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Johne M, Helgers SOA, Alam M, Jelinek J, Hubka P, Krauss JK, Scheper V, Kral A, Schwabe K. Processing of auditory information in forebrain regions after hearing loss in adulthood: Behavioral and electrophysiological studies in a rat model. Front Neurosci 2022; 16:966568. [DOI: 10.3389/fnins.2022.966568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 10/20/2022] [Indexed: 11/12/2022] Open
Abstract
BackgroundHearing loss was proposed as a factor affecting development of cognitive impairment in elderly. Deficits cannot be explained primarily by dysfunctional neuronal networks within the central auditory system. We here tested the impact of hearing loss in adult rats on motor, social, and cognitive function. Furthermore, potential changes in the neuronal activity in the medial prefrontal cortex (mPFC) and the inferior colliculus (IC) were evaluated.Materials and methodsIn adult male Sprague Dawley rats hearing loss was induced under general anesthesia with intracochlear injection of neomycin. Sham-operated and naive rats served as controls. Postsurgical acoustically evoked auditory brainstem response (ABR)-measurements verified hearing loss after intracochlear neomycin-injection, respectively, intact hearing in sham-operated and naive controls. In intervals of 8 weeks and up to 12 months after surgery rats were tested for locomotor activity (open field) and coordination (Rotarod), for social interaction and preference, and for learning and memory (4-arms baited 8-arms radial maze test). In a final setting, electrophysiological recordings were performed in the mPFC and the IC.ResultsLocomotor activity did not differ between deaf and control rats, whereas motor coordination on the Rotarod was disturbed in deaf rats (P < 0.05). Learning the concept of the radial maze test was initially disturbed in deaf rats (P < 0.05), whereas retesting every 8 weeks did not show long-term memory deficits. Social interaction and preference was also not affected by hearing loss. Final electrophysiological recordings in anesthetized rats revealed reduced firing rates, enhanced irregular firing, and reduced oscillatory theta band activity (4–8 Hz) in the mPFC of deaf rats as compared to controls (P < 0.05). In the IC, reduced oscillatory theta (4–8 Hz) and gamma (30–100 Hz) band activity was found in deaf rats (P < 0.05).ConclusionMinor and transient behavioral deficits do not confirm direct impact of long-term hearing loss on cognitive function in rats. However, the altered neuronal activities in the mPFC and IC after hearing loss indicate effects on neuronal networks in and outside the central auditory system with potential consequences on cognitive function.
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Kluever V, Fornasiero EF. Principles of brain aging: Status and challenges of modeling human molecular changes in mice. Ageing Res Rev 2021; 72:101465. [PMID: 34555542 DOI: 10.1016/j.arr.2021.101465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 01/22/2023]
Abstract
Due to the extension of human life expectancy, the prevalence of cognitive impairment is rising in the older portion of society. Developing new strategies to delay or attenuate cognitive decline is vital. For this purpose, it is imperative to understand the cellular and molecular events at the basis of brain aging. While several organs are directly accessible to molecular analysis through biopsies, the brain constitutes a notable exception. Most of the molecular studies are performed on postmortem tissues, where cell death and tissue damage have already occurred. Hence, the study of the molecular aspects of cognitive decline largely relies on animal models and in particular on small mammals such as mice. What have we learned from these models? Do these animals recapitulate the changes observed in humans? What should we expect from future mouse studies? In this review we answer these questions by summarizing the state of the research that has addressed cognitive decline in mice from several perspectives, including genetic manipulation and omics strategies. We conclude that, while extremely valuable, mouse models have limitations that can be addressed by the optimal design of future studies and by ensuring that results are cross-validated in the human context.
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Fonseca-Rodrigues D, Amorim D, Almeida A, Pinto-Ribeiro F. Emotional and cognitive impairments in the peripheral nerve chronic constriction injury model (CCI) of neuropathic pain: A systematic review. Behav Brain Res 2020; 399:113008. [PMID: 33171146 DOI: 10.1016/j.bbr.2020.113008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/29/2020] [Accepted: 11/04/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVE Emotional and cognitive impairments are common comorbidities of chronic neuropathic pain that significantly impact the quality of life of patients. While the nociceptive components of the peripheral nerve chronic constriction injury (CCI) animal model have been extensively analyzed, data related to the development of mood and cognitive disorders, and especially its impact on female rats remains fragmented. We systematically reviewed the literature analyzing the methods used to induce and evaluate the development of emotional- and cognitive-like impairments and sex-specific differences in the CCI model. DATABASES AND DATA TREATMENT We searched PubMed, Google Scholar and Web of Science from inception to September 30th, 2019, and a total of 44 papers were considered eligible for inclusion. We included animal studies assessing nociception, locomotion, anxious-like, depressive-like and cognitive behaviours after the CCI induction. RESULTS The overall quality of the studies was considered moderate to high. Overall, the induction of CCI leads to the development of emotional impairments, namely anxiety- and depressive-like behaviours, as well as cognitive impairments. With the majority of the studies using male subjects, the lack of evidence on female animals prevents the evaluation of sex-specific differences. CONCLUSIONS This review supports the development of an anxiodepressive-like phenotype, associated with cognitive impairments, in CCI-induced animals. These results support the use of this animal model for the study of the mechanisms underlying these comorbidities, as well as a screening tool for the development/repurposing of drugs that tackle both the neuropathy-induced nociceptive and emotional impairments, such as tricyclic antidepressants. Importantly, our review also highlights the need for studies performed in female rodents as these are almost non-existent.
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Affiliation(s)
- Diana Fonseca-Rodrigues
- Life and Health Sciences Research Institute (ICVS), School of Medicine, Campus of Gualtar, University of Minho, 4710-057, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Diana Amorim
- Life and Health Sciences Research Institute (ICVS), School of Medicine, Campus of Gualtar, University of Minho, 4710-057, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Armando Almeida
- Life and Health Sciences Research Institute (ICVS), School of Medicine, Campus of Gualtar, University of Minho, 4710-057, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal
| | - Filipa Pinto-Ribeiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, Campus of Gualtar, University of Minho, 4710-057, Braga, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.
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4
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Albergaria C, Silva NT, Darmohray DM, Carey MR. Cannabinoids modulate associative cerebellar learning via alterations in behavioral state. eLife 2020; 9:61821. [PMID: 33077026 PMCID: PMC7575324 DOI: 10.7554/elife.61821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023] Open
Abstract
Cannabinoids are notorious and profound modulators of behavioral state. In the brain, endocannabinoids act via Type 1-cannabinoid receptors (CB1) to modulate synaptic transmission and mediate multiple forms of synaptic plasticity. CB1 knockout (CB1KO) mice display a range of behavioral phenotypes, in particular hypoactivity and various deficits in learning and memory, including cerebellum-dependent delay eyeblink conditioning. Here we find that the apparent effects of CB1 deletion on cerebellar learning are not due to direct effects on CB1-dependent plasticity, but rather, arise as a secondary consequence of altered behavioral state. Hypoactivity of CB1KO mice accounts for their impaired eyeblink conditioning across both animals and trials. Moreover, learning in these mutants is rescued by walking on a motorized treadmill during training. Finally, cerebellar granule-cell-specific CB1KOs exhibit normal eyeblink conditioning, and both global and granule-cell-specific CB1KOs display normal cerebellum-dependent locomotor coordination and learning. These findings highlight the modulation of behavioral state as a powerful independent means through which individual genes contribute to complex behaviors.
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Affiliation(s)
- Catarina Albergaria
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - N Tatiana Silva
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Dana M Darmohray
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Megan R Carey
- Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal
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Gigg J, McEwan F, Smausz R, Neill J, Harte MK. Synaptic biomarker reduction and impaired cognition in the sub-chronic PCP mouse model for schizophrenia. J Psychopharmacol 2020; 34:115-124. [PMID: 31580184 DOI: 10.1177/0269881119874446] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Sub-chronic phencyclidine treatment (scPCP) provides a translational rat model for cognitive impairments associated with schizophrenia (CIAS). CIAS genetic risk factors may be more easily studied in mice; however, CIAS associated biomarker changes are relatively unstudied in the scPCP mouse. AIM To characterize deficits in object recognition memory and synaptic markers in frontal cortex and hippocampus of the scPCP mouse. METHODS Female c57/bl6 mice received 10 daily injections of PCP (scPCP; 10 mg/kg, s.c.) or vehicle (n = 8/group). Mice were tested for novel object recognition memory after either remaining in the arena ('no distraction') or being removed to a holding cage ('distraction') during the inter-trial interval. Expression changes for parvalbumin (PV), glutamic acid decarboxylase (GAD67), synaptosomal-associated protein 25 (SNAP-25) and postsynaptic density 95 (PDS95) were measured in frontal cortex, dorsal and ventral hippocampus. RESULTS scPCP mice showed object memory deficits when distracted by removal from the arena, where they treated previously experienced objects as novel at test. scPCP significantly reduced PV expression in all regions and lower PSD95 levels in frontal cortex and ventral hippocampus. Levels of GAD67 and SNAP-25 were unchanged. CONCLUSIONS We show for the first time that scPCP mice: (a) can encode and retain object information, but that this memory is susceptible to distraction; (b) display amnesia after distraction; and (c) express reduced PV and PSD95 in frontal cortex and hippocampus. These data further support reductions in PV-dependent synaptic inhibition and NMDAR-dependent glutamatergic plasticity in CIAS and highlight the translational significance of the scPCP mouse.
