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Orlowski D, Elfving B, Müller HK, Wegener G, Bjarkam CR. Wistar rats subjected to chronic restraint stress display increased hippocampal spine density paralleled by increased expression levels of synaptic scaffolding proteins. Stress 2012; 15:514-23. [PMID: 22128856 DOI: 10.3109/10253890.2011.643516] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The aim of this study was to investigate whether the previously reported effect of chronic restraint stress (CRS) on hippocampal neuron morphology and spine density is paralleled by a similar change in the expression levels of synaptic scaffolding proteins. Adult male Wistar rats were subjected either to CRS (6 h/day) for 21 days or to control conditions. The resulting brains were divided and one hemisphere was impregnated with Golgi-Cox before coronal sectioning and autometallographic development. Neurons from CA1, CA3b, CA3c, and dentate gyrus (DG) area were reconstructed and subjected to Sholl analysis and spine density estimation. The contralateral hippocampus was used for quantitative real-time polymerase chain reaction and protein analysis of genes associated with spine density and morphology (the synaptic scaffolding proteins: Spinophilin, Homer1-3, and Shank1-3). In the CA3c area, CRS decreased the number of apical dendrites and their total length, whereas CA1 and DG spine density were significantly increased. Analysis of the contralateral hippocampal homogenate displayed an increased gene expression of Spinophilin, Homer1, Shank1, and Shank2 and increased protein expression of Spinophilin and Homer1 in the CRS animals. In conclusion, CRS influences hippocampal neuroplasticity by modulation of dendrite branching pattern and spine density paralleled by increased expression levels of synaptic scaffolding proteins.
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Affiliation(s)
- D Orlowski
- Department of Biomedicine, Faculty of Health Sciences, Aarhus University, Aarhus C, Denmark.
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52
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Sato K. Disruption of spine homeostasis causes dopaminergic compensatory up-regulation, resulting in schizophrenia. Med Hypotheses 2012; 79:304-7. [DOI: 10.1016/j.mehy.2012.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/03/2012] [Accepted: 05/10/2012] [Indexed: 10/28/2022]
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Gruss M, Appenroth D, Flubacher A, Enzensperger C, Bock J, Fleck C, Gille G, Braun K. 9-Methyl-β-carboline-induced cognitive enhancement is associated with elevated hippocampal dopamine levels and dendritic and synaptic proliferation. J Neurochem 2012; 121:924-31. [PMID: 22380576 DOI: 10.1111/j.1471-4159.2012.07713.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
β-Carbolines (BCs) belong to the heterogenous family of carbolines, which have been found exogenously, that is, in various fruits, meats, tobacco smoke, alcohol and coffee, but also endogenously, that is, blood, brain and CSF. These exogenous and endogenous BCs and some of their metabolites can exert neurotoxic effects, however, an unexpected stimulatory effect of 9-methyl-β-carboline (9-me-BC) on dopaminergic neurons in primary mesencephalic cultures was recently discovered. The aim of the present study was to extend our knowledge on the stimulatory effects of 9-me-BC and to test the hypothesis that 9-me-BC may act as a cognitive enhancer. We found that 10 days (but not 5 days) of pharmacological treatment with 9-me-BC (i) improves spatial learning in the radial maze, (ii) elevates dopamine levels in the hippocampal formation, and (iii) results after 10 days of treatment in elongated, more complex dendritic trees and higher spine numbers on granule neurons in the dentate gyrus of 9-me-BC-treated rats. Our results demonstrate that beyond its neuroprotective/neurorestorative and anti-inflammatory effects, 9-me-BC acts as a cognitive enhancer in a hippocampus-dependent task, and that the behavioral effects may be associated with a stimulatory impact on hippocampal dopamine levels and dendritic and synaptic proliferation.
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Affiliation(s)
- Michael Gruss
- Otto von Guericke University Magdeburg, Institute of Biology, Magdeburg, Germany.
