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Shi MM, Xu XF, Sun QM, Luo M, Liu DD, Guo DM, Chen L, Zhong XL, Xu Y, Cao WY. Betaine prevents cognitive dysfunction by suppressing hippocampal microglial activation in chronic social isolated male mice. Phytother Res 2023; 37:4755-4770. [PMID: 37846157 DOI: 10.1002/ptr.7944] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 06/22/2023] [Accepted: 06/23/2023] [Indexed: 10/18/2023]
Abstract
Chronic social isolation (SI) stress, which became more prevalent during the COVID-19 pandemic, contributes to abnormal behavior, including mood changes and cognitive impairment. Known as a functional nutrient, betaine has potent antioxidant and anti-inflammatory properties in vivo. However, whether betaine can alleviate the abnormal behavior induced by chronic SI in mice remains unknown. In this study, we investigated the efficacy of betaine in the treatment of behavioral changes and its underlying mechanism. Three-week-old male mice were randomly housed for 8 weeks in either group housing (GH) or SI. The animals were divided into normal saline-treated GH, normal saline-treated SI, and betaine-treated SI groups in the sixth week. The cognitive and depression-like behavior was determined in the eighth week. We found that long-term betaine administration improved cognitive behavior in SI mice but failed to prevent depression-like behavior. Moreover, long-term betaine administration inhibited hippocampal microglia over-activation and polarized microglia toward the M2 phenotype, which effectively inhibited the expression of inflammatory factors in SI mice. Finally, the protective effect of betaine treatment in SI mice might not be due to altered activity of the hypothalamic-pituitary-adrenal axis. Collectively, our findings reveal that betaine can improve SI-induced cognitive impairment, thus providing an alternative natural source for the prevention of memory loss caused by SI or loneliness.
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Affiliation(s)
- Meng Meng Shi
- Clinical Anatomy and Reproductive Medicine Application Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Xiao Fan Xu
- Clinical Anatomy and Reproductive Medicine Application Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Qiu Min Sun
- Department of Nursing, Yiyang Medical College, Yiyang, Hunan, China
| | - Mingying Luo
- Department of Anatomy and Histology and Embryology, Kunming Medical University, Kunming, Yunnan, China
| | - Dan Dan Liu
- Institute of Clinical Medicine, The First Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Dong Min Guo
- Clinical Anatomy and Reproductive Medicine Application Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Ling Chen
- Institute of Clinical Medicine, The First Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Xiao Lin Zhong
- Institute of Clinical Medicine, The First Affiliated Hospital of the University of South China, Hengyang, Hunan, China
| | - Yang Xu
- Institute of Neuroscience, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Wen Yu Cao
- Clinical Anatomy and Reproductive Medicine Application Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, China
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Li SH, Abd-Elrahman KS, Ferguson SS. Targeting mGluR2/3 for treatment of neurodegenerative and neuropsychiatric diseases. Pharmacol Ther 2022; 239:108275. [DOI: 10.1016/j.pharmthera.2022.108275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 10/15/2022]
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3
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Rubio Arzola P, Shansky RM. Considering Organismal Physiology in Laboratory Studies of Rodent Behavior. Annu Rev Neurosci 2022; 45:387-402. [PMID: 35395164 DOI: 10.1146/annurev-neuro-111020-085500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Any experiment conducted in a rodent laboratory is done so against the backdrop of each animal's physiological state at the time of the experiment. This physiological state can be the product of multiple factors, both internal (e.g., animal sex, strain, hormone cycles, or circadian rhythms) and external (e.g., housing conditions, social status, and light/dark phases). Each of these factors has the potential to influence experimental outcomes, either independently or via interactions with others, and yet there is little consistency across laboratories in terms of the weight with which they are considered in experimental design. Such discrepancies-both in practice and in reporting-likely contribute to the perception of a reproducibility crisis in the field of behavioral neuroscience. In this review, we discuss how several of these sources of variability can impact outcomes within the realm of common learning and memory paradigms. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
| | - Rebecca M Shansky
- Department of Psychology, Northeastern University, Boston, Massachusetts, USA;
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Kryszkowski W, Boczek T. The G Protein-Coupled Glutamate Receptors as Novel Molecular Targets in Schizophrenia Treatment-A Narrative Review. J Clin Med 2021; 10:jcm10071475. [PMID: 33918323 PMCID: PMC8038150 DOI: 10.3390/jcm10071475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 12/02/2022] Open
Abstract
Schizophrenia is a severe neuropsychiatric disease with an unknown etiology. The research into the neurobiology of this disease led to several models aimed at explaining the link between perturbations in brain function and the manifestation of psychotic symptoms. The glutamatergic hypothesis postulates that disrupted glutamate neurotransmission may mediate cognitive and psychosocial impairments by affecting the connections between the cortex and the thalamus. In this regard, the greatest attention has been given to ionotropic NMDA receptor hypofunction. However, converging data indicates metabotropic glutamate receptors as crucial for cognitive and psychomotor function. The distribution of these receptors in the brain regions related to schizophrenia and their regulatory role in glutamate release make them promising molecular targets for novel antipsychotics. This article reviews the progress in the research on the role of metabotropic glutamate receptors in schizophrenia etiopathology.
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Affiliation(s)
- Waldemar Kryszkowski
- General Psychiatric Ward, Babinski Memorial Hospital in Lodz, 91229 Lodz, Poland;
| | - Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University of Lodz, 92215 Lodz, Poland
- Correspondence:
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Ingram J, Hand CJ, Maciejewski G. Social isolation during COVID-19 lockdown impairs cognitive function. APPLIED COGNITIVE PSYCHOLOGY 2021; 35:935-947. [PMID: 34230768 PMCID: PMC8250848 DOI: 10.1002/acp.3821] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 02/04/2023]
Abstract
Studies examining the effect of social isolation on cognitive function typically involve older adults and/or specialist groups (e.g., expeditions). We considered the effects of COVID‐19‐induced social isolation on cognitive function within a representative sample of the general population. We additionally considered how participants ‘shielding’ due to underlying health complications, or living alone, performed. We predicted that performance would be poorest under strictest, most‐isolating conditions. At five timepoints over 13 weeks, participants (N = 342; aged 18–72 years) completed online tasks measuring attention, memory, decision‐making, time‐estimation, and learning. Participants indicated their mood as ‘lockdown’ was eased. Performance typically improved as opportunities for social contact increased. Interactions between participant sub‐groups and timepoint demonstrated that performance was shaped by individuals' social isolation levels. Social isolation is linked to cognitive decline in the absence of ageing covariates. The impact of social isolation on cognitive function should be considered when implementing prolonged pandemic‐related restrictive conditions.
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Affiliation(s)
- Joanne Ingram
- School of Education and Social Science University of the West of Scotland Paisley UK
| | | | - Greg Maciejewski
- School of Education and Social Science University of the West of Scotland Paisley UK
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Maturation of amygdala inputs regulate shifts in social and fear behaviors: A substrate for developmental effects of stress. Neurosci Biobehav Rev 2021; 125:11-25. [PMID: 33581221 DOI: 10.1016/j.neubiorev.2021.01.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 11/21/2022]
Abstract
Stress can negatively impact brain function and behaviors across the lifespan. However, stressors during adolescence have particularly harmful effects on brain maturation, and on fear and social behaviors that extend beyond adolescence. Throughout development, social behaviors are refined and the ability to suppress fear increases, both of which are dependent on amygdala activity. We review rodent literature focusing on developmental changes in social and fear behaviors, cortico-amygdala circuits underlying these changes, and how this circuitry is altered by stress. We first describe changes in fear and social behaviors from adolescence to adulthood and parallel developmental changes in cortico-amygdala circuitry. We propose a framework in which maturation of cortical inputs to the amygdala promote changes in social drive and fear regulation, and the particularly damaging effects of stress during adolescence may occur through lasting changes in this circuit. This framework may explain why anxiety and social pathologies commonly co-occur, adolescents are especially vulnerable to stressors impacting social and fear behaviors, and predisposed towards psychiatric disorders related to abnormal cortico-amygdala circuits.
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7
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Diminished excitatory synaptic transmission correlates with impaired spatial working memory in neurodevelopmental rodent models of schizophrenia. Pharmacol Biochem Behav 2021; 202:173103. [PMID: 33444600 DOI: 10.1016/j.pbb.2021.173103] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 11/23/2022]
Abstract
Neurodevelopmental abnormalities are associated with cognitive dysfunction in schizophrenia. In particular, deficits of working memory, are consistently observed in schizophrenia, reflecting prefrontal cortex (PFc) dysfunction. To elucidate the mechanism of such deficits in working memory, the pathophysiological properties of PFc neurons and synaptic transmission have been studied in several developmental models of schizophrenia. Given the pathogenetic heterogeneity of schizophrenia, comparison of PFc synaptic transmission between models of prenatal and postnatal defect would promote our understanding on the developmental components of the biological vulnerability to schizophrenia. In the present study, we investigated the excitatory synaptic transmission onto pyramidal cells localized in layer 5 of the medial PFc (mPFc) in two developmental models of schizophrenia: gestational methylazoxymethanol acetate (MAM) administration and post-weaning social isolation (SI). We found that both models exhibited defective spatial working memory, as indicated by lower spontaneous alternations in a Y-maze paradigm. The recordings from pyramidal neurons in both models exhibited decreased spontaneous excitatory postsynaptic current (sEPSC), representing the reduction of excitatory synaptic transmission in the mPFc. Interestingly, a positive correlation between the impaired spontaneous alternation behavior and the decreased excitatory synaptic transmission of pyramidal neurons was found in both models. These findings suggest that diminished excitatory neurotransmission in the mPFc could be a common pathophysiology regardless of the prenatal and postnatal pathogenesis in developmental models of schizophrenia, and that it might underlie the mechanism of defective working memory in those models.
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8
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Zhang XQ, Jiang HJ, Xu L, Yang SY, Wang GZ, Jiang HD, Wu T, Du H, Yu ZP, Zhao QQ, Ling Y, Zhang ZY, Shen HW. The metabotropic glutamate receptor 2/3 antagonist LY341495 improves working memory in adult mice following juvenile social isolation. Neuropharmacology 2020; 177:108231. [DOI: 10.1016/j.neuropharm.2020.108231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/26/2020] [Accepted: 07/04/2020] [Indexed: 11/30/2022]
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9
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Kaneda Y, Kawata A, Suzuki K, Matsunaga D, Yasumatsu M, Ishiwata T. Comparison of neurotransmitter levels, physiological conditions, and emotional behavior between isolation-housed rats with group-housed rats. Dev Psychobiol 2020; 63:452-460. [PMID: 32945540 DOI: 10.1002/dev.22036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/17/2020] [Accepted: 08/25/2020] [Indexed: 11/11/2022]
Abstract
Brain monoaminergic neurotransmitters, such as dopamine (DA), serotonin (5-HT), and noradrenaline (NA), play crucial roles in neuronal and physiological functions, including social behaviors. Isolation housing may induce behavioral and neurochemical abnormalities in rats, although its influence on neurotransmitter levels remains obscure. This study investigated the influence of isolation- or group-housing on core body temperature (Tcore ), locomotor activity (ACT), emotional behavior, and neurotransmitter levels in male Wistar rats. Behavioral changes were monitored using the open field test (OFT) and social interaction test (SIT). After 4 weeks, brain tissues were collected to quantify 5-HT, DA, and NA concentrations. Body weight and basal Tcore during both the light and dark phase were higher in isolation-housed than in group-housed rats, although no significant difference was seen in ACT. No significant differences were observed during the OFT. Isolation-housed rats showed increased line crossing and decreased social behavior during the SIT. Isolation-housed rats exhibited decreased levels of 5-HT in the caudate putamen and amygdala, and elevated and decreased NA levels in the paraventricular hypothalamic nucleus and hippocampus, respectively. However, DA levels were unaffected. Thus, housing environments may affect brain areas that regulate various neuronal and physiological functions, such as memory, stress responses, and emotional behavior.