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Affiliation(s)
- John Gigg
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK
| | - Francesca McEwan
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK
| | - Rebecca Smausz
- Division of Neuroscience and Experimental Psychology, University of Manchester, Manchester, UK
| | - Joanna Neill
- Division of Pharmacy and Optometry, University of Manchester, Manchester, UK
| | - Michael K Harte
- Division of Pharmacy and Optometry, University of Manchester, Manchester, UK
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Seok BS, Cao F, Bélanger-Nelson E, Provost C, Gibbs S, Jia Z, Mongrain V. The effect of Neuroligin-2 absence on sleep architecture and electroencephalographic activity in mice. Mol Brain 2018; 11:52. [PMID: 30231918 PMCID: PMC6146600 DOI: 10.1186/s13041-018-0394-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 09/06/2018] [Indexed: 02/06/2023] Open
Abstract
Sleep disorders are comorbid with most psychiatric disorders, but the link between these is not well understood. Neuroligin-2 (NLGN2) is a cell adhesion molecule that plays roles in synapse formation and neurotransmission. Moreover, NLGN2 has been associated with psychiatric disorders, but its implication in sleep remains underexplored. In the present study, the effect of Nlgn2 knockout (Nlgn2−/−) on sleep architecture and electroencephalographic (EEG) activity in mice has been investigated. The EEG and electromyogram (EMG) were recorded in Nlgn2−/− mice and littermates for 24 h from which three vigilance states (i.e., wakefulness, rapid eye movement [REM] sleep, non-REM [NREM] sleep) were visually identified. Spectral analysis of the EEG was performed for the three states. Nlgn2−/− mice showed more wakefulness and less NREM and REM sleep compared to wild-type (Nlgn2+/+) mice, especially during the dark period. This was accompanied by changes in the number and duration of individual episodes of wakefulness and sleep, indexing changes in state consolidation, as well as widespread changes in EEG spectral activity in all states. Abnormal ‘hypersynchronized’ EEG events have also been observed predominantly in Nlgn2−/− mice. These events were mainly observed during wakefulness and REM sleep. In addition, Nlgn2−/− mice showed alterations in the daily time course of NREM sleep delta (1–4 Hz) activity, pointing to modifications in the dynamics of sleep homeostasis. These data suggest that NLGN2 participates in the regulation of sleep duration as well as EEG activity during wakefulness and sleep.
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Affiliation(s)
- Bong Soo Seok
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada.,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada
| | | | - Erika Bélanger-Nelson
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada
| | - Chloé Provost
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada
| | - Steve Gibbs
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada.,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada
| | | | - Valérie Mongrain
- Research Center and Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Cœur de Montréal (CIUSSS-NIM), 5400 Gouin West blvd, Montréal, QC, H4J 1C5, Canada. .,Department of Neuroscience, Université de Montréal, 2960 chemin de la Tour, Montreal, QC, H3T 1J4, Canada.
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Vesikansa A. Unraveling of Central Nervous System Disease Mechanisms Using CRISPR Genome Manipulation. J Cent Nerv Syst Dis 2018; 10:1179573518787469. [PMID: 30013417 PMCID: PMC6043941 DOI: 10.1177/1179573518787469] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/09/2018] [Indexed: 12/26/2022] Open
Abstract
The complex structure and highly variable gene expression profile of the brain makes it among the most challenging fields to study in both basic and translational biological research. Most of the brain diseases are multifactorial and despite the rapidly increasing genomic data, molecular pathways and causal links between genes and central nervous system (CNS) diseases are largely unknown. The advent of an easy and flexible CRISPR-Cas genome editing technology has rapidly revolutionized the field of functional genomics and opened unprecedented possibilities to dissect the mechanisms of CNS disease. CRISPR-Cas allows a plenitude of applications for both gene-focused and genome-wide approaches, ranging from original “gene scissors” making permanent modifications in the genome to the regulation of gene expression and epigenetics. CRISPR technology provides a unique opportunity to establish new cellular and animal models of CNS diseases and holds potential for breakthroughs in the CNS research and drug development.
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Affiliation(s)
- Aino Vesikansa
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.,Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
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8
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London SE. Developmental song learning as a model to understand neural mechanisms that limit and promote the ability to learn. Behav Processes 2017; 163:13-23. [PMID: 29162376 DOI: 10.1016/j.beproc.2017.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 10/04/2017] [Accepted: 11/10/2017] [Indexed: 12/27/2022]
Abstract
Songbirds famously learn their vocalizations. Some species can learn continuously, others seasonally, and still others just once. The zebra finch (Taeniopygia guttata) learns to sing during a single developmental "Critical Period," a restricted phase during which a specific experience has profound and permanent effects on brain function and behavioral patterns. The zebra finch can therefore provide fundamental insight into features that promote and limit the ability to acquire complex learned behaviors. For example, what properties permit the brain to come "on-line" for learning? How does experience become encoded to prevent future learning? What features define the brain in receptive compared to closed learning states? This piece will focus on epigenomic, genomic, and molecular levels of analysis that operate on the timescales of development and complex behavioral learning. Existing data will be discussed as they relate to Critical Period learning, and strategies for future studies to more directly address these questions will be considered. Birdsong learning is a powerful model for advancing knowledge of the biological intersections of maturation and experience. Lessons from its study not only have implications for understanding developmental song learning, but also broader questions of learning potential and the enduring effects of early life experience on neural systems and behavior.
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Affiliation(s)
- Sarah E London
- Department of Psychology, Institute for Mind and Biology, Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, 940 E 57th Street, Chicago, IL 60637, USA.
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Urban A, Golgher L, Brunner C, Gdalyahu A, Har-Gil H, Kain D, Montaldo G, Sironi L, Blinder P. Understanding the neurovascular unit at multiple scales: Advantages and limitations of multi-photon and functional ultrasound imaging. Adv Drug Deliv Rev 2017; 119:73-100. [PMID: 28778714 DOI: 10.1016/j.addr.2017.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 07/17/2017] [Accepted: 07/22/2017] [Indexed: 02/07/2023]
Abstract
Developing efficient brain imaging technologies by combining a high spatiotemporal resolution and a large penetration depth is a key step for better understanding the neurovascular interface that emerges as a main pathway to neurodegeneration in many pathologies such as dementia. This review focuses on the advances in two complementary techniques: multi-photon laser scanning microscopy (MPLSM) and functional ultrasound imaging (fUSi). MPLSM has become the gold standard for in vivo imaging of cellular dynamics and morphology, together with cerebral blood flow. fUSi is an innovative imaging modality based on Doppler ultrasound, capable of recording vascular brain activity over large scales (i.e., tens of cubic millimeters) at unprecedented spatial and temporal resolution for such volumes (up to 10μm pixel size at 10kHz). By merging these two technologies, researchers may have access to a more detailed view of the various processes taking place at the neurovascular interface. MPLSM and fUSi are also good candidates for addressing the major challenge of real-time delivery, monitoring, and in vivo evaluation of drugs in neuronal tissue.
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Affiliation(s)
- Alan Urban
- Neuroelectronics Research Flanders, Leuven, Belgium; VIB, Leuven, Belgium and/or IMEC, Leuven, Belgium; Department of Neurosciences, KU Leuven, Leuven, Belgium; Neurobiology Dept., Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Lior Golgher
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Clément Brunner
- Neuroelectronics Research Flanders, Leuven, Belgium; VIB, Leuven, Belgium and/or IMEC, Leuven, Belgium
| | - Amos Gdalyahu
- Neurobiology Dept., Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Hagai Har-Gil
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - David Kain
- Neurobiology Dept., Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Gabriel Montaldo
- Neuroelectronics Research Flanders, Leuven, Belgium; VIB, Leuven, Belgium and/or IMEC, Leuven, Belgium
| | - Laura Sironi
- Physics Dept., Universita degli Studi di Milano Bicocca, Italy
| | - Pablo Blinder
- Neurobiology Dept., Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel; Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.
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10
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Gravett M, Cepek J, Fenster A. An ultra-high field strength MR image-guided robotic needle delivery system for in-bore small animal interventions. Med Phys 2017; 44:5544-5555. [PMID: 28849592 DOI: 10.1002/mp.12534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/10/2017] [Accepted: 07/18/2017] [Indexed: 11/05/2022] Open
Abstract
PURPOSE The purpose of this study was to develop and validate an image-guided robotic needle delivery system for accurate and repeatable needle targeting procedures in mouse brains inside the 12 cm inner diameter gradient coil insert of a 9.4 T MR scanner. Many preclinical research techniques require the use of accurate needle deliveries to soft tissues, including brain tissue. Soft tissues are optimally visualized in MR images, which offer high-soft tissue contrast, as well as a range of unique imaging techniques, including functional, spectroscopy and thermal imaging, however, there are currently no solutions for delivering needles to small animal brains inside the bore of an ultra-high field MR scanner. This paper describes the mechatronic design, evaluation of MR compatibility, registration technique, mechanical calibration, the quantitative validation of the in-bore image-guided needle targeting accuracy and repeatability, and demonstrated the system's ability to deliver needles in situ. METHODS Our six degree-of-freedom, MR compatible, mechatronic system was designed to fit inside the bore of a 9.4 T MR scanner and is actuated using a combination of piezoelectric and hydraulic mechanisms. The MR compatibility and targeting accuracy of the needle delivery system are evaluated to ensure that the system is precisely calibrated to perform the needle targeting procedures. A semi-automated image registration is performed to link the robot coordinates to the MR coordinate system. Soft tissue targets can be accurately localized in MR images, followed by automatic alignment of the needle trajectory to the target. Intra-procedure visualization of the needle target location and the needle were confirmed through MR images after needle insertion. RESULTS The effects of geometric distortions and signal noise were found to be below threshold that would have an impact on the accuracy of the system. The system was found to have negligible effect on the MR image signal noise and geometric distortion. The system was mechanically calibrated and the mean image-guided needle targeting and needle trajectory accuracies were quantified in an image-guided tissue mimicking phantom experiment to be 178 ± 54 μm and 0.27 ± 0.65°, respectively. CONCLUSIONS An MR image-guided system for in-bore needle deliveries to soft tissue targets in small animal models has been developed. The results of the needle targeting accuracy experiments in phantoms indicate that this system has the potential to deliver needles to the smallest soft tissue structures relevant in preclinical studies, at a wide variety of needle trajectories. Future work in the form of a fully-automated needle driver with precise depth control would benefit this system in terms of its applicability to a wider range of animal models and organ targets.