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de Bartolomeis A, Tomasetti C. Calcium-Dependent Networks in Dopamine–Glutamate Interaction: The Role of Postsynaptic Scaffolding Proteins. Mol Neurobiol 2012; 46:275-96. [DOI: 10.1007/s12035-012-8293-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/21/2012] [Indexed: 01/11/2023]
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Antipsychotic induced alteration of growth and proteome of rat neural stem cells. Neurochem Res 2012; 37:1649-59. [PMID: 22528831 DOI: 10.1007/s11064-012-0768-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 01/19/2012] [Accepted: 03/27/2012] [Indexed: 01/19/2023]
Abstract
Neural stem cells (NSCs) play a crucial role in the development and maturation of the central nervous system and therefore have the potential to target by therapeutic agents for a wide variety of diseases including neurodegenerative and neuropsychiatric illnesses. It has been suggested that antipsychotic drugs have significant effects on NSC activities. However, the molecular mechanisms underlying antipsychotic-induced changes of NSC activities, particularly growth and protein expression, are largely unknown. NSCs were treated with either haloperidol (HD; 3 μM), risperidone (RS; 3 μM) or vehicle (DMSO) for 96 h. Protein expression profiles were studied through a proteomics approach. RS promoted and HD inhibited the growth of NSCs. Proteomics analysis revealed that 15 protein spots identified as 12 unique proteins in HD-, and 20 protein spots identified as 14 proteins in RS-treated groups, were differentially expressed relative to control. When these identified proteins were compared between the two drug-treated groups, 2 proteins overlapped leaving 10 HD-specific and 12 RS-specific proteins. Further comparison of the overlapped altered proteins of 96 h treatment with the neuroleptics-induced overlapped proteins at 24 h time interval (Kashem et al. [40] in Neurochem Int 55:558-565, 2009) suggested that overlapping altered proteins expression at 24 h was decreased (17 proteins i.e. 53 % of total expressed proteins) with the increase of time (96 h) (2 proteins; 8 % of total expressed proteins). This result indicated that at early stage both drugs showed common mode of action but the action was opposite to each other while administration was prolonged. The opposite morphological pattern of cellular growth at 96 h has been associated with dominant expression of oxidative stress and apoptosis cascades in HD, and activation of growth regulating metabolic pathways in RS treated cells. These results may explain RS induced repairing of neural damage caused by a wide variety of neural diseases including schizophrenia.
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Lennertz L, Wagner M, Wölwer W, Schuhmacher A, Frommann I, Berning J, Schulze-Rauschenbach S, Landsberg MW, Steinbrecher A, Alexander M, Franke PE, Pukrop R, Ruhrmann S, Bechdolf A, Gaebel W, Klosterkötter J, Häfner H, Maier W, Mössner R. A promoter variant of SHANK1 affects auditory working memory in schizophrenia patients and in subjects clinically at risk for psychosis. Eur Arch Psychiatry Clin Neurosci 2012; 262:117-24. [PMID: 21901269 DOI: 10.1007/s00406-011-0233-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 07/26/2011] [Indexed: 12/13/2022]
Abstract
Mutations in postsynaptic scaffolding genes contribute to autism, thus suggesting a role in pathological processes in neurodevelopment. Recently, two de novo mutations in SHANK3 were described in schizophrenia patients. In most cases, abnormal SHANK3 genotype was also accompanied by cognitive disruptions. The present study queries whether common SHANK variants may also contribute to neuropsychological dysfunctions in schizophrenia. We genotyped five common coding or promoter variants located in SHANK1, SHANK2 and SHANK3. A comprehensive test battery was used to assess neuropsychological functions in 199 schizophrenia patients and 206 healthy control subjects. In addition, an independent sample of 77 subjects at risk for psychosis was analyzed for replication of significant findings. We found the T allele of the SHANK1 promoter variant rs3810280 to lead to significantly impaired auditory working memory as assessed with digit span (12.5 ± 3.6 vs. 14.8 ± 4.1, P < .001) in schizophrenia cases, applying strict Bonferroni correction for multiple testing. This finding was replicated for forward digit span in the at-risk sample (7.1 ± 2.0 vs. 8.3 ± 2.0, P = .044). Previously, altered memory functions and reduced dendritic spines and postsynaptic density of excitatory synapses were reported in SHANK1 knock-out mice. Moreover, the atypical neuroleptic clozapine was found to increase SHANK1 density in rats. Our findings suggest a role of SHANK1 in working memory deficits in schizophrenia, which may arise from neurodevelopmental changes to prefrontal cortical areas.