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Affiliation(s)
- Yuta Kaneda
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
| | - Akira Kawata
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
| | - Kota Suzuki
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
| | - Daisuke Matsunaga
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
| | - Mikinobu Yasumatsu
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
| | - Takayuki Ishiwata
- Graduate School of Community & Human Services, Rikkyo University, Saitama, Japan
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10
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Shortall SE, Brown AM, Newton-Mann E, Dawe-Lane E, Evans C, Fowler M, King MV. Calbindin Deficits May Underlie Dissociable Effects of 5-HT 6 and mGlu 7 Antagonists on Glutamate and Cognition in a Dual-Hit Neurodevelopmental Model for Schizophrenia. Mol Neurobiol 2020; 57:3439-3457. [PMID: 32533466 PMCID: PMC7340678 DOI: 10.1007/s12035-020-01938-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/13/2020] [Indexed: 12/11/2022]
Abstract
Despite several compounds entering clinical trials for the negative and cognitive symptoms of schizophrenia, few have progressed beyond phase III. This is partly attributed to a need for improved preclinical models, to understand disease and enable predictive evaluation of novel therapeutics. To this end, one recent approach incorporates "dual-hit" neurodevelopmental insults like neonatal phencyclidine plus isolation rearing (PCP-Iso). Glutamatergic dysfunction contributes to schizophrenia pathophysiology and may represent a treatment target, so we used enzyme-based microsensors to evaluate basal- and drug-evoked glutamate release in hippocampal slices from rats that received neonatal PCP and/or isolation rearing. 5-HT6 antagonist-evoked glutamate release (thought to be mediated indirectly via GABAergic disinhibition) was reduced in PCP-Iso, as were cognitive effects of a 5-HT6 antagonist in a hippocampal glutamate-dependent novel object discrimination task. Yet mGlu7 antagonist-evoked glutamatergic and cognitive responses were spared. Immunohistochemical analyses suggest these findings (which mirror the apparent lack of clinical response to 5-HT6 antagonists in schizophrenia) are not due to reduced hippocampal 5-HT input in PCP-Iso, but may be explained by reduced calbindin expression. This calcium-binding protein is present in a subset of GABAergic interneurons receiving preferential 5-HT innervation and expressing 5-HT6 receptors. Its loss (in schizophrenia and PCP-Iso) would be expected to reduce interneuron firing and potentially prevent further 5-HT6 antagonist-mediated disinhibition, without impacting on responses of VIP-expressing interneurons to mGlu7 antagonism. This research highlights the importance of improved understanding for selection of appropriate preclinical models, especially where disease neurobiology impacts on cells mediating the effects of potential therapeutics.
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Affiliation(s)
- Sinead E Shortall
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Angus M Brown
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Eliot Newton-Mann
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Erin Dawe-Lane
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Chanelle Evans
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Maxine Fowler
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK
| | - Madeleine V King
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, NG7 2UH, UK.
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Comparative Pro-cognitive and Neurochemical Profiles of Glycine Modulatory Site Agonists and Glycine Reuptake Inhibitors in the Rat: Potential Relevance to Cognitive Dysfunction and Its Management. Mol Neurobiol 2020; 57:2144-2166. [PMID: 31960362 PMCID: PMC7170834 DOI: 10.1007/s12035-020-01875-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/09/2020] [Indexed: 12/30/2022]
Abstract
Frontocortical NMDA receptors are pivotal in regulating cognition and mood, are hypofunctional in schizophrenia, and may contribute to autistic spectrum disorders. Despite extensive interest in agents potentiating activity at the co-agonist glycine modulatory site, few comparative functional studies exist. This study systematically compared the actions of the glycine reuptake inhibitors, sarcosine (40–200 mg/kg) and ORG24598 (0.63–5 mg/kg), the agonists, glycine (40–800 mg/kg), and D-serine (10–160 mg/kg) and the partial agonists, S18841 (2.5 mg/kg s.c.) and D-cycloserine (2.5–40 mg/kg) that all dose-dependently prevented scopolamine disruption of social recognition in adult rats. Over similar dose ranges, they also prevented a delay-induced impairment of novel object recognition (NOR). Glycine reuptake inhibitors specifically elevated glycine but not D-serine levels in rat prefrontal cortical (PFC) microdialysates, while glycine and D-serine markedly increased levels of glycine and D-serine, respectively. D-Cycloserine slightly elevated D-serine levels. Conversely, S18841 exerted no influence on glycine, D-serine, other amino acids, monamines, or acetylcholine. Reversal of NOR deficits by systemic S18841 was prevented by the NMDA receptor antagonist, CPP (20 mg/kg), and the glycine modulatory site antagonist, L701,324 (10 mg/kg). S18841 blocked deficits in NOR following microinjection into the PFC (2.5–10 μg/side) but not the striatum. Finally, in rats socially isolated from weaning (a neurodevelopmental model of schizophrenia), S18841 (2.5 and 10 mg/kg s.c.) reversed impairment of NOR and contextual fear-motivated learning without altering isolation-induced hyperactivity. In conclusion, despite contrasting neurochemical profiles, partial glycine site agonists and glycine reuptake inhibitors exhibit comparable pro-cognitive effects in rats of potential relevance to treatment of schizophrenia and other brain disorders where cognitive performance is impaired.
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12
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Liu JY, Chen HY, Lin JJ, Lu MK, Tan HP, Jang FL, Lin SH. Alterations of plasma cytokine biomarkers for identifying age at onset of schizophrenia with neurological soft signs. Int J Med Sci 2020; 17:255-262. [PMID: 32038109 PMCID: PMC6990880 DOI: 10.7150/ijms.38891] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/19/2019] [Indexed: 01/22/2023] Open
Abstract
Several studies have been suggested that immunity plays a part in neurodevelopment and schizophrenia pathogenesis. Early age of onset in schizophrenia is associated with genetic factors which affect neurodevelopment. This study aims to identify immune abnormalities associated with neurodevelopmental impairments in early-onset schizophrenia (EOS) and adult-onset schizophrenia (AOS) patients. We determined the plasma levels of six cytokines (IL-1β, IL-4, IL-6, IL-10, IL-12 and TNF-α) in schizophrenia patients and healthy controls. Measurements included neurological soft signs (NSS) to distinguish and subgroup those with neurodevelopmental impairments. The study included 210 schizophrenia patients, which were divided into 84 EOS and 126 AOS patients, as well as 122 healthy controls. We observed significant differences in levels of IL-4, IL-6 and IL-10 between EOS and AOS patients. The results demonstrated the area under ROC curve (AUC) of the IL-4 in EOS and healthy controls was 0.81. Moreover, these results indicated that AUC of the IL-4 and the combination of IL-4, IL-6 and IL-12 in EOS with NSS and healthy controls were 0.91 and 0.95. These cytokines are altered in EOS and schizophrenia patients with neurodevelopmental impairments and demonstrated good classification abilities. These findings manifested that both pro- and anti-inflammatory cytokines are contributed to the clinical and pathophysiological features of schizophrenia. Future works are expected to explore potential genetic effectors and predictors as well as therapeutic directions in personalized medicine for early-onset schizophrenia.
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Affiliation(s)
- Jia-Yun Liu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Medical Research, Center for Medical Genetics, Changhua Christian Hospital, Changhua, Taiwan.,Department of Genomic Medicine, Center for Medical Genetics, Changhua Christian Hospital, Changhua, Taiwan
| | - Han-Yu Chen
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jin-Jia Lin
- Department of Psychiatry, Chimei Medical Center, Tainan, Taiwan
| | - Ming-Kun Lu
- Department of Health, Jianan Mental Hospital, Tainan, Taiwan.,Department of Applied Life Science and Health, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Hung-Pin Tan
- Department of Psychiatry, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, Taiwan.,Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Fong-Lin Jang
- Department of Psychiatry, Chimei Medical Center, Tainan, Taiwan
| | - Sheng-Hsiang Lin
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Biostatistics Consulting Center, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Neale JH, Olszewski R. A role for N-acetylaspartylglutamate (NAAG) and mGluR3 in cognition. Neurobiol Learn Mem 2019; 158:9-13. [PMID: 30630041 DOI: 10.1016/j.nlm.2019.01.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/03/2018] [Accepted: 01/05/2019] [Indexed: 12/18/2022]
Abstract
The peptide transmitter N-acetylaspartylglutamate (NAAG) and its receptor, the type 3 metabotropic glutamate receptor (mGluR3, GRM3), are prevalent and widely distributed in the mammalian nervous system. Drugs that inhibit the inactivation of synaptically released NAAG have procognitive activity in object recognition and other behavioral models. These inhibitors also reverse cognitive deficits in animal models of clinical disorders. Antagonists of mGluR3 block these actions and mice that are null mutant for this receptor are insensitive to the actions of these procognitive drugs. A positive allosteric modulator of this receptor also has procognitive activity. While some data suggest that drugs acting on mGluR3 achieve their procognitive action by increasing arousal during acquisition training, exploration of the procognitive efficacy of NAAG is in its early stages and thus substantial opportunities exist to define the breadth and nature of this activity.
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Affiliation(s)
- Joseph H Neale
- Department of Biology, Georgetown University, Washington, DC, USA.
| | - Rafal Olszewski
- Department of Biology, Georgetown University, Washington, DC, USA.
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14
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Pezze MA, Marshall HJ, Cassaday HJ. Infusions of scopolamine in dorsal hippocampus reduce anticipatory responding in an appetitive trace conditioning procedure. Brain Behav 2018; 8:e01147. [PMID: 30378776 PMCID: PMC6305963 DOI: 10.1002/brb3.1147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/30/2018] [Accepted: 09/28/2018] [Indexed: 01/28/2023] Open
Abstract
INTRODUCTION Trace conditioning is impaired by lesions to dorsal hippocampus, as well as by treatment with the muscarinic acetylcholine antagonist scopolamine. However, the role of muscarinic receptors within hippocampus has received little attention. METHODS The present study examined the effects of intra-hippocampal infusion of scopolamine (30 µg/side) in an appetitive (2 vs. 10 s) trace conditioning procedure using sucrose pellets as the unconditioned stimulus (US). Locomotor activity (LMA) was examined in a different apparatus. RESULTS Intra-hippocampal scopolamine reduced responding to the 2 s trace conditioned stimulus (CS). Intra-hippocampal scopolamine similarly depressed responding within the inter-stimulus interval (ISI) at both 2 and 10 s trace intervals, but there was no such effect in the inter-trial interval. There was also some overall reduction in responding when the US was delivered; significant at the 10 s but not at the 2 s trace interval. A similar pattern of results to that seen in response to the CS during acquisition was shown drug-free (in the 5 s post-CS) in the extinction tests of conditioned responding. LMA was increased under scopolamine. CONCLUSIONS The results suggest that nonspecific changes in activity or motivation to respond for the US cannot explain the reduction in trace conditioning as measured by reduced CS responding and in the ISI. Rather, the findings of the present study point to the importance of associative aspects of the task in determining its sensitivity to the effects of scopolamine, suggesting that muscarinic receptors in the hippocampus are important modulators of short-term working memory.
