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Abstract
Objective: The aim of the study was to compare the development of working memory and preliminary stages of attentional processing in individuals with ADHD over a 23- to 25-year period. Method: Individuals with ADHD (n = 19) and healthy controls (n = 26) were followed up after 13 years (T2) and 23 to 25 years (T3) after initial assessment (T1). They were reassessed with diagnostic measures and the Backward masking task (pre-attention) and the Digit span distractibility test with and without distraction conditions (working memory). Results: The ADHD group performed below the healthy controls on all time points on the Digit span distractibility test. On the distractibility condition, we found a selective decline in performance from T2 to T3 for the ADHD group. Conclusion: The results highlight that ADHD individuals continue to display working memory deficits, also in adulthood, thus creating an imperative for cognitive rehabilitation techniques to help address attention difficulties.
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Affiliation(s)
| | | | - Merete Glenne Øie
- University of Oslo, Norway.,Research Division, Innlandet Hospital Trust, Lillehammer, Norway
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2
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Lee J, Thwaites S, Gogos A, van den Buuse M. Pharmacological Mechanisms Involved in Sensory Gating Disruption Induced by (±)-3,4-Methylene- Dioxymethamphetamine (MDMA): Relevance to Schizophrenia. Brain Sci 2020; 10:brainsci10010044. [PMID: 31941052 PMCID: PMC7016806 DOI: 10.3390/brainsci10010044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/26/2019] [Accepted: 01/10/2020] [Indexed: 11/25/2022] Open
Abstract
Sensory gating deficits have been demonstrated in schizophrenia, but the mechanisms involved remain unclear. In the present study, we used disruption of paired-pulse gating of evoked potentials in rats by the administration of (±)-3,4-methylene-dioxymethamphetamine (MDMA) to study serotonergic and dopaminergic mechanisms involved in auditory sensory gating deficits. Male Sprague-Dawley rats were instrumented with cortical surface electrodes to record evoked potential changes in response to pairs of 85dB tones (S1 and S2), 500msec apart. Administration of MDMA eliminated the normal reduction in the amplitude of S2 compared to S1, representing disruption of auditory sensory gating. Pretreatment of the animals with the dopamine D1 receptor antagonist, SCH23390, the dopamine D2 receptor antagonist, haloperidol, the serotonin (5-HT)1A receptor antagonist, WAY100635, or the 5-HT2A receptor antagonist, ketanserin, all blocked the effect of MDMA, although the drugs differentially affected the individual S1 and S2 amplitudes. These data show involvement of both dopaminergic and serotonergic mechanisms in disruption of auditory sensory gating by MDMA. These and previous results suggest that MDMA targets serotonergic pathways, involving both 5-HT1A and 5-HT2A receptors, leading to dopaminergic activation, involving both D1 and D2 receptors, and ultimately sensory gating deficits. It is speculated that similar interactive mechanisms are affected in schizophrenia.
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Affiliation(s)
- Jaime Lee
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne 3010, Australia
| | - Shane Thwaites
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne 3010, Australia
| | - Andrea Gogos
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne 3010, Australia
| | - Maarten van den Buuse
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne 3010, Australia
- School of Psychology and Public Health, La Trobe University, Melbourne 3086, Australia
- Correspondence: ; Tel.: +61-394-795-257
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Mena A, Ruiz-Salas JC, Puentes A, Dorado I, Ruiz-Veguilla M, De la Casa LG. Reduced Prepulse Inhibition as a Biomarker of Schizophrenia. Front Behav Neurosci 2016; 10:202. [PMID: 27803654 PMCID: PMC5067522 DOI: 10.3389/fnbeh.2016.00202] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/04/2016] [Indexed: 01/24/2023] Open
Abstract
The startle response is composed by a set of reflex behaviors intended to prepare the organism to face a potentially relevant stimulus. This response can be modulated by several factors as, for example, repeated presentations of the stimulus (startle habituation), or by previous presentation of a weak stimulus (Prepulse Inhibition [PPI]). Both phenomena appear disrupted in schizophrenia that is thought to reflect an alteration in dopaminergic and glutamatergic neurotransmission. In this paper we analyze whether the reported deficits are indicating a transient effect restricted to the acute phase of the disease, or if it reflects a more general biomarker or endophenotype of the disorder. To this end, we measured startle responses in the same set of thirteen schizophrenia patients with a cross-sectional design at two periods: 5 days after hospital admission and 3 months after discharge. The results showed that both startle habituation and PPI were impaired in the schizophrenia patients at the acute stage as compared to a control group composed by 13 healthy participants, and that PPI but not startle habituation remained disrupted when registered 3 months after the discharge. These data point to the consideration of PPI, but not startle habituation, as a schizophrenia biomarker.