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Affiliation(s)
- Leonhard Lennertz
- Department of Psychiatry and Psychotherapy, University of Bonn, Sigmund-Freud-Straße 25, 53105, Bonn, Germany
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Bringas ME, Morales-Medina JC, Flores-Vivaldo Y, Negrete-Diaz JV, Aguilar-Alonso P, León-Chávez BA, Lazcano-Ortiz Z, Monroy E, Rodríguez-Moreno A, Quirion R, Flores G. Clozapine administration reverses behavioral, neuronal, and nitric oxide disturbances in the neonatal ventral hippocampus rat. Neuropharmacology 2012; 62:1848-57. [DOI: 10.1016/j.neuropharm.2011.12.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 11/18/2011] [Accepted: 12/07/2011] [Indexed: 11/30/2022]
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58
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Bennett M. Schizophrenia: susceptibility genes, dendritic-spine pathology and gray matter loss. Prog Neurobiol 2011; 95:275-300. [DOI: 10.1016/j.pneurobio.2011.08.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/01/2023]
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The putative functional rs1045881 marker of neurexin-1 in schizophrenia and clozapine response. Schizophr Res 2011; 132:121-4. [PMID: 21890328 DOI: 10.1016/j.schres.2011.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 08/09/2011] [Accepted: 08/12/2011] [Indexed: 10/17/2022]
Abstract
Neurexin-1 (NRXN1) modulates recruitment of NMDA receptors. Furthermore, clozapine reduces hyperactivity of NMDA receptors. Thus, regulation of the NRXN1 gene may mediate the efficacy of clozapine at reducing cortical hyperactivity. We examined the putative functional SNP, rs1045881, for association with schizophrenia, and the potential role of this SNP in clozapine response. The rs1045881 variant was not significantly associated with schizophrenia (N=302 case-control pairs), but with clozapine response (N=163; p=0.030). Baseline and BPRS scores after six months revealed a trend for rs1045881 genotype by treatment interaction (p=0.079). In the post hoc analysis, a significant association between BPRS negative symptoms score and genotype was observed (p=0.033). These results suggest that the rs1045881 NRXN1 polymorphism may influence clozapine response.
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Horiguchi M, Huang M, Meltzer HY. Interaction of mGlu2/3 agonism with clozapine and lurasidone to restore novel object recognition in subchronic phencyclidine-treated rats. Psychopharmacology (Berl) 2011; 217:13-24. [PMID: 21432027 DOI: 10.1007/s00213-011-2251-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 03/01/2011] [Indexed: 10/18/2022]
Abstract
RATIONALE Subchronic administration to rodents of the N-methyl-D-aspartate non-competitive antagonist, phencyclidine (PCP), impairs novel object recognition (NOR). Atypical antipsychotic drugs (APDs) reverse the effects of subchronic PCP on NOR. The effect of metabotropic glutamate₂/₃ receptor (mGlu₂/₃) agonists upon NOR is unknown. OBJECTIVES AND METHODS We tested the hypotheses that the mGlu₂/₃ agonist, LY379268, by itself, or in combination with APDs or pimavanserin, a 5-HT(2A) inverse agonist, would reverse the deficit in NOR induced by subchronic treatment with PCP (2 mg/kg, b.i.d., for 7 days). RESULTS The mGlu₂/₃ agonist LY379268 (1 or 3 mg/kg) did not attenuate the PCP-induced NOR deficit. However, together with sub-effective dose of the atypical APDs, clozapine (0.1 mg/kg) or lurasidone (0.03 mg/kg), but not the typical APD, haloperidol (0.1 mg/kg), or pimavanserin (3 mg/kg), LY379268, 1 mg/kg, significantly reversed the PCP-induced NOR deficit. Moreover, the effect of clozapine was blocked by the mGlu₂/₃ antagonist, LY341495 (1 mg/kg). CONCLUSIONS These results indicate that mGlu₂/₃ agonism can potentiate the ability of atypical, but not typical APDs, to ameliorate the effect of subchronic PCP on NOR, that mGlu₂/₃ agonism may contribute to the ability of atypical APDs to acutely reverse the effect of subchronic PCP on NOR, but that by itself, mGlu₂/₃ agonism, is ineffective in this model of cognitive impairment in schizophrenia. These results suggest that mGlu₂/₃ receptor agonism should be investigated as an adjunctive treatment of cognitive impairment in schizophrenia rather than as monotherapy, which may be effective for control of psychosis, but not for cognitive impairment.
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Affiliation(s)
- Masakuni Horiguchi
- Division of Psychopharmacology, Vanderbilt University Medical Center, Nashville, TN 37212, USA
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61
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Dyck BA, Beyaert MGR, Ferro MA, Mishra RK. Medial prefrontal cortical synapsin II knock-down induces behavioral abnormalities in the rat: examining synapsin II in the pathophysiology of schizophrenia. Schizophr Res 2011; 130:250-9. [PMID: 21689907 DOI: 10.1016/j.schres.2011.05.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/17/2011] [Accepted: 05/19/2011] [Indexed: 01/11/2023]
Abstract
Synapsin II is a synaptic vesicle-associated phosphoprotein that has been implicated in the pathophysiology of schizophrenia. Studies have demonstrated reductions in synapsin II mRNA and protein in medial prefrontal cortical post-mortem samples from patients with schizophrenia, genetic associations between synapsin II and schizophrenia, and synapsin II protein regulation by dopamine receptor activation. Collectively, this research indicates a relationship between synapsin II dysregulation and schizophrenia; however, it remains unknown whether perturbations in synapsin II play a role in the pathophysiology of this disease. The aim of this project was to evaluate animals with selective knock-down of synapsin II in the medial prefrontal cortex. After continuous infusion of synapsin II antisense sequences, animals were examined for the presence of schizophrenic-like behavioral phenotypes and assessed on the response to clinically relevant antipsychotic drugs. Our results indicate that rats with selective reductions in medial prefrontal cortical synapsin II demonstrate deficits in sensorimotor gating (prepulse inhibition), reduced social behavior, and hyperlocomotion, which are corrected by the atypical antipsychotic drug olanzapine. Additionally, synapsin II knock-down disrupts serial search efficiency. These behavioral changes are accompanied by reductions in vesicular neurotransmitter transporter protein concentrations for glutamate (VGLUT1 and VGLUT2) and GABA (VGAT), without affecting dopamine (VMAT2). These results implicate a causal role for decreased synapsin II in the medial prefrontal cortex in the pathophysiology of schizophrenia and the mechanisms of aberrant prefrontal cortical circuitry, and suggest that synapsin II may potentially serve as a novel therapeutic target for this disorder.
