait measurements. THE NEW PHYTOLOGIST 2021; 232:973-1122. [PMID: 34608637 PMCID: PMC8518129 DOI: 10.1111/nph.17572] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/22/2021] [Indexed: 05/17/2023]
Abstract
In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting-edge, meaningful and integrated knowledge. Consideration of the below-ground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, will improve trait comparisons across studies and integration of information across databases by providing standardised methods and controlled vocabularies. It is meant to be used not only as starting point by students and scientists who desire working on below-ground ecosystems, but also by experts for consolidating and broadening their views on multiple aspects of root ecology. Beyond the classical compilation of measurement protocols, we have synthesised recommendations from the literature to provide key background knowledge useful for: (1) defining below-ground plant entities and giving keys for their meaningful dissection, classification and naming beyond the classical fine-root vs coarse-root approach; (2) considering the specificity of root research to produce sound laboratory and field data; (3) describing typical, but overlooked steps for studying roots (e.g. root handling, cleaning and storage); and (4) gathering metadata necessary for the interpretation of results and their reuse. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers not to solely extract protocol recommendations for trait measurements from this work, but to take a moment to read and reflect on the extensive information contained in this broader guide to root ecology, including sections I-VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers' views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.
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Affiliation(s)
- Grégoire T. Freschet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
| | - Loïc Pagès
- UR 1115 PSHCentre PACA, site AgroparcINRAE84914Avignon cedex 9France
| | - Colleen M. Iversen
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Louise H. Comas
- USDA‐ARS Water Management Research Unit2150 Centre Avenue, Bldg D, Suite 320Fort CollinsCO80526USA
| | - Boris Rewald
- Department of Forest and Soil SciencesUniversity of Natural Resources and Life SciencesVienna1190Austria
| | - Catherine Roumet
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Jitka Klimešová
- Department of Functional EcologyInstitute of Botany CASDukelska 13537901TrebonCzech Republic
| | - Marcin Zadworny
- Institute of DendrologyPolish Academy of SciencesParkowa 562‐035KórnikPoland
| | - Hendrik Poorter
- Plant Sciences (IBG‐2)Forschungszentrum Jülich GmbHD‐52425JülichGermany
- Department of Biological SciencesMacquarie UniversityNorth RydeNSW2109Australia
| | | | - Thomas S. Adams
- Department of Plant SciencesThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Agnieszka Bagniewska‐Zadworna
- Department of General BotanyInstitute of Experimental BiologyFaculty of BiologyAdam Mickiewicz UniversityUniwersytetu Poznańskiego 661-614PoznańPoland
| | - A. Glyn Bengough
- The James Hutton InstituteInvergowrie, Dundee,DD2 5DAUK
- School of Science and EngineeringUniversity of DundeeDundee,DD1 4HNUK
| | | | - Ivano Brunner
- Forest Soils and BiogeochemistrySwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
| | - Johannes H. C. Cornelissen
- Department of Ecological ScienceFaculty of ScienceVrije Universiteit AmsterdamDe Boelelaan 1085Amsterdam1081 HVthe Netherlands
| | - Eric Garnier
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Arthur Gessler
- Forest DynamicsSwiss Federal Research Institute WSLZürcherstr. 1118903BirmensdorfSwitzerland
- Institute of Terrestrial EcosystemsETH Zurich8092ZurichSwitzerland
| | - Sarah E. Hobbie
- Department of Ecology, Evolution and BehaviorUniversity of MinnesotaSt PaulMN55108USA
| | - Ina C. Meier
- Functional Forest EcologyUniversity of HamburgHaidkrugsweg 122885BarsbütelGermany
| | - Liesje Mommer
- Plant Ecology and Nature Conservation GroupDepartment of Environmental SciencesWageningen University and ResearchPO Box 476700 AAWageningenthe Netherlands
| | | | - Laura Rose
- Station d’Ecologie Théorique et ExpérimentaleCNRS2 route du CNRS09200MoulisFrance
- Senckenberg Biodiversity and Climate Research Centre (BiK-F)Senckenberganlage 2560325Frankfurt am MainGermany
| | - Peter Ryser
- Laurentian University935 Ramsey Lake RoadSudburyONP3E 2C6Canada
| | | | - Nadejda A. Soudzilovskaia
- Environmental Biology DepartmentInstitute of Environmental SciencesCMLLeiden UniversityLeiden2300 RAthe Netherlands
| | - Alexia Stokes
- INRAEAMAPCIRAD, IRDCNRSUniversity of MontpellierMontpellier34000France
| | - Tao Sun
- Institute of Applied EcologyChinese Academy of SciencesShenyang110016China
| | - Oscar J. Valverde‐Barrantes
- International Center for Tropical BotanyDepartment of Biological SciencesFlorida International UniversityMiamiFL33199USA
| | - Monique Weemstra
- CEFEUniv Montpellier, CNRS, EPHE, IRD1919 route de MendeMontpellier34293France
| | - Alexandra Weigelt
- Systematic Botany and Functional BiodiversityInstitute of BiologyLeipzig UniversityJohannisallee 21-23Leipzig04103Germany
| | - Nina Wurzburger
- Odum School of EcologyUniversity of Georgia140 E. Green StreetAthensGA30602USA
| | - Larry M. York
- Biosciences Division and Center for Bioenergy InnovationOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Sarah A. Batterman
- School of Geography and Priestley International Centre for ClimateUniversity of LeedsLeedsLS2 9JTUK
- Cary Institute of Ecosystem StudiesMillbrookNY12545USA
| | - Moemy Gomes de Moraes
- Department of BotanyInstitute of Biological SciencesFederal University of Goiás1974690-900Goiânia, GoiásBrazil
| | - Štěpán Janeček
- School of Biological SciencesThe University of Western Australia35 Stirling HighwayCrawley (Perth)WA 6009Australia
| | - Hans Lambers
- School of Biological SciencesThe University of Western AustraliaCrawley (Perth)WAAustralia
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science InstituteOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Nishanth Tharayil
- Department of Plant and Environmental SciencesClemson UniversityClemsonSC29634USA
| | - M. Luke McCormack
- Center for Tree ScienceMorton Arboretum, 4100 Illinois Rt. 53LisleIL60532USA
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22
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Freschet GT, Pagès L, Iversen CM, Comas LH, Rewald B, Roumet C, Klimešová J, Zadworny M, Poorter H, Postma JA, Adams TS, Bagniewska-Zadworna A, Bengough AG, Blancaflor EB, Brunner I, Cornelissen JHC, Garnier E, Gessler A, Hobbie SE, Meier IC, Mommer L, Picon-Cochard C, Rose L, Ryser P, Scherer-Lorenzen M, Soudzilovskaia NA, Stokes A, Sun T, Valverde-Barrantes OJ, Weemstra M, Weigelt A, Wurzburger N, York LM, Batterman SA, Gomes de Moraes M, Janeček Š, Lambers H, Salmon V, Tharayil N, McCormack ML. A starting guide to root ecology: strengthening ecological concepts and standardising root classification, sampling, processing and trait measurements. THE NEW PHYTOLOGIST 2021. [PMID: 34608637 DOI: 10.1111/nph.17572.hal-03379708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In the context of a recent massive increase in research on plant root functions and their impact on the environment, root ecologists currently face many important challenges to keep on generating cutting-edge, meaningful and integrated knowledge. Consideration of the below-ground components in plant and ecosystem studies has been consistently called for in recent decades, but methodology is disparate and sometimes inappropriate. This handbook, based on the collective effort of a large team of experts, will improve trait comparisons across studies and integration of information across databases by providing standardised methods and controlled vocabularies. It is meant to be used not only as starting point by students and scientists who desire working on below-ground ecosystems, but also by experts for consolidating and broadening their views on multiple aspects of root ecology. Beyond the classical compilation of measurement protocols, we have synthesised recommendations from the literature to provide key background knowledge useful for: (1) defining below-ground plant entities and giving keys for their meaningful dissection, classification and naming beyond the classical fine-root vs coarse-root approach; (2) considering the specificity of root research to produce sound laboratory and field data; (3) describing typical, but overlooked steps for studying roots (e.g. root handling, cleaning and storage); and (4) gathering metadata necessary for the interpretation of results and their reuse. Most importantly, all root traits have been introduced with some degree of ecological context that will be a foundation for understanding their ecological meaning, their typical use and uncertainties, and some methodological and conceptual perspectives for future research. Considering all of this, we urge readers not to solely extract protocol recommendations for trait measurements from this work, but to take a moment to read and reflect on the extensive information contained in this broader guide to root ecology, including sections I-VII and the many introductions to each section and root trait description. Finally, it is critical to understand that a major aim of this guide is to help break down barriers between the many subdisciplines of root ecology and ecophysiology, broaden researchers' views on the multiple aspects of root study and create favourable conditions for the inception of comprehensive experiments on the role of roots in plant and ecosystem functioning.