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Affiliation(s)
- Auxiliadora Mena
- Department of Experimental Psychology, University of Seville Seville, Spain
| | - Juan C Ruiz-Salas
- Department of Experimental Psychology, University of Seville Seville, Spain
| | - Andrea Puentes
- Neurosciences Institute, El Bosque University Bogotá, Colombia
| | - Inmaculada Dorado
- Institute of Biomedicine, University Hospital Virgen del Rocío Seville, Spain
| | | | - Luis G De la Casa
- Department of Experimental Psychology, University of Seville Seville, Spain
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Santos CM, Peres FF, Diana MC, Justi V, Suiama MA, Santana MG, Abílio VC. Peripubertal exposure to environmental enrichment prevents schizophrenia-like behaviors in the SHR strain animal model. Schizophr Res 2016; 176:552-559. [PMID: 27338757 DOI: 10.1016/j.schres.2016.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/04/2016] [Accepted: 06/07/2016] [Indexed: 11/28/2022]
Abstract
Schizophrenia is a highly disabling mental disorder, in which genetics and environmental factors interact culminating in the disease. The treatment of negative symptoms and cognitive deficits with antipsychotics is currently inefficient and is an important field of research. Environmental enrichment (EE) has been suggested to improve some cognitive deficits in animal models of various psychiatric disorders. In this study, we aimed to evaluate a possible beneficial effect of early and long-term exposure to EE on an animal model of schizophrenia, the SHR strain. Young male Wistar rats (control strain) and SHRs (21 post-natal days) were housed for 6weeks in two different conditions: in large cages (10 animals per cage) containing objects of different textures, forms, colors and materials that were changed 3 times/week (EE condition) or in standard cages (5 animals per cage - Control condition). Behavioral evaluations - social interaction (SI), locomotion, prepulse inhibition of startle (PPI) and spontaneous alternation (SA) - were performed 6weeks after the end of EE. SHRs presented deficits in PPI (a sensorimotor impairment), SI (mimicking the negative symptoms) and SA (a working memory deficit), and also hyperlocomotion (modeling the positive symptoms). EE was able to reduce locomotion and increase PPI in both strains, and to prevent the working memory deficit in SHRs. EE also increased the number of neurons in the CA1 and CA3 of the hippocampus. In conclusion, EE can be a potential nonpharmacological strategy to prevent some behavioral deficits associated with schizophrenia.
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Affiliation(s)
- Camila Mauricio Santos
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Fernanda Fiel Peres
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil; Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 5° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Mariana Cepollaro Diana
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Veronica Justi
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Mayra Akimi Suiama
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil; Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 5° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Marcela Gonçalves Santana
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil; Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 5° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
| | - Vanessa Costhek Abílio
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 3° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil; Department of Pharmacology, Universidade Federal de São Paulo (UNIFESP), Rua Pedro de Toledo, 669, 5° andar, Ed. de Pesquisas II, CEP 04039-032 São Paulo, SP, Brazil
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5
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Ahnaou A, Biermans R, Drinkenburg WH. Modulation of mGlu2 Receptors, but Not PDE10A Inhibition Normalizes Pharmacologically-Induced Deviance in Auditory Evoked Potentials and Oscillations in Conscious Rats. PLoS One 2016; 11:e0147365. [PMID: 26808689 PMCID: PMC4726622 DOI: 10.1371/journal.pone.0147365] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/04/2016] [Indexed: 12/20/2022] Open
Abstract
Improvement of cognitive impairments represents a high medical need in the development of new antipsychotics. Aberrant EEG gamma oscillations and reductions in the P1/N1 complex peak amplitude of the auditory evoked potential (AEP) are neurophysiological biomarkers for schizophrenia that indicate disruption in sensory information processing. Inhibition of phosphodiesterase (i.e. PDE10A) and activation of metabotropic glutamate receptor (mGluR2) signaling are believed to provide antipsychotic efficacy in schizophrenia, but it is unclear whether this occurs with cognition-enhancing potential. The present study used the auditory paired click paradigm in passive awake Sprague Dawley rats to 1) model disruption of AEP waveforms and oscillations as observed in schizophrenia by peripheral administration of amphetamine and the N-methyl-D-aspartate (NMDA) antagonist phencyclidine (PCP); 2) confirm the potential of the antipsychotics risperidone and olanzapine to attenuate these disruptions; 3) evaluate the potential of mGluR2 agonist LY404039 and PDE10 inhibitor PQ-10 to improve AEP deficits in both the amphetamine and PCP models. PCP and amphetamine disrupted auditory information processing to the first click, associated with suppression of the P1/N1 complex peak amplitude, and increased cortical gamma oscillations. Risperidone and olanzapine normalized PCP and amphetamine-induced abnormalities in AEP waveforms and aberrant gamma/alpha oscillations, respectively. LY404039 increased P1/N1 complex peak amplitudes and potently attenuated the disruptive effects of both PCP and amphetamine on AEPs amplitudes and oscillations. However, PQ-10 failed to show such effect in either models. These outcomes indicate that modulation of the mGluR2 results in effective restoration of abnormalities in AEP components in two widely used animal models of psychosis, whereas PDE10A inhibition does not.