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Affiliation(s)
- Bailey A Dyck
- Department of Psychiatry and Behavioral Neurosciences, McMaster University, Hamilton, ON, Canada, L8N 3Z5
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62
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Iasevoli F, Ambesi-Impiombato A, Fiore G, Panariello F, Muscettola G, de Bartolomeis A. Pattern of acute induction of Homer1a gene is preserved after chronic treatment with first- and second-generation antipsychotics: effect of short-term drug discontinuation and comparison with Homer1a-interacting genes. J Psychopharmacol 2011; 25:875-87. [PMID: 20147574 DOI: 10.1177/0269881109358199] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Homer1a is a glutamate-related gene whose expression is induced by antipsychotics acutely (i.e. 90 min after treatment). Acute Homer1a expression is preserved after prolonged antipsychotic treatments, while the effects of short-term discontinuation after chronic antipsychotic treatment have not yet been assessed. Here, we studied early and long-term effects on gene expression by antipsychotics for Homer1a and other components of glutamatergic synapses. In the first paradigm, we evaluated Homer1a acute expression by single administration of antipsychotics (haloperidol 0.8 mg/kg, ziprasidone 10 and 4 mg/kg, clozapine 15 mg/kg). Haloperidol and ziprasidone induced Homer1a in the striatum. Induction by ziprasidone was dose-dependent. These results suggest that acute Homer1a expression correlates with dopaminergic affinity and motor side effects of antipsychotics. In the second paradigm, we studied antipsychotic-mediated long-term changes in Homer1a and glutamate-related genes. Rats were treated (21 days) with haloperidol 0.8 mg/kg, ziprasidone 4 mg/kg, or vehicle, and then sacrificed at 90 min (early time-point) or 24 h (delayed time-point) after last injection. Gene expression at these two time-points was compared. Homer1a preserved its pattern of expression at the early but not at the delayed time-point. Significant changes were also observed for PSD-95. The results suggest that Homer1a preserves its expression profile after chronic antipsychotics.
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Affiliation(s)
- Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapy, Section of Psychiatry, Department of Neuroscience, University School of Medicine 'Federico II', Naples, Italy
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63
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Lindquist DM, Dunn RS, Cecil KM. Long term antipsychotic treatment does not alter metabolite concentrations in rat striatum: an in vivo magnetic resonance spectroscopy study. Schizophr Res 2011; 128:83-90. [PMID: 21429713 PMCID: PMC3085587 DOI: 10.1016/j.schres.2011.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 02/18/2011] [Accepted: 02/24/2011] [Indexed: 10/18/2022]
Abstract
Proton magnetic resonance spectroscopy (MRS) studies of schizophrenic patients generally reveal reduced levels of N-acetyl aspartate (NAA) when compared with healthy controls. Whether this reduction is due to the disease or to the drugs used for treatment remains an open question. Numerous human and animal studies have attempted to determine the effects of antipsychotics on NAA levels with mixed results. The majority of the animal studies were ex vivo, which may not accurately reflect the in vivo situation, and limitations of the human studies include previous or concomitant medications or other confounds. To overcome these limitations, we dosed 10 rats/group for six months via drinking water with 0.2 or 2 mg/kg/day haloperidol or 10 or 30 mg/kg/day clozapine. Control rats received unadulterated water. Proton MRS data were collected longitudinally over the six month period from a 64 μL voxel containing primarily the right striatum prior to and monthly during drug administration and used to estimate the concentrations of NAA, creatine, and choline. Ratios of NAA, choline, inositol and glutamate+glutamine to creatine were also calculated. Only the Cho/Cr ratio showed a significant time-by-treatment effect (p=0.0285). These results are in agreement with previous studies of the striatum. However, regional and disease-specific effects remain unresolved.
