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Percelay S, Lahogue C, Billard JM, Freret T, Boulouard M, Bouet V. The 3-hit animal models of schizophrenia: Improving strategy to decipher and treat the disease? Neurosci Biobehav Rev 2024; 157:105526. [PMID: 38176632 DOI: 10.1016/j.neubiorev.2023.105526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/08/2023] [Accepted: 12/23/2023] [Indexed: 01/06/2024]
Abstract
Schizophrenia is a complex disease related to combination and interactions between genetic and environmental factors, with an epigenetic influence. After the development of the first mono-factorial animal models of schizophrenia (1-hit), that reproduced patterns of either positive, negative and/or cognitive symptoms, more complex models combining two factors (2-hit) have been developed to better fit with the multifactorial etiology of the disease. In the two past decades, a new way to design animal models of schizophrenia have emerged by adding a third hit (3-hit). This review aims to discuss the relevance of the risk factors chosen for the tuning of the 3-hit animal models, as well as the validities measurements and their contribution to schizophrenia understanding. We intended to establish a comprehensive overview to help in the choice of factors for the design of multiple-hit animal models of schizophrenia.
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Affiliation(s)
- Solenn Percelay
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France
| | - Caroline Lahogue
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France.
| | - Jean-Marie Billard
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France
| | - Thomas Freret
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France
| | - Michel Boulouard
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France
| | - Valentine Bouet
- Normandie Univ, UNICAEN, INSERM, CYCERON, CHU Caen, COMETE UMR 1075, 14000 Caen, France.
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Oliveras I, Cañete T, Sampedro-Viana D, Río-Álamos C, Tobeña A, Corda MG, Giorgi O, Fernández-Teruel A. Neurobehavioral Profiles of Six Genetically-based Rat Models of Schizophrenia- related Symptoms. Curr Neuropharmacol 2023; 21:1934-1952. [PMID: 36809938 PMCID: PMC10514524 DOI: 10.2174/1570159x21666230221093644] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/02/2022] [Accepted: 11/28/2022] [Indexed: 02/24/2023] Open
Abstract
Schizophrenia is a chronic and severe mental disorder with high heterogeneity in its symptoms clusters. The effectiveness of drug treatments for the disorder is far from satisfactory. It is widely accepted that research with valid animal models is essential if we aim at understanding its genetic/ neurobiological mechanisms and finding more effective treatments. The present article presents an overview of six genetically-based (selectively-bred) rat models/strains, which exhibit neurobehavioral schizophrenia-relevant features, i.e., the Apomorphine-susceptible (APO-SUS) rats, the Low-prepulse inhibition rats, the Brattleboro (BRAT) rats, the Spontaneously Hypertensive rats (SHR), the Wisket rats and the Roman High-Avoidance (RHA) rats. Strikingly, all the strains display impairments in prepulse inhibition of the startle response (PPI), which remarkably, in most cases are associated with novelty-induced hyperlocomotion, deficits of social behavior, impairment of latent inhibition and cognitive flexibility, or signs of impaired prefrontal cortex (PFC) function. However, only three of the strains share PPI deficits and dopaminergic (DAergic) psychostimulant-induced hyperlocomotion (together with prefrontal cortex dysfunction in two models, the APO-SUS and RHA), which points out that alterations of the mesolimbic DAergic circuit are a schizophrenia-linked trait that not all models reproduce, but it characterizes some strains that can be valid models of schizophrenia-relevant features and drug-addiction vulnerability (and thus, dual diagnosis). We conclude by putting the research based on these genetically-selected rat models in the context of the Research Domain Criteria (RDoC) framework, suggesting that RDoC-oriented research programs using selectively-bred strains might help to accelerate progress in the various aspects of the schizophrenia-related research agenda.