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Affiliation(s)
- Abdallah Ahnaou
- Department of Neuroscience, Janssen Research & Development, A Division of Janssen Pharmaceutica N.V., Turnhoutseweg 30, B-2340 Beerse, Belgium
- * E-mail:
| | - Ria Biermans
- Department of Neuroscience, Janssen Research & Development, A Division of Janssen Pharmaceutica N.V., Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Wilhelmus H. Drinkenburg
- Department of Neuroscience, Janssen Research & Development, A Division of Janssen Pharmaceutica N.V., Turnhoutseweg 30, B-2340 Beerse, Belgium
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6
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Diana MC, Santoro ML, Xavier G, Santos CM, Spindola LN, Moretti PN, Ota VK, Bressan RA, Abilio VC, Belangero SI. Low expression of Gria1 and Grin1 glutamate receptors in the nucleus accumbens of Spontaneously Hypertensive Rats (SHR). Psychiatry Res 2015; 229:690-4. [PMID: 26296755 DOI: 10.1016/j.psychres.2015.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/03/2015] [Accepted: 08/12/2015] [Indexed: 10/23/2022]
Abstract
The Spontaneously Hypertensive Rat (SHR) strain is a classical animal model for the study of essential hypertension. Recently, our group suggested that this strain could be a useful animal model for schizophrenia, which is a severe mental illness with involvement of glutamatergic system. The aim of this study is to investigate glutamatergic receptors (Gria1 and Grin1) and glycine transporter (Glyt1) gene expression in the prefrontal cortex (PFC) and nucleus accumbens (NAcc) of SHR animals. The effects in gene expression of a chronic treatment with antipsychotic drugs (risperidone, haloperidol and clozapine) were also analyzed. Animals were treated daily for 30 days, and euthanized for brain tissue collection. The expression pattern was evaluated by Real Time Reverse-Transcriptase (RT) PCR technique. In comparison to control rats, SHR animals present a lower expression of both NMDA (Grin1) and AMPA (Gria1) gene receptors in the NAcc. Antipsychotic treatments were not able to change gene expressions in any of the regions evaluated. These findings provide evidence for the role of glutamatergic changes in schizophrenia-like phenotype of the SHR strain.
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Affiliation(s)
- Mariana C Diana
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP 04039032, Brazil
| | - Marcos L Santoro
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil
| | - Gabriela Xavier
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil
| | - Camila Mauricio Santos
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP 04039032, Brazil
| | - Leticia N Spindola
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil
| | - Patrícia N Moretti
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil
| | - Vanessa K Ota
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil
| | - Rodrigo A Bressan
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil
| | - Vanessa C Abilio
- LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil; Department of Pharmacology, Universidade Federal de Sao Paulo (UNIFESP), Rua Pedro de Toledo 669, 5th floor, CEP 04039032, Brazil
| | - Sintia I Belangero
- Genetics Division, Department of Morphology and Genetics, Universidade Federal de Sao Paulo (UNIFESP), Rua Botucatu, 740, Edifício Leitao da Cunha, 1º andar, CEP 04023-900 São Paulo, Brazil; LiNC - Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, UNIFESP, Rua Pedro de Toledo, 669, 3º floor, CEP 05039-032 São Paulo, Brazil.
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Ayhan Y, McFarland R, Pletnikov MV. Animal models of gene-environment interaction in schizophrenia: A dimensional perspective. Prog Neurobiol 2015; 136:1-27. [PMID: 26510407 DOI: 10.1016/j.pneurobio.2015.10.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 09/07/2015] [Accepted: 10/22/2015] [Indexed: 12/12/2022]
Abstract
Schizophrenia has long been considered as a disorder with multifactorial origins. Recent discoveries have advanced our understanding of the genetic architecture of the disease. However, even with the increase of identified risk variants, heritability estimates suggest an important contribution of non-genetic factors. Various environmental risk factors have been proposed to play a role in the etiopathogenesis of schizophrenia. These include season of birth, maternal infections, obstetric complications, adverse events at early childhood, and drug abuse. Despite the progress in identification of genetic and environmental risk factors, we still have a limited understanding of the mechanisms whereby gene-environment interactions (G × E) operate in schizophrenia and psychoses at large. In this review we provide a critical analysis of current animal models of G × E relevant to psychotic disorders and propose that dimensional perspective will advance our understanding of the complex mechanisms of these disorders.
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Affiliation(s)
- Yavuz Ayhan
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Hacettepe University Faculty of Medicine, Department of Psychiatry, Turkey
| | - Ross McFarland
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, USA
| | - Mikhail V Pletnikov
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, USA; Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, USA; Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, USA; Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, USA.