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Affiliation(s)
- Marie A. Pezze
- School of PsychologyUniversity of NottinghamNottinghamUK
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15
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Mumtaz F, Khan MI, Zubair M, Dehpour AR. Neurobiology and consequences of social isolation stress in animal model-A comprehensive review. Biomed Pharmacother 2018; 105:1205-1222. [PMID: 30021357 DOI: 10.1016/j.biopha.2018.05.086] [Citation(s) in RCA: 200] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 05/10/2018] [Accepted: 05/18/2018] [Indexed: 12/09/2022] Open
Abstract
The brain is a vital organ, susceptible to alterations under genetic influences and environmental experiences. Social isolation (SI) acts as a stressor which results in alterations in reactivity to stress, social behavior, function of neurochemical and neuroendocrine system, physiological, anatomical and behavioral changes in both animal and humans. During early stages of life, acute or chronic SIS has been proposed to show signs and symptoms of psychiatric and neurological disorders such as anxiety, depression, schizophrenia, epilepsy and memory loss. Exposure to social isolation stress induces a variety of endocrinological changes including the activation of hypothalamic-pituitary-adrenal (HPA) axis, culminating in the release of glucocorticoids (GCs), release of catecholamines, activation of the sympatho-adrenomedullary system, release of Oxytocin and vasopressin. In several regions of the central nervous system (CNS), SIS alters the level of neurotransmitter such as dopamine, serotonin, gamma aminobutyric acid (GABA), glutamate, nitrergic system and adrenaline as well as leads to alteration in receptor sensitivity of N-methyl-D-aspartate (NMDA) and opioid system. A change in the function of oxidative and nitrosative stress (O&NS) mediated mitochondrial dysfunction, inflammatory factors, neurotrophins and neurotrophicfactors (NTFs), early growth response transcription factor genes (Egr) and C-Fos expression are also involved as a pathophysiological consequences of SIS which induce neurological and psychiatric disorders.
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Affiliation(s)
- Faiza Mumtaz
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Muhammad Imran Khan
- Department of Pharmacy, Kohat University of Science and Technology, 26000 Kohat, KPK, Pakistan; Drug Detoxification Health Welfare Research Center, Bannu, KPK, Pakistan
| | - Muhammad Zubair
- Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agriculture University, Nanjing, 210095, PR China
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Arakawa H. Ethological approach to social isolation effects in behavioral studies of laboratory rodents. Behav Brain Res 2018; 341:98-108. [DOI: 10.1016/j.bbr.2017.12.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/15/2017] [Accepted: 12/17/2017] [Indexed: 12/31/2022]
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Characterization of Behavioral, Signaling and Cytokine Alterations in a Rat Neurodevelopmental Model for Schizophrenia, and Their Reversal by the 5-HT 6 Receptor Antagonist SB-399885. Mol Neurobiol 2018; 55:7413-7430. [PMID: 29423817 PMCID: PMC6096968 DOI: 10.1007/s12035-018-0940-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/28/2018] [Indexed: 12/15/2022]
Abstract
Post-weaning social isolation of rats produces neuroanatomical, neurochemical and behavioral alterations resembling some core features of schizophrenia. This study examined the ability of the 5-HT6 receptor antagonist SB-399885 to reverse isolation-induced cognitive deficits, then investigated alterations in hippocampal cell proliferation and hippocampal and frontal cortical expression of selected intracellular signaling molecules and cytokines. Male Lister hooded rats (weaned on post-natal days 21-24 and housed individually or in groups of 3-4) received six i.p. injections of vehicle (1% Tween 80, 1 mL/kg) or SB-399885 (5 or 10 mg/kg) over a 2-week period starting 40 days post-weaning, on the days that locomotor activity, novel object discrimination (NOD), pre-pulse inhibition of acoustic startle and acquisition, retention and extinction of a conditioned freezing response (CFR) were assessed. Tissue was collected 24 h after the final injection for immunohistochemistry, reverse-phase protein microarray and western blotting. Isolation rearing impaired NOD and cue-mediated CFR, decreased cell proliferation within the dentate gyrus, and elevated hippocampal TNFα levels and Cdc42 expression. SB-399885 reversed the NOD deficit and partially normalized CFR and cell proliferation. These effects were accompanied by altered expression of several members of the c-Jun N-terminal Kinase (JNK) and p38 MAPK signaling pathways (including TAK1, MKK4 and STAT3). Although JNK and p38 themselves were unaltered at this time point hippocampal TAK1 expression and phosphorylation correlated with visual recognition memory in the NOD task. Continued use of this neurodevelopmental model could further elucidate the neurobiology of schizophrenia and aid assessment of novel therapies for drug-resistant cognitive symptoms.
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The role of N-methyl-d-aspartate receptors and metabotropic glutamate receptor 5 in the prepulse inhibition paradigms for studying schizophrenia: pharmacology, neurodevelopment, and genetics. Behav Pharmacol 2018; 29:13-27. [DOI: 10.1097/fbp.0000000000000352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Phencyclidine increased while isolation rearing did not affect progressive ratio responding in rats: Investigating potential models of amotivation in schizophrenia. Behav Brain Res 2017; 364:413-422. [PMID: 29175446 DOI: 10.1016/j.bbr.2017.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/20/2017] [Accepted: 11/21/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Schizophrenia is a debilitating neurodevelopmental disorder affecting 1% of the global population with heterogeneous symptoms including positive, negative, and cognitive. While treatment for positive symptoms exists, none have been developed to treat negative symptoms. Animal models of schizophrenia are required to test targeted treatments and since patients exhibit reduced effort (breakpoints) for reward in a progressive ratio (PR) task, we examined the PR breakpoints of rats treated with the NMDA receptor antagonist phencyclidine or those reared in isolation - two common manipulations used to induce schizophrenia-relevant behaviors in rodents. METHODS In two cohorts, the PR breakpoint for a palatable food reward was examined in Long Evans rats after: 1) a repeated phencyclidine regimen; 2) A subchronic phencyclidine regimen followed by drug washout; and 3) post-weaning social isolation. RESULTS Rats treated with repeated phencyclidine and those following washout from phencyclidine exhibited higher PR breakpoints than vehicle-treated rats. The breakpoint of isolation reared rats did not differ from those socially reared, despite abnormalities of these rats in other schizophrenia-relevant behaviors. CONCLUSION Despite their common use for modeling other schizophrenia-relevant behaviors neither phencyclidine treatment nor isolation rearing recreated the motivational deficits observed in patients with schizophrenia, as measured by PR breakpoint. Other manipulations, and negative symptom-relevant behaviors, require investigation prior to testing putative therapeutics.
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Dauvermann MR, Lee G, Dawson N. Glutamatergic regulation of cognition and functional brain connectivity: insights from pharmacological, genetic and translational schizophrenia research. Br J Pharmacol 2017. [PMID: 28626937 DOI: 10.1111/bph.13919] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The pharmacological modulation of glutamatergic neurotransmission to improve cognitive function has been a focus of intensive research, particularly in relation to the cognitive deficits seen in schizophrenia. Despite this effort, there has been little success in the clinical use of glutamatergic compounds as procognitive drugs. Here, we review a selection of the drugs used to modulate glutamatergic signalling and how they impact on cognitive function in rodents and humans. We highlight how glutamatergic dysfunction, and NMDA receptor hypofunction in particular, is a key mechanism contributing to the cognitive deficits observed in schizophrenia and outline some of the glutamatergic targets that have been tested as putative procognitive targets for this disorder. Using translational research in this area as a leading exemplar, namely, models of NMDA receptor hypofunction, we discuss how the study of functional brain network connectivity can provide new insight into how the glutamatergic system impacts on cognitive function. Future studies characterizing functional brain network connectivity will increase our understanding of how glutamatergic compounds regulate cognition and could contribute to the future success of glutamatergic drug validation. Linked Articles This article is part of a themed section on Pharmacology of Cognition: a Panacea for Neuropsychiatric Disease? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.19/issuetoc.
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Affiliation(s)
- Maria R Dauvermann
- School of Psychology, National University of Ireland, Galway, Ireland.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Graham Lee
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Neil Dawson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, UK
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Pezze MA, Marshall HJ, Cassaday HJ. Scopolamine Impairs Appetitive But Not Aversive Trace Conditioning: Role of the Medial Prefrontal Cortex. J Neurosci 2017; 37:6289-6298. [PMID: 28559376 PMCID: PMC5490064 DOI: 10.1523/jneurosci.3308-16.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 04/07/2017] [Accepted: 04/18/2017] [Indexed: 12/14/2022] Open
Abstract
The muscarinic acetylcholine receptor is an important modulator of medial prefrontal cortex (mPFC) functions, such as the working memory required to bridge a trace interval in associative leaning. Aversive and appetitive trace conditioning procedures were used to examine the effects of scopolamine (0.1 and 0.5 mg/kg, i.p.) in male rats. Follow-up experiments tested the effects of microinfusion of 0.15 μg of scopolamine (0.075 μg of in 0.5 μl/side) in infralimbic (IL) versus prelimbic regions of rat mPFC, in appetitive trace and locomotor activity (LMA) procedures. Systemic scopolamine was without effect in an aversive trace conditioning procedure, but impaired appetitive conditioning at a 2 s trace interval. This effect was demonstrated as reduced responding during presentations of the conditioned stimulus (CS) and during the interstimulus interval (ISI). There was no such effect on responding during food (unconditioned stimulus, US) responding or in the intertrial interval (ITI). In contrast, systemic scopolamine dose-relatedly increased LMA. Trace conditioning was similarly impaired at the 2 s trace (shown as reduced responding to the CS and during the ISI, but not during US presentations or in the ITI) after infusion in mPFC, whereas LMA was increased (after infusion in IL only). Therefore, our results point to the importance of cholinergic modulation in mPFC for trace conditioning and show that the observed effects cannot be attributed to reduced activity.SIGNIFICANCE STATEMENT Events are very often separated in time, in which case working memory is necessary to condition their association in "trace conditioning." The present study used conditioning variants motivated aversively with foot shock and appetitively with food. The drug scopolamine was used to block muscarinic acetylcholine receptors involved in working memory. The results show that reduced cholinergic transmission in medial prefrontal cortex (mPFC) impaired appetitive trace conditioning at a 2 s trace interval. However, scopolamine was without effect in the aversive procedure, revealing the importance of procedural differences to the demonstration of the drug effect. The finding that blockade of muscarinic receptors in mPFC impaired trace conditioning shows that these receptors are critical modulators of short-term working memory.
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Affiliation(s)
- Marie-Astrid Pezze
- School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Hayley J Marshall
- School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Helen J Cassaday
- School of Psychology, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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Maksymetz J, Moran SP, Conn PJ. Targeting metabotropic glutamate receptors for novel treatments of schizophrenia. Mol Brain 2017; 10:15. [PMID: 28446243 PMCID: PMC5405554 DOI: 10.1186/s13041-017-0293-z] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 04/04/2017] [Indexed: 12/22/2022] Open
Abstract
Support for the N-methyl-D-aspartate receptor (NMDAR) hypofunction hypothesis of schizophrenia has led to increasing focus on restoring proper glutamatergic signaling as an approach for treatment of this devastating disease. The ability of metabotropic glutamate (mGlu) receptors to modulate glutamatergic neurotransmission has thus attracted considerable attention for the development of novel antipsychotics. Consisting of eight subtypes classified into three groups based on sequence homology, signal transduction, and pharmacology, the mGlu receptors provide a wide range of targets to modulate NMDAR function as well as glutamate release. Recently, allosteric modulators of mGlu receptors have been developed that allow unprecedented selectivity among subtypes, not just groups, facilitating the investigation of the effects of subtype-specific modulation. In preclinical animal models, positive allosteric modulators (PAMs) of the group I mGlu receptor mGlu5 have efficacy across all three symptom domains of schizophrenia (positive, negative, and cognitive). The discovery and development of mGlu5 PAMs that display unique signal bias suggests that efficacy can be retained while avoiding the neurotoxic effects of earlier compounds. Interestingly, mGlu1 negative allosteric modulators (NAMs) appear efficacious in positive symptom models of the disease but are still in early preclinical development. While selective group II mGlu receptor (mGlu2/3) agonists have reached clinical trials but were unsuccessful, specific mGlu2 or mGlu3 receptor targeting still hold great promise. Genetic studies implicated mGlu2 in the antipsychotic effects of group II agonists and mGlu2 PAMs have since entered into clinical trials. Additionally, mGlu3 appears to play an important role in cognition, may confer neuroprotective effects, and thus is a promising target to alleviate cognitive deficits in schizophrenia. Although group III mGlu receptors (mGlu4/6/7/8) have attracted less attention, mGlu4 agonists and PAMs appear to have efficacy across all three symptoms domains in preclinical models. The recent discovery of heterodimers comprising mGlu2 and mGlu4 may explain the efficacy of mGlu4 selective compounds but this remains to be determined. Taken together, compounds targeting mGlu receptors, specifically subtype-selective allosteric modulators, provide a compelling alternative approach to fill the unmet clinical needs for patients with schizophrenia.