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Affiliation(s)
- Grégoire T Freschet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
- Station d'Ecologie Théorique et Expérimentale, CNRS, 2 route du CNRS, 09200, Moulis, France
| | - Loïc Pagès
- UR 1115 PSH, Centre PACA, site Agroparc, INRAE, 84914, Avignon cedex 9, France
| | - Colleen M Iversen
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Louise H Comas
- USDA-ARS Water Management Research Unit, 2150 Centre Avenue, Bldg D, Suite 320, Fort Collins, CO, 80526, USA
| | - Boris Rewald
- Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna, 1190, Austria
| | - Catherine Roumet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Jitka Klimešová
- Department of Functional Ecology, Institute of Botany CAS, Dukelska 135, 37901, Trebon, Czech Republic
| | - Marcin Zadworny
- Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035, Kórnik, Poland
| | - Hendrik Poorter
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, 2109, Australia
| | - Johannes A Postma
- Plant Sciences (IBG-2), Forschungszentrum Jülich GmbH, D-52425, Jülich, Germany
| | - Thomas S Adams
- Department of Plant Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Agnieszka Bagniewska-Zadworna
- Department of General Botany, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - A Glyn Bengough
- The James Hutton Institute, Invergowrie, Dundee,, DD2 5DA, UK
- School of Science and Engineering, University of Dundee, Dundee,, DD1 4HN, UK
| | - Elison B Blancaflor
- Noble Research Institute, LLC, 2510 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Ivano Brunner
- Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
| | - Johannes H C Cornelissen
- Department of Ecological Science, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, the Netherlands
| | - Eric Garnier
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903, Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, 8092, Zurich, Switzerland
| | - Sarah E Hobbie
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Ina C Meier
- Functional Forest Ecology, University of Hamburg, Haidkrugsweg 1, 22885, Barsbütel, Germany
| | - Liesje Mommer
- Plant Ecology and Nature Conservation Group, Department of Environmental Sciences, Wageningen University and Research, PO Box 47, 6700 AA, Wageningen, the Netherlands
| | | | - Laura Rose
- Station d'Ecologie Théorique et Expérimentale, CNRS, 2 route du CNRS, 09200, Moulis, France
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Peter Ryser
- Laurentian University, 935 Ramsey Lake Road, Sudbury, ON, P3E 2C6, Canada
| | | | - Nadejda A Soudzilovskaia
- Environmental Biology Department, Institute of Environmental Sciences, CML, Leiden University, Leiden, 2300 RA, the Netherlands
| | - Alexia Stokes
- INRAE, AMAP, CIRAD, IRD, CNRS, University of Montpellier, Montpellier, 34000, France
| | - Tao Sun
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Oscar J Valverde-Barrantes
- International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Monique Weemstra
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 route de Mende, Montpellier, 34293, France
| | - Alexandra Weigelt
- Systematic Botany and Functional Biodiversity, Institute of Biology, Leipzig University, Johannisallee 21-23, Leipzig, 04103, Germany
| | - Nina Wurzburger
- Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA, 30602, USA
| | - Larry M York
- Biosciences Division and Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Sarah A Batterman
- School of Geography and Priestley International Centre for Climate, University of Leeds, Leeds, LS2 9JT, UK
- Cary Institute of Ecosystem Studies, Millbrook, NY, 12545, USA
| | - Moemy Gomes de Moraes
- Department of Botany, Institute of Biological Sciences, Federal University of Goiás, 19, 74690-900, Goiânia, Goiás, Brazil
| | - Štěpán Janeček
- School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley (Perth), WA 6009, Australia
| | - Hans Lambers
- School of Biological Sciences, The University of Western Australia, Crawley (Perth), WA, Australia
| | - Verity Salmon
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Nishanth Tharayil
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | - M Luke McCormack
- Center for Tree Science, Morton Arboretum, 4100 Illinois Rt. 53, Lisle, IL, 60532, USA
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23
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Sil A, Bespalov A, Dalla C, Ferland-Beckham C, Herremans A, Karantzalos K, Kas MJ, Kokras N, Parnham MJ, Pavlidi P, Pristouris K, Steckler T, Riedel G, Emmerich CH. PEERS - An Open Science "Platform for the Exchange of Experimental Research Standards" in Biomedicine. Front Behav Neurosci 2021; 15:755812. [PMID: 34744655 PMCID: PMC8567102 DOI: 10.3389/fnbeh.2021.755812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/29/2021] [Indexed: 12/26/2022] Open
Abstract
Laboratory workflows and preclinical models have become increasingly diverse and complex. Confronted with the dilemma of a multitude of information with ambiguous relevance for their specific experiments, scientists run the risk of overlooking critical factors that can influence the planning, conduct and results of studies and that should have been considered a priori. To address this problem, we developed "PEERS" (Platform for the Exchange of Experimental Research Standards), an open-access online platform that is built to aid scientists in determining which experimental factors and variables are most likely to affect the outcome of a specific test, model or assay and therefore ought to be considered during the design, execution and reporting stages. The PEERS database is categorized into in vivo and in vitro experiments and provides lists of factors derived from scientific literature that have been deemed critical for experimentation. The platform is based on a structured and transparent system for rating the strength of evidence related to each identified factor and its relevance for a specific method/model. In this context, the rating procedure will not solely be limited to the PEERS working group but will also allow for a community-based grading of evidence. We here describe a working prototype using the Open Field paradigm in rodents and present the selection of factors specific to each experimental setup and the rating system. PEERS not only offers users the possibility to search for information to facilitate experimental rigor, but also draws on the engagement of the scientific community to actively expand the information contained within the platform. Collectively, by helping scientists search for specific factors relevant to their experiments, and to share experimental knowledge in a standardized manner, PEERS will serve as a collaborative exchange and analysis tool to enhance data validity and robustness as well as the reproducibility of preclinical research. PEERS offers a vetted, independent tool by which to judge the quality of information available on a certain test or model, identifies knowledge gaps and provides guidance on the key methodological considerations that should be prioritized to ensure that preclinical research is conducted to the highest standards and best practice.