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Affiliation(s)
- Ignasi Oliveras
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine & Institute of Neurosciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Toni Cañete
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine & Institute of Neurosciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Daniel Sampedro-Viana
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine & Institute of Neurosciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Barcelona, 08193, Spain
| | | | - Adolf Tobeña
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine & Institute of Neurosciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Maria Giuseppa Corda
- Department of Life and Environmental Sciences (DiSVA), University of Cagliari, Sardinia, Italy
| | - Osvaldo Giorgi
- Department of Life and Environmental Sciences (DiSVA), University of Cagliari, Sardinia, Italy
| | - Alberto Fernández-Teruel
- Medical Psychology Unit, Department of Psychiatry and Forensic Medicine & Institute of Neurosciences, School of Medicine, Autonomous University of Barcelona, Bellaterra, Barcelona, 08193, Spain
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McEwan F, Glazier JD, Hager R. The impact of maternal immune activation on embryonic brain development. Front Neurosci 2023; 17:1146710. [PMID: 36950133 PMCID: PMC10025352 DOI: 10.3389/fnins.2023.1146710] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/15/2023] [Indexed: 03/08/2023] Open
Abstract
The adult brain is a complex structure with distinct functional sub-regions, which are generated from an initial pool of neural epithelial cells within the embryo. This transition requires a number of highly coordinated processes, including neurogenesis, i.e., the generation of neurons, and neuronal migration. These take place during a critical period of development, during which the brain is particularly susceptible to environmental insults. Neurogenesis defects have been associated with the pathogenesis of neurodevelopmental disorders (NDDs), such as autism spectrum disorder and schizophrenia. However, these disorders have highly complex multifactorial etiologies, and hence the underlying mechanisms leading to aberrant neurogenesis continue to be the focus of a significant research effort and have yet to be established. Evidence from epidemiological studies suggests that exposure to maternal infection in utero is a critical risk factor for NDDs. To establish the biological mechanisms linking maternal immune activation (MIA) and altered neurodevelopment, animal models have been developed that allow experimental manipulation and investigation of different developmental stages of brain development following exposure to MIA. Here, we review the changes to embryonic brain development focusing on neurogenesis, neuronal migration and cortical lamination, following MIA. Across published studies, we found evidence for an acute proliferation defect in the embryonic MIA brain, which, in most cases, is linked to an acceleration in neurogenesis, demonstrated by an increased proportion of neurogenic to proliferative divisions. This is accompanied by disrupted cortical lamination, particularly in the density of deep layer neurons, which may be a consequence of the premature neurogenic shift. Although many aspects of the underlying pathways remain unclear, an altered epigenome and mitochondrial dysfunction are likely mechanisms underpinning disrupted neurogenesis in the MIA model. Further research is necessary to delineate the causative pathways responsible for the variation in neurogenesis phenotype following MIA, which are likely due to differences in timing of MIA induction as well as sex-dependent variation. This will help to better understand the underlying pathogenesis of NDDs, and establish therapeutic targets.
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Caffeine-Induced Acute and Delayed Responses in Cerebral Metabolism of Control and Schizophrenia-Like Wisket Rats. Int J Mol Sci 2022; 23:ijms23158186. [PMID: 35897774 PMCID: PMC9331118 DOI: 10.3390/ijms23158186] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 12/04/2022] Open
Abstract
Recently, morphological impairments have been detected in the brain of a triple-hit rat schizophrenia model (Wisket), and delayed depressive effects of caffeine treatment in both control and Wisket animals have also been shown. The aims of this study were to determine the basal and caffeine-induced acute (30 min) and delayed (24 h) changes in the cerebral 18fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography (PET) in control and Wisket rats. No significant differences were identified in the basal whole-brain metabolism between the two groups, and the metabolism was not modified acutely by a single intraperitoneal caffeine (20 mg/kg) injection in either group. However, one day after caffeine administration, significantly enhanced 18F-FDG uptake was detected in the whole brain and the investigated areas (hippocampus, striatum, thalamus, and hypothalamus) in the control group. Although the Wisket animals showed only moderate enhancements in the 18F-FDG uptake, significantly lower brain metabolism was observed in this group than in the caffeine-treated control group. This study highlights that the basal brain metabolism of Wisket animals was similar to control rats, and that was not influenced acutely by single caffeine treatment at the whole-brain level. Nevertheless, the distinct delayed responsiveness to this psychostimulant in Wisket model rats suggests impaired control of the cerebral metabolism.