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Affiliation(s)
- James Maksymetz
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
| | - Sean P. Moran
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232 USA
- Vanderbilt Center for Neuroscience Drug Discovery, Nashville, TN 37232 USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232 USA
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23
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Johnson MP, Muhlhauser MA, Nisenbaum ES, Simmons RMA, Forster BM, Knopp KL, Yang L, Morrow D, Li DL, Kennedy JD, Swanson S, Monn JA. Broad spectrum efficacy with LY2969822, an oral prodrug of metabotropic glutamate 2/3 receptor agonist LY2934747, in rodent pain models. Br J Pharmacol 2017; 174:822-835. [PMID: 28177520 DOI: 10.1111/bph.13740] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/27/2017] [Accepted: 01/31/2017] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE A body of evidence suggests activation of metabotropic glutamate 2/3 (mGlu2/3 ) receptors would be an effective analgesic in chronic pain conditions. Thus, the analgesic properties of a novel mGlu2/3 receptor agonist prodrug were investigated. EXPERIMENTAL APPROACH After oral absorption, the prodrug LY2969822 rapidly converts to the brain penetrant, potent and subtype-selective mGlu2/3 receptor agonist LY2934747. Behavioural assessments of allodynia, hyperalgesia and nocifensive behaviours were determined in preclinical pain models after administration of LY2969822 0.3-10 mg·kg-1 . In addition, the ability of i.v. LY2934747 to modulate dorsal horn spinal cord wide dynamic range (WDR) neurons in spinal nerve ligated (SNL) rats was assessed. KEY RESULTS Following treatment with LY2934747, the spontaneous activity and electrically-evoked wind-up of WDR neurons in rats that had undergone spinal nerve ligation and developed mechanical allodynia were suppressed. In a model of sensitization, orally administered LY2969822 prevented the nociceptive behaviours induced by an intraplantar injection of formalin. The on-target nature of this effect was confirmed by blockade with an mGlu2/3 receptor antagonist. LY2969822 prevented capsaicin-induced tactile hypersensitivity, reversed the SNL-induced tactile hypersensitivity and reversed complete Freund's adjuvant - induced mechanical hyperalgesia. The mGlu2/3 receptor agonist prodrug demonstrated efficacy in visceral pain models, including a colorectal distension model and partially prevented the nocifensive behaviours in the mouse acetic acid writhing model. CONCLUSIONS AND IMPLICATIONS Following oral administration of the prodrug LY2969822, the mGlu2/3 receptor agonist LY2934747 was formed and this attenuated pain behaviours across a broad range of preclinical pain models.
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Affiliation(s)
- Michael P Johnson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Mark A Muhlhauser
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Eric S Nisenbaum
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Rosa M A Simmons
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Beth M Forster
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Kelly L Knopp
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Lijuan Yang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Denise Morrow
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Dominic L Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Jeffrey D Kennedy
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Steven Swanson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - James A Monn
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
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Olszewski RT, Janczura KJ, Bzdega T, Der EK, Venzor F, O'Rourke B, Hark TJ, Craddock KE, Balasubramanian S, Moussa C, Neale JH. NAAG Peptidase Inhibitors Act via mGluR3: Animal Models of Memory, Alzheimer's, and Ethanol Intoxication. Neurochem Res 2017; 42:2646-2657. [PMID: 28285415 PMCID: PMC5603630 DOI: 10.1007/s11064-017-2181-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 01/08/2017] [Accepted: 01/16/2017] [Indexed: 11/26/2022]
Abstract
Glutamate carboxypeptidase II (GCPII) inactivates the peptide neurotransmitter N-acetylaspartylglutamate (NAAG) following synaptic release. Inhibitors of GCPII increase extracellular NAAG levels and are efficacious in animal models of clinical disorders via NAAG activation of a group II metabotropic glutamate receptor. mGluR2 and mGluR3 knock-out (ko) mice were used to test the hypothesis that mGluR3 mediates the activity of GCPII inhibitors ZJ43 and 2-PMPA in animal models of memory and memory loss. Short- (1.5 h) and long- (24 h) term novel object recognition tests were used to assess memory. Treatment with ZJ43 or 2-PMPA prior to acquisition trials increased long-term memory in mGluR2, but not mGluR3, ko mice. Nine month-old triple transgenic Alzheimer's disease model mice exhibited impaired short-term novel object recognition memory that was rescued by treatment with a NAAG peptidase inhibitor. NAAG peptidase inhibitors and the group II mGluR agonist, LY354740, reversed the short-term memory deficit induced by acute ethanol administration in wild type mice. 2-PMPA also moderated the effect of ethanol on short-term memory in mGluR2 ko mice but failed to do so in mGluR3 ko mice. LY354740 and ZJ43 blocked ethanol-induced motor activation. Both GCPII inhibitors and LY354740 also significantly moderated the loss of motor coordination induced by 2.1 g/kg ethanol treatment. These data support the conclusion that inhibitors of glutamate carboxypeptidase II are efficacious in object recognition models of normal memory and memory deficits via an mGluR3 mediated process, actions that could have widespread clinical applications.
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Affiliation(s)
- Rafal T Olszewski
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Karolina J Janczura
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Tomasz Bzdega
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Elise K Der
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Faustino Venzor
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Brennen O'Rourke
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Timothy J Hark
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Kirsten E Craddock
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Shankar Balasubramanian
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA
| | - Charbel Moussa
- Department of Neuroscience, Georgetown University, Washington, D.C., 20057, USA
| | - Joseph H Neale
- Department of Biology, Georgetown University, 37th and O Sts., N.W., Washington, D.C., 20057-1225, USA.
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25
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Li J, Xie X, Li Y, Liu X, Liao X, Su YA, Si T. Differential Behavioral and Neurobiological Effects of Chronic Corticosterone Treatment in Adolescent and Adult Rats. Front Mol Neurosci 2017; 10:25. [PMID: 28210212 PMCID: PMC5288376 DOI: 10.3389/fnmol.2017.00025] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 01/20/2017] [Indexed: 11/13/2022] Open
Abstract
Adolescence is a critical period with ongoing maturational processes in stress-sensitive systems. While adolescent individuals show heightened stress-induced hormonal responses compared to adults, it is unclear whether and how the behavioral and neurobiological consequences of chronic stress would differ between the two age groups. Here we address this issue by examining the effects of chronic exposure to the stress hormone, corticosterone (CORT), in both adolescent and adult animals. Male Sprague-Dawley (SD) rats were injected intraperitoneally with CORT (40 mg/kg) or vehicle for 21 days during adolescence (post-natal day (PND) 29–49) or adulthood (PND 71–91) and then subjected to behavioral testing or sacrifice for western blot analyses. Despite of similar physical and neuroendocrine effects in both age groups, chronic CORT treatment produced a series of behavioral and neurobiological effects with striking age differences. While CORT-treated adult animals exhibited decreased sucrose preference, increased anxiety levels and cognitive impairment, CORT-treated adolescent animals demonstrated increased sucrose preference, decreased anxiety levels, and increased sensorimotor gating functions. These differential behavioral alterations were accompanied by opposite changes in the two age groups in the expression levels of brain-derived neurotrophic factor (BDNF), the phosphorylation of the obligatory subunit of the NMDA receptor, GluN1, and PSD-95 in rat hippocampus. These results suggest that prolonged glucocorticoid exposure during adolescence produces different behavioral and neurobiological effects from those in adulthood, which may be due to the complex interaction between glucocorticoids and the ongoing neurodevelopmental processes during this period.
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Affiliation(s)
- Jitao Li
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
| | - Xiaomeng Xie
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
| | - Youhong Li
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
| | - Xiao Liu
- Department of Psychiatry and Mental Health, North China University of Science and Technology Tangshan, China
| | - Xuemei Liao
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
| | - Yun-Ai Su
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
| | - Tianmei Si
- National Clinical Research Center for Mental Disorders (Peking University Sixth Hospital/Institute of Mental Health) and the Key Laboratory of Mental Health, Ministry of Health (Peking University) Beijing, China
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26
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Witkin JM, Mitchell SN, Wafford KA, Carter G, Gilmour G, Li J, Eastwood BJ, Overshiner C, Li X, Rorick-Kehn L, Rasmussen K, Anderson WH, Nikolayev A, Tolstikov VV, Kuo MS, Catlow JT, Li R, Smith SC, Mitch CH, Ornstein PL, Swanson S, Monn JA. Comparative Effects of LY3020371, a Potent and Selective Metabotropic Glutamate (mGlu) 2/3 Receptor Antagonist, and Ketamine, a Noncompetitive N-Methyl-d-Aspartate Receptor Antagonist in Rodents: Evidence Supporting the Use of mGlu2/3 Antagonists, for the Treatment of Depression. J Pharmacol Exp Ther 2017; 361:68-86. [PMID: 28138040 DOI: 10.1124/jpet.116.238121] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 01/05/2017] [Indexed: 12/17/2022] Open
Abstract
The ability of the N-methyl-d-aspartate receptor antagonist ketamine to alleviate symptoms in patients suffering from treatment-resistant depression (TRD) is well documented. In this paper, we directly compare in vivo biologic responses in rodents elicited by a recently discovered metabotropic glutamate (mGlu) 2/3 receptor antagonist 2-amino-3-[(3,4-difluorophenyl)sulfanylmethyl]-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY3020371) with those produced by ketamine. Both LY3020371 and ketamine increased the number of spontaneously active dopamine cells in the ventral tegmental area of anesthetized rats, increased O2 in the anterior cingulate cortex, promoted wakefulness, enhanced the efflux of biogenic amines in the prefrontal cortex, and produced antidepressant-related behavioral effects in rodent models. The ability of LY3020371 to produce antidepressant-like effects in the forced-swim assay in rats was associated with cerebrospinal fluid (CSF) drug levels that matched concentrations required for functional antagonist activity in native rat brain tissue preparations. Metabolomic pathway analyses from analytes recovered from rat CSF and hippocampus demonstrated that both LY3020371 and ketamine activated common pathways involving GRIA2 and ADORA1. A diester analog of LY3020371 [bis(((isopropoxycarbonyl)oxy)-methyl) (1S,2R,3S,4S,5R,6R)-2-amino-3-(((3,4-difluorophenyl)thio)methyl)-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylate (LY3027788)] was an effective oral prodrug; when given orally, it recapitulated effects of intravenous doses of LY3020371 in the forced-swim and wake-promotion assays, and augmented the antidepressant-like effects of fluoxetine or citalopram without altering plasma or brain levels of these compounds. The broad overlap of biologic responses produced by LY3020371 and ketamine supports the hypothesis that mGlu2/3 receptor blockade might be a novel therapeutic approach for the treatment of TRD patients. LY3020371 and LY3027788 represent molecules that are ready for clinical tests of this hypothesis.