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Lackner CL, Santesso DL, Dywan J, Wade TJ, Segalowitz SJ. Event-related Potentials Elicited to Performance Feedback in High-Shy and Low-Shy Adolescents. INFANT AND CHILD DEVELOPMENT 2014. [DOI: 10.1002/icd.1865] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Jane Dywan
- Psychology Department; Brock University; St. Catharines ON Canada
| | - Terrance J. Wade
- Department of Community Health Sciences; Brock University; St. Catharines ON Canada
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Glass MJ, Robinson DC, Waters E, Pickel VM. Deletion of the NMDA-NR1 receptor subunit gene in the mouse nucleus accumbens attenuates apomorphine-induced dopamine D1 receptor trafficking and acoustic startle behavior. Synapse 2013; 67:265-79. [PMID: 23345061 DOI: 10.1002/syn.21637] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/15/2013] [Indexed: 12/21/2022]
Abstract
The nucleus accumbens (Acb) contains subpopulations of neurons defined by their receptor content and potential involvement in sensorimotor gating and other behaviors that are dysfunctional in schizophrenia. In Acb neurons, the NMDA NR1 (NR1) subunit is coexpressed not only with the dopamine D1 receptor (D1R), but also with the µ-opioid receptor (µ-OR), which mediates certain behaviors that are adversely impacted by schizophrenia. The NMDA-NR1 subunit has been suggested to play a role in the D1R trafficking and behavioral dysfunctions resulting from systemic administration of apomorphine, a D1R and dopamine D2 receptor agonist that impacts prepulse inhibition to auditory-evoked startle (AS). Together, this evidence suggests that the NMDA receptor may regulate D1R trafficking in Acb neurons, including those expressing µ-OR, in animals exposed to auditory startle and apomorphine. We tested this hypothesis by combining spatial-temporal gene deletion technology, dual labeling immunocytochemistry, and behavioral analysis. Deleting NR1 in Acb neurons prevented the increase in the dendritic density of plasma membrane D1Rs in single D1R and dual (D1R and µ-OR) labeled dendrites in the Acb in response to apomorphine and AS. Deleting NR1 also attenuated the decrease in AS induced by apomorphine. In the absence of apomorphine and startle, deletion of Acb NR1 diminished social interaction, without affecting novel object recognition, or open field activity. These results suggest that NR1 expression in the Acb is essential for apomorphine-induced D1R surface trafficking, as well as auditory startle and social behaviors that are impaired in multiple psychiatric disorders.
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Affiliation(s)
- Michael J Glass
- Brain and Mind Research Institute, Weill Cornell Medical College, New York 10065, USA.
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Utkan T, Gocmez SS, Regunathan S, Aricioglu F. Agmatine, a metabolite of L-arginine, reverses scopolamine-induced learning and memory impairment in rats. Pharmacol Biochem Behav 2012; 102:578-84. [PMID: 22796489 DOI: 10.1016/j.pbb.2012.07.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 06/26/2012] [Accepted: 07/07/2012] [Indexed: 01/28/2023]
Abstract
Agmatine (l-amino-4-guanidino-butane), a metabolite of L-arginine through the action of arginine decarboxylase, is a novel neurotransmitter. In the present study, effects of agmatine on cognitive functions have been evaluated by using one trial step-down passive avoidance and three panel runway task. Agmatine (20, 40, 80 mg/kg i.p.) was administered either in the presence or absence of a cholinergic antagonist, scopolamine (1 mg/kg i.p.). Scopolamine significantly impaired learning and memory in both passive avoidance and three panel runway test. Agmatine did not affect emotional learning, working and reference memory but significantly improved scopolamine-induced impairment of learning and memory in a dose dependent manner. Our results indicate that agmatine, as an endogenous substance, may have an important role in modulation of learning and memory functions.
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Affiliation(s)
- Tijen Utkan
- Kocaeli University Medical Faculty, Pharmacology Department and Experimental Medical Research and Application Unit, 41380 Kocaeli, Turkey.