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Schonfeld L, Jaehne EJ, Ogden AR, Spiers JG, Hogarth S, van den Buuse M. Differential effects of chronic adolescent glucocorticoid or methamphetamine on drug-induced locomotor hyperactivity and disruption of prepulse inhibition in adulthood in mice. Prog Neuropsychopharmacol Biol Psychiatry 2022; 117:110552. [PMID: 35337859 DOI: 10.1016/j.pnpbp.2022.110552] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/17/2022] [Accepted: 03/17/2022] [Indexed: 11/29/2022]
Abstract
Sensitization of dopaminergic activity has been suggested as an underlying mechanism in the psychotic symptoms of schizophrenia. Adolescent stress and chronic abuse of methamphetamine (Meth) are well-known risk factors for psychosis and schizophrenia; however it remains unknown how these factors compare in terms of dopaminergic behavioural sensitization in adulthood. In addition, while Brain-Derived Neurotrophic Factor (BDNF) has been implicated in dopaminergic activity and schizophrenia, its role in behavioural sensitization remains unclear. In this study we therefore compared the effect of chronic adolescent treatment with the stress hormone, corticosterone (Cort), or with Meth, on drug-induced locomotor hyperactivity and disruption of prepulse inhibition in adulthood in BDNF heterozygous mice and their wild-type controls, as well as on dopamine receptor gene expression. Between 6 and 9 weeks of age, the animals either received Cort in the drinking water or were treated with an escalating Meth dose protocol. In adulthood, Cort-pretreated mice showed significantly reduced Meth-induced locomotor hyperactivity compared to vehicle-pretreated mice. In contrast, Meth hyperlocomotion was significantly enhanced in animals pretreated with the drug in adolescence. There were no effects of either pretreatment on prepulse inhibition. BDNF Het mice showed greater Meth-induced hyperlocomotion and lower prepulse inhibition than WT mice. There were no effects of either pretreatment on D1 or D2 gene expression in either the dorsal or ventral striatum, while D3 mRNA was shown to be reduced in male mice only irrespective of genotype. These results suggest that in adolescence, chronically elevated glucocorticoid levels, a component of chronic stress, do not cause dopaminergic sensitization adulthood, in contrast to the effect of chronic Meth treatment in the same age period. BDNF does not appear to be involved in the effects of chronic Cort or chronic Meth.
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Affiliation(s)
- Lina Schonfeld
- Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Emily J Jaehne
- Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Alexandra R Ogden
- Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Jereme G Spiers
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Samuel Hogarth
- Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Maarten van den Buuse
- Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Melbourne, Australia; Department of Pharmacology, University of Melbourne, Australia; College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia.
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Adlan LG, Csordás-Nagy M, Bodosi B, Kalmár G, Nyúl LG, Nagy A, Kekesi G, Büki A, Horvath G. Sleep-Wake Rhythm and Oscillatory Pattern Analysis in a Multiple Hit Schizophrenia Rat Model (Wisket). Front Behav Neurosci 2022; 15:799271. [PMID: 35153694 PMCID: PMC8831724 DOI: 10.3389/fnbeh.2021.799271] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Electroencephalography studies in schizophrenia reported impairments in circadian rhythm and oscillatory activity, which may reflect the deficits in cognitive and sensory processing. The current study evaluated the circadian rhythm and the state-dependent oscillatory pattern in control Wistar and a multiple hit schizophrenia rat model (Wisket) using custom-made software for identification of the artifacts and the classification of sleep-wake stages and the active and quiet awake substages. The Wisket animals have a clear light-dark cycle similar to controls, and their sleep-wake rhythm showed only a tendency to spend more time in non-rapid eye movement (NREM) and less in rapid eye movement (REM) stages. In spite of the weak diurnal variation in oscillation in both groups, the Wisket rats had higher power in the low-frequency delta, alpha, and beta bands and lower power in the high-frequency theta and gamma bands in most stages. Furthermore, the significant differences between the two groups were pronounced in the active waking substage. These data suggest that the special changes in the oscillatory pattern of this schizophrenia rat model may have a significant role in the impaired cognitive functions observed in previous studies.