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Affiliation(s)
- J M Witkin
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - S N Mitchell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - K A Wafford
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - G Carter
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - G Gilmour
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - J Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - B J Eastwood
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - C Overshiner
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - X Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - L Rorick-Kehn
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - K Rasmussen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - W H Anderson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - A Nikolayev
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - V V Tolstikov
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - M-S Kuo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - J T Catlow
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - R Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - S C Smith
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - C H Mitch
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - P L Ornstein
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - S Swanson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
| | - J A Monn
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN (J.M.W., C.O., X.L., L.R.-K., K.R., W.H.A., A.N., V.V.T., M.-S.K., J.T.C., R.L., S.C.S., C.H.M., P.L.O., S.S., J.A.M.); and Lilly Research Laboratories, Eli Lilly and Company, Windlesham, Surrey, United Kingdom (S.N.M., K.A.W., G.C., G.G., J.L., B.J.E.)
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27
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Robbins TW. Neurobehavioural sequelae of social deprivation in rodents revisited: Modelling social adversity for developmental neuropsychiatric disorders. J Psychopharmacol 2016; 30:1082-1089. [PMID: 27678088 DOI: 10.1177/0269881116664450] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The significance of investigating effects of deprivation of social experience in rodents is reviewed in the context of the review by Robbins et al. (1996) in the Journal of Psychopharmacology (10: 39-47). The early development of the paradigm by which rats were reared post-weaning in social isolation is described and compared with other early experience manipulations. The specification of the neural and behavioural phenotype of the isolate is brought up-to-date, focusing on changes in motivation and cognitive function, as well as on contrasting changes in the dopamine and serotonin systems, and in cortical (including hippocampal) structure and function. The relevance of the isolate for animal models of psychiatric disorders such as attention deficit hyperactivity disorder and schizophrenia is reviewed, and it is considered that the paradigm best exemplifies a manipulation that can be applied to test effects of certain forms of social adversity during adolescence on brain development and behaviour.
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Affiliation(s)
- T W Robbins
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
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28
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Chen W, An D, Xu H, Cheng X, Wang S, Yu W, Yu D, Zhao D, Sun Y, Deng W, Tang Y, Yin S. Effects of social isolation and re-socialization on cognition and ADAR1 (p110) expression in mice. PeerJ 2016; 4:e2306. [PMID: 27602277 PMCID: PMC4994079 DOI: 10.7717/peerj.2306] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 07/09/2016] [Indexed: 11/20/2022] Open
Abstract
It has been reported that social isolation stress could be a key factor that leads to cognitive deficit for both humans and rodent models. However, detailed mechanisms are not yet clear. ADAR1 (Adenosine deaminase acting on RNA) is an enzyme involved in RNA editing that has a close relation to cognitive function. We have hypothesized that social isolation stress may impact the expression of ADAR1 in the brain of mice with cognitive deficit. To test our hypothesis, we evaluated the cognition ability of mice isolated for different durations (2, 4, and 8 weeks) using object recognition and object location tests; we also measured ADAR1 expression in hippocampus and cortex using immunohistochemistry and western blot. Our study showed that social isolation stress induced spatial and non-spatial cognition deficits of the tested mice. In addition, social isolation significantly increased both the immunoreactivity and protein expression of ADAR1 (p110) in the hippocampus and frontal cortex. Furthermore, re-socialization could not only recover the cognition deficits, but also bring ADAR1 (p110) immunoreactivity of hippocampus and frontal cortex, as well as ADAR1 (p110) protein expression of hippocampus back to the normal level for the isolated mice in adolescence. In conclusion, social isolation stress significantly increases ADAR1 (p110) expression in the hippocampus and frontal cortex of the mice with cognitive deficit. This finding may open a window to better understand the reasons (e.g., epigenetic change) that are responsible for social isolation-induced cognitive deficit and help the development of novel therapies for the resulted diseases.
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Affiliation(s)
- Wei Chen
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Dong An
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Hong Xu
- Department of Physiology Laboratory, Dalian Medical University, Dalian, China
| | - Xiaoxin Cheng
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Shiwei Wang
- Menzies Research Institute, University of Tasmania, Tasmania, Australia
| | - Weizhi Yu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Deqin Yu
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Dan Zhao
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yiping Sun
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Wuguo Deng
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Yiyuan Tang
- Department of Psychological Sciences, Texas Tech University, Lubbock, United States
| | - Shengming Yin
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
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29
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Pezze MA, Marshall HJ, Cassaday HJ. The dopamine D1 receptor agonist SKF81297 has dose-related effects on locomotor activity but is without effect in a CER trace conditioning procedure conducted with two versus four trials. LEARNING AND MOTIVATION 2016; 55:53-64. [PMID: 27524835 PMCID: PMC4974238 DOI: 10.1016/j.lmot.2016.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In an appetitively motivated procedure, we have previously reported that systemic treatment with the dopamine (DA) D1 receptor agonist SKF81297 (0.4 and 0.8 mg/kg) depressed acquisition at a 2 s inter-stimulus-interval (ISI), suitable to detect trace conditioning impairment. However since DA is involved in reinforcement processes, the generality of effects across appetitively- and aversively-motivated trace conditioning procedures cannot be assumed. The present study tested the effects of SKF81297 (0.4 and 0.8 mg/kg) in an established conditioned emotional response (CER) procedure. Trace-dependent conditioning was clearly shown in two experiments: while conditioning was relatively strong at a 3-s ISI, it was attenuated at a 30-s ISI. This was shown after two (Experiment 1) or four (Experiment 2) conditioning trials conducted in – as far as possible – the same CER procedure. Contrary to prediction, in neither experiment was there any indication that trace conditioning was attenuated by treatment with 0.4 or 0.8 mg/kg SKF81297. In the same rats, locomotor activity was significantly enhanced at the 0.8 mg/kg dose of SKF81297. These results suggest that procedural details of the trace conditioning variant in use are an important determinant of the profile of dopaminergic modulation.
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Affiliation(s)
- M A Pezze
- School of Psychology, University of Nottingham, United Kingdom
| | - H J Marshall
- School of Psychology, University of Nottingham, United Kingdom
| | - H J Cassaday
- School of Psychology, University of Nottingham, United Kingdom
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30
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Shortall SE, Green AR, Fone KC, King MV. Caffeine alters the behavioural and body temperature responses to mephedrone without causing long-term neurotoxicity in rats. J Psychopharmacol 2016; 30:698-706. [PMID: 27257032 DOI: 10.1177/0269881116650408] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Administration of caffeine with 3,4-methylenedioxymethamphetamine (MDMA) alters the pharmacological properties of MDMA in rats. The current study examined whether caffeine alters the behavioural and neurochemical effects of mephedrone, which has similar psychoactive effects to MDMA. Rats received either saline, mephedrone (10 mg/kg), caffeine (10 mg/kg) or combined caffeine and mephedrone intraperitoneally twice weekly on consecutive days for three weeks. Locomotor activity (days 1 and 16), novel object discrimination (NOD, day 2), elevated plus maze (EPM) exploration (day 8), rectal temperature changes (day 9) and pre-pulse inhibition (PPI) of acoustic startle response (day 15) were assessed. Seven days after the final injection, brain regions were collected for the measurement of 5-hydroxytryptamine (5-HT), dopamine and their metabolites. Combined caffeine and mephedrone further enhanced the locomotor response observed following either drug administered alone, and converted mephedrone-induced hypothermia to hyperthermia. Co-administration also abolished mephedrone-induced anxiogenic response on the EPM, but had no effect on NOD or PPI. Importantly, no long-term neurotoxicity was detected following repeated mephedrone alone or when co-administered with caffeine. In conclusion, the study suggests a potentially dangerous effect of concomitant caffeine and mephedrone, and highlights the importance of taking polydrug use into consideration when investigating the acute adverse effect profile of popular recreational drugs.
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Affiliation(s)
- Sinead E Shortall
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, UK
| | - A Richard Green
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, UK
| | - Kevin Cf Fone
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, UK
| | - Madeleine V King
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, UK
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31
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Early life adversities or high fat diet intake reduce cognitive function and alter BDNF signaling in adult rats: Interplay of these factors changes these effects. Int J Dev Neurosci 2016; 50:16-25. [DOI: 10.1016/j.ijdevneu.2016.03.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/01/2016] [Indexed: 01/09/2023] Open
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32
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Watson DJG, King MV, Gyertyán I, Kiss B, Adham N, Fone KCF. The dopamine D₃-preferring D₂/D₃ dopamine receptor partial agonist, cariprazine, reverses behavioural changes in a rat neurodevelopmental model for schizophrenia. Eur Neuropsychopharmacol 2016; 26:208-224. [PMID: 26723167 DOI: 10.1016/j.euroneuro.2015.12.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/19/2015] [Accepted: 12/04/2015] [Indexed: 02/07/2023]
Abstract
Current antipsychotic medication is largely ineffective against the negative and cognitive symptoms of schizophrenia. One promising therapeutic development is to design new molecules that balance actions on dopamine D2 and D3 receptors to maximise benefits and limit adverse effects. This study used two rodent paradigms to investigate the action of the dopamine D3-preferring D3/D2 receptor partial agonist cariprazine. In adult male rats, cariprazine (0.03-0.3 mg/kg i.p.), and the atypical antipsychotic aripiprazole (1-3 mg/kg i.p.) caused dose-dependent reversal of a delay-induced impairment in novel object recognition (NOR). Treating neonatal rat pups with phencyclidine (PCP) and subsequent social isolation produced a syndrome of behavioural alterations in adulthood including hyperactivity in a novel arena, deficits in NOR and fear motivated learning and memory, and a reduction and change in pattern of social interaction accompanied by increased ultrasonic vocalisations (USVs). Acute administration of cariprazine (0.1 and 0.3 mg/kg) and aripiprazole (3 mg/kg) to resultant adult rats reduced neonatal PCP-social isolation induced locomotor hyperactivity and reversed NOR deficits. Cariprazine (0.3 mg/kg) caused a limited reversal of the social interaction deficit but neither drug affected the change in USVs or the deficit in fear motivated learning and memory. Results suggest that in the behavioural tests investigated cariprazine is at least as effective as aripiprazole and in some paradigms it showed additional beneficial features further supporting the advantage of combined dopamine D3/D2 receptor targeting. These findings support recent clinical studies demonstrating the efficacy of cariprazine in treatment of negative symptoms and functional impairment in schizophrenia patients.