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11
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Baisley SK, Fallace KL, Rajbhandari AK, Bakshi VP. Mutual independence of 5-HT(2) and α1 noradrenergic receptors in mediating deficits in sensorimotor gating. Psychopharmacology (Berl) 2012; 220:465-79. [PMID: 21947334 PMCID: PMC4090044 DOI: 10.1007/s00213-011-2490-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 09/05/2011] [Indexed: 12/20/2022]
Abstract
RATIONALE Prepulse inhibition (PPI), a preattentional information-filtering mechanism, is disrupted by serotonin (5-HT) or norepinephrine (NE) agonists to model deficits seen in schizophrenia, but whether this effect occurs through interactions between these systems is not known. OBJECTIVES These studies investigated whether PPI/activity changes induced by agonists of one system were dependent on neurotransmission within the other. METHODS Male Sprague-Dawley rats received the 5-HT(2) receptor agonist DOI (1-[2,5-dimethoxy-4-iodophenyl]-2-aminopropane) (0, 0.3 mg/kg), with or without antagonists for α1 (prazosin:0, 0.3, or 1 mg/kg) or β (timolol:0, 3, or 10 mg/kg) receptors or their combination (0 or 0.3 mg/kg prazosin + 3 mg/kg timolol), or the 5-HT(2) antagonist ritanserin (0, 2 mg/kg). Separately, the α1-adrenergic receptor agonist cirazoline (0, 0.68 mg/kg) was given with and without ritanserin (0, 0.5, or 2 mg/kg) or the NE antagonists (0 or 0.3 mg/kg prazosin + 3 mg/kg timolol). Finally, combinations of subthreshold doses of DOI (0, 0.01, 0.025 mg/kg) and cirazoline (0, 0.1, 0.25 mg/kg) were tested for their ability to disrupt PPI, and concomitant administration of all three antagonists (0 vs. 0.3 mg/kg prazosin + 3 mg/kg timolol + 2 mg/kg ritanserin) was assessed for its ability to modify PPI. Locomotion was assessed in an additional set of experiments. RESULTS Doses/combinations of prazosin and timolol that reversed cirazoline-induced effects did not alter DOI-induced effects, and ritanserin did not affect cirazoline at doses that blocked DOI-mediated effects. Concomitant antagonism of α1 + β + 5-HT(2) receptors did not modify PPI, nor did combinations of subthreshold doses of cirazoline and DOI. CONCLUSIONS 5-HT(2) receptors and α1 and β NE receptors may act through independent mechanisms to modulate sensorimotor gating and locomotor activity.
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Affiliation(s)
- Sarah K. Baisley
- Department of Psychiatry, UW-Madison, Madison, WI, USA,Neuroscience Training Program, UW-Madison, Madison, WI, USA
| | | | - Abha K. Rajbhandari
- Department of Psychiatry, UW-Madison, Madison, WI, USA,Neuroscience Training Program, UW-Madison, Madison, WI, USA
| | - Vaishali P. Bakshi
- Department of Psychiatry, UW-Madison, Madison, WI, USA,Neuroscience Training Program, UW-Madison, Madison, WI, USA,Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, 6001 Research Park Blvd, Madison, WI 53719, USA
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12
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Rosenzweig-Lipson S, Comery TA, Marquis KL, Gross J, Dunlop J. 5-HT(2C) agonists as therapeutics for the treatment of schizophrenia. Handb Exp Pharmacol 2012:147-165. [PMID: 23027415 DOI: 10.1007/978-3-642-25758-2_6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The 5-HT(2C) receptor is a highly complex, highly regulated receptor which is widely distributed throughout the brain. The 5-HT(2C) receptor couples to multiple signal transduction pathways leading to engagement of a number of intracellular signaling molecules. Moreover, there are multiple allelic variants of the 5-HT(2C) receptor and the receptor is subject to RNA editing in the coding regions. The complexity of this receptor is further emphasized by the studies suggesting the utility of either agonists or antagonists in the treatment of schizophrenia. While several 5-HT(2C) agonists have demonstrated clinical efficacy in obesity (lorcaserin, PRX-000933), the focus of this review is on the therapeutic potential of 5-HT(2C) agonists in schizophrenia. To this end, the preclinical profile of 5-HT(2C) agonists from a neurochemical, electrophysiological, and a behavioral perspective is indicative of antipsychotic-like efficacy without extrapyramidal symptoms or weight gain. Recently, the selective 5-HT(2C) agonist vabicaserin demonstrated clinical efficacy in a Phase II trial in schizophrenia patients without weight gain and with low EPS liability. These data are highly encouraging and suggest that 5-HT(2C) agonists are potential therapeutics for the treatment of psychiatric disorders.
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Lazar NL, Neufeld RWJ, Cain DP. Contribution of nonprimate animal models in understanding the etiology of schizophrenia. J Psychiatry Neurosci 2011; 36:E5-29. [PMID: 21247514 PMCID: PMC3120891 DOI: 10.1503/jpn.100054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia is a severe psychiatric disorder that is characterized by positive and negative symptoms and cognitive impairments. The etiology of the disorder is complex, and it is thought to follow a multifactorial threshold model of inheritance with genetic and neurodevelop mental contributions to risk. Human studies are particularly useful in capturing the richness of the phenotype, but they are often limited to the use of correlational approaches. By assessing behavioural abnormalities in both humans and rodents, nonprimate animal models of schizophrenia provide unique insight into the etiology and mechanisms of the disorder. This review discusses the phenomenology and etiology of schizophrenia and the contribution of current nonprimate animal models with an emphasis on how research with models of neuro transmitter dysregulation, environmental risk factors, neurodevelopmental disruption and genetic risk factors can complement the literature on schizophrenia in humans.