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Affiliation(s)
- Matthew Gravett
- Robarts Research Institute, London, ON, N6A 5B7, Canada.,Biomedical Engineering, Western University, London, ON, N6A 5B9, Canada
| | - Jeremy Cepek
- Robarts Research Institute, London, ON, N6A 5B7, Canada.,Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Aaron Fenster
- Robarts Research Institute, London, ON, N6A 5B7, Canada.,Biomedical Engineering, Western University, London, ON, N6A 5B9, Canada
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Wang L, Li MY, Qu C, Miao WY, Yin Q, Liao J, Cao HT, Huang M, Wang K, Zuo E, Peng G, Zhang SX, Chen G, Li Q, Tang K, Yu Q, Li Z, Wong CC, Xu G, Jing N, Yu X, Li J. CRISPR-Cas9-mediated genome editing in one blastomere of two-cell embryos reveals a novel Tet3 function in regulating neocortical development. Cell Res 2017; 27:815-829. [PMID: 28429771 DOI: 10.1038/cr.2017.58] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/23/2017] [Accepted: 03/10/2017] [Indexed: 12/17/2022] Open
Abstract
Studying the early function of essential genes is an important and challenging problem in developmental biology. Here, we established a method for rapidly inducing CRISPR-Cas9-mediated mutations in one blastomere of two-cell stage embryos, termed 2-cell embryo-CRISPR-Cas9 injection (2CC), to study the in vivo function of essential (or unknown) genes in founder chimeric mice. By injecting both Cre mRNA and CRISPR-Cas9 targeting the gene of interest into fluorescent reporter mice, the 2CC method can trace both wild-type and mutant cells at different developmental stages, offering internal control for phenotypic analyses of mutant cells. Using this method, we identified novel functions of the essential gene Tet3 in regulating excitatory and inhibitory synaptic transmission in the developing mouse cerebral cortex. By generating chimeric mutant mice, the 2CC method allows for the rapid screening of gene function in multiple tissues and cell types in founder chimeric mice, significantly expanding the current armamentarium of genetic tools.
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Affiliation(s)
- Lingbo Wang
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Min-Yin Li
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Chao Qu
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Wan-Ying Miao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Qi Yin
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jiaoyang Liao
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Hua-Teng Cao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Min Huang
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201203, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China
| | - Kai Wang
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Erwei Zuo
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Guangdun Peng
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Shu-Xin Zhang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Guodong Chen
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Qing Li
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Ke Tang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi 330031, China
| | - Qian Yu
- Animal Core Facility, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhoujie Li
- Animal Core Facility, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Catherine Cl Wong
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201203, China.,Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China
| | - Guoliang Xu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Naihe Jing
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Xiang Yu
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jinsong Li
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
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12
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The Phe932Ile mutation in KCNT1 channels associated with severe epilepsy, delayed myelination and leukoencephalopathy produces a loss-of-function channel phenotype. Neuroscience 2017; 351:65-70. [PMID: 28366665 DOI: 10.1016/j.neuroscience.2017.03.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 03/08/2017] [Accepted: 03/22/2017] [Indexed: 12/13/2022]
Abstract
Sodium-activated potassium (KNa) channels contribute to firing frequency adaptation and slow after hyperpolarization. The KCNT1 gene (also known as SLACK) encodes a KNa subunit that is expressed throughout the central and peripheral nervous systems. Missense mutations of the SLACK C-terminus have been reported in several patients with rare forms of early onset epilepsy and in some cases severely delayed myelination. To date, such mutations identified in patients with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), epilepsy of infancy with migrating focal seizures (EIMFS) and Ohtahara syndrome (OS) have been reported to be gain-of-function mutations (Villa and Combi, 2016). An exome sequencing study identified a p.Phe932Ile KCNT1 mutation as the disease-causing change in a child with severe early infantile epileptic encephalopathy and abnormal myelination (Vanderver et al., 2014). We characterized an analogous mutation in the rat Slack channel and unexpectedly found this mutation to produce a loss-of-function phenotype. In an effort to restore current, we tested the known Slack channel opener loxapine. Loxapine exhibited no effect, indicating that this mutation either caused the channel to be insensitive to this established opener or proper translation and trafficking to the membrane was disrupted. Protein analysis confirmed that while total mutant protein did not differ from wild type, membrane expression of the mutant channel was substantially reduced. Although gain-of-function mutations to the Slack channel are linked to epileptic phenotypes, this is the first reported loss-of-function mutation linked to severe epilepsy and delayed myelination.
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McCullough KM, Morrison FG, Ressler KJ. Bridging the Gap: Towards a cell-type specific understanding of neural circuits underlying fear behaviors. Neurobiol Learn Mem 2016; 135:27-39. [PMID: 27470092 PMCID: PMC5123437 DOI: 10.1016/j.nlm.2016.07.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 11/15/2022]
Abstract
Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders.
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Affiliation(s)
- K M McCullough
- Department of Psychiatry and Behavioral Sciences and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Graduate Program in Neuroscience, Emory University, Atlanta, Georgia; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States.
| | - F G Morrison
- Department of Psychiatry and Behavioral Sciences and Yerkes National Primate Research Center, Emory University, Atlanta, Georgia; Department of Graduate Program in Neuroscience, Emory University, Atlanta, Georgia; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
| | - K J Ressler
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States
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14
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A mouse retinal explant model for use in studying neuroprotection in glaucoma. Exp Eye Res 2016; 151:38-44. [DOI: 10.1016/j.exer.2016.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 06/30/2016] [Accepted: 07/16/2016] [Indexed: 11/17/2022]
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15
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Abstract
The behavioral phenotypes of mice are the result of a complex interplay between overall health, sensory abilities, learning and memory, motor function as well as developmental milestones, feeding, sexual, parental, and social behaviors. This chapter lists a selected number of key behavioral tests, specifically designed to assay fundamental behavioral features such as memory, activity, and motor skills in mice models.
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16
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Jain V, Srivastava I, Palchaudhuri S, Goel M, Sinha-Mahapatra SK, Dhingra NK. Classical Photoreceptors Are Primarily Responsible for the Pupillary Light Reflex in Mouse. PLoS One 2016; 11:e0157226. [PMID: 27295136 PMCID: PMC4905644 DOI: 10.1371/journal.pone.0157226] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/26/2016] [Indexed: 11/23/2022] Open
Abstract
Pupillary light reflex (PLR) is an important clinical tool to assess the integrity of visual pathways. The available evidence suggests that melanopsin-expressing retinal ganglion cells (mRGCs) mediate PLR—driven by the classical photoreceptors (rods and cones) at low irradiances and by melanopsin activation at high irradiances. However, genetic or pharmacological elimination of melanopsin does not completely abolish PLR at high irradiances, raising the possibility that classical photoreceptors may have a role even at high irradiances. Using an inducible mouse model of photoreceptor degeneration, we asked whether classical photoreceptors are responsible for PLR at all irradiances, and found that the PLR was severely attenuated at all irradiances. Using multiple approaches, we show that the residual PLR at high irradiances in this mouse was primarily from the remnant rods and cones, with a minor contribution from melanopsin activation. In contrast, in rd1 mouse where classical photoreceptor degeneration occurs during development, the PLR was absent at low irradiances but intact at high irradiances, as reported previously. Since mRGCs receive inputs from classical photoreceptors, we also asked whether developmental loss of classical photoreceptors as in rd1 mouse leads to compensatory takeover of the high-irradiance PLR by mRGCs. Specifically, we looked at a distinct subpopulation of mRGCs that express Brn3b transcription factor, which has been shown to mediate PLR. We found that rd1 mouse had a significantly higher proportion of Brn3b-expressing M1 type of mRGCs than in the inducible model. Interestingly, inducing classical photoreceptor degeneration during development also resulted in a higher proportion of Brn3b-expressing M1 cells and partially rescued PLR at high irradiances. These results suggest that classical photoreceptors are primarily responsible for PLR at all irradiances, while melanopsin activation makes a minor contribution at very high irradiances.
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Affiliation(s)
- Varsha Jain
- National Brain Research Centre, Manesar (Gurgaon), Haryana, India 122051
| | - Ipsit Srivastava
- National Brain Research Centre, Manesar (Gurgaon), Haryana, India 122051
| | | | - Manvi Goel
- National Brain Research Centre, Manesar (Gurgaon), Haryana, India 122051
| | | | - Narender K. Dhingra
- National Brain Research Centre, Manesar (Gurgaon), Haryana, India 122051
- * E-mail:
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17
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Identification and Characterization of the V(D)J Recombination Activating Gene 1 in Long-Term Memory of Context Fear Conditioning. Neural Plast 2015; 2016:1752176. [PMID: 26843989 PMCID: PMC4710954 DOI: 10.1155/2016/1752176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/12/2015] [Indexed: 12/17/2022] Open
Abstract
An increasing body of evidence suggests that mechanisms related to the introduction and repair of DNA double strand breaks (DSBs) may be associated with long-term memory (LTM) processes. Previous studies from our group suggested that factors known to function in DNA recombination/repair machineries, such as DNA ligases, polymerases, and DNA endonucleases, play a role in LTM. Here we report data using C57BL/6 mice showing that the V(D)J recombination-activating gene 1 (RAG1), which encodes a factor that introduces DSBs in immunoglobulin and T-cell receptor genes, is induced in the amygdala, but not in the hippocampus, after context fear conditioning. Amygdalar induction of RAG1 mRNA, measured by real-time PCR, was not observed in context-only or shock-only controls, suggesting that the context fear conditioning response is related to associative learning processes. Furthermore, double immunofluorescence studies demonstrated the neuronal localization of RAG1 protein in amygdalar sections prepared after perfusion and fixation. In functional studies, intra-amygdalar injections of RAG1 gapmer antisense oligonucleotides, given 1 h prior to conditioning, resulted in amygdalar knockdown of RAG1 mRNA and a significant impairment in LTM, tested 24 h after training. Overall, these findings suggest that the V(D)J recombination-activating gene 1, RAG1, may play a role in LTM consolidation.