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Affiliation(s)
- Leatitia Gabriella Adlan
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Mátyás Csordás-Nagy
- Department of Technical Informatics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - Balázs Bodosi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - György Kalmár
- Department of Technical Informatics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - László G. Nyúl
- Department of Image Processing and Computer Graphics, Faculty of Science and Informatics, Institute of Informatics, University of Szeged, Szeged, Hungary
| | - Attila Nagy
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Gabriella Kekesi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Alexandra Büki
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Gyongyi Horvath
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
- *Correspondence: Gyongyi Horvath,
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Büki A, Bohár Z, Kekesi G, Vécsei L, Horvath G. Wisket rat model of schizophrenia: Impaired motivation and, altered brain structure, but no anhedonia. Physiol Behav 2021; 244:113651. [PMID: 34800492 DOI: 10.1016/j.physbeh.2021.113651] [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: 08/09/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 01/17/2023]
Abstract
It is well-known that the poor cognition in schizophrenia is strongly linked to negative symptoms, including motivational deficit, which due to, at least partially, anhedonia. The goal of this study was to explore whether the schizophrenia-like Wisket animals with impaired motivation (obtained in the reward-based hole-board test), also show decreased hedonic behavior (investigated with the sucrose preference test). While neurochemical alterations of different neurotransmitter systems have been detected in the Wisket rats, no research has been performed on structural changes. Therefore, our additional aim was to reveal potential neuroanatomical and structural alterations in different brain regions in these rats. The rats showed decreased general motor activity (locomotion, rearing and exploration) and impaired task performance in the hole-board test compared to the controls, whereas no significant difference was observed in the sucrose preference test between the groups. The Wisket rats exhibited a significant decrease in the frontal cortical thickness and the hippocampal area, and moderate increases in the lateral ventricles and cell disarray in the CA3 subfield of hippocampus. To our knowledge, this is the first study to investigate the hedonic behavior and neuroanatomical alterations in a multi-hit animal model of schizophrenia. The results obtained in the sucrose preference test suggest that anhedonic behavior might not be involved in the impaired motivation obtained in the hole-board test. The neuropathological changes agree with findings obtained in patients with schizophrenia, which refine the high face validity of the Wisket model.
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Affiliation(s)
- Alexandra Büki
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., Szeged, H-6720, Hungary.
| | - Zsuzsanna Bohár
- MTA-SZTE Neuroscience Research Group, Semmelweis u. 6, Szeged, H-6725, Hungary
| | - Gabriella Kekesi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., Szeged, H-6720, Hungary
| | - László Vécsei
- MTA-SZTE Neuroscience Research Group, Semmelweis u. 6, Szeged, H-6725, Hungary; Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., Szeged, H-6725, Hungary; Interdisciplinary Excellence Center, Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., Szeged, H-6725 Hungary
| | - Gyongyi Horvath
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., Szeged, H-6720, Hungary
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Interaction of clozapine with metformin in a schizophrenia rat model. Sci Rep 2021; 11:16862. [PMID: 34413440 PMCID: PMC8376983 DOI: 10.1038/s41598-021-96478-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
The low efficacy of antipsychotic drugs (e.g., clozapine) for negative symptoms and cognitive impairment has led to the introduction of adjuvant therapies. Because previous data suggest the procognitive potential of the antidiabetic drug metformin, this study aimed to assess the effects of chronic clozapine and metformin oral administration (alone and in combination) on locomotor and exploratory activities and cognitive function in a reward-based test in control and a schizophrenia-like animal model (Wisket rats). As impaired dopamine D1 receptor (D1R) function might play a role in the cognitive dysfunctions observed in patients with schizophrenia, the second goal of this study was to determine the brain-region-specific D1R-mediated signaling, ligand binding, and mRNA expression. None of the treatments affected the behavior of the control animals significantly; however, the combination treatment enhanced D1R binding and activation in the cerebral cortex. The Wisket rats exhibited impaired motivation, attention, and cognitive function, as well as a lower level of cortical D1R binding, signaling, and gene expression. Clozapine caused further deterioration of the behavioral parameters, without a significant effect on the D1R system. Metformin blunted the clozapine-induced impairments, and, similarly to that observed in the control animals, increased the functional activity of D1R. This study highlights the beneficial effects of metformin (at the behavioral and cellular levels) in blunting clozapine-induced adverse effects.