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Affiliation(s)
- Annesha Sil
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Christina Dalla
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | | | - Martien J. Kas
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Nikolaos Kokras
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- First Department of Psychiatry, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Michael J. Parnham
- EpiEndo Pharmaceuticals, Seltjanarnes, Iceland, and Pharmacology Consultant, Bad Soden, Germany
| | - Pavlina Pavlidi
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | | | | | - Gernot Riedel
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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24
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Capitanio JP. Knowledge of Biobehavioral Organization Can Facilitate Better Science: A Review of the BioBehavioral Assessment Program at the California National Primate Research Center. Animals (Basel) 2021; 11:2445. [PMID: 34438902 PMCID: PMC8388628 DOI: 10.3390/ani11082445] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/11/2021] [Accepted: 08/18/2021] [Indexed: 11/17/2022] Open
Abstract
Animals vary on intrinsic characteristics such as temperament and stress responsiveness, and this information can be useful to experimentalists for identifying more homogeneous subsets of animals that show consistency in risk for a particular research outcome. Such information can also be useful for balancing experimental groups, ensuring animals within an experiment have similar characteristics. In this review, we describe the BioBehavioral Assessment Program at the California National Primate Research Center, which, since its inception in 2001, has been providing quantitative information on intrinsic characteristics to scientists for subject selection and balancing, and to colony management staff for management purposes. We describe the program and review studies relating to asthma, autism, behavioral inhibition, etc., where the BBA Program was used to select animals. We also review our work, showing that factors such as rearing, ketamine exposure, and prenatal experience can affect biobehavioral organization in ways that some investigators might want to control for in their studies. Attention to intrinsic characteristics of subject populations is consistent with the growing interest in precision medicine and can lead to a reduction in animal numbers, savings in time and money for investigators, and reduced distress for the animals.
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Affiliation(s)
- John P Capitanio
- California National Primate Research Center, University of California, Davis, CA 95616, USA
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25
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Ferguson L, Giza CC, Serpa RO, Greco T, Robert H, Folkerts M, Prins ML. Sex Differences in Neurophysiological Changes Following Voluntary Exercise in Adolescent Rats. Front Neurol 2021; 12:685822. [PMID: 34367052 PMCID: PMC8339288 DOI: 10.3389/fneur.2021.685822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/28/2021] [Indexed: 11/15/2022] Open
Abstract
Background: Adolescence is a period of time characterized by the onset of puberty and is marked by cognitive and social developments and gross physical changes that can play a role in athletic performance. Sex differences are present with differences in body size, height, physiology and behavior which contribute to differences in athletic performance as well. Pre-clinical studies representing this active group are lacking. Methods: Acute and chronic effects of exercise were evaluated. Male and female adolescent rats were given voluntary access to a running wheel for 10 consecutive days. Running behavior (males and females) and estrous cycling (females only) were analyzed daily. A second group was given 10 days of voluntary access to a running wheel, then rested for 10 days to determine the long-term effects of exercise on the adolescent brain. Brain and muscle tissue were harvested at 10 and 20 day time points to understand exercise-dependent changes in mitochondrial activity and neuroplasticity. Animal cohorts were carried out at two different sites: University of California Los Angeles and Pepperdine University. Results: On average, running distance, intensity of run, and length of running bout increased for both male and female rats across the 10 days measured. Females ran significantly further and for longer intervals compared to males. Cortical and muscle expression of PGC1α showed similar levels at 10 days regardless of sex and exercise. There was a significant increase in expression at 20 days in all groups correlating with body size (p's < 0.05). Cortical and hippocampal levels of BDNF were similar across all groups, however, BDNF was significantly higher in exercised females at the acute compared to long-term time point. Discussion: Adolescent rats allowed 10 days of exercise show changes in physiologic function. There are sex differences in running behavior not impacted by sex hormones. These results are important to further our understanding of how exercise impacts the adolescent brain.
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Affiliation(s)
- Lindsay Ferguson
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Christopher C Giza
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Rebecka O Serpa
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Tiffany Greco
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
| | - Hannah Robert
- Department of Psychology, Seaver College, Pepperdine University, Malibu, CA, United States
| | - Michael Folkerts
- Department of Psychology, Seaver College, Pepperdine University, Malibu, CA, United States
| | - Mayumi L Prins
- Department of Neurosurgery, Brain Injury Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Steve Tisch BrainSPORT Program, University of California, Los Angeles, Los Angeles, CA, United States
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26
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Eggel M, Würbel H. Internal consistency and compatibility of the 3Rs and 3Vs principles for project evaluation of animal research. Lab Anim 2021; 55:233-243. [PMID: 33215575 PMCID: PMC8182293 DOI: 10.1177/0023677220968583] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/04/2020] [Indexed: 12/27/2022]
Abstract
Using animals for research raises ethical concerns that are addressed in project evaluation by weighing expected harm to animals against expected benefit to society. A harm-benefit analysis (HBA) relies on two preconditions: (a) the study protocol is scientifically suitable and (b) the use of (sentient) animals and harm imposed on them are necessary for achieving the study's aims. The 3Rs (Replace, Reduce and Refine) provide a guiding principle for evaluating whether the use of animals, their number and the harm imposed on them are necessary. A similar guiding principle for evaluating whether a study protocol is scientifically suitable has recently been proposed: the 3Vs principle referring to the three main aspects of scientific validity in animal research (construct, internal and external validity). Here, we analyse the internal consistency and compatibility of these two principles, address conflicts within and between the 3Rs and 3Vs principles and discuss their implications for project evaluation. We show that a few conflicts and trade-offs exist, but that these can be resolved either by appropriate study designs or by ethical deliberation in the HBA. In combination, the 3Vs, 3Rs and the HBA thus offer a coherent framework for a logically structured evaluation procedure to decide about the legitimacy of animal research projects.