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Jadhav S, Cubinkova V, Zimova I, Brezovakova V, Madari A, Cigankova V, Zilka N. Tau-mediated synaptic damage in Alzheimer's disease. Transl Neurosci 2015; 6:214-226. [PMID: 28123806 PMCID: PMC4936631 DOI: 10.1515/tnsci-2015-0023] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/04/2015] [Indexed: 12/16/2022] Open
Abstract
Synapses are the principal sites for chemical communication between neurons and are essential for performing the dynamic functions of the brain. In Alzheimer’s disease and related tauopathies, synapses are exposed to disease modified protein tau, which may cause the loss of synaptic contacts that culminate in dementia. In recent decades, structural, transcriptomic and proteomic studies suggest that Alzheimer’s disease represents a synaptic disorder. Tau neurofibrillary pathology and synaptic loss correlate well with cognitive impairment in these disorders. Moreover, regional distribution and the load of neurofibrillary lesions parallel the distribution of the synaptic loss. Several transgenic models of tauopathy expressing various forms of tau protein exhibit structural synaptic deficits. The pathological tau proteins cause the dysregulation of synaptic proteome and lead to the functional abnormalities of synaptic transmission. A large body of evidence suggests that tau protein plays a key role in the synaptic impairment of human tauopathies.
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Affiliation(s)
- Santosh Jadhav
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic
| | - Veronika Cubinkova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
| | - Ivana Zimova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
| | - Veronika Brezovakova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic
| | - Aladar Madari
- Small animal clinic, University of Veterinary Medicine and Pharmacy, Komenskeho 73, Kosice, Slovak Republic
| | - Viera Cigankova
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy, Komenskeho 73, 041 81 Kosice, Slovak Republic
| | - Norbert Zilka
- Institute of Neuroimmunology, Slovak Academy of Sciences, Centre of Excellence for Alzheimer's Disease and Related Disorders, Dubravska 9, 845 10 Bratislava, Slovak Republic; Axon Neuroscience SE, Grosslingova 45, Bratislava, Slovak Republic
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Abstract
In this article, we refer to an original opinion paper written by Prof. Frank Beach in 1950 ("The Snark was a Boojum"). In his manuscript, Beach explicitly criticised the field of comparative psychology because of the disparity between the original understanding of comparativeness and its practical overly specialised implementation. Specialisation encompassed both experimental species (rats accounted for 70% of all subjects) and test paradigms (dominated by conditioning/learning experiments). Herein, we attempt to evaluate the extent to which these considerations apply to current behavioural neuroscience. Such evaluation is particularly interesting in the context of "translational research" that has recently gained growing attention. As a community, we believe that preclinical findings are intended to inform clinical practice at the level of therapies and knowledge advancements. Yet, limited reproducibility of experimental results and failures to translate preclinical research into clinical trial sindicate that these expectations are not entirely fulfilled. Theoretical considerations suggest that, before concluding that a given phenomenon is of relevance to our species, it should be observed in more than a single experimental model (be it an animal strain or species) and tested in more than a single standardized test battery. Yet, current approaches appear limited in terms of variability and overspecialised in terms of operative procedures. Specifically, as in 1950, rodents (mice instead of rats) still constitute the vast majority of animal species investigated. Additionally, the scientific community strives to homogenise experimental test strategies, thereby not only limiting the generalizability of the findings, but also working against the design of innovative approaches. Finally, we discuss the importance of evolutionary-adaptive considerations within the field of laboratory research. Specifically, resting upon empirical evidence indicating that developing individuals adjust their long-term phenotype according to early environmental demands, we propose that current rearing and housing standards do not adequately prepare experimental subjects to their actual adult environments. Specifically, while the adult life of a laboratory animal is characterized by frequent stimulations and challenges, the neonatal life is dominated by quietness and stability. We suggest that such form of mismatch may remarkably influence the reproducibility and reliability of experimental findings.
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Affiliation(s)
- Simone Macrì
- Section of Behavioural Neuroscience, Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Roma, Italy
| | - S Helene Richter
- Department of Behavioural Biology, Institute of Neuro and Behavioural Biology, University of Münster, Badestraße 13, 48149 Münster, Germany
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20
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Real-time imaging of brain activity in freely moving rats using functional ultrasound. Nat Methods 2015; 12:873-8. [DOI: 10.1038/nmeth.3482] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/11/2015] [Indexed: 01/09/2023]
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21
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Pan X, Lee YK, Jeong H. Farnesoid X Receptor Agonist Represses Cytochrome P450 2D6 Expression by Upregulating Small Heterodimer Partner. Drug Metab Dispos 2015; 43:1002-7. [PMID: 25926433 DOI: 10.1124/dmd.115.064758] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 04/29/2015] [Indexed: 01/05/2023] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is a major drug-metabolizing enzyme responsible for eliminating approximately 20% of marketed drugs. Studies have shown that differential transcriptional regulation of CYP2D6 may contribute to large interindividual variability in CYP2D6-mediated drug metabolism. However, the factors governing CYP2D6 transcription are largely unknown. We previously demonstrated small heterodimer partner (SHP) as a novel transcriptional repressor of CYP2D6 expression. SHP is a representative target gene of the farnesoid X receptor (FXR). The objective of this study is to investigate whether an agonist of FXR, 3-(2,6-dichlorophenyl)-4-(3'-carboxy-2-chlorostilben-4-yl)oxymethyl-5-isopropylisoxazole (GW4064), alters CYP2D6 expression and activity. In CYP2D6-humanized transgenic mice, GW4064 decreased hepatic CYP2D6 expression and activity (by 2-fold) while increasing SHP expression (by 2-fold) and SHP recruitment to the CYP2D6 promoter. CYP2D6 repression by GW4064 was abrogated in Shp(-/-);CYP2D6 mice, indicating a critical role of SHP in CYP2D6 regulation by GW4064. Also, GW4064 decreased CYP2D6 expression (by 2-fold) in primary human hepatocytes, suggesting that the results obtained in CYP2D6-humanized transgenic mice can be translated to humans. This proof of concept study provides evidence for CYP2D6 regulation by an inducer of SHP expression, namely, the FXR agonist GW4064.
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Affiliation(s)
- Xian Pan
- Departments of Pharmacy Practice (H.J.) and Biopharmaceutical Sciences (X.P., H.J.), College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois; and Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio (Y.K.L.)
| | - Yoon-Kwang Lee
- Departments of Pharmacy Practice (H.J.) and Biopharmaceutical Sciences (X.P., H.J.), College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois; and Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio (Y.K.L.)
| | - Hyunyoung Jeong
- Departments of Pharmacy Practice (H.J.) and Biopharmaceutical Sciences (X.P., H.J.), College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois; and Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio (Y.K.L.)
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22
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Straub C, Granger AJ, Saulnier JL, Sabatini BL. CRISPR/Cas9-mediated gene knock-down in post-mitotic neurons. PLoS One 2014; 9:e105584. [PMID: 25140704 PMCID: PMC4139396 DOI: 10.1371/journal.pone.0105584] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/22/2014] [Indexed: 12/22/2022] Open
Abstract
The prokaryotic adaptive immune system CRISPR/Cas9 has recently been adapted for genome editing in eukaryotic cells. This technique allows for sequence-specific induction of double-strand breaks in genomic DNA of individual cells, effectively resulting in knock-out of targeted genes. It thus promises to be an ideal candidate for application in neuroscience where constitutive genetic modifications are frequently either lethal or ineffective due to adaptive changes of the brain. Here we use CRISPR/Cas9 to knock-out Grin1, the gene encoding the obligatory NMDA receptor subunit protein GluN1, in a sparse population of mouse pyramidal neurons. Within this genetically mosaic tissue, manipulated cells lack synaptic current mediated by NMDA-type glutamate receptors consistent with complete knock-out of the targeted gene. Our results show the first proof-of-principle demonstration of CRISPR/Cas9-mediated knock-down in neurons in vivo, where it can be a useful tool to study the function of specific proteins in neuronal circuits.
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Affiliation(s)
- Christoph Straub
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Adam J. Granger
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jessica L. Saulnier
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bernardo L. Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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23
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Pravetoni M, Vervacke JS, Distefano MD, Tucker AM, Laudenbach M, Pentel PR. Effect of currently approved carriers and adjuvants on the pre-clinical efficacy of a conjugate vaccine against oxycodone in mice and rats. PLoS One 2014; 9:e96547. [PMID: 24797666 PMCID: PMC4010527 DOI: 10.1371/journal.pone.0096547] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 04/08/2014] [Indexed: 11/19/2022] Open
Abstract
Vaccination against the highly abused prescription opioid oxycodone has shown pre-clinical efficacy for blocking oxycodone effects. The current study further evaluated a candidate vaccine composed of oxycodone derivatized at the C6 position (6OXY) conjugated to the native keyhole limpet hemocyanin (nKLH) carrier protein. To provide an oxycodone vaccine formulation suitable for human studies, we studied the effect of alternative carriers and adjuvants on the generation of oxycodone-specific serum antibody and B cell responses, and the effect of immunization on oxycodone distribution and oxycodone-induced antinociception in mice and rats. 6OXY conjugated to tetanus toxoid (TT) or a GMP grade KLH dimer (dKLH) was as effective as 6OXY conjugated to the nKLH decamer in mice and rats, while the 6OXY hapten conjugated to a TT-derived peptide was not effective in preventing oxycodone-induced antinociception in mice. Immunization with 6OXY-TT s.c. absorbed on alum adjuvant provided similar protection to 6OXY-TT administered i.p. with Freund's adjuvant in rats. The toll-like receptor 4 (TLR4) agonist monophosphoryl lipid A (MPLA) adjuvant, alone or in combination with alum, offered no advantage over alum alone for generating oxycodone-specific serum antibodies or 6OXY-specific antibody secreting B cells in mice vaccinated with 6OXY-nKLH or 6OXY-TT. The immunogenicity of oxycodone vaccines may be modulated by TLR4 signaling since responses to 6OXY-nKLH in alum were decreased in TLR4-deficient mice. These data suggest that TT, nKLH and dKLH carriers provide consistent 6OXY conjugate vaccine immunogenicity across species, strains and via different routes of administration, while adjuvant formulations may need to be tailored to individual immunogens or patient populations.