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Caffeine - treat or trigger? Disparate behavioral and long-term dopaminergic changes in control and schizophrenia-like Wisket rats. Physiol Behav 2021; 236:113410. [PMID: 33819453 DOI: 10.1016/j.physbeh.2021.113410] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/12/2021] [Accepted: 03/26/2021] [Indexed: 11/20/2022]
Abstract
The influence of caffeine on behavioral functions in both healthy and schizophrenic subjects is controversial. Here we aimed to reveal the effects of repeated caffeine pre- and post-training treatments on motor and exploratory activities and cognitive functions in a reward-based test (Ambitus) along with a brain region-specific dopamine D2 receptor profile in control and schizophrenia-like WISKET model rats. In the control animals, pre-treatment caused temporary enhancement in motor activity, while permanent improvement in learning function was detected in the WISKET animals. Post-treatment produced significant impairments in both groups. Caffeine caused short-lasting hyperactivity followed by a rebound in the inactive phase determined in undisturbed circumstance. Caffeine treatment substantially enhanced the dopamine D2 receptor mediated G-protein activation in the prefrontal cortex and olfactory bulb of both groups, while it increased in the dorsal striatum and cerebral cortex only in the WISKET animals. Caffeine enhanced the maximal binding capacity in the hippocampus and cerebral cortex of WISKET animals, but it decreased in the prefrontal cortex of the control animals. Regarding the dopamine D2 receptor mRNA expression, caffeine treatment caused significant enhancement in the prefrontal cortex of WISKET animals, while it increased the hippocampal dopamine D2 receptor protein amount in both groups. This study highlights the disparate effects of caffeine pre- versus post-training treatments on behavioral parameters in both control and schizophrenia-like animals and the prolonged changes in the dopaminergic system. It is supposed that the delayed depressive effects of caffeine might be compensated by frequent coffee intake, as observed in schizophrenic patients.
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Péczely L, Kékesi G, Kállai V, Ollmann T, László K, Büki A, Lénárd L, Horváth G. Effects of D 2 dopamine receptor activation in the ventral pallidum on sensory gating and food-motivated learning in control and schizophrenia model (Wisket) rats. Behav Brain Res 2020; 400:113047. [PMID: 33279633 DOI: 10.1016/j.bbr.2020.113047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 11/28/2022]
Abstract
Dopamine D2 receptors (D2Rs) of the ventral pallidum (VP) play important role in motivational and learning processes, however, their potential role in triggering schizophrenic symptoms has not been investigated, yet. In the present experiments the effects of locally administered D2R agonist quinpirole were investigated on behavioral parameters related to sensorimotor gating, motor activity and food-motivated labyrinth learning. Two weeks after bilateral implantation of microcannulae into the VP, the acute (30 min) and delayed (3, 21 and 24 h) effects of quinpirole microinjection (1 μg/0.4 μL at both sides) were investigated in Wistar and schizophrenia model (Wisket substrain) rats in prepulse inhibition (PPI) and the reward-based Ambitus tests. Quinpirole administration did not modify the impaired sensorimotor gating in Wisket rats, but it led to significant deficit in Wistar animals. Regarding the locomotor activity in the Ambitus test, no effects of quinpirole were detected in either groups at the investigated time points. In contrast, quinpirole resulted in decreased exploratory and food-collecting activities in Wistar rats with 21 and 24 h delay. Though, impaired food-related motivation could be observed in Wisket rats, but quinpirole treatment did not result in further deterioration. In summary, our results showed that the VP D2R activation in Wistar rats induces symptoms similar to those observed in schizophrenia model Wisket rats. These data suggest that Wisket rats might have significant alterations in the functional activity of VP, which might be due to its enhanced dopaminergic activity.
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Affiliation(s)
- László Péczely
- Institute of Physiology, Faculty of Medicine, University of Pécs, Pécs, Hungary; Centre for Neuroscience, Pécs University, Pécs, Hungary.
| | - Gabriella Kékesi
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Veronika Kállai
- Institute of Physiology, Faculty of Medicine, University of Pécs, Pécs, Hungary; Centre for Neuroscience, Pécs University, Pécs, Hungary
| | - Tamás Ollmann
- Institute of Physiology, Faculty of Medicine, University of Pécs, Pécs, Hungary; Centre for Neuroscience, Pécs University, Pécs, Hungary
| | - Kristóf László
- Institute of Physiology, Faculty of Medicine, University of Pécs, Pécs, Hungary; Centre for Neuroscience, Pécs University, Pécs, Hungary
| | - Alexandra Büki
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - László Lénárd
- Institute of Physiology, Faculty of Medicine, University of Pécs, Pécs, Hungary; Molecular Neuroendocrinology and Neurophysiology Research Group, Szentágothai Research Centre, Pécs University, Pécs, Hungary; Centre for Neuroscience, Pécs University, Pécs, Hungary
| | - Gyöngyi Horváth
- Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary
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