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Affiliation(s)
- Matthias Eggel
- Institute for Biomedical Ethics and History of
Medicine, University of Zurich, Switzerland
| | - Hanno Würbel
- Animal Welfare Division, Veterinary Public Health
Institute University of Bern, Switzerland
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27
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Usui T, Macleod MR, McCann SK, Senior AM, Nakagawa S. Meta-analysis of variation suggests that embracing variability improves both replicability and generalizability in preclinical research. PLoS Biol 2021; 19:e3001009. [PMID: 34010281 PMCID: PMC8168858 DOI: 10.1371/journal.pbio.3001009] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 06/01/2021] [Accepted: 05/04/2021] [Indexed: 01/11/2023] Open
Abstract
The replicability of research results has been a cause of increasing concern to the scientific community. The long-held belief that experimental standardization begets replicability has also been recently challenged, with the observation that the reduction of variability within studies can lead to idiosyncratic, lab-specific results that cannot be replicated. An alternative approach is to, instead, deliberately introduce heterogeneity, known as "heterogenization" of experimental design. Here, we explore a novel perspective in the heterogenization program in a meta-analysis of variability in observed phenotypic outcomes in both control and experimental animal models of ischemic stroke. First, by quantifying interindividual variability across control groups, we illustrate that the amount of heterogeneity in disease state (infarct volume) differs according to methodological approach, for example, in disease induction methods and disease models. We argue that such methods may improve replicability by creating diverse and representative distribution of baseline disease state in the reference group, against which treatment efficacy is assessed. Second, we illustrate how meta-analysis can be used to simultaneously assess efficacy and stability (i.e., mean effect and among-individual variability). We identify treatments that have efficacy and are generalizable to the population level (i.e., low interindividual variability), as well as those where there is high interindividual variability in response; for these, latter treatments translation to a clinical setting may require nuance. We argue that by embracing rather than seeking to minimize variability in phenotypic outcomes, we can motivate the shift toward heterogenization and improve both the replicability and generalizability of preclinical research.
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Affiliation(s)
- Takuji Usui
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
- The Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Malcolm R. Macleod
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Sarah K. McCann
- QUEST Center for Transforming Biomedical Research, Berlin Institute of Health (BIH), Berlin, Germany
- Charité—Universitätsmedizin Berlin Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alistair M. Senior
- The Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Shinichi Nakagawa
- Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
- The Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
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28
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Farrar BG, Voudouris K, Clayton NS. Replications, Comparisons, Sampling and the Problem of Representativeness in Animal Cognition Research. ANIMAL BEHAVIOR AND COGNITION 2021; 8:273-295. [PMID: 34046521 PMCID: PMC7610843 DOI: 10.26451/abc.08.02.14.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Animal cognition research often involves small and idiosyncratic samples. This can constrain the generalizability and replicability of a study's results and prevent meaningful comparisons between samples. However, there is little consensus about what makes a strong replication or comparison in animal research. We apply a resampling definition of replication to answer these questions in Part 1 of this article, and, in Part 2, we focus on the problem of representativeness in animal research. Through a case study and a simulation study, we highlight how and when representativeness may be an issue in animal behavior and cognition research and show how the representativeness problems can be viewed through the lenses of, i) replicability, ii) generalizability and external validity, iii) pseudoreplication and, iv) theory testing. Next, we discuss when and how researchers can improve their ability to learn from small sample research through, i) increasing heterogeneity in experimental design, ii) increasing homogeneity in experimental design, and, iii) statistically modeling variation. Finally, we describe how the strongest solutions will vary depending on the goals and resources of individual research programs and discuss some barriers towards implementing them.
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29
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Cho C, Deol HK, Martin LJ. Bridging the Translational Divide in Pain Research: Biological, Psychological and Social Considerations. Front Pharmacol 2021; 12:603186. [PMID: 33935700 PMCID: PMC8082136 DOI: 10.3389/fphar.2021.603186] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 02/22/2021] [Indexed: 12/29/2022] Open
Abstract
A gap exists between translating basic science research into effective pain therapies in humans. While preclinical pain research has primarily used animal models to understand biological processes, a lesser focus has been toward using animal models to fully consider other components of the pain experience, such as psychological and social influences. Herein, we provide an overview of translational studies within pain research by breaking them down into purely biological, psychological and social influences using a framework derived from the biopsychosocial model. We draw from a wide landscape of studies to illustrate that the pain experience is highly intricate, and every attempt must be made to address its multiple components and interactors to aid in fully understanding its complexity. We highlight our work where we have developed animal models to assess the cognitive and social effects on pain modulation while conducting parallel experiments in people that provide proof-of-importance for human pain modulation. In some instances, human pain research has sparked the development of novel animal models, with these animal models used to better understand the complexity of phenomena considered to be uniquely human such as placebo responses and empathy.
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Affiliation(s)
- Chulmin Cho
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Harashdeep K Deol
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Loren J Martin
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
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30
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Increasing the statistical power of animal experiments with historical control data. Nat Neurosci 2021; 24:470-477. [PMID: 33603229 DOI: 10.1038/s41593-020-00792-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 12/23/2020] [Indexed: 01/30/2023]
Abstract
Low statistical power reduces the reliability of animal research; yet, increasing sample sizes to increase statistical power is problematic for both ethical and practical reasons. We present an alternative solution using Bayesian priors based on historical control data, which capitalizes on the observation that control groups in general are expected to be similar to each other. In a simulation study, we show that including data from control groups of previous studies could halve the minimum sample size required to reach the canonical 80% power or increase power when using the same number of animals. We validated the approach on a dataset based on seven independent rodent studies on the cognitive effects of early-life adversity. We present an open-source tool, RePAIR, that can be widely used to apply this approach and increase statistical power, thereby improving the reliability of animal experiments.