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Affiliation(s)
- Marco Pravetoni
- Minneapolis Medical Research Foundation, Minneapolis, Minnesota, United States of America
- University of Minnesota, School of Medicine, Department of Medicine, Minneapolis, Minnesota, United States of America
- University of Minnesota, School of Medicine, Department of Pharmacology, Minneapolis, Minnesota, United States of America
- University of Minnesota, Center for Immunology, Minneapolis, Minnesota, United States of America
- * E-mail:
| | - Jeffrey S. Vervacke
- University of Minnesota, Department of Chemistry, Minneapolis, Minnesota, United States of America
| | - Mark D. Distefano
- University of Minnesota, Department of Chemistry, Minneapolis, Minnesota, United States of America
| | - Ashli M. Tucker
- Minneapolis Medical Research Foundation, Minneapolis, Minnesota, United States of America
| | - Megan Laudenbach
- Minneapolis Medical Research Foundation, Minneapolis, Minnesota, United States of America
| | - Paul R. Pentel
- Minneapolis Medical Research Foundation, Minneapolis, Minnesota, United States of America
- University of Minnesota, School of Medicine, Department of Medicine, Minneapolis, Minnesota, United States of America
- University of Minnesota, School of Medicine, Department of Pharmacology, Minneapolis, Minnesota, United States of America
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Overexpression of mutant ataxin-3 in mouse cerebellum induces ataxia and cerebellar neuropathology. THE CEREBELLUM 2014; 12:441-55. [PMID: 23242710 DOI: 10.1007/s12311-012-0432-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Machado-Joseph disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), is a fatal, dominant neurodegenerative disorder caused by the polyglutamine-expanded protein ataxin-3. Clinical manifestations include cerebellar ataxia and pyramidal signs culminating in severe neuronal degeneration. Currently, there is no therapy able to modify disease progression. In the present study, we aimed at investigating one of the most severely affected brain regions in the disorder--the cerebellum--and the behavioral defects associated with the neuropathology in this region. For this purpose, we injected lentiviral vectors encoding full-length human mutant ataxin-3 in the mouse cerebellum of 3-week-old C57/BL6 mice. We show that circumscribed expression of human mutant ataxin-3 in the cerebellum mediates within a short time frame--6 weeks, the development of a behavioral phenotype including reduced motor coordination, wide-based ataxic gait, and hyperactivity. Furthermore, the expression of mutant ataxin-3 resulted in the accumulation of intranuclear inclusions, neuropathological abnormalities, and neuronal death. These data show that lentiviral-based expression of mutant ataxin-3 in the mouse cerebellum induces localized neuropathology, which is sufficient to generate a behavioral ataxic phenotype. Moreover, this approach provides a physiologically relevant, cost-effective and time-effective animal model to gain further insights into the pathogenesis of MJD and for the evaluation of experimental therapeutics of MJD.
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Abstract
The background of aggression is very complicated and the basis of its occurrence has not been well explained yet. It is thought that tendency to aggressiveness is an effect of both environmental and genetic factors. Aggression is a very undesirable behavioural trait in dogs living with humans. The aim of this study was to determine the relationship between two polymorphisms: DRD4 intron II VNTR and C/T substitution in exon I HTR2B genes and aggressive behaviour in dogs. The VNTR polymorphism in the DRD4 gene was detected by agarose gel electrophoresis following PCR amplification, whereas C/T substitution in the HTR2B gene was analysed using amplification created restriction site-polymerase chain reaction (ACRS-PCR). A total of 121 dogs of several breeds were analyzed. All animals were classified based on a veterinary interview and observation in two groups: aggressive (n = 21) and non-aggressive (n = 100). Significant differences in DRD4 genotype frequencies between aggressive and non-aggressive dogs were observed (P < 0.05). The study provides a clear evidence of an association of VNTR polymorphism within intron II of the DRD4 gene with the occurrence of aggressive behaviour in dogs. Moreover, the findings give good justification for further research aimed at evaluation of the possibility of using this genetic marker in Marker-assisted Selection.
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Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation. Sci Rep 2013; 3:3281. [PMID: 24257461 PMCID: PMC3836031 DOI: 10.1038/srep03281] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/15/2013] [Indexed: 12/20/2022] Open
Abstract
A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided "point-and-transfect" user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits.
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Gonzalez ST, Welch ES, Colwill RM. Pavlovian contextual and instrumental biconditional discrimination learning in mice. Behav Brain Res 2013; 256:398-404. [PMID: 24016837 PMCID: PMC4306232 DOI: 10.1016/j.bbr.2013.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/31/2013] [Accepted: 09/03/2013] [Indexed: 11/24/2022]
Abstract
Genetically-modified animal models are a powerful tool for investigating the link between neurological and behavioral changes and for the development of therapeutic interventions. Executive function deficits are symptomatic of many human clinical disorders but few tasks exist for studying executive functions in mice. To address this need, we describe procedures for establishing Pavlovian contextual and instrumental biconditional discriminations (BCDs) in C57BL/6J mice. In the first experiment, contextual cues disambiguated when two short duration stimulus targets would be followed by food pellets. In the second experiment, discrete visual cues signaled when lever press or nose poke responses would be continuously reinforced with food pellets. Mice learned both BCDs as evidenced by differential responding in each cue during training and, more critically, during extinction testing. The implications of these findings for using BCD tasks to analyze the neural substrates of executive processing in animal models are discussed.
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Kemp SWP, Phua PD, Stanoulis KN, Wood MD, Liu EH, Gordon T, Borschel GH. Functional recovery following peripheral nerve injury in the transgenic Thy1
-GFP rat. J Peripher Nerv Syst 2013; 18:220-31. [DOI: 10.1111/jns5.12035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 05/25/2013] [Accepted: 05/31/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Stephen W. P. Kemp
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
- The Hospital for Sick Children Research Institute Program in Neuroscience and Mental Health; Toronto Ontario Canada
| | - Peter D. Phua
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
| | - Krisanne N. Stanoulis
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
| | - Matthew D. Wood
- The Hospital for Sick Children Research Institute Program in Neuroscience and Mental Health; Toronto Ontario Canada
| | - Edward H. Liu
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
| | - Tessa Gordon
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
- The Hospital for Sick Children Research Institute Program in Neuroscience and Mental Health; Toronto Ontario Canada
- Division of Plastic and Reconstructive Surgery; University of Toronto; Toronto Ontario Canada
| | - Gregory H. Borschel
- Department of Surgery, Division of Plastic and Reconstructive Surgery; The Hospital for Sick Children; Toronto Ontario Canada
- The Hospital for Sick Children Research Institute Program in Neuroscience and Mental Health; Toronto Ontario Canada
- Division of Plastic and Reconstructive Surgery; University of Toronto; Toronto Ontario Canada
- University of Toronto Institute of Biomaterials and Biomedical Engineering; Toronto Ontario Canada
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Abstract
Astrocytes are the predominant glial cell type in the CNS. Although astrocytes are electrically nonexcitable, their excitability is manifested by their Ca2+ signaling, which serves as a mediator of neuron-glia bidirectional interactions via tripartite synapses. Studies from in vivo two-photon imaging indicate that in healthy animals, the properties of spontaneous astrocytic Ca2+ signaling are affected by animal species, age, wakefulness and the location of astrocytes in the brain. Intercellular Ca2+ waves in astrocytes can be evoked by a variety of stimulations. In animal models of some brain disorders, astrocytes can exhibit enhanced Ca2+ excitability featured as regenerative intercellular Ca2+ waves. This review first briefly summarizes the astrocytic Ca2+ signaling pathway and the procedure of in vivo two-photon Ca2+ imaging of astrocytes. It subsequently summarizes in vivo astrocytic Ca2+ signaling in health and brain disorders from experimental studies of animal models, and discusses the possible mechanisms and therapeutic implications underlying the enhanced Ca2+ excitability in astrocytes in brain disorders. Finally, this review summarizes molecular genetic approaches used to selectively manipulate astrocyte function in vivo and their applications to study the role of astrocytes in synaptic plasticity and brain disorders.
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Affiliation(s)
- Shinghua Ding
- Dalton Cardiovascular Research Center, Department of Biological Engineering, University of Missouri, Columbia, MO 65211, USA
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30
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Welch KD, Pfister JA, Gardner DR, Green BT, Panter KE. The role of the α7 subunit of the nicotinic acetylcholine receptor on motor coordination in mice treated with methyllycaconitine and anabasine. J Appl Toxicol 2013; 33:1017-26. [PMID: 23702881 DOI: 10.1002/jat.2894] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/08/2013] [Accepted: 04/09/2013] [Indexed: 11/07/2022]
Abstract
The adverse effects of methyllycaconitine (MLA) have been attributed to competitive antagonism of nicotinic acetylcholine receptors (nAChR). Research has indicated a correlation between the LD50 of MLA and the amount of α7 nAChR in various mouse strains, suggesting that mice with more α7 nAChR require more MLA to be poisoned. However, recent research demonstrated that there was no difference in the acute lethality (LD50 ) to MLA in mice lacking the α7 nAChR subunit compared with wild-type mice. The objective of this study was to determine if the α7 nAChR subunit plays a role in motor coordination deficiencies that result from exposure to nAChR antagonists and agonists. We compared the motor function and coordination in wild-type mice to mice lacking the α7 subunit of the nAChR, after treating them with a non-lethal dose of MLA or anabasine, using the following tests: balance beam, grip strength, rotarod, open field and tremor monitor. Analysis of the data indicated that overall there was no difference between the wild-type and knockout mice (P = 0.39 for grip strength; P = 0.21 for rotarod; P = 0.41 for balance beam; P = 0.22 for open field; and P = 0.62 for tremors). Thus results from this study suggest that α7 nAChR does not play an integral role in the acute effects of MLA or anabasine on motor function/coordination. Consequently other subunits of nAChRs found in the neuromuscular junction are likely the primary target for MLA and anabasine resulting in motor coordination deficiencies and acute toxicosis.
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Affiliation(s)
- K D Welch
- USDA-ARS Poisonous Plant Research Laboratory, Logan, Utah 84341, USA.