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64
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Souza RP, Meltzer HY, Lieberman JA, Le Foll B, Kennedy JL. Influence of neurexin 1 (NRXN1) polymorphisms in clozapine response. Hum Psychopharmacol 2010; 25:582-5. [PMID: 20860064 DOI: 10.1002/hup.1146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 08/11/2010] [Indexed: 11/06/2022]
Abstract
Schizophrenia patients show alterations in the synaptic connectivity. However, it remains unknown whether antipsychotic response may be altered depending on the synaptic connectivity. We tested this association using polymorphisms in the neurexin 1 gene (NRXN1). Large NRXN1 deletions have also been associated with schizophrenia. We genotyped four variants in 140 schizophrenia patients assessed prospectively for clozapine response after 6 months. We observed a trend toward association of clozapine response with the rs12467557 (permuted p = 0.051). These results should be read with caution before independent replication.
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Affiliation(s)
- Renan P Souza
- Neurogenetics Section, Neuroscience Department, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
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65
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Iasevoli F, Tomasetti C, Marmo F, Bravi D, Arnt J, de Bartolomeis A. Divergent acute and chronic modulation of glutamatergic postsynaptic density genes expression by the antipsychotics haloperidol and sertindole. Psychopharmacology (Berl) 2010; 212:329-44. [PMID: 20652539 DOI: 10.1007/s00213-010-1954-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Accepted: 07/09/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE A pivotal role for glutamate in the pathophysiology and treatment of schizophrenia has been suggested. Few reports have investigated the impact of antipsychotics on postsynaptic density (PSD) molecules involved in glutamatergic transmission and synaptic remodeling. Homer is a key PSD molecule putatively implicated in schizophrenia. OBJECTIVES We studied the effect, in acute and chronic paradigms, of a first and a second generation antipsychotic (haloperidol and sertindole, respectively) on the expression of Homer1a and Homer-interacting PSD molecules. RESULTS In the acute paradigm, Homer1a expression was induced by haloperidol but not sertindole in the striatum, consistent with the less propensity of sertindole to affect nigrostriatal neurotransmission. The profile of expression of two other inducible genes, Ania3 and Arc, was highly similar to Homer1a. In the cortex, haloperidol reduced Homer1a and induced Ania3. In the chronic paradigm, striatal expression of Homer1a and Ania3 resembled that observed in the acute paradigm. In the cortex, haloperidol induced Homer1a, while sertindole did not. Homer1b expression was increased by haloperidol in the striatum and cortex whereas sertindole selectively induced Homer1b in the cortex. The expression of mGluR5 was increased by both antipsychotics. A modulation by haloperidol was also seen for PSD-95 and αCaMKII. CONCLUSIONS These results suggest that haloperidol and sertindole may significantly modulate glutamatergic transcripts of the postsynaptic density. Sertindole induces constitutive genes in the cortex predominantly, which may correlate with its propensity to improve cognitive functions. Haloperidol preferentially modulates gene expression in the striatum, consistent with its action at nigrostriatal projections and its propensity to give motor side effects.
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Affiliation(s)
- Felice Iasevoli
- Laboratory of Molecular Psychiatry and Psychopharmacotherapeutics, Section of Psychiatry, Department of Neuroscience, University School of Medicine Federico II, Edificio 18, Via Pansini 5, 80131, Naples, Italy
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Hayashi-Takagi A, Sawa A. Disturbed synaptic connectivity in schizophrenia: convergence of genetic risk factors during neurodevelopment. Brain Res Bull 2010; 83:140-6. [PMID: 20433911 DOI: 10.1016/j.brainresbull.2010.04.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 02/07/2010] [Accepted: 04/19/2010] [Indexed: 12/13/2022]
Abstract
The pathological mechanisms underlying schizophrenia are unclear. Although genetic susceptibility factors for schizophrenia likely influence neurodevelopmental processes, the onset of the disease is in adolescence and young adulthood. Here we review recent literatures implicating neurodevelopmental deficits in schizophrenia and discuss how genetic factors are involved in the processes toward onset of the disease. We emphasize the importance of postnatal glutamate synapse development in the pathology of the disorder. These genetic risk factors contribute to the process possibly in a synergistic manner. The notion of signal pathways involving more than one genetic factor is in accord with the multifactorial nature of schizophrenia.
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Affiliation(s)
- Akiko Hayashi-Takagi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, United States.