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32
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Social isolation in rats: Effects on animal welfare and molecular markers for neuroplasticity. PLoS One 2020; 15:e0240439. [PMID: 33108362 PMCID: PMC7591026 DOI: 10.1371/journal.pone.0240439] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 09/27/2020] [Indexed: 12/18/2022] Open
Abstract
Early life stress compromises brain development and can contribute to the development of mental illnesses. A common animal model used to study different facets of psychiatric disorders is social isolation from early life on. In rats, this isolation can induce long-lasting alterations in molecular expression and in behavior. Since social isolation models severe psychiatric symptoms, it is to be expected that it affects the overall wellbeing of the animals. As also promoted by the 3Rs principle, though, it is pivotal to decrease the burden of laboratory animals by limiting the number of subjects (reduce, replace) and by improving the animals’ wellbeing (refine). The aim of this study was therefore to test possible refinement strategies such as resocialization and mere adult social isolation. We examined whether the alternatives still triggered the necessary phenotype while minimizing the stress load on the animals. Interestingly, we did not find reduced wellbeing-associated burrowing performance in isolated rats. The hyperactive phenotype seen in socially isolated animals was observed for rats undergoing the adult-only isolation, but resocializing ameliorated the locomotor abnormality. Isolation strongly affected markers of neuroplasticity in the prefrontal cortex independent of timing: mRNA levels of Arc, Bdnf and the pool of Bdnf transcripts with the 3’ long UTR were reduced in all groups. Bdnf splice variant IV expression was reduced in lifelong-isolated animals. Some of these deficits normalized after resocialization; likewise, exon VI Bdnf mRNA levels were reduced only in animals persistently isolated. Conversely, social deprivation did not affect the expression of Gad67 and Pvb, two GABAergic markers, whereas changes occurred in the expression of dopamine d1 and d2 receptors. As adult isolation was sufficient to trigger the hyperactive phenotype and impaired neuroplasticity in the prefrontal cortex, it could be a candidate for a refinement strategy for certain research questions. To fully grade the severity of post-weaning social isolation and the alternatives, adult isolation and resocialization, a more profound and multimodal assessment approach is necessary.
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33
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von Kortzfleisch VT, Karp NA, Palme R, Kaiser S, Sachser N, Richter SH. Improving reproducibility in animal research by splitting the study population into several 'mini-experiments'. Sci Rep 2020; 10:16579. [PMID: 33024165 PMCID: PMC7538440 DOI: 10.1038/s41598-020-73503-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/11/2020] [Indexed: 01/16/2023] Open
Abstract
In light of the hotly discussed 'reproducibility crisis', a rethinking of current methodologies appears essential. Implementing multi-laboratory designs has been shown to enhance the external validity and hence the reproducibility of findings from animal research. We here aimed at proposing a new experimental strategy that transfers this logic into a single-laboratory setting. We systematically introduced heterogeneity into our study population by splitting an experiment into several 'mini-experiments' spread over different time points a few weeks apart. We hypothesised to observe improved reproducibility in such a 'mini-experiment' design in comparison to a conventionally standardised design, according to which all animals are tested at one specific point in time. By comparing both designs across independent replicates, we could indeed show that the use of such a 'mini-experiment' design improved the reproducibility and accurate detection of exemplary treatment effects (behavioural and physiological differences between four mouse strains) in about half of all investigated strain comparisons. Thus, we successfully implemented and empirically validated an easy-to-handle strategy to tackle poor reproducibility in single-laboratory studies. Since other experiments within different life science disciplines share the main characteristics with the investigation reported here, these studies are likely to also benefit from this approach.
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Affiliation(s)
- Vanessa Tabea von Kortzfleisch
- Department of Behavioural Biology, University of Münster, Badestraße 13, Münster, Germany.
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
| | - Natasha A Karp
- Data Sciences and Quantitative Biology, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Sylvia Kaiser
- Department of Behavioural Biology, University of Münster, Badestraße 13, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - Norbert Sachser
- Department of Behavioural Biology, University of Münster, Badestraße 13, Münster, Germany
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany
| | - S Helene Richter
- Department of Behavioural Biology, University of Münster, Badestraße 13, Münster, Germany.
- Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
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34
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Tam WY, Cheung KK. Phenotypic characteristics of commonly used inbred mouse strains. J Mol Med (Berl) 2020; 98:1215-1234. [PMID: 32712726 DOI: 10.1007/s00109-020-01953-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 07/13/2020] [Accepted: 07/16/2020] [Indexed: 12/16/2022]
Abstract
The laboratory mouse is the most commonly used mammalian model for biomedical research. An enormous number of mouse models, such as gene knockout, knockin, and overexpression transgenic mice, have been created over the years. A common practice to maintain a genetically modified mouse line is backcrossing with standard inbred mice over several generations. However, the choice of inbred mouse for backcrossing is critical to phenotypic characterization because phenotypic variabilities are often observed between mice with different genetic backgrounds. In this review, the major features of commonly used inbred mouse lines are discussed. The aim is to provide information for appropriate selection of inbred mouse lines for genetic and behavioral studies.
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Affiliation(s)
- Wing Yip Tam
- University Research Facility in Behavioral and Systems Neuroscience, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Kwok-Kuen Cheung
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, SAR, China.
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Effects of weaning age and housing conditions on phenotypic differences in mice. Sci Rep 2020; 10:11684. [PMID: 32669633 PMCID: PMC7363894 DOI: 10.1038/s41598-020-68549-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/26/2020] [Indexed: 01/22/2023] Open
Abstract
Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined with rigorous environmental standardization within studies. Due to phenotypic plasticity, study-specific differences in environmental conditions during development can induce differences in the animals’ responsiveness to experimental treatments, thereby contributing to poor reproducibility of experimental results. Here, we studied how variation in weaning age (14–30 days) and housing conditions (single versus group housing) affects the phenotype of SWISS mice as measured by a range of behavioral and physiological outcome variables. Weaning age, housing conditions, and their interaction had little effect on the development of stereotypies, as well as on body weight, glucocorticoid metabolite concentrations, and behavior in the elevated plus-maze and open field test. These results are surprising and partly in conflict with previously published findings, especially with respect to the effects of early weaning. Our results thus question the external validity of previous findings and call for further research to identify the sources of variation between replicate studies and study designs that produce robust and reproducible experimental results.
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36
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Reproducibility of animal research in light of biological variation. Nat Rev Neurosci 2020; 21:384-393. [PMID: 32488205 DOI: 10.1038/s41583-020-0313-3] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2020] [Indexed: 12/16/2022]
Abstract
Context-dependent biological variation presents a unique challenge to the reproducibility of results in experimental animal research, because organisms' responses to experimental treatments can vary with both genotype and environmental conditions. In March 2019, experts in animal biology, experimental design and statistics convened in Blonay, Switzerland, to discuss strategies addressing this challenge. In contrast to the current gold standard of rigorous standardization in experimental animal research, we recommend the use of systematic heterogenization of study samples and conditions by actively incorporating biological variation into study design through diversifying study samples and conditions. Here we provide the scientific rationale for this approach in the hope that researchers, regulators, funders and editors can embrace this paradigm shift. We also present a road map towards better practices in view of improving the reproducibility of animal research.