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Affiliation(s)
- Noah L Lazar
- Department of Psychology, University of Western Ontario, London, Ont.
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Mouse behavioral endophenotypes for schizophrenia. Brain Res Bull 2010; 83:147-61. [PMID: 20433908 DOI: 10.1016/j.brainresbull.2010.04.008] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 12/25/2009] [Accepted: 04/19/2010] [Indexed: 01/20/2023]
Abstract
An endophenotype is a heritable trait that is generally considered to be more highly, associated with a gene-based neurological deficit than a disease phenotype itself. Such, endophenotypic deficits may therefore be observed in the non-affected relatives of disease patients. Once endophenotypes have been established for a given illness, such as schizophrenia, mechanisms of, action may then be established and treatment options developed in order to target such measures. The, current paper describes and assesses the merits and limitations of utilizing behavioral and, electrophysiological endophenotypes of schizophrenia in mice. Such endophenotypic deficits include: decreased auditory event related potential (ERP) amplitude and gating (specifically, that of the P20, N40, P80 and P120); impaired mismatch negativity (MMN); changes in theta and gamma frequency, analyses; decreased pre-pulse inhibition (PPI); impaired working and episodic memories (for instance, novel object recognition [NOR], contextual and cued fear conditioning, latent inhibition, Morris and, radial arm maze identification and nose poke); sociability; and locomotor activity. A variety of, pharmacological treatments, including ketamine, MK-801 and phencyclidine (PCP) can be used to, induce some of the deficits described above, and numerous transgenic mouse strains have been, developed to address the mechanisms responsible for such endophenotypic differences. We also, address the viability and validity of using such measures regarding their potential clinical implications, and suggest several practices that could increase the translatability of preclinical data.
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Mazzoncini R, Zoli M, Tosato S, Lasalvia A, Ruggeri M. Can the role of genetic factors in schizophrenia be enlightened by studies of candidate gene mutant mice behaviour? World J Biol Psychiatry 2010; 10:778-97. [PMID: 19396727 DOI: 10.1080/15622970902875152] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Schizophrenia is one of the most severe psychiatric disorders. Despite the knowledge accumulated over years, aetiology and pathophysiology remain uncertain. Research on families and twins suggests that genetic factors are largely responsible for the disease and implies specific genes as risk factors. Genetic epidemiology indicates a complex transmission mode, compatible with a multi-locus model, with single genes accounting for specific traits rather than for the entire phenotype. To better understand every single gene contribution to schizophrenia, the use of intermediate endophenotypes has been proposed. A straight communication between preclinical and clinical researchers could facilitate research on the association between genes and endophenotypes. Many behavioural tasks are available for humans and animals to measure endophenotypes. Here, firstly, we reviewed the most promising mouse behavioural tests modelling human behavioural tasks altered in schizophrenia. Secondly, we systematically reviewed animal models availability for a selection of candidate genes, derived from linkage and association studies. Thirdly, we systematically reviewed the studies which tested mutant mice in the above behavioural tasks. Results indicate a large mutant mice availability for schizophrenia candidate genes but they have been insufficiently tested in behavioural tasks. On the other hand, multivariate and translational approach should be implemented in several behavioural domains.
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Affiliation(s)
- Rodolfo Mazzoncini
- Department of Medicine and Public Health, Section of Psychiatry and Clinical Psychology, University of Verona, Verona, Italy.
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Castagné V, Moser PC, Porsolt RD. Preclinical behavioral models for predicting antipsychotic activity. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2009; 57:381-418. [PMID: 20230767 DOI: 10.1016/s1054-3589(08)57010-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Schizophrenia is a major psychiatric disease that is characterized by three distinct symptom domains: positive symptoms, negative symptoms, and cognitive impairment. Additionally, treatment with classical antipsychotic medication can be accompanied by important side effects that involve extrapyramidal symptoms (EPS). The discovery of clozapine in the 1970s, which is efficacious in all three symptom domains and has a reduced propensity to induce EPS, has driven research for new antipsychotic agents with a wider spectrum of activity and a lower propensity to induce EPS. The following chapter reviews existing behavioral procedures in animals for their ability to predict compound efficacy against schizophrenia symptoms and liability to induce EPS. Rodent models of positive symptoms include procedures related to hyperfunction in central dopamine and serotonin (5-hydroxytryptamine) systems and hypofunction of central glutamatergic (N-methyl-d-aspartate) neurotransmission. Procedures for evaluating negative symptoms include rodent models of anhedonia, affective flattening, and diminished social interaction. Cognitive deficits can be assessed in rodent models of attention (prepulse inhibition (PPI), latent inhibition) and of learning and memory (passive avoidance, object and social recognition, Morris water maze, and operant-delayed alternation). The relevance of the conditioned avoidance response (CAR) is also discussed. A final section reviews animal procedures for assessing EPS liability, in particular parkinsonism (catalepsy), acute dystonia (purposeless chewing in rodents, dystonia in monkeys), akathisia (defecation in rodents), and tardive dyskinesia (long-term antipsychotic treatment in rodents and monkeys).