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67
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Ruscher K, Erickson A, Kuric E, Inácio AR, Wieloch T. Effects of chronic Clozapine administration on apolipoprotein D levels and on functional recovery following experimental stroke. Brain Res 2010; 1321:152-63. [PMID: 20083089 DOI: 10.1016/j.brainres.2010.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/07/2010] [Accepted: 01/09/2010] [Indexed: 10/20/2022]
Abstract
Elevated brain levels of apolipoprotein D (ApoD) correlate with improved neurological recovery after experimental stroke. Hence, a pharmacological induction of ApoD in the postischemic brain could be beneficial for recovery after stroke. Here we investigated the effect of Clozapine, a compound that increases the expression of ApoD, in two rat models of experimental stroke. Rats were subjected to permanent occlusion of the middle cerebral artery (pMCAO) and treated with Clozapine (i.p. 10 mg/kg body weight) or saline for 8 or 28 days starting on the second day after MCAO. ApoD levels increased by 35% in the peri-infarct area after 10 and 30 days after pMCAO, mainly in neuron-specific nuclear protein (NeuN) positive neurons and glial fibrillary acidic protein (GFAP) positive astrocytes. Clozapine did not affect the neurological deficit assessed by the rotating pole test and a grip strength test at 7 days, 14 days, 21 days, and 28 days after pMCAO. Functional outcome and the infarct size were similar in rats subjected to transient MCAO and injected with Clozapine (i.p. 10 mg/kg body weight) or saline for 26 days starting on the second day after tMCAO. We conclude that Clozapine affects cellular processes involved in peri-infarct tissue reorganization, but does not affect functional recovery after MCAO.
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Affiliation(s)
- Karsten Ruscher
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, University of Lund, BMC A13, S-22184 Lund, Sweden.
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68
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Ertugrul A, Volkan-Salanci B, Basar K, Karli Oguz K, Demir B, Ergun EL, Senturk S, Erbas B, Cila A, Ulug B. The effect of clozapine on regional cerebral blood flow and brain metabolite ratios in schizophrenia: relationship with treatment response. Psychiatry Res 2009; 174:121-9. [PMID: 19837567 DOI: 10.1016/j.pscychresns.2009.04.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2007] [Revised: 01/13/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
Abstract
The purpose of this study was to investigate the effect of clozapine on regional cerebral blood flow (rCBF) and its relationship with response to treatment. In addition, we aimed to study the influence of clozapine on proton magnetic resonance spectroscopy ((1)H-MRS) findings in the dorsolateral prefrontal cortex (DLPFC) in a subgroup of patients. Psychopathology, neurocognitive functioning, and SPECT imaging of 22 patients were assessed at the baseline and 8 weeks after the initiation of clozapine treatment. In 10 of these patients intermediate-echo (TE: 135 ms) single-voxel (1)H-MRS was also performed at the baseline and after 8 weeks. Clozapine treatment increased the right frontal (superior and medial)/caudate perfusion ratio in the whole group, while it increased bilateral frontal (superior and medial)/caudate perfusion ratios in treatment responders. In addition, percentage changes in left and right frontal (superior and medial)/caudate perfusion ratios compared to the baseline were higher in treatment responders than in non-responders. The improvement in attention was related to the increase in percentage change in the right frontal (superior and medial)/caudate perfusion ratio, while the improvement in verbal fluency was related to the increase in percentage changes in both right and left frontal (superior and medial)/caudate perfusion ratios and to right frontal (superior and medial)/thalamus perfusion. Baseline frontal (superior and medial)/thalamus perfusion could explain 32% of the variability of percentage improvements in psychopathology. (1)H-MRS showed that the baseline PANSS general psychopathology score was inversely correlated with the baseline NAA/Cre ratio. An increased NAA/Cre ratio in DLPFC after 8 weeks of clozapine treatment was also revealed by (1)H-MRS. Our SPECT imaging results suggest the presence of an imbalance in fronto-striato-thalamic circuitry that changes with clozapine, especially in the responders, while (1)H-MRS results indicate a supportive effect of clozapine on neuronal integrity.
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Affiliation(s)
- Aygun Ertugrul
- Hacettepe University, Faculty of Medicine, Department of Psychiatry, Ankara, Turkey.