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Richter SH. Automated Home-Cage Testing as a Tool to Improve Reproducibility of Behavioral Research? Front Neurosci 2020; 14:383. [PMID: 32390795 PMCID: PMC7193758 DOI: 10.3389/fnins.2020.00383] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 01/08/2023] Open
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38
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Scearce-Levie K, Sanchez PE, Lewcock JW. Leveraging preclinical models for the development of Alzheimer disease therapeutics. Nat Rev Drug Discov 2020; 19:447-462. [PMID: 32612262 DOI: 10.1038/s41573-020-0065-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2020] [Indexed: 02/06/2023]
Abstract
A large number of mouse models have been engineered, characterized and used to advance biomedical research in Alzheimer disease (AD). Early models simply damaged the rodent brain through toxins or lesions. Later, the spread of genetic engineering technology enabled investigators to develop models of familial AD by overexpressing human genes such as those encoding amyloid precursor protein (APP) or presenilins (PSEN1 or PSEN2) carrying mutations linked to early-onset AD. Recently, more complex models have sought to explore the impact of multiple genetic risk factors in the context of different biological challenges. Although none of these models has proven to be a fully faithful reproduction of the human disease, models remain essential as tools to improve our understanding of AD biology, conduct thorough pharmacokinetic and pharmacodynamic analyses, discover translatable biomarkers and evaluate specific therapeutic approaches. To realize the full potential of animal models as new technologies and knowledge become available, it is critical to define an optimal strategy for their use. Here, we review progress and challenges in the use of AD mouse models, highlight emerging scientific innovations in model development, and introduce a conceptual framework for use of preclinical models for therapeutic development.
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Abstract
Animal welfare is a growing societal concern and the well-being of animals used
for experimental purposes is under particular scrutiny. The vast majority of
laboratory animals are mice living in small cages that do not offer very much
variety. Moreover, the experimental procedure often takes very little time
compared to the time these animals have been bred to the desired age or are
being held available for animal experimentation. However, for the assessment of
animal welfare, the time spent waiting for an experiment or the time spent after
finishing an experiment has also to be taken into account. In addition to
experimental animals, many additional animals (e.g. for breeding and maintenance
of genetic lines, surplus animals) are related to animal experimentation and
usually face similar living conditions. Therefore, in terms of improving the
overall welfare of laboratory animals, there is not only a need for refinement
of experimental conditions but especially for improving living conditions
outside the experiment. The improvement of animal welfare thus depends to a
large extent on the housing and maintenance conditions of all animals related to
experimentation. Given the current state of animal welfare research there is
indeed a great potential for improving the overall welfare of laboratory
animals.
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Affiliation(s)
- Lars Lewejohann
- German Federal Institute for Risk Assessment (BfR), German Centre for the Protection of Laboratory Animals (Bf3R), Berlin, Germany.,Institute of Animal Welfare, Animal Behavior and Laboratory Animal Science, Freie Universität Berlin, Germany
| | - Kerstin Schwabe
- Department of Neurosurgery, Hannover Medical School, Germany
| | - Christine Häger
- Institute for Laboratory Animal Science, Hannover Medical School, Germany
| | - Paulin Jirkof
- Department Animal Welfare and 3Rs, University of Zurich, Switzerland
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40
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Gaskill BN, Garner JP. Power to the People: Power, Negative Results and Sample Size. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2019; 59:9-16. [PMID: 31852563 DOI: 10.30802/aalas-jaalas-19-000042] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The practical application of statistical power is becoming an increasingly important part of experimental design, data analysis, and reporting. Power is essential to estimating sample size as part of planning studies and obtaining ethical approval for them. Furthermore, power is essential for publishing and interpreting negative results. In this manuscript, we review what power is, how it can be calculated, and reporting recommendations if a null result is found. Power can be thought of as reflecting the signal to noise ratio of an experiment. The conventional wisdom that statistical power is driven by sample size (which increases the signal in the data), while true, is a misleading oversimplification. Relatively little discussion covers the use of experimental designs which control and reduce noise. Even small improvements in experimental design can achieve high power at much lower sample sizes than (for instance) a simple t test. Failure to report experimental design or the proposed statistical test on animal care and use protocols creates a dilemma for IACUCs, because it is unknown whether sample size has been correctly calculated. Traditional power calculations, which are primarily provided for animal number justifications, are only available for simple, yet low powered, experimental designs, such as paired t tests. Thus, in most controlled experimental studies, the only analyses for which power can be calculated are those that inheriently have low statistical power; these analyses should not be used because they require more animals than necessary. We provide suggestions for more powerful experimental designs (such as randomized block and factorial designs) that increase power, and we describe methods to easily calculate sample size for these designs that are suitable for IACUC number justifications. Finally we also provide recommendations for reporting negative results, so that readers and reviewers can determine whether an experiment had sufficient power. The use of more sophisticated designs in animal experiments will inevitably improve power, reproducibility, and reduce animal use.
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Jirkof P, Abdelrahman A, Bleich A, Durst M, Keubler L, Potschka H, Struve B, Talbot SR, Vollmar B, Zechner D, Häger C. A safe bet? Inter-laboratory variability in behaviour-based severity assessment. Lab Anim 2019; 54:73-82. [PMID: 31696771 DOI: 10.1177/0023677219881481] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Evidence-based severity assessment is essential as a basis for ethical evaluation in animal experimentation to ensure animal welfare, legal compliance and scientific quality. To fulfil these tasks scientists, animal care and veterinary personnel need assessment tools that provide species-relevant measurements of the animals' physical and affective state. In a three-centre study inter-laboratory robustness of body weight monitoring, mouse grimace scale (MGS) and burrowing test were evaluated. The parameters were assessed in naïve and tramadol treated female C57BL/6J mice. During tramadol treatment a body weight loss followed by an increase, when treatment was terminated, was observed in all laboratories. Tramadol treatment did not affect the MGS or burrowing performance. Results were qualitatively comparable between the laboratories, but quantitatively significantly different (inter-laboratory analysis). Burrowing behaviour seems to be highly sensitive to inter-laboratory differences in testing protocol. All locations obtained comparable information regarding the qualitative effect of tramadol treatment in C57BL/6J mice, however, datasets differed as a result of differences in test and housing conditions. In conclusion, our study confirms that results of behavioural testing can be affected by many factors and may differ between laboratories. Nevertheless, the evaluated parameters appeared relatively robust even when conditions were not harmonized extensively and present useful tools for severity assessment. However, analgesia-related side effects on parameters have to be considered carefully.