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Affiliation(s)
- Vincent Castagné
- Porsolt & Partners Pharmacology, 9 Bis Rue Henri Martin, 92100 Boulogne-Billancourt, France
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Singer P, Feldon J, Yee BK. Are DBA/2 mice associated with schizophrenia-like endophenotypes? A behavioural contrast with C57BL/6 mice. Psychopharmacology (Berl) 2009; 206:677-98. [PMID: 19484222 DOI: 10.1007/s00213-009-1568-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 05/07/2009] [Indexed: 01/02/2023]
Abstract
RATIONALE Due to its intrinsic deficiency in prepulse inhibition (PPI), the inbred DBA/2 mouse strain has been considered as an animal model for evaluating antipsychotic drugs. However, the PPI impairment observed in DBA/2 mice relative to the common C57BL/6 strain is confounded by a concomitant reduction in baseline startle reactivity. In this study, we examined the robustness of the PPI deficit when this confound is fully taken into account. MATERIALS AND METHODS Male DBA/2 and C57BL/6 mice were compared in a PPI experiment using multiple pulse stimulus intensities, allowing the possible matching of startle reactivity prior to examination of PPI. The known PPI-enhancing effect of the antipsychotic, clozapine, was then evaluated in half of the animals, whilst the other half was subjected to two additional schizophrenia-relevant behavioural tests: latent inhibition (LI) and locomotor reaction to the psychostimulants-amphetamine and phencyclidine. RESULTS PPI deficiency in DBA/2 relative to C57BL/6 mice was essentially independent of the strain difference in baseline startle reactivity. Yet, there was no evidence that DBA/2 mice were superior in detecting the PPI-facilitating effect of clozapine when startle difference was balanced. Compared with C57BL/6 mice, DBA/2 mice also showed impaired LI and a different temporal profile in their responses to amphetamine and phencyclidine. CONCLUSION Relative to the C57BL/6 strain, DBA/2 mice displayed multiple behavioural traits relevant to schizophrenia psycho- and physiopathology, indicative of both dopaminergic and glutamatergic/N-methyl-D: -aspartic acid receptor dysfunctions. Further examination of their underlying neurobiological differences is therefore warranted in order to enhance the power of this specific inter-strain comparison as a model of schizophrenia.
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Affiliation(s)
- Philipp Singer
- Laboratory of Behavioural Neurobiology, Federal Institute of Technology Zurich, Schorenstrasse 16, Schwerzenbach, Switzerland
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18
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Acoustic startle and prepulse inhibition in the Mongolian gerbil. Physiol Behav 2009; 98:460-6. [DOI: 10.1016/j.physbeh.2009.07.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 07/03/2009] [Accepted: 07/27/2009] [Indexed: 11/22/2022]
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19
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Differential effects of i.c.v. microinfusion of agmatine on spatial working and reference memory in the rat. Neuroscience 2009; 159:951-61. [DOI: 10.1016/j.neuroscience.2009.01.039] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 01/15/2009] [Accepted: 01/18/2009] [Indexed: 11/24/2022]
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Green MF, Butler PD, Chen Y, Geyer MA, Silverstein S, Wynn JK, Yoon JH, Zemon V. Perception measurement in clinical trials of schizophrenia: promising paradigms from CNTRICS. Schizophr Bull 2009; 35:163-81. [PMID: 19023123 PMCID: PMC2635893 DOI: 10.1093/schbul/sbn156] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The third meeting of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) focused on selecting promising measures for each of the cognitive constructs selected in the first CNTRICS meeting. In the domain of perception, the 2 constructs of interest were gain control and visual integration. CNTRICS received 5 task nominations for gain control and three task nominations for visual integration. The breakout group for perception evaluated the degree to which each of these tasks met prespecified criteria. For gain control, the breakout group for perception believed that 2 of the tasks (prepulse inhibition of startle and mismatch negativity) were already mature and in the process of being incorporated into multisite clinical trials. However, the breakout group recommended that steady-state visual-evoked potentials be combined with contrast sensitivity to magnocellular vs parvocellular biased stimuli and that this combined task and the contrast-contrast effect task be recommended for translation for use in clinical trial contexts in schizophrenia research. For visual integration, the breakout group recommended the Contour Integration and Coherent Motion tasks for translation for use in clinical trials. This manuscript describes the ways in which each of these tasks met the criteria used by the breakout group to evaluate and recommend tasks for further development.