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31
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Li JX, Thorn DA, Jin C. The GPR88 receptor agonist 2-PCCA does not alter the behavioral effects of methamphetamine in rats. Eur J Pharmacol 2012; 698:272-7. [PMID: 23123351 DOI: 10.1016/j.ejphar.2012.10.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 10/16/2012] [Accepted: 10/23/2012] [Indexed: 10/27/2022]
Abstract
GPR88 is a novel orphan G protein-coupled receptor that is primarily located at the striatum. Genetic knockout studies reveal phenotypes of increased dopamine D(2) receptor sensitivity in mice, suggesting that GPR88 receptors may be involved in the modulation of dopaminergic system. However, there is no study that examines the pharmacological effects of GPR88 receptor ligands in in vivo preparations. This study examined the effects of a GPR88 receptor agonist, (1R, 2R)-2-pyridin-2-yl-cyclopropane carboxylic acid ((2S, 3S)-2-amino-3-methyl-pentyl)-(4'-propylbiphenyl-4-yl)-amide (2-PCCA), on the motor activity in rats and on methamphetamine-induced hyperactivity and discriminative stimulus effects. 2-PCCA (0.1-3.2mg/kg) dose-dependently decreased the locomotor activity in rats and, when studied in combination with 1.0mg/kg methamphetamine, also dose-dependently decreased methamphetamine-induced hyperactivity. However, the dose of 2-PCCA that significantly attenuated methamphetamine-induced hyperactivity was also the dose that by itself markedly decreased the baseline locomotor activity. In rats discriminating 0.32mg/kg methamphetamine, 2-PCCA (1-3.2mg/kg) itself did not produce methamphetamine-like discriminative stimulus effects and, when studied in combination, did not alter the discriminative stimulus effects of methamphetamine. Together, these data have provided the first line of evidence that activation of GPR88 receptors does not alter the behavioral effects of methamphetamine. The potential implications of these findings are also discussed.
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Affiliation(s)
- Jun-Xu Li
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, the State University of New York, Buffalo, NY 14214, USA.
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32
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Wahlsten D. The hunt for gene effects pertinent to behavioral traits and psychiatric disorders: from mouse to human. Dev Psychobiol 2012; 54:475-92. [PMID: 22674524 DOI: 10.1002/dev.21043] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The field of behavioral genetics was reviewed in the classic 1960 text by Fuller and Thompson. Since then, there has been remarkable progress in the genetic analysis of animal behavior. Many molecular genetic methods in common use today were not even anticipated in 1960. Animal models for many human psychiatric disorders have been discovered or created. In human behavior genetics, however, powerful new methods have failed to reveal even one bona fide, replicable gene effect pertinent to the normal range of variation in intelligence and personality. There is no explanatory or predictive value in that genetic information. For several psychiatric disorders, including autism and schizophrenia, many large genetic effects arise from de novo mutations. Genetically, the disorders are heterogeneous; different cases with the same diagnosis have different causes. The promises of the molecular genetic revolution have not been fulfilled in behavioral domains of most interest to human psychology.
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Affiliation(s)
- Douglas Wahlsten
- Department of Psychology, University of North Carolina Greensboro, Greensboro, NC 27402, USA.
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33
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Abstract
Eye movements are very important in order to track an object or to stabilize an image on the retina during movement. Animals without a fovea, such as the mouse, have a limited capacity to lock their eyes onto a target. In contrast to these target directed eye movements, compensatory ocular eye movements are easily elicited in afoveate animals1,2,3,4. Compensatory ocular movements are generated by processing vestibular and optokinetic information into a command signal that will drive the eye muscles. The processing of the vestibular and optokinetic information can be investigated separately and together, allowing the specification of a deficit in the oculomotor system. The oculomotor system can be tested by evoking an optokinetic reflex (OKR), vestibulo-ocular reflex (VOR) or a visually-enhanced vestibulo-ocular reflex (VVOR). The OKR is a reflex movement that compensates for "full-field" image movements on the retina, whereas the VOR is a reflex eye movement that compensates head movements. The VVOR is a reflex eye movement that uses both vestibular as well as optokinetic information to make the appropriate compensation. The cerebellum monitors and is able to adjust these compensatory eye movements. Therefore, oculography is a very powerful tool to investigate brain-behavior relationship under normal as well as under pathological conditions (f.e. of vestibular, ocular and/or cerebellar origin). Testing the oculomotor system, as a behavioral paradigm, is interesting for several reasons. First, the oculomotor system is a well understood neural system5. Second, the oculomotor system is relative simple6; the amount of possible eye movement is limited by its ball-in-socket architecture ("single joint") and the three pairs of extra-ocular muscles7. Third, the behavioral output and sensory input can easily be measured, which makes this a highly accessible system for quantitative analysis8. Many behavioral tests lack this high level of quantitative power. And finally, both performance as well as plasticity of the oculomotor system can be tested, allowing research on learning and memory processes9. Genetically modified mice are nowadays widely available and they form an important source for the exploration of brain functions at various levels10. In addition, they can be used as models to mimic human diseases. Applying oculography on normal, pharmacologically-treated or genetically modified mice is a powerful research tool to explore the underlying physiology of motor behaviors under normal and pathological conditions. Here, we describe how to measure video-oculography in mice8.
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Affiliation(s)
- Marcel de Jeu
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.
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34
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Yeung BHY, Law AYS, Wong CKC. Evolution and roles of stanniocalcin. Mol Cell Endocrinol 2012; 349:272-80. [PMID: 22115958 DOI: 10.1016/j.mce.2011.11.007] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 11/07/2011] [Indexed: 12/11/2022]
Abstract
In fish, stanniocalcin-1 (STC1) is a key endocrine factor that acts on gill, intestine and kidney to regulate serum calcium and phosphate homeostasis. The recent identification and study of mammalian STCs (STC1 and STC2) revealed that the hormones are made in virtually all tissues and they act primarily as paracrine/autocrine factors to regulate various biological functions. Based on their ubiquitous expression patterns and generally undetectable levels in blood serum, it is unlikely that the mammalian STCs play important roles in serum Ca(2+)/P(i) homeostasis. However current evidences still support the local action of STCs in Ca(2+) and P(i) transport, probably via their action on Ca(2+)-channels and Na(+)/P(i) co-transporter. At present, information about the sequence, expression and distribution of the STC receptor(s) is lacking. However, recent emerging evidence hints the involvement of STC1 and STC2 in the sub-cellular functions of mitochondria and endoplasmic reticulum respectively, particularly responding to oxidative stress and unfolded protein response. With increasing evidence that demonstrates the local actions of STCs, the focus of the research has been moved to cellular inflammation and carcinogenesis. This review integrates the information available on STCs in fish and mammals, focusing mainly on their embryonic origin, tissue distribution, their potential regulatory mechanisms and the modes of action, and their physiological and pathophysiological functions, particularly in cancer biology.
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Affiliation(s)
- B H Y Yeung
- Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong
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35
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Nissar AA, Zemanek B, Labatia R, Atkinson DJ, van der Ven PFM, Fürst DO, Hawke TJ. Skeletal muscle regeneration is delayed by reduction in Xin expression: consequence of impaired satellite cell activation? Am J Physiol Cell Physiol 2012; 302:C220-7. [DOI: 10.1152/ajpcell.00298.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Xin is a striated muscle-specific actin-binding protein whose mRNA expression has been observed in damaged skeletal muscle. Here we demonstrate increased Xin protein expression early postinjury (≤12 h) and localization primarily to the periphery of damaged myofibers. At 1 day postinjury, Xin is colocalized with MyoD, confirming expression in activated satellite cells (SCs). By 5 days postinjury, Xin is evident in newly regenerated myofibers, with a return to preinjury levels by 14 days of regeneration. To determine whether the increased Xin expression is functionally relevant, tibialis anterior muscles of wild-type mice were infected with Xin-short hairpin RNA (shRNA) adenovirus, whereas the contralateral tibialis anterior received control adenovirus (Control). Four days postinfection, muscles were harvested or injured with cardiotoxin and collected at 3, 5, or 14 days thereafter. When compared with Control, Xin-shRNA infection attenuated muscle regeneration as demonstrated by Myh3 expression and fiber areas. Given the colocalization of Xin and MyoD, we isolated single myofibers from infected muscles to investigate the effect of silencing Xin on SC function. Relative to Control, SC activation, but not proliferation, was significantly impaired in Xin-shRNA-infected muscles. To determine whether Xin affects the G0-G1 transition, cell cycle reentry was assessed on infected C2C12 myoblasts using a methylcellulose assay. No difference in reentry was noted between groups, suggesting that Xin contributes to SC activation by means other than affecting G0-G1 transition. Together these data demonstrate a critical role for Xin in SC activation and reduction in Xin expression results in attenuated skeletal muscle repair.
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Affiliation(s)
- Aliyah A. Nissar
- Department of Pathology and Molecular Medicine, McMaster University. Hamilton, Ontario
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada; and
| | - Bart Zemanek
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada; and
| | - Rita Labatia
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada; and
| | - Daniel J. Atkinson
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada; and
| | | | - Dieter O. Fürst
- Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Thomas J. Hawke
- Department of Pathology and Molecular Medicine, McMaster University. Hamilton, Ontario
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada; and
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36
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Pfrieger FW, Slezak M. Genetic approaches to study glial cells in the rodent brain. Glia 2011; 60:681-701. [PMID: 22162024 DOI: 10.1002/glia.22283] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 11/18/2011] [Indexed: 01/02/2023]
Abstract
The development, function, and pathology of the brain depend on interactions of neurons and different types of glial cells, namely astrocytes, oligodendrocytes, microglia, and ependymal cells. Understanding neuron-glia interactions in vivo requires dedicated experimental approaches to manipulate each cell type independently. In this review, we first summarize techniques that allow for cell-specific gene modification including targeted mutagenesis and viral transduction. In the second part, we describe the genetic models that allow to target the main glial cell types in the central nervous system. The existing arsenal of approaches to study glial cells in vivo and its expansion in the future are key to understand neuron-glia interactions under normal and pathologic conditions.