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Affiliation(s)
- Paulin Jirkof
- Division of Surgical Research, University Hospital Zurich, Switzerland.,Department of Animal Welfare and 3Rs, University of Zurich, Switzerland
| | - Ahmed Abdelrahman
- Rudolf-Zenker-Institute of Experimental Surgery, Rostock University Medical Center, Germany
| | - André Bleich
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany
| | - Mattea Durst
- Division of Surgical Research, University Hospital Zurich, Switzerland
| | - Lydia Keubler
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University, Germany
| | - Birgitta Struve
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany
| | - Steven R Talbot
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker-Institute of Experimental Surgery, Rostock University Medical Center, Germany
| | - Dietmar Zechner
- Rudolf-Zenker-Institute of Experimental Surgery, Rostock University Medical Center, Germany
| | - Christine Häger
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Germany
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Mallien AS, Soukup ST, Pfeiffer N, Brandwein C, Kulling SE, Chourbaji S, Gass P. Effects of Soy in Laboratory Rodent Diets on the Basal, Affective, and Cognitive Behavior of C57BL/6 Mice. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2019; 58:532-541. [PMID: 31466555 DOI: 10.30802/aalas-jaalas-18-000129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Soy is one of the most common sources of protein in many commercial formulas for laboratory rodent diets. Soy contains isoflavones, which are estrogenic. Therefore, soy-containing animal diets might influence estrogen-regulated systems, including basal behavioral domains, as well as affective behavior and cognition. Furthermore, the isoflavone content of soy varies, potentially unpredictably confounding behavioral results. Therefore researchers are increasingly considering completely avoiding dietary soy to circumvent this problem. Several animal studies have investigated the effects of soy free diets but produced inconsistent results. In addition, most of these previous studies were performed in outbred rat or mouse strains. In the current study, we assessed whether a soy-free diet altered locomotion, exploration, nesting, anxiety-related behaviors, learning, and memory in C57BL/6 mice, the most common inbred strain used in biomedical research. The parameters evaluated address measures of basic health, natural behavior, and affective state that also are landmarks for animal welfare. We found minor differences between feeding groups but no indications of altered welfare. We therefore suggest that a soy-free diet can be used as a standard diet to prevent undesirable side effects of isoflavones and to further optimize diet standardization, quality assurance, and ultimately increase the reproducibility of experiments.
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Affiliation(s)
- Anne S Mallien
- Department of Psychiatry and Psychotherapy Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany;,
| | - Sebastian T Soukup
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner Institut, Karlsruhe, Germany
| | - Natascha Pfeiffer
- Department of Psychiatry and Psychotherapy Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Christiane Brandwein
- Department of Psychiatry and Psychotherapy Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sabine E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner Institut, Karlsruhe, Germany
| | - Sabine Chourbaji
- Interfaculty Biomedical Research Facility, Heidelberg University, Heidelberg, Germany
| | - Peter Gass
- Department of Psychiatry and Psychotherapy Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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43
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Bolker JA. Selection of Models: Evolution and the Choice of Species for Translational Research. BRAIN, BEHAVIOR AND EVOLUTION 2019; 93:82-91. [PMID: 31416088 DOI: 10.1159/000500317] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 04/10/2019] [Indexed: 11/19/2022]
Abstract
Evolutionary thinking can inform the choice and assessment of model species in neuroscience, particularly when such models are intended to generate knowledge that will translate to humans. Avoiding errors that arise from oversimplified notions of phylogeny or genotype-phenotype mapping is one contribution; evolutionary biology also offers positive guidance. The challenge of finding adequate non-human models for translational research is particularly acute in neuroscience: neurobiological and behavioral phenotypes are complex and plastic, and many traits important in humans are absent, radically different, or difficult to assess in other species. Evolutionary perspectives help to articulate and address these challenges. Darwin's description of "descent with modification" points to two aspects of evolution that can help us assess the matching between a prospective model species and its intended target. One is trees that represent the structure of phylogenetic relationships; the other is phenotypic traits, i.e. the unique characteristics of each species' evolved biology and natural history. Mapping traits onto a phylogeny is the first step toward analyzing the source of similarities between a target and a potential model. Whether similar traits arise from shared ancestry or from adaptive convergence has important implications for what kinds of inferences can be justified, and for the likely translatability of findings. Evolution offers both a rich source of possible models, and guidance for choosing the best ones for a given purpose. Considering model choice from an evolutionary angle not only helps to answer the question "What species might be a good model for studying x?" but also suggests additional questions we should be asking to assess the utility of both potential and current models. Recognizing the diverse ways model organisms can function expands our search image as we seek species to study that can both extend general knowledge, and generate translatable insights relevant to human neurobiology and disease.
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Affiliation(s)
- Jessica A Bolker
- Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire, USA,
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44
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Rossetti AC, Paladini MS, Trepci A, Mallien A, Riva MA, Gass P, Molteni R. Differential Neuroinflammatory Response in Male and Female Mice: A Role for BDNF. Front Mol Neurosci 2019; 12:166. [PMID: 31379496 PMCID: PMC6658805 DOI: 10.3389/fnmol.2019.00166] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/17/2019] [Indexed: 12/30/2022] Open
Abstract
A growing body of evidence supports the close relationship between major depressive disorder (MDD), a severe psychiatric disease more common among women than men, and alterations of the immune/inflammatory system. However, despite the large number of studies aimed at understanding the molecular bases of this association, a lack of information exists on the potential cross-talk between systems known to be involved in depression and components of the inflammatory response, especially with respect to sex differences. Brain-derived neurotrophic factor (BDNF) is a neurotrophin with a well-established role in MDD etiopathology: it is altered in depressed patients as well as in animal models of the disease and its changes are restored by antidepressant drugs. Interestingly, this neurotrophin is also involved in the inflammatory response. Indeed, it can be secreted by microglia, the primary innate immune cells in the central nervous system whose functions may be in turn regulated by BDNF. With these premises, in this study, we investigated the reciprocal impact of BDNF and the immune system by evaluating the neuroinflammatory response in male and female BDNF-heterozygous mutant mice acutely treated with the cytokine-inducer lipopolysaccharide (LPS). Specifically, we assessed the potential onset of an LPS-induced sickness behavior as well as changes of inflammatory mediators in the mouse hippocampus and frontal cortex, with respect to both genotype and sex. We found that the increased inflammatory response induced by LPS in the brain of male mice was independent of the genotype, whereas in the female, it was restricted to the heterozygous mice with no changes in the wild-type group, suggestive of a role for BDNF in the sex-dependent effect of the inflammatory challenge. Considering the involvement of both BDNF and neuroinflammation in several psychiatric diseases and the diverse incidence of such pathologies in males and females, a deeper investigation of the mechanisms underlying their interaction may have a critical translational relevance.