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Affiliation(s)
- David J G Watson
- School of Life Sciences, Queen׳s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Madeleine V King
- School of Life Sciences, Queen׳s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK
| | - Istvan Gyertyán
- Pharmacological and Safety Research, Gedeon Richter Plc, Gyömrői út 19-21, Budapest H-1103 Hungary
| | - Béla Kiss
- Pharmacological and Safety Research, Gedeon Richter Plc, Gyömrői út 19-21, Budapest H-1103 Hungary
| | - Nika Adham
- Forest Research Institute, Inc., Harborside Financial Center, Plaza V, Jersey City, NJ 07311, USA
| | - Kevin C F Fone
- School of Life Sciences, Queen׳s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
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33
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Witkin JM, Ornstein PL, Mitch CH, Li R, Smith SC, Heinz BA, Wang XS, Xiang C, Carter JH, Anderson WH, Li X, Broad LM, Pasqui F, Fitzjohn SM, Sanger HE, Smith JL, Catlow J, Swanson S, Monn JA. In vitro pharmacological and rat pharmacokinetic characterization of LY3020371, a potent and selective mGlu 2/3 receptor antagonist. Neuropharmacology 2015; 115:100-114. [PMID: 26748052 DOI: 10.1016/j.neuropharm.2015.12.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 12/09/2015] [Accepted: 12/22/2015] [Indexed: 12/27/2022]
Abstract
Metabotropic glutamate 2/3 (mGlu2/3) receptors are of considerable interest owing to their role in modulating glutamate transmission via presynaptic, postsynaptic and glial mechanisms. As part of our ongoing efforts to identify novel ligands for these receptors, we have discovered (1S,2R,3S,4S,5R,6R)-2-amino-3-[(3,4-difluorophenyl)sulfanylmethyl]-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid; (LY3020371), a potent and selective orthosteric mGlu2/3 receptor antagonist. In this account, we characterize the effects of LY3020371 in membranes and cells expressing human recombinant mGlu receptor subtypes as well as in native rodent and human brain tissue preparations, providing important translational information for this molecule. In membranes from cells expressing recombinant human mGlu2 and mGlu3 receptor subtypes, LY3020371.HCl competitively displaced binding of the mGlu2/3 agonist ligand [3H]-459477 with high affinity (hmGlu2 Ki = 5.26 nM; hmGlu3 Ki = 2.50 nM). In cells expressing hmGlu2 receptors, LY3020371.HCl potently blocked mGlu2/3 agonist (DCG-IV)-inhibited, forskolin-stimulated cAMP formation (IC50 = 16.2 nM), an effect that was similarly observed in hmGlu3-expressing cells (IC50 = 6.21 nM). Evaluation of LY3020371 in cells expressing the other human mGlu receptor subtypes revealed high mGlu2/3 receptor selectivity. In rat native tissue assays, LY3020371 demonstrated effective displacement of [3H]-459477 from frontal cortical membranes (Ki = 33 nM), and functional antagonist activity in cortical synaptosomes measuring both the reversal of agonist-suppressed second messenger production (IC50 = 29 nM) and agonist-inhibited, K+-evoked glutamate release (IC50 = 86 nM). Antagonism was fully recapitulated in both primary cultured cortical neurons where LY3020371 blocked agonist-suppressed spontaneous Ca2+ oscillations (IC50 = 34 nM) and in an intact hippocampal slice preparation (IC50 = 46 nM). Functional antagonist activity was similarly demonstrated in synaptosomes prepared from epileptic human cortical or hippocampal tissues, suggesting a translation of the mGlu2/3 antagonist pharmacology from rat to human. Intravenous dosing of LY3020371 in rats led to cerebrospinal fluid drug levels that are expected to effectively block mGlu2/3 receptors in vivo. Taken together, these results establish LY3020371 as an important new pharmacological tool for studying mGlu2/3 receptors in vitro and in vivo. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
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Affiliation(s)
- Jeffrey M Witkin
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Paul L Ornstein
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Charles H Mitch
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Renhua Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Stephon C Smith
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Beverly A Heinz
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Xu-Shan Wang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Chuanxi Xiang
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Joan H Carter
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Wesley H Anderson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Xia Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | | | | | | | | | | | - John Catlow
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Steven Swanson
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - James A Monn
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA.
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34
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Wierońska JM, Zorn SH, Doller D, Pilc A. Metabotropic glutamate receptors as targets for new antipsychotic drugs: Historical perspective and critical comparative assessment. Pharmacol Ther 2015; 157:10-27. [PMID: 26549541 DOI: 10.1016/j.pharmthera.2015.10.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this review, we aim to present, discuss and clarify our current understanding regarding the prediction of possible antipsychotic effects of metabotropic glutamate (mGlu) receptor ligands. The number of preclinical trials clearly indicates, that this group of compounds constitutes an excellent alternative to presently used antipsychotic therapy, being effective not only to positive, but also negative and cognitive symptoms of schizophrenia. Although the results of clinical trials that were performed for the group of mGlu2/3 agonists were not so enthusiastic as in animal studies, they still showed that mGlu ligands do not induced variety of side effects typical for presently used antipsychotics, and were generally well tolerated. The lack of satisfactory effectiveness towards schizophrenia symptoms of mGlu2/3 activators in humans could be a result of variety of uncontrolled factors and unidentified biomarkers different for each schizophrenia patient, that should be taken into consideration in the future set of clinical trials. The subject is still open for further research, and the novel classes of mGlu5 or mGlu2/3 agonists/PAMs were recently introduced, including the large group of compounds from the third group of mGlu receptors, especially of mGlu4 subtype. Finally, more precise treatment based on simultaneous administration of minimal doses of the ligands for two or more receptors, seems to be promising in the context of symptoms-specific schizophrenia treatment.
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Affiliation(s)
- Joanna M Wierońska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland
| | | | | | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Krakow, Poland.
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Ligation of metabotropic glutamate receptor 3 (Grm3) ameliorates lupus-like disease by reducing B cells. Clin Immunol 2015; 160:142-54. [DOI: 10.1016/j.clim.2015.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/27/2015] [Accepted: 05/31/2015] [Indexed: 11/22/2022]
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Li ML, Hu XQ, Li F, Gao WJ. Perspectives on the mGluR2/3 agonists as a therapeutic target for schizophrenia: Still promising or a dead end? Prog Neuropsychopharmacol Biol Psychiatry 2015; 60:66-76. [PMID: 25724760 PMCID: PMC4426221 DOI: 10.1016/j.pnpbp.2015.02.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/16/2015] [Accepted: 02/17/2015] [Indexed: 01/08/2023]
Abstract
Group II metabotropic glutamate receptor (mGluR2/3) agonists once showed promise as non-dopaminergic antipsychotic drugs because of their efficacy in alleviating symptoms of schizophrenia (SZ) in both animal models and human patients. However, the recent failure of Phase III clinical trials dealt a huge blow to the scientific community and the aftershock of the setback in mGluR2/3 research can be felt everywhere from grant support and laboratory studies to paper publication. An immediate question raised is whether mGluR2/3 is still a promising therapeutic target for schizophrenia. Answering this question is not easy, but apparently a new strategy is needed. This article provides a focused review of literature on the study of mGluR2/3 agonists, especially on mGluR2/3 agonists' mechanism of action and efficacy in both normal conditions and animal models of SZ, as well as clinical studies in human patients with the disease. We argue that the cellular and molecular actions of mGluR2/3 agonists, the distinct roles between mGluR2 and mGluR3, as well as their effects on different stages of the disease and different subpopulations of patients, remain incompletely studied. Until the mechanisms associated with mGluR2/3 are clearly elucidated and all treatment options are tested, it would be a great mistake to terminate the study of mGluR2/3 as a therapeutic target for schizophrenia. This review will thus shed light on the comprehensive features of the translational potential mGluR2/3 agonists as well as the need for further research into the more selective activation of mGluR2.
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Affiliation(s)
- Meng-Lin Li
- Drexel University College of Medicine, Philadelphia, PA, USA,Department of Rehabilitation, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Xi-Quan Hu
- Department of Rehabilitation, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Feng Li
- Department of Neurobiology and Anatomy, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Wen-Jun Gao
- Drexel University College of Medicine, Philadelphia, PA, USA.
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Khodaie B, Lotfinia AA, Ahmadi M, Lotfinia M, Jafarian M, Karimzadeh F, Coulon P, Gorji A. Structural and functional effects of social isolation on the hippocampus of rats with traumatic brain injury. Behav Brain Res 2015; 278:55-65. [DOI: 10.1016/j.bbr.2014.09.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/04/2014] [Accepted: 09/21/2014] [Indexed: 01/08/2023]
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Isolation rearing effects on probabilistic learning and cognitive flexibility in rats. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2014; 14:388-406. [PMID: 23943516 DOI: 10.3758/s13415-013-0204-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Isolation rearing is a neurodevelopmental manipulation that produces neurochemical, structural, and behavioral alterations in rodents that in many ways are consistent with schizophrenia. Symptoms induced by isolation rearing that mirror clinically relevant aspects of schizophrenia, such as cognitive deficits, open up the possibility of testing putative therapeutics in isolation-reared animals prior to clinical development. We investigated what effect isolation rearing would have on cognitive flexibility, a cognitive function characteristically disrupted in schizophrenia. For this purpose, we assessed cognitive flexibility using between- and within-session probabilistic reversal-learning tasks based on clinical tests. Isolation-reared rats required more sessions, though not more task trials, to acquire criterion performance in the reversal phase of the task, and were slower to adjust their task strategy after reward contingencies were switched. Isolation-reared rats also completed fewer trials and exhibited lower levels of overall activity in the probabilistic reversal-learning task than did the socially reared rats. This finding contrasted with the elevated levels of unconditioned investigatory activity and reduced levels of locomotor habituation that isolation-reared rats displayed in the behavioral pattern monitor. Finally, isolation-reared rats also exhibited sensorimotor gating deficits, reflected by decreased prepulse inhibition of the startle response, consistent with previous studies. We concluded that isolation rearing constitutes a valuable, noninvasive manipulation for modeling schizophrenia-like cognitive deficits and assessing putative therapeutics.
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Pezze M, McGarrity S, Mason R, Fone KC, Bast T. Too little and too much: hypoactivation and disinhibition of medial prefrontal cortex cause attentional deficits. J Neurosci 2014; 34:7931-46. [PMID: 24899715 PMCID: PMC4044251 DOI: 10.1523/jneurosci.3450-13.2014] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 04/11/2014] [Accepted: 04/24/2014] [Indexed: 12/21/2022] Open
Abstract
Attentional deficits are core symptoms of schizophrenia, contributing strongly to disability. Prefrontal dysfunction has emerged as a candidate mechanism, with clinical evidence for prefrontal hypoactivation and disinhibition (reduced GABAergic inhibition), possibly reflecting different patient subpopulations. Here, we tested in rats whether imbalanced prefrontal neural activity impairs attention. To induce prefrontal hypoactivation or disinhibition, we microinfused the GABA-A receptor agonist muscimol (C4H6N2O2; 62.5, 125, 250 ng/side) or antagonist picrotoxin (C30H34O13; 75, 150, 300 ng/side), respectively, into the medial prefrontal cortex. Using the five-choice serial reaction time (5CSRT) test, we showed that both muscimol and picrotoxin impaired attention (reduced accuracy, increased omissions). Muscimol also impaired response control (increased premature responses). In addition, muscimol dose dependently reduced open-field locomotor activity, whereas 300 ng of picrotoxin caused locomotor hyperactivity; sensorimotor gating (startle prepulse inhibition) was unaffected. Therefore, infusion effects on the 5CSRT test can be dissociated from sensorimotor effects. Combining microinfusions with in vivo electrophysiology, we showed that muscimol inhibited prefrontal firing, whereas picrotoxin increased firing, mainly within bursts. Muscimol reduced and picrotoxin enhanced bursting and both drugs changed the temporal pattern of bursting. Picrotoxin also markedly enhanced prefrontal LFP power. Therefore, prefrontal hypoactivation and disinhibition both cause attentional deficits. Considering the electrophysiological findings, this suggests that attention requires appropriately tuned prefrontal activity. Apart from attentional deficits, prefrontal disinhibition caused additional neurobehavioral changes that may be relevant to schizophrenia pathophysiology, including enhanced prefrontal bursting and locomotor hyperactivity, which have been linked to psychosis-related dopamine hyperfunction.