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Affiliation(s)
- Frank W Pfrieger
- CNRS UPR 3212, University of Strasbourg, Institute of Cellular and Integrative Neurosciences (INCI), 67084 Strasbourg, France.
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37
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Jerusalinsky D, Baez MV, Epstein AL. Herpes simplex virus type 1-based amplicon vectors for fundamental research in neurosciences and gene therapy of neurological diseases. ACTA ACUST UNITED AC 2011; 106:2-11. [PMID: 22108428 DOI: 10.1016/j.jphysparis.2011.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 10/11/2011] [Accepted: 11/04/2011] [Indexed: 12/24/2022]
Abstract
Somatic manipulation of the nervous system without the involvement of the germinal line appears as a powerful counterpart of the transgenic strategy. The use of viral vectors to produce specific, transient and localized knockout, knockdown, ectopic expression or overexpression of a gene, leads to the possibility of analyzing both in vitro and in vivo molecular basis of neural function. In this approach, viral particles engineered to carry transgenic sequences are delivered into discrete brain regions, to transduce cells that will express the transgenic products. Amplicons are replication-incompetent helper-dependent vectors derived from herpes simplex virus type 1 (HSV-1), with several advantages that potentiate their use in neurosciences: (1) minimal toxicity: amplicons do not encode any virus proteins, are neither toxic for the infected cells nor pathogenic for the inoculated animals and elicit low levels of adaptive immune responses; (2) extensive transgene capacity to carry up to 150-kb of foreign DNA; i.e., entire genes with regulatory sequences could be delivered; (3) widespread cellular tropism: amplicons can experimentally infect several cell types including glial cells, though naturally the virus infects mainly neurons and epithelial cells; (4) since the viral genome does not integrate into cellular chromosomes there is low probability to induce insertional mutagenesis. Recent investigations on gene transfer into the brain using these vectors, have focused on gene therapy of inherited genetic diseases affecting the nervous system, such as ataxias, or on neurodegenerative disorders using experimental models of Parkinson's or Alzheimer's disease. Another group of studies used amplicons to investigate complex neural functions such as neuroplasticity, anxiety, learning and memory. In this short review, we summarize recent data supporting the potential of HSV-1 based amplicon vector model for gene delivery and modulation of gene expression in primary cultures of neuronal cells and into the brain of living animals.
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Affiliation(s)
- Diana Jerusalinsky
- Instituto de Biología Celular y Neurociencia (IBCN), CONICET-UBA. Buenos Aires, Argentina.
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38
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Bøttger P, Doğanlı C, Lykke-Hartmann K. Migraine- and dystonia-related disease-mutations of Na+/K+-ATPases: relevance of behavioral studies in mice to disease symptoms and neurological manifestations in humans. Neurosci Biobehav Rev 2011; 36:855-71. [PMID: 22067897 DOI: 10.1016/j.neubiorev.2011.10.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 10/20/2011] [Accepted: 10/26/2011] [Indexed: 10/15/2022]
Abstract
The two autosomal dominantly inherited neurological diseases: familial hemiplegic migraine type 2 (FHM2) and familial rapid-onset of dystonia-parkinsonism (Familial RDP) are caused by in vivo mutations of specific alpha subunits of the sodium-potassium pump (Na(+)/K(+)-ATPase). Intriguingly, patients with classical FHM2 and RDP symptoms additionally suffer from other manifestations, such as epilepsy/seizures and developmental disabilities. Recent studies of FHM2 and RDP mouse models provide valuable tools for dissecting the vital roles of the Na(+)/K(+)-ATPases, and we discuss their relevance to the complex patient symptoms and manifestations. Thus, it is interesting that mouse models targeting a specific α-isoform cause different, although still comparable, phenotypes consistent with classical symptoms and other manifestations observed in FHM2 and RDP patients. This review highlights that use of mouse models have broad potentials for future research concerning migraine and dystonia-related diseases, which will contribute towards understanding the, yet unknown, pathophysiologies.
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Affiliation(s)
- Pernille Bøttger
- Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Danish National Research Foundation, Denmark; Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Aarhus C, Denmark
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39
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O'Connor EC, Stephens DN, Crombag HS. Modeling appetitive Pavlovian-instrumental interactions in mice. CURRENT PROTOCOLS IN NEUROSCIENCE 2011; Chapter 8:Unit 8.25. [PMID: 20938924 DOI: 10.1002/0471142301.ns0825s53] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In appetitive Pavlovian associative learning, a stimulus (conditioned stimulus, CS) that has been associated with the delivery of a reinforcing event (unconditioned stimulus, US; e.g., food) can subsequently elicit or modulate goal-directed instrumental behaviors. For example, a Pavlovian CS can serve to reinforce (novel) instrumental behavior (conditioned reinforcement or CRf), or it can energize and potentiate ongoing instrumental responses when presented non-contingently (Pavlovian-instrumental transfer or PIT). Notably, these different effects of a Pavlovian CS on instrumental behavior are mediated by dissociable psychological and neurobiological mechanisms. Given the critical role that Pavlovian-instrumental interactions play in regulating motivated behavior and maladaptive manifestations of motivation such as eating disorders and addictions, understanding the underlying psychological and neurobiological mechanisms will be important. This unit describes behavioral protocols that produce robust and reliable PIT and CRf in mice and that open the door for future studies using transgenic approaches into the molecular mechanisms underlying associative learning and motivation.
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Affiliation(s)
- Eoin C O'Connor
- Behavioral and Clinical Neuroscience Research Group, School of Psychology, The University of Sussex, Brighton, East Sussex, United Kingdom
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40
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Dhaliwal J, Lagace DC. Visualization and genetic manipulation of adult neurogenesis using transgenic mice. Eur J Neurosci 2011; 33:1025-36. [PMID: 21395845 DOI: 10.1111/j.1460-9568.2011.07600.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Many laboratories have focused efforts on the creation of transgenic mouse models to study adult neurogenesis. In the last decade several constitutive reporter, as well as inducible transgenic lines have been published that allowed for visualization, tracking and alteration of specific neurogenic cell populations in the adult brain. Given the popularity of this approach, multiple mouse lines are available, and this review summarizes the differences in the basic techniques that have been used to create these mice, highlighting the different constructs and reporter proteins used, as well as the strengths and limitations of each of these models. Representative examples from the literature demonstrate some of the diverse and seminal findings that have come to fruition through the laborious, yet highly rewarding work of creating transgenic mouse lines for adult neurogenesis research.
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Affiliation(s)
- Jagroop Dhaliwal
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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41
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Automated test of behavioral flexibility in mice using a behavioral sequencing task in IntelliCage. Behav Brain Res 2011; 221:172-81. [PMID: 21377499 DOI: 10.1016/j.bbr.2011.02.037] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Revised: 02/23/2011] [Accepted: 02/28/2011] [Indexed: 11/20/2022]
Abstract
There has been a long-standing need to develop efficient and standardized behavioral test methods for evaluating higher-order brain functions in mice. Here, we developed and validated a behavioral flexibility test in mice using IntelliCage, a fully automated behavioral analysis system for mice in a group-housed environment. We first developed a "behavioral sequencing task" in the IntelliCage that enables us to assess the learning ability of place discrimination and behavioral sequence for reward acquisition. In the serial reversal learning using the task, the discriminated spatial patterns of the rewarded and never-rewarded places were serially reversed, and thus, mice were accordingly expected to realign the previously acquired behavioral sequence. In general, the tested mice showed rapid acquisition of the behavioral sequencing task and behavioral flexibility in the subsequent serial reversal stages both in intra- and inter-session analyses. It was found that essentially the same results were obtained among three different laboratories, which confirm the high stability of the present test protocol in different strains of mice (C57BL/6, DBA/2, and ICR). In particular, the most trained cohort of C57BL/6 mice achieved a markedly rapid adaptation to the reversal task in the final phase of the long-term serial reversal test, which possibly indicated that the mice adapted to the "reversal rule" itself. In conclusion, the newly developed behavioral test was shown to be a valid assay of behavioral flexibility in mice, and is expected to be utilized in tests of mouse models of cognitive deficits.
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42
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Ardia DR, Parmentier HK, Vogel LA. The role of constraints and limitation in driving individual variation in immune response. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2010.01759.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Daniel R. Ardia
- Department of Biology, Franklin & Marshall College, Lancaster, Pennsylvania 17604, USA
| | - Henk K. Parmentier
- Adaptation Physiology Group, Department of Animal Sciences, Wageningen Institute of Animal Sciences, Marijkeweg 40, 6709 PG Wageningen, The Netherlands
| | - Laura A. Vogel
- School of Biological Sciences, Illinois State University, Normal, Illinois 61790, USA
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Pratte M, Panayotis N, Ghata A, Villard L, Roux JC. Progressive motor and respiratory metabolism deficits in post-weaning Mecp2-null male mice. Behav Brain Res 2011; 216:313-20. [DOI: 10.1016/j.bbr.2010.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 07/30/2010] [Accepted: 08/08/2010] [Indexed: 12/11/2022]
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44
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Bender C, de Olmos S, Bueno A, de Olmos J, Lorenzo A. Comparative analyses of the neurodegeneration induced by the non-competitive NMDA-receptor-antagonist drug MK801 in mice and rats. Neurotoxicol Teratol 2010; 32:542-50. [DOI: 10.1016/j.ntt.2010.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 05/03/2010] [Accepted: 05/05/2010] [Indexed: 10/19/2022]
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45
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Hwang YK, Song JC, Han SH, Cho J, Smith DR, Gallagher M, Han JS. Differences in hippocampal CREB phosphorylation in trace fear conditioning of two inbred mouse strains. Brain Res 2010; 1345:156-63. [PMID: 20501325 DOI: 10.1016/j.brainres.2010.05.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 03/20/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022]
Abstract
The effects of genetic background on fear trace conditioning were evaluated in relation to phosphorylated levels of cAMP response element-binding protein (CREB) in the hippocampus using two different inbred strains of mice, C57BL/6 and DBA/2. The male mice received a trace fear conditioning protocol and unpaired control groups were included to assess nonassociative effects on test performance. Both C57BL/6 and DBA/2 mice with paired training displayed higher freezing responses during testing than those with unpaired training, respectively. The C57BL/6 mice with paired training also displayed higher freezing responses to the tone-CS during testing than the DBA/2 mice with paired training. Because much evidence implicates the hippocampus as an important neural substrate for trace fear conditioning, the engagement of the hippocampus was examined after testing by measuring levels of CREB and phosphorylated CREB (pCREB). The results revealed that hippocampal CREB levels in both strains of mice were not significantly altered according to the type of training (unpaired vs. paired). However, the hippocampal pCREB levels were significantly higher in the paired training group than the unpaired control group in C57BL/6 mice, but not in DBA/2 mice. These findings indicate that hippocampal pCREB is closely tied to this form of associative conditioning only in C57BL/6 mice and that different neural substrates may support trace conditioning in C57BL/6 and DBA/2 strains.