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Affiliation(s)
- Andrea Carlo Rossetti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Maria Serena Paladini
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Ada Trepci
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Anne Mallien
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Marco Andrea Riva
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Peter Gass
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Raffaella Molteni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
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45
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Lima-Ojeda JM, Mallien AS, Brandwein C, Lang UE, Hefter D, Inta D. Altered prepulse inhibition of the acoustic startle response in BDNF-deficient mice in a model of early postnatal hypoxia: implications for schizophrenia. Eur Arch Psychiatry Clin Neurosci 2019; 269:439-447. [PMID: 29453493 DOI: 10.1007/s00406-018-0882-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 02/12/2018] [Indexed: 12/14/2022]
Abstract
The brain-derived neurotrophic factor (BDNF) is a major proliferative agent in the nervous system. Both BDNF-deficiency and perinatal hypoxia represent genetic/environmental risk factors for schizophrenia. Moreover, a decreased BDNF response to birth hypoxia was associated with the disease. BDNF expression is influenced by neuronal activity and environmental conditions such as hypoxia. Thus, it may partake in neuroprotective and reparative mechanisms in acute or chronic neuronal insults. However, the interaction of hypoxia and BDNF is insufficiently understood and the behavioral outcome unknown. Therefore, we conducted a battery of behavioral tests in a classical model of chronic early postnatal mild hypoxia (10% O2), known to significantly impair brain development, in BDNF-deficient mice. We found selective deficits in measures associated with sensorimotor gating, namely enhanced acoustic startle response (ASR) and reduced prepulse inhibition (PPI) of ASR in BDNF-deficient mice. Unexpectedly, the alterations of sensorimotor gating were caused only by BDNF-deficiency alone, whereas hypoxia failed to evoke severe deficits and even leads to a milder phenotype in BDNF-deficient mice. As deficits in sensorimotor gating are present in schizophrenia and animal models of the disease, our results are of relevance regarding the involvement of BDNF in its pathogenesis. On the other hand, they suggest that the effect of perinatal hypoxia on long-term brain abnormalities is complex, ranging from protective to deleterious actions, and may critically depend on the degree of hypoxia. Therefore, future studies may refine existing hypoxia protocols to better understand neurodevelopmental consequences associated with schizophrenia.
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Affiliation(s)
- Juan M Lima-Ojeda
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany.,Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Anne S Mallien
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Christiane Brandwein
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Undine E Lang
- Department of Psychiatry (UPK), University of Basel, Wilhelm Klein-Strasse 27, 4012, Basel, Switzerland
| | - Dimitri Hefter
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Dragos Inta
- RG Animal Models in Psychiatry, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany. .,Department of Psychiatry (UPK), University of Basel, Wilhelm Klein-Strasse 27, 4012, Basel, Switzerland.
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46
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Åhlgren J, Voikar V. Experiments done in Black-6 mice: what does it mean? Lab Anim (NY) 2019; 48:171-180. [DOI: 10.1038/s41684-019-0288-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/19/2019] [Indexed: 02/06/2023]
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47
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Kronenberg G, Petermann M, Dormann C, Bader M, Gass P, Hellweg R, Klempin F. Brain serotonin critically contributes to the biological effects of electroconvulsive seizures. Eur Arch Psychiatry Clin Neurosci 2018; 268:861-864. [PMID: 30019210 DOI: 10.1007/s00406-018-0924-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 07/09/2018] [Indexed: 10/28/2022]
Abstract
Compounds targeting serotonin (5-HT) are widely used as antidepressants. However, the role of 5-HT in mediating the effects of electroconvulsive seizure (ECS) therapy remains undefined. Using Tph2-/- mice depleted of brain 5-HT, we studied the effects of ECS on behavior and neurobiology. ECS significantly prolonged the start latency in the elevated O-Maze test, an effect that was abolished in Tph2-/- mice. Furthermore, in the absence of 5-HT, the ECS-induced increase in adult neurogenesis and in brain-derived neurotrophic factor signaling in the hippocampus were significantly reduced. Our results indicate that brain 5-HT critically contributes to the neurobiological responses to ECS.
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Affiliation(s)
- Golo Kronenberg
- Klinik und Poliklinik für Psychiatrie und Psychotherapie, Universitätsmedizin Rostock, 18147, Rostock, Germany.,Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany.,Berlin Institute of Health, 10178, Berlin, Germany
| | - Markus Petermann
- Berlin Institute of Health, 10178, Berlin, Germany.,Max Delbruck Center for Molecular Medicine (MDC), 13125, Berlin, Germany
| | - Christof Dormann
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health Mannheim (CIMH), University of Heidelberg, J 5, 68159, Mannheim, Germany
| | - Michael Bader
- Berlin Institute of Health, 10178, Berlin, Germany.,Max Delbruck Center for Molecular Medicine (MDC), 13125, Berlin, Germany.,Charité-University Medicine Berlin, 10117, Berlin, Germany
| | - Peter Gass
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health Mannheim (CIMH), University of Heidelberg, J 5, 68159, Mannheim, Germany
| | - Rainer Hellweg
- Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Friederike Klempin
- Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Charitéplatz 1, 10117, Berlin, Germany. .,Berlin Institute of Health, 10178, Berlin, Germany. .,Max Delbruck Center for Molecular Medicine (MDC), 13125, Berlin, Germany.
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48
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Maternal stress during pregnancy induces depressive-like behavior only in female offspring and correlates to their hippocampal Avp and Oxt receptor expression. Behav Brain Res 2018; 353:1-10. [DOI: 10.1016/j.bbr.2018.06.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 06/17/2018] [Accepted: 06/25/2018] [Indexed: 02/07/2023]
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49
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Körholz JC, Zocher S, Grzyb AN, Morisse B, Poetzsch A, Ehret F, Schmied C, Kempermann G. Selective increases in inter-individual variability in response to environmental enrichment in female mice. eLife 2018; 7:e35690. [PMID: 30362941 PMCID: PMC6203437 DOI: 10.7554/elife.35690] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 09/14/2018] [Indexed: 11/17/2022] Open
Abstract
One manifestation of individualization is a progressively differential response of individuals to the non-shared components of the same environment. Individualization has practical implications in the clinical setting, where subtle differences between patients are often decisive for the success of an intervention, yet there has been no suitable animal model to study its underlying biological mechanisms. Here we show that enriched environment (ENR) can serve as a model of brain individualization. We kept 40 isogenic female C57BL/6JRj mice for 3 months in ENR and compared these mice to an equally sized group of standard-housed control animals, looking at the effects on a wide range of phenotypes in terms of both means and variances. Although ENR influenced multiple parameters and restructured correlation patterns between them, it only increased differences among individuals in traits related to brain and behavior (adult hippocampal neurogenesis, motor cortex thickness, open field and object exploration), in agreement with the hypothesis of a specific activity-dependent development of brain individuality.
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Affiliation(s)
- Julia C Körholz
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Sara Zocher
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Anna N Grzyb
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Benjamin Morisse
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Alexandra Poetzsch
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Fanny Ehret
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Christopher Schmied
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) DresdenDresdenGermany
- CRTD – Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
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Bogomolov M, Heller R. Assessing replicability of findings across two studies of multiple features. Biometrika 2018. [DOI: 10.1093/biomet/asy029] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Marina Bogomolov
- The William Davidson Faculty of Industrial Engineering and Management, Technion–Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Ruth Heller
- Department of Statistics and Operations Research, Tel-Aviv University, P.O. Box 39040, Tel-Aviv 6997801, Israel
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