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Affiliation(s)
- Marie Pezze
- School of Psychology, Neuroscience@Nottingham, and
| | | | - Rob Mason
- Neuroscience@Nottingham, and School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Kevin C Fone
- Neuroscience@Nottingham, and School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Tobias Bast
- School of Psychology, Neuroscience@Nottingham, and
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Gaskin PLR, Alexander SPH, Fone KCF. Neonatal phencyclidine administration and post-weaning social isolation as a dual-hit model of 'schizophrenia-like' behaviour in the rat. Psychopharmacology (Berl) 2014; 231:2533-45. [PMID: 24402141 DOI: 10.1007/s00213-013-3424-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 12/16/2013] [Indexed: 01/07/2023]
Abstract
RATIONALE Schizophrenia is a debilitating disorder comprising positive, negative and cognitive deficits with a poorly defined neurobiological aetiology; therefore, animal models with greater translational reliability are essential to develop improved therapies. OBJECTIVES This study combines two developmental challenges in rats, neonatal phencyclidine (PCP) injection and subsequent rearing in social isolation from weaning, to attempt to produce more robust behavioural deficits with greater translational relevance to schizophrenia than either challenge alone. METHODS Forty-two male Lister-hooded rat pups received the N-methyl-D-aspartate (NMDA) receptor antagonist, phencyclidine (PCP, 10 mg/kg, s.c.), or vehicle on post-natal day (PND) 7, 9 and 11 and were weaned on PND 23 into group housing (saline-treated n = 11 or PCP-treated n = 10) or isolation (saline n = 10 or PCP n = 11). Six weeks post-weaning, novelty- and PCP-induced (3.2 mg/kg) locomotor activity, novel object discrimination, prepulse inhibition of acoustic startle and contextual memory in a conditioned emotion response (CER) were recorded. RESULTS Isolation rearing alone significantly elevated baseline locomotor activity and induced visual recognition memory impairment in novel object discrimination. Neonatal PCP treatment did not induce locomotor sensitisation to a subsequent acute PCP injection, but it impaired prepulse inhibition when combined with isolation rearing. CER freezing behaviour was significantly reduced by isolation rearing but an even greater effect occurred when combined with neonatal PCP treatment. CONCLUSIONS Neonatal PCP and isolation rearing both produce behavioural deficits in adult rats, but combined treatment caused a wider range of more severe cognitive impairments, providing a more comprehensive preclinical model to determine the neurobiological aetiology of schizophrenia than either treatment alone.
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Affiliation(s)
- Philip L R Gaskin
- School of Life Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
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Pitsikas N, Markou A. The metabotropic glutamate 2/3 receptor agonist LY379268 counteracted ketamine-and apomorphine-induced performance deficits in the object recognition task, but not object location task, in rats. Neuropharmacology 2014; 85:27-35. [PMID: 24859609 DOI: 10.1016/j.neuropharm.2014.05.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/29/2014] [Accepted: 05/03/2014] [Indexed: 10/25/2022]
Abstract
Experimental evidence indicates that the non competitive N-methyl-d-aspartate (NMDA) receptor antagonist ketamine and the mixed dopamine (DA) D1/D2 receptor agonist apomorphine induce schizophrenia-like symptoms in rodents, including cognitive deficits. Activation of Group II metabotropic glutamate 2/3 (mGlu2/3) receptors reduces the excessive glutamate release that is hypothesized to be associated with psychiatric disorders. Thus, mGlu2/3 receptor agonists may reverse deficits induced by excessive glutamate or DA release induced by administration of NMDA receptor antagonists and DA receptor agonists, respectively, and potentially those seen in schizophrenia. LY379268 is a selective mGlu2/3 receptor agonist that has shown to be effective in several animal models of stroke, epilepsy, and drug abuse. The present study investigated whether LY379268 antagonizes non-spatial and spatial recognition memory deficits induced by ketamine and apomorphine administration in rats. To assess the effects of the compounds on non-spatial and spatial recognition memory, the object recognition task and object location task were used. Post-training administration of LY379268 (1-3 mg/kg, i.p.) counteracted ketamine (3 mg/kg, i.p.) and apomorphine (1 mg/kg, i.p.)-induced performance deficits in the object recognition task. In contrast, LY379268 (1-3 mg/kg, i.p.) did not attenuate spatial recognition memory deficits produced by ketamine (3 mg/kg, i.p.) or apomorphine (1 mg/kg, i.p.) in the object location task. The present data show that the mGlu2/3 receptor agonist LY379268 reversed non-spatial, but not spatial, recognition memory deficits induced by NMDA receptor blockade or DA receptor agonism in rodents. Thus, such mGlu2/3 receptor agonists may be efficacious in reversing some memory deficits seen in schizophrenia patients.
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Affiliation(s)
- Nikolaos Pitsikas
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Panepistimiou 3, Biopolis, 41500 Larissa, Greece.
| | - Athina Markou
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
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Napolitano A, Shah K, Schubert MI, Porkess V, Fone KCF, Auer DP. In vivo neurometabolic profiling to characterize the effects of social isolation and ketamine-induced NMDA antagonism: a rodent study at 7.0 T. Schizophr Bull 2014; 40:566-74. [PMID: 23671195 PMCID: PMC3984514 DOI: 10.1093/schbul/sbt067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Continued efforts are undertaken to develop animal models of schizophrenia with translational value in the quest for much needed novel drugs. Existing models mimic specific neurobiological aspects of schizophrenia, but not its full complexity. Here, we used proton magnetic resonance spectroscopy ((1)H-MRS) to assess the metabolic profile in the prefrontal cortex (PFC) of two established models, rearing in social isolation and acute N-methyl-D-aspartate receptor (NMDA-R) antagonism and their combination. Rats reared in social isolation or group housed underwent (1)H-MRS at baseline and dynamically after ketamine challenge (25mg/kg, intraperitoneal) under isoflurane anesthesia. A 7 T animal scanner was used to perform spectra acquisition from the anterior cingulate/medial PFC. LCModel was used for metabolite quantification and effects of rearing and ketamine injection were analyzed. Social isolation did not lead to significant differences in the metabolic profile of the PFC at baseline. Ketamine induced a significant increase in glutamine in both groups with significance specifically reached by the group-housed animals alone. Only rats reared in social isolation showed a significant 11% γ-aminobutyric acid (GABA) decrease. This study provides preliminary evidence that social interactions in early life predict the glutamatergic and GABAergic response to acute NMDA-R blockade. The similarity between the prefrontal GABA reduction in patients with schizophrenia and in rats reared as social isolates after challenge with ketamine suggests good potential translational value of this combined animal model for drug development.
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Affiliation(s)
- Antonio Napolitano
- *To whom correspondence should be addressed; tel: +39 06 68592437, fax: +39 06 68593856, e-mail:
| | - Khalid Shah
- Division of Radiological and Imaging Sciences, School of Clinical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, UK
| | - Mirjam I. Schubert
- Division of Radiological and Imaging Sciences, School of Clinical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, UK
| | - Veronica Porkess
- School of Biomedical Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
| | - Kevin C. F. Fone
- School of Biomedical Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
| | - Dorothee P. Auer
- Division of Radiological and Imaging Sciences, School of Clinical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, UK
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Sławińska A, Wierońska JM, Stachowicz K, Marciniak M, Lasoń-Tyburkiewicz M, Gruca P, Papp M, Kusek M, Tokarski K, Doller D, Pilc A. The antipsychotic-like effects of positive allosteric modulators of metabotropic glutamate mGlu4 receptors in rodents. Br J Pharmacol 2014; 169:1824-39. [PMID: 23714045 DOI: 10.1111/bph.12254] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 04/24/2013] [Accepted: 05/12/2013] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND AND PURPOSE Because agonists at metabotropic glutamate receptors exert beneficial effects in schizophrenia, we have assessed the actions of Lu AF21934 and Lu AF32615, two chemically distinct, selective and brain-penetrant positive allosteric modulators (PAMs) of the mGlu4 receptor, in several tests reflecting positive, negative and cognitive symptoms of schizophrenia in rodents. EXPERIMENTAL APPROACH Hyperactivity induced by MK-801 or amphetamine and head twitches induced by 2,5-dimethoxy-4-iodoamphetamine (DOI) in mice were used as models for positive symptoms. Disruption of social interaction and spatial delayed alternation tests induced by MK-801 in rats were used as models for negative and cognitive symptoms of schizophrenia, respectively. KEY RESULTS Lu AF21934 (0.1-5 mg·kg(-1) ) and Lu AF32615 (2-10 mg·kg(-1) ) dose-dependently inhibited hyperactivity induced by MK-801 or amphetamine. They also antagonized head twitches and increased frequency of spontaneous excitatory postsynaptic currents (EPSCs) in brain slices, induced by DOI. In mice lacking the mGlu4 receptor (mGlu4 (-/-) ) mice, Lu AF21934 did not antagonize DOI-induced head twitches. MK-801-induced disruption in the social interaction test was decreased by Lu AF21934 at 0.5 mg·kg(-1) and by Lu AF32615 at 10 mg·kg(-1) . In the delayed spatial alternation test, Lu AF21934 was active at 1 and 2 mg·kg(-1) , while Lu AF32615 was active at 10 mg·kg(-1) . CONCLUSIONS AND IMPLICATIONS We propose that activation by PAMs of the mGlu4 receptor is a promising approach to the discovery of novel antipsychotic drugs.
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Affiliation(s)
- Anna Sławińska
- Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
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Lins BR, Ballendine SA, Howland JG. Altered object exploration but not temporal order memory retrieval in an object recognition test following treatment of rats with the group II metabotropic glutamate receptor agonist LY379268. Neurosci Lett 2013; 560:41-5. [PMID: 24361135 DOI: 10.1016/j.neulet.2013.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/08/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
Abstract
Temporal order memory refers to the ability to distinguish past experiences in the order that they occurred. Temporal order memory for objects is often tested in rodents using spontaneous object recognition paradigms. The circuitry mediating memory in these tests is distributed and involves ionotropic glutamate receptors in the perirhinal cortex and medial prefrontal cortex. It is unknown what role, if any, metabotropic glutamate receptors have in temporal order memory for objects. The present experiment examined the role of metabotropic glutamate receptors in temporal memory retrieval using the group II metabotropic glutamate receptor selective agonist LY379268. Rats were trained on a temporal memory test with three phases: two sample phases (60 min between them) in which rats explored two novel objects and a test phase (60 min after the second sample phase) which included a copy of each object previously encountered. Under these conditions, we confirmed that rats showed a significant exploratory preference for the object presented during the first sample phase. In a second experiment, we found that LY379268 (0.3, 1.0, or 3.0mg/kg; i.p.; 30 min before the test phase) had no effect on temporal memory retrieval but dose-dependently reduced time spent exploring the objects. Our results show that enhancing mGluR2 activity under conditions when TM is intact does not influence memory retrieval.
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Affiliation(s)
- Brittney R Lins
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada
| | - Stephanie A Ballendine
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada
| | - John G Howland
- Department of Physiology, University of Saskatchewan, GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK S7N 5E5, Canada.