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Affiliation(s)
- Yoo Kyeong Hwang
- Department of Biological Sciences, Konkuk University, Seoul, South Korea
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Laarakker MC, Raai JRV, van Lith HA, Ohl F. The role of the alpha 2A-adrenoceptor in mouse stress-coping behaviour. Psychoneuroendocrinology 2010; 35:490-502. [PMID: 19766405 DOI: 10.1016/j.psyneuen.2009.08.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 08/18/2009] [Accepted: 08/21/2009] [Indexed: 11/30/2022]
Abstract
Acute stress is known to impair memory functions in both men and laboratory rodents. In human the alpha 2A-adrenoceptor system is known to play a critical role in regulating acute neuropsychological stress responses and, ultimately, stress-coping behaviour. In search for neurobiological and central nervous mechanisms behind these behaviours we investigated if the alpha 2A-adrenoceptor is involved in these mechanisms in mice. Phenotypical differences between the A/J and C57BL/6J (B6) mouse inbred strains were evaluated in previous studies. These data showed significant strain differences in various motivational systems (anxiety, exploration, locomotion, memory etc.). From the literature it is known that chromosome 19 contains the gene for the adrenergic alpha 2A receptor that is thought to be involved in emotional behaviours, among others anxiety-related avoidance behaviour and arousal. We investigated if this pathway could possibly be involved in avoidance/arousal susceptibility by applying an agonist (dexmedetomidine) and an antagonist (atipamezole) of the alpha 2A-adrenoceptor to male mice from a consomic strain (C57BL/6J-Chr 19(A)/NaJ, abbreviated to CSS19=anxious), and the corresponding donor (A/J=anxious) and host (B6=non-anxious) strains. The mice were tested in the modified hole board (mHB) test which allows for the assessment of a variety of behavioural patterns by use of only one test. In addition, a forced swimming test (FST) was conducted to test for stress-coping behaviour. Results of the behavioural testing in the mHB-test showed significant strains differences and strain-specific treatment effects for parameters describing anxiety-related endophenotypes. The FST revealed effects of dexmedetomidine and atipamezole on stress-coping behaviour. In conclusion, the involvement of the alpha 2A-adrenoceptor, located on mouse chromosome 19, on anxiety-related behaviour remains unclear and will possibly not play a main role in the development of anxiety-related behaviour in mice. However, we could show involvement of this receptor in stress-coping behaviour in mice.
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Affiliation(s)
- Marijke C Laarakker
- Department of Animals in Science & Society, Division of Laboratory Animal Science, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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Coremans V, Ahmed T, Balschun D, D'Hooge R, DeVriese A, Cremer J, Antonucci F, Moons M, Baekelandt V, Reumers V, Cremer H, Eisch A, Lagace D, Janssens T, Bozzi Y, Caleo M, Conway EM. Impaired neurogenesis, learning and memory and low seizure threshold associated with loss of neural precursor cell survivin. BMC Neurosci 2010; 11:2. [PMID: 20051123 PMCID: PMC2817683 DOI: 10.1186/1471-2202-11-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 01/05/2010] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Survivin is a unique member of the inhibitor of apoptosis protein (IAP) family in that it exhibits antiapoptotic properties and also promotes the cell cycle and mediates mitosis as a chromosome passenger protein. Survivin is highly expressed in neural precursor cells in the brain, yet its function there has not been elucidated. RESULTS To examine the role of neural precursor cell survivin, we first showed that survivin is normally expressed in periventricular neurogenic regions in the embryo, becoming restricted postnatally to proliferating and migrating NPCs in the key neurogenic sites, the subventricular zone (SVZ) and the subgranular zone (SGZ). We then used a conditional gene inactivation strategy to delete the survivin gene prenatally in those neurogenic regions. Lack of embryonic NPC survivin results in viable, fertile mice (SurvivinCamcre) with reduced numbers of SVZ NPCs, absent rostral migratory stream, and olfactory bulb hypoplasia. The phenotype can be partially rescued, as intracerebroventricular gene delivery of survivin during embryonic development increases olfactory bulb neurogenesis, detected postnatally. SurvivinCamcre brains have fewer cortical inhibitory interneurons, contributing to enhanced sensitivity to seizures, and profound deficits in memory and learning. CONCLUSIONS The findings highlight the critical role that survivin plays during neural development, deficiencies of which dramatically impact on postnatal neural function.
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Affiliation(s)
- Vanessa Coremans
- KU Leuven, VIB Vesalius Research Center, Herestraat 49, Gasthuisberg O&N1, B3000 Leuven, Belgium
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Routh BN, Johnston D, Harris K, Chitwood RA. Anatomical and electrophysiological comparison of CA1 pyramidal neurons of the rat and mouse. J Neurophysiol 2009; 102:2288-302. [PMID: 19675296 PMCID: PMC2775381 DOI: 10.1152/jn.00082.2009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 08/07/2009] [Indexed: 11/22/2022] Open
Abstract
The study of learning and memory at the single-neuron level has relied on the use of many animal models, most notably rodents. Although many physiological and anatomical studies have been carried out in rats, the advent of genetically engineered mice has necessitated the comparison of new results in mice to established results from rats. Here we compare fundamental physiological and morphological properties and create three-dimensional compartmental models of identified hippocampal CA1 pyramidal neurons of one strain of rat, Sprague-Dawley, and two strains of mice, C57BL/6 and 129/SvEv. We report several differences in neuronal physiology and anatomy among the three animal groups, the most notable being that neurons of the 129/SvEv mice, but not the C57BL/6 mice, have higher input resistance, lower dendritic surface area, and smaller spines than those of rats. A surprising species-specific difference in membrane resonance indicates that both mouse strains have lower levels of the hyperpolarization-activated nonspecific cation current I(h). Simulations suggest that differences in I(h) kinetics rather than maximal conductance account for the lower resonance. Our findings indicate that comparisons of data obtained across strains or species will need to account for these and potentially other physiological and anatomical differences.
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Affiliation(s)
- Brandy N Routh
- Center for Learning and Memory, University of Texas at Austin, 1 University Station, Austin, Texas 78712, USA.
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Boy J, Schmidt T, Schumann U, Grasshoff U, Unser S, Holzmann C, Schmitt I, Karl T, Laccone F, Wolburg H, Ibrahim S, Riess O. A transgenic mouse model of spinocerebellar ataxia type 3 resembling late disease onset and gender-specific instability of CAG repeats. Neurobiol Dis 2009; 37:284-93. [PMID: 19699305 DOI: 10.1016/j.nbd.2009.08.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 07/31/2009] [Accepted: 08/10/2009] [Indexed: 10/20/2022] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3), or Machado-Joseph disease (MJD), is caused by the expansion of a polyglutamine repeat in the ataxin-3 protein. We generated a mouse model of SCA3 expressing ataxin-3 with 148 CAG repeats under the control of the huntingtin promoter, resulting in ubiquitous expression throughout the whole brain. The model resembles many features of the disease in humans, including a late onset of symptoms and CAG repeat instability in transmission to offspring. We observed a biphasic progression of the disease, with hyperactivity during the first months and decline of motor coordination after about 1 year of age; however, intranuclear aggregates were not visible at this age. Few and small intranuclear aggregates appeared first at the age of 18 months, further supporting the claim that neuronal dysfunction precedes the formation of intranuclear aggregates.
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Affiliation(s)
- Jana Boy
- Medical Genetics, University of Tuebingen, Tuebingen, Germany
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Kwilasz AJ, Harris LS, Vann RE. Removal of continuous nicotine infusion produces somatic but not behavioral signs of withdrawal in mice. Pharmacol Biochem Behav 2009; 94:114-8. [PMID: 19660491 DOI: 10.1016/j.pbb.2009.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/15/2009] [Accepted: 07/27/2009] [Indexed: 11/26/2022]
Abstract
The introduction of transgenic and knockout mice has shaped new interest in developing novel and modified behavioral methods for mice that evaluate the various manifestations of nicotine withdrawal syndromes. This study assessed the disruption of operant baselines during drug withdrawal, an established rat model of nicotine dependence, in mice. Subjects were trained to lever press for food reinforcement during daily operant sessions. After stable operant baselines were established, mice were implanted with osmotic minipumps containing 0 (saline), 6, 12, 24, or 48 mg/kg/day nicotine base. Operant responding was assessed for disruptions in daily sessions throughout the experiment. Somatic signs of withdrawal were assessed after the operant session on day 7, following administration of mecamylamine (1 mg/kg), and on days 12, 13, and 14, following spontaneous removal of nicotine. Spontaneous removal of nicotine increased somatic signs of withdrawal but did not disrupt operant responding. Mecamylamine failed to produce signs of precipitated withdrawal in either procedure. This study demonstrated nicotine dependence in mice during spontaneous removal of nicotine. Moreover, since signs of behavioral withdrawal (i.e. disruptions in operant response rates) were not observed, these findings suggest the importance of considering differences in the apparent manifestations of withdrawal syndromes while evaluating nicotine dependence.
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Affiliation(s)
- Andrew J Kwilasz
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia 23298-0613, USA
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