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Chana G, Lucero G, Salaria S, Lozach J, Du P, Woelk C, Everall I. Upregulation of NRG-1 and VAMP-1 in human brain aggregates exposed to clozapine. Schizophr Res 2009; 113:273-6. [PMID: 19502011 PMCID: PMC2759675 DOI: 10.1016/j.schres.2009.05.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 05/14/2009] [Accepted: 05/19/2009] [Indexed: 11/30/2022]
Abstract
Growing genetic evidence has implicated a role for neuregulin-1 (NRG-1) in schizophrenia pathogenesis as well as alterations in SNAP receptor (SNARE) proteins at both gene and protein levels in post-mortem investigations. In relation to a potential therapeutic mechanism for atypical antipsychotic medications, clozapine has been shown to increase both NRG-1 levels and synaptic markers in rodents. As evidence continues to mount for a potential restoration in connectivity by antipsychotic medications being a mode of efficacy we chose to examine the effects of the atypical antipsychotic clozapine and the typical antipsychotic haloperidol on NRG-1 and SNARE protein transcripts in human brain aggregates exposed to plasma levels chronically for a period of three weeks. At the end of this exposure period we performed quantitative real-time PCR to investigate the mRNA levels of NRG-1, VAMP-1 and SNAP-25. Overall we found that clozapine had the ability to upregulate NRG-1 (+3.58 fold change) and VAMP-1 (+1.92) while SNAP-25 remained unchanged. Changes for haloperidol exposed aggregates were below our cut-off of +1.5. Overall the results of our investigation lend further support to atypical antipsychotic medications having the potential to increase levels of neurotrophic and synaptic markers such as NRG-1 and VAMP-1, the former being a strong candidate susceptibility gene for schizophrenia. In the absence of frank neuronal loss in schizophrenia, restoration of neuronal and synaptic functions by atypical antipsychotics in the brains of schizophrenics maybe a key mechanism of therapeutic efficacy by re-establishing normal connectivity and functioning.
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Affiliation(s)
- Gursharan Chana
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093-0603, USA.
| | - Ginger Lucero
- Department Of Psychiatry, University of California, San Diego, La Jolla, CA, 92093-0603
| | - Shahid Salaria
- Department Of Psychiatry, University of California, San Diego, La Jolla, CA, 92093-0603
| | - Jean Lozach
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093-0651
| | - Pinyi Du
- Center for Aids Research, Genomics Core, Department of Medicine, University of California, San Diego, CA, 92093-0716
| | - Christopher Woelk
- Center for Aids Research, Genomics Core, Department of Medicine, University of California, San Diego, CA, 92093-0716
| | - Ian Everall
- Department Of Psychiatry, University of California, San Diego, La Jolla, CA, 92093-0603
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Hozumi Y, Watanabe M, Otani K, Goto K. Diacylglycerol kinase beta promotes dendritic outgrowth and spine maturation in developing hippocampal neurons. BMC Neurosci 2009; 10:99. [PMID: 19691842 PMCID: PMC3224667 DOI: 10.1186/1471-2202-10-99] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Accepted: 08/19/2009] [Indexed: 12/15/2022] Open
Abstract
Background Diacylglycerol kinase (DGK) is an enzyme that phosphorylates diacylglycerol to phosphatidic acid and comprises multiple isozymes of distinct properties. Of DGKs, mRNA signal for DGKβ is strongly detected in the striatum, and one of the transcripts derived from the human DGKβ locus is annotated in GenBank as being differentially expressed in bipolar disorder patients. Recently, we have reported that DGKβ is expressed in medium spiny neurons of the striatum and is highly concentrated at the perisynapse of dendritic spines. However, it remains elusive how DGKβ is implicated in pathophysiological role in neurons at the cellular level. Results In the present study, we investigated the expression and subcellular localization of DGKβ in the hippocampus, together with its functional implication using transfected hippocampal neurons. DGKβ is expressed not only in projection neurons but also in interneurons and is concentrated at perisynaptic sites of asymmetrical synapses. Overexpression of wild-type DGKβ promotes dendrite outgrowth at 7 d in vitro (DIV) and spine maturation at 14 DIV in transfected hippocampal neurons, although its kinase-dead mutant has no effect. Conclusion In the hippocampus, DGKβ is expressed in both projection neurons and interneurons and is accumulated at the perisynapse of dendritic spines in asymmetrical synapses. Transfection experiments suggest that DGKβ may be involved in the molecular machineries of dendrite outgrowth and spinogenesis through its kinase activity.
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Affiliation(s)
- Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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71
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Stephan KE, Friston KJ, Frith CD. Dysconnection in schizophrenia: from abnormal synaptic plasticity to failures of self-monitoring. Schizophr Bull 2009; 35:509-27. [PMID: 19155345 PMCID: PMC2669579 DOI: 10.1093/schbul/sbn176] [Citation(s) in RCA: 814] [Impact Index Per Article: 54.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the last 2 decades, a large number of neurophysiological and neuroimaging studies of patients with schizophrenia have furnished in vivo evidence for dysconnectivity, ie, abnormal functional integration of brain processes. While the evidence for dysconnectivity in schizophrenia is strong, its etiology, pathophysiological mechanisms, and significance for clinical symptoms are unclear. First, dysconnectivity could result from aberrant wiring of connections during development, from aberrant synaptic plasticity, or from both. Second, it is not clear how schizophrenic symptoms can be understood mechanistically as a consequence of dysconnectivity. Third, if dysconnectivity is the primary pathophysiology, and not just an epiphenomenon, then it should provide a mechanistic explanation for known empirical facts about schizophrenia. This article addresses these 3 issues in the framework of the dysconnection hypothesis. This theory postulates that the core pathology in schizophrenia resides in aberrant N-methyl-D-aspartate receptor (NMDAR)-mediated synaptic plasticity due to abnormal regulation of NMDARs by neuromodulatory transmitters like dopamine, serotonin, or acetylcholine. We argue that this neurobiological mechanism can explain failures of self-monitoring, leading to a mechanistic explanation for first-rank symptoms as pathognomonic features of schizophrenia, and may provide a basis for future diagnostic classifications with physiologically defined patient subgroups. Finally, we test the explanatory power of our theory against a list of empirical facts about schizophrenia.