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Shortall SE, Macerola AE, Swaby RTR, Jayson R, Korsah C, Pillidge KE, Wigmore PM, Ebling FJP, Richard Green A, Fone KCF, King MV. Behavioural and neurochemical comparison of chronic intermittent cathinone, mephedrone and MDMA administration to the rat. Eur Neuropsychopharmacol 2013; 23:1085-95. [PMID: 23051939 DOI: 10.1016/j.euroneuro.2012.09.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 08/10/2012] [Accepted: 09/13/2012] [Indexed: 10/27/2022]
Abstract
The synthetic cathinone derivative, mephedrone, is a controlled substance across Europe. Its effects have been compared by users to 3,4-methylenedioxymethamphetamine (MDMA), but little data exist on its pharmacological properties. This study compared the behavioural and neurochemical effects of mephedrone with cathinone and MDMA in rats. Young-adult male Lister hooded rats received i.p. cathinone (1 or 4 mg/kg), mephedrone (1, 4 or 10mg/kg) or MDMA (10mg/kg) on two consecutive days weekly for 3 weeks or as a single acute injection (for neurochemical analysis). Locomotor activity (LMA), novel object discrimination (NOD), conditioned emotional response (CER) and prepulse inhibition of the acoustic startle response (PPI) were measured following intermittent drug administration. Dopamine, 5-hydroxytryptamine (5-HT) and their major metabolites were measured in striatum, frontal cortex and hippocampus by high performance liquid chromatography 7 days after intermittent dosing and 2h after acute injection. Cathinone (1, 4 mg/kg), mephedrone (10mg/kg) and MDMA (10mg/kg) induced hyperactivity following the first and sixth injections and sensitization to cathinone and mephedrone occurred with chronic dosing. All drugs impaired NOD and mephedrone (10mg/kg) reduced freezing in response to contextual re-exposure during the CER retention trial. Acute MDMA reduced hippocampal 5-HT and 5-HIAA but the only significant effect on dopamine, 5-HT and their metabolites following chronic dosing was altered hippocampal 3,4-dihydroxyphenylacetic acid (DOPAC), following mephedrone (4, 10mg/kg) and MDMA. At the doses examined, mephedrone, cathinone, and MDMA induced similar effects on behaviour and failed to induce neurotoxic damage when administered intermittently over 3 weeks.
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Affiliation(s)
- Sinead E Shortall
- School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK
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Wierońska JM, Sławińska A, Stachowicz K, Łasoń-Tyburkiewicz M, Gruca P, Papp M, Pilc A. The reversal of cognitive, but not negative or positive symptoms of schizophrenia, by the mGlu₂/₃ receptor agonist, LY379268, is 5-HT₁A dependent. Behav Brain Res 2013; 256:298-304. [PMID: 23948211 DOI: 10.1016/j.bbr.2013.08.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/26/2013] [Accepted: 08/02/2013] [Indexed: 11/24/2022]
Abstract
mGlu(2/3) receptor agonists were shown to possess an antipsychotic-like potential in animal studies. Recent clinical investigations revealed that their antipsychotic potential might also manifest in humans. LY379268, the group II mGlu receptor orthosteric agonist, was previously shown to exhibit antipsychotic-like action in animal models of schizophrenia. However, the mechanism of its action is not fully recognized. Here, we decided to investigate the involvement of 5-HT1A receptors in the LY379268-induced antipsychotic effects. We used models of positive, negative and cognitive symptoms of schizophrenia, such as MK-801- and amphetamine-induced hyperactivity tests, DOI-induced head twitches, social interaction and novel object recognition. LY379268 was active in a wide range of doses (0.5-5 mg/kg), depending on the paradigm. The effects of the drug were not antagonized by 5-HT(1A) antagonist, WAY100635 (0.1 mg/kg) in the models of positive and negative symptoms. Conversely, in the novel object recognition test, which exerts cognitive disturbances, the action of LY379268 was antagonized by WAY100635. Concomitantly, the action of a sub-effective dose of the drug was enhanced by the administration of a sub-effective dose of 5-HT(1A) agonist, (R)-(+)-8-Hydroxy-DPAT. Altogether, we propose that the antipsychotic-like action of group II mGlu receptors' agonist is 5-HT(1A) independent in context of positive and negative symptoms, while the action toward cognitive disturbances seems to be 5-HT(1A) dependent.
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Affiliation(s)
- Joanna M Wierońska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland.
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McIntosh AL, Ballard TM, Steward LJ, Moran PM, Fone KCF. The atypical antipsychotic risperidone reverses the recognition memory deficits induced by post-weaning social isolation in rats. Psychopharmacology (Berl) 2013; 228:31-42. [PMID: 23397053 DOI: 10.1007/s00213-013-3011-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/23/2013] [Indexed: 01/31/2023]
Abstract
RATIONALE Rearing rats in isolation from weaning is an established preclinical neurodevelopmental model which induces behavioural deficits with apparent translational relevance to some core symptoms of schizophrenia. OBJECTIVE This study evaluated the ability of the atypical antipsychotic risperidone to reverse behavioural deficits induced by post-weaning social isolation of rat pups and to further characterise the predictive validity of this model. METHOD Forty-five male Lister hooded rats were housed in groups of 3-4 (n = 16) or singly (n = 29) for 4 weeks immediately after weaning on postnatal day (PND) 22-24. On PND 51, novel cage-induced locomotor activity (LMA) was assessed to subdivide rats into groups balanced for behavioural response. On PNDs 58, 59, 65 and 72, rats received either vehicle (1 ml/kg; i.p.) or risperidone (0.2 or 0.5 mg/kg; i.p.) 30 min prior to testing in LMA, novel object discrimination (NOD), prepulse inhibition (PPI) of acoustic startle and conditioned emotional response (CER) learning paradigms, respectively. RESULTS Isolation rearing had no effect on PPI, but produced LMA hyperactivity and impaired NOD and CER compared to group-housed controls. Risperidone caused a dose-dependent reduction in LMA, irrespective of rearing condition, but selectively reversed the NOD deficit in isolation-reared rats. Risperidone did not reverse the isolation rearing-induced CER deficit. CONCLUSIONS Similar to its clinical profile, risperidone only partially reverses the schizophrenic symptomology; since it reversed some, but not all, of the learning and memory deficits induced by post-weaning isolation, the isolation rearing model may be useful to predict antipsychotic activity of novel therapeutic agents.
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Affiliation(s)
- Allison L McIntosh
- School of Biomedical Sciences, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
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48
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Ago Y, Araki R, Tanaka T, Sasaga A, Nishiyama S, Takuma K, Matsuda T. Role of social encounter-induced activation of prefrontal serotonergic systems in the abnormal behaviors of isolation-reared mice. Neuropsychopharmacology 2013; 38:1535-47. [PMID: 23426384 PMCID: PMC3682148 DOI: 10.1038/npp.2013.52] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Isolation-reared male rodents show abnormal behaviors such as hyperlocomotion, aggressive behaviors, deficits of prepulse inhibition, and depression- and anxiety-like behaviors, but the neurochemical mechanism for the effects of psychological stress in these animals is not fully understood. This study examined the effects of social interactions between isolation-reared mice and intruder mice on brain monoaminergic systems. A cage was divided into two compartments by a mesh partition to prevent direct physical interactions. The 20-min encounter with an intruder elicited a restless and hyperexcitable state (hyperactivity) in male, but not in female, isolation-reared mice, whereas encounters with a sleeping intruder or a novel object did not. Although the encounter did not affect prefrontal neuronal-activity-marker c-Fos expression, dopamine (DA) levels, or serotonin (5-HT) levels in male group-reared mice or female isolation-reared mice, it increased prefrontal c-Fos expression, DA levels, and 5-HT levels in male isolation-reared mice. Furthermore, encounter-induced increases in c-Fos expression in the dorsal raphe nucleus and ventral tegmental area, but not in the nucleus accumbens shell, were much greater in isolation-reared than group-reared male mice. A 5-HT1A receptor agonist, a metabotropic glutamate 2/3 receptor agonist, and a gamma-aminobutyric acid A receptor agonist attenuated isolation-induced aggressive behaviors and encounter-induced hyperactivity, c-Fos expression in the prefrontal cortex and dorsal raphe nucleus, and increases in prefrontal 5-HT levels. These findings suggest that the prefrontal DA and 5-HT systems are activated by encounter stimulation in male isolation-reared mice, and the encounter-induced activation of 5-HT system triggers the induction of some abnormal behaviors in male isolation-reared mice. Furthermore, this study implies that the encounter stimulation-induced signal has a pharmacological significance.
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Affiliation(s)
- Yukio Ago
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Ryota Araki
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Tatsunori Tanaka
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Asuka Sasaga
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Saki Nishiyama
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Kazuhiro Takuma
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Toshio Matsuda
- Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan,United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Suita, Osaka, Japan,Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan, Tel: +81 6 6879 8161, Fax: +81 6 6879 8159, E-mail:
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49
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Green MR, McCormick CM. Effects of stressors in adolescence on learning and memory in rodent models. Horm Behav 2013; 64:364-79. [PMID: 23998678 DOI: 10.1016/j.yhbeh.2012.09.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 09/04/2012] [Accepted: 09/23/2012] [Indexed: 02/07/2023]
Abstract
This article is part of a Special Issue "Puberty and Adolescence". Learning and memory is affected by a myriad of factors, including exposure to stressors and the corresponding rise in circulating glucocorticoids. Nevertheless, the effects of stressors depend on the sex, species, the type of stressor used, the duration of exposure, as well as the developmental time-point in which stressors are experienced. Effects of stress in adolescence, however, have received less attention than other developmental periods. In adolescence, the hypothalamic-pituitary-adrenal axis and brain regions involved in learning and memory, which also richly express corticosteroid receptors, are continuing to develop, and thus the effects of stress exposures would be expected to differ from those in adulthood. We conclude from a review of the available literature in animal models that hippocampal function is particularly sensitive to adolescent stressors, and the effects tend to be most evident several weeks after the exposure, suggesting stressors alter the developmental trajectory of the hippocampus.
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Affiliation(s)
- Matthew R Green
- Department of Psychology, Brock University, 500 Glenridge Ave., St. Catharines, Ontario, Canada
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Grivas V, Markou A, Pitsikas N. The metabotropic glutamate 2/3 receptor agonist LY379268 induces anxiety-like behavior at the highest dose tested in two rat models of anxiety. Eur J Pharmacol 2013; 715:105-10. [PMID: 23769742 DOI: 10.1016/j.ejphar.2013.05.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/28/2013] [Accepted: 05/29/2013] [Indexed: 11/19/2022]
Abstract
The activation of Group II metabotropic glutamate 2/3 (mGlu2/3) receptors reduces the excessive glutamate release that is hypothesized to be associated with neurodegenerative and psychiatric disorders. LY379268 is a highly potent mGlu2/3 receptor agonist that has shown efficacy in several animal models of stroke, epilepsy, drug abuse, schizophrenia, and pain. The present study investigated the effects of LY379268 on anxiety-like behavior in rats assessed in the light/dark and open field tests. The effects of LY379268 on motility in a locomotor activity chamber were also investigated in rats. Administration of the two lower doses of LY379268 used (0.3 and 1mg/kg) did not influence rats' performance either in the light/dark or in the open field test. Importantly, the administration of a higher LY379268 dose (3mg/kg) induced decrease in the number of transitions between the light and dark chambers and time spent in the light chamber compared to the vehicle-treated animals in the light/dark test. In the open field test, rats that received 3mg/kg LY379268 made fewer entries and spent less time in the central zone of the apparatus, exhibited a decrease of rearing episodes, but displayed higher grooming activity compared to controls. Nevertheless, the 3mg/kg dose did not alter locomotor activity compared with vehicle-treated rats in a motility test. The present results indicate that the highest LY379268 dose used in this study induced an anxiety-like effect in the light/dark and open field tests that cannot be attributed to changes in locomotor activity, while lower doses had no effect.
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Affiliation(s)
- Vasilios Grivas
- Department of Pharmacology, School of Medicine, University of Thessaly, Mezourlo, P.O. Box 1400, 411-10 Larissa, Greece
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