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Affiliation(s)
- Klaas E. Stephan
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK,Laboratory for Social and Neural Systems Research, Institute for Empirical Research in Economics, University of Zurich, Zurich, Switzerland,To whom correspondence should be addressed; tel: +44-207-8337472, fax: +44-207-8131420, e-mail:
| | - Karl J. Friston
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK
| | - Chris D. Frith
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK,Centre of Functionally Integrative Neuroscience (CFIN), Aarhus University Hospital, 8000-Aarhus, Denmark
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Martins-de-Souza D, Gattaz WF, Schmitt A, Rewerts C, Maccarrone G, Dias-Neto E, Turck CW. Prefrontal cortex shotgun proteome analysis reveals altered calcium homeostasis and immune system imbalance in schizophrenia. Eur Arch Psychiatry Clin Neurosci 2009; 259:151-63. [PMID: 19165527 DOI: 10.1007/s00406-008-0847-2] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 09/19/2008] [Indexed: 01/20/2023]
Abstract
Schizophrenia is a complex disease, likely to be caused by a combination of serial alterations in a number of genes and environmental factors. The dorsolateral prefrontal cortex (Brodmann's Area 46) is involved in schizophrenia and executes high-level functions such as working memory, differentiation of conflicting thoughts, determination of right and wrong concepts and attitudes, correct social behavior and personality expression. Global proteomic analysis of post-mortem dorsolateral prefrontal cortex samples from schizophrenia patients and non-schizophrenic individuals was performed using stable isotope labeling and shotgun proteomics. The analysis resulted in the identification of 1,261 proteins, 84 of which showed statistically significant differential expression, reinforcing previous data supporting the involvement of the immune system, calcium homeostasis, cytoskeleton assembly, and energy metabolism in schizophrenia. In addition a number of new potential markers were found that may contribute to the understanding of the pathogenesis of this complex disease.
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Affiliation(s)
- Daniel Martins-de-Souza
- Laboratório de Neurociências, Instituto de Psiquiatria, Universidade de São Paulo, Rua. Dr. Ovidio Pires de Campos, no 785, Consolação, São Paulo, SP 05403-010, Brazil
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Hozumi Y, Fukaya M, Adachi N, Saito N, Otani K, Kondo H, Watanabe M, Goto K. Diacylglycerol kinaseβaccumulates on the perisynaptic site of medium spiny neurons in the striatum. Eur J Neurosci 2008; 28:2409-22. [DOI: 10.1111/j.1460-9568.2008.06547.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Jay T. Effets des antipsychotiques sur la neuroplasticité : données animales. Encephale 2008. [DOI: 10.1016/s0013-7006(08)75512-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Boikess SR, Marshall JF. A sensitizing d-amphetamine regimen induces long-lasting spinophilin protein upregulation in the rat striatum and limbic forebrain. Eur J Neurosci 2008; 28:2099-107. [DOI: 10.1111/j.1460-9568.2008.06481.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Penzes P, Jones KA. Dendritic spine dynamics--a key role for kalirin-7. Trends Neurosci 2008; 31:419-27. [PMID: 18597863 PMCID: PMC3973420 DOI: 10.1016/j.tins.2008.06.001] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/23/2008] [Accepted: 06/02/2008] [Indexed: 11/20/2022]
Abstract
Changes in the structure and function of dendritic spines contribute to numerous physiological processes such as synaptic transmission and plasticity, as well as behavior, including learning and memory. Moreover, altered dendritic spine morphogenesis and plasticity is an endophenotype of many neurodevelopmental and neuropsychiatric disorders. Hence, the molecular mechanisms that control spine plasticity and pathology have been under intense investigation over the past few years. A series of recent studies has improved our understanding of spine dynamics by establishing kalirin-7 as an important regulator of dendritic spine development as well as structural and functional plasticity, providing a model for the molecular control of structural plasticity and implicating kalirin-7 in synaptic pathology in several disorders including schizophrenia and Alzheimer's disease.
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Affiliation(s)
- Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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