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Affiliation(s)
- Michael F. Green
- Semel Institute at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA,To whom correspondence should be addressed; tel: (310) 794-1993; fax: (310) 825-6626, e-mail:
| | - Pamela D. Butler
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY,Department of Psychiatry, New York University School of Medicine, New York, NY,Cognitive Neuroscience Program, University of New York, New York, NY
| | - Yue Chen
- McLean Hospital, Department of Psychiatry, Harvard Medical School, Belmont, MA
| | - Mark A. Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093-0804
| | - Steven Silverstein
- University Behavioral HealthCare and Robert Wood Johnson Medical School, Piscataway, NJ
| | - Jonathan K. Wynn
- Semel Institute at UCLA and VA Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Jong H. Yoon
- Department of Psychiatry, University of California, Davis, CA
| | - Vance Zemon
- Ferkauf Graduate School of Psychology, Yeshiva University, Bronx, NY
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Gandal MJ, Ehrlichman RS, Rudnick ND, Siegel SJ. A novel electrophysiological model of chemotherapy-induced cognitive impairments in mice. Neuroscience 2008; 157:95-104. [PMID: 18835334 DOI: 10.1016/j.neuroscience.2008.08.060] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 08/29/2008] [Accepted: 08/29/2008] [Indexed: 11/19/2022]
Abstract
PURPOSE Chemotherapeutic agents are known to produce persistent cognitive deficits in cancer patients. However, little progress has been made in developing animal models to explore underlying mechanisms and potential therapeutic interventions. We report an electrophysiological model of chemotherapy-induced cognitive deficits using a sensory gating paradigm, to correspond with performance in two behavioral tasks. EXPERIMENTAL DESIGN Mice received four weekly injections of methotrexate and 5-fluorouracil. Whole-brain event-related potentials (ERPs) were recorded throughout using a paired-click paradigm. Mice underwent contextual fear conditioning (CFC) and novel-object recognition testing (NOR). RESULTS Chemotherapy-treated animals showed significantly impaired gating 5 weeks after drug treatments began, as measured by the ratio of the first positive peak in the ERP (P1) minus the first negative peak (N1) between first and second auditory stimuli. There was no effect of drug on the amplitude of P1-N1 or latency of P1. The drug-treated animals also showed significantly increased freezing during fear conditioning and increased exploration without memory impairment during novel object recognition. CONCLUSIONS Chemotherapy causes decreased ability to gate incoming auditory stimuli, which may underlie associated cognitive impairments. These gating deficits were associated with a hyperactive response to fear conditioning and reduced adaptation to novel objects, suggesting an additional component of emotional dysregulation. However, amplitudes and latencies of ERP components were unaffected, as was NOR performance, highlighting the subtle nature of these deficits.
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Affiliation(s)
- M J Gandal
- Medical Scientist Training Program, University of Pennsylvania, Philadelphia, PA 19104, USA
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Silvagni A, Barros VG, Mura C, Antonelli MC, Carboni E. Prenatal restraint stress differentially modifies basal and stimulated dopamine and noradrenaline release in the nucleus accumbens shell: an ‘in vivo’ microdialysis study in adolescent and young adult rats. Eur J Neurosci 2008; 28:744-58. [DOI: 10.1111/j.1460-9568.2008.06364.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Hajós M, Hoffmann WE, Kocsis B. Activation of cannabinoid-1 receptors disrupts sensory gating and neuronal oscillation: relevance to schizophrenia. Biol Psychiatry 2008; 63:1075-83. [PMID: 18261715 DOI: 10.1016/j.biopsych.2007.12.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 12/11/2007] [Accepted: 12/14/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Impaired auditory gating and abnormal neuronal synchrony are indicators of dysfunctional information processing in schizophrenia patients and possible underlying mechanisms of their impaired sensory and cognitive functions. Because cannabinoid receptors and endocannabinoids have been linked to psychiatric disorders, including schizophrenia, the aim of this study was to evaluate the effects of cannabinoid-1 (CB1) receptor activation on sensory gating and neuronal oscillations in rats. METHODS Auditory sensory gating has been recorded from the hippocampus and entorhinal cortex (EC) in anesthetized rats. Neuronal network oscillations were recorded from the hippocampus, medial septum, EC, and medial prefrontal cortex in anesthetized and freely moving rats. Effects of systemic administration of CB1 receptor agonist CP-55940 were evaluated on these parameters. RESULTS CP-55940 significantly disrupted auditory gating both in the hippocampus and EC in anesthetized rats. Theta field potential oscillations were disrupted in the hippocampus and EC, with simultaneous interruption of theta-band oscillations of septal neurons. Administration of the CB1 receptor antagonist AM-251 reversed both the agonist-induced gating deficit and the diminished oscillations. In freely moving rats, CP-55940 significantly reduced theta and gamma power in the hippocampus, whereas in the EC, only gamma power was attenuated. However, novelty-induced theta and gamma activities were significantly diminished by CP-55940 in both the hippocampus and EC. CONCLUSIONS Our data indicate that activation of CB1 receptors interferes with neuronal network oscillations and impairs sensory gating function in the limbic circuitry, further supporting the connection between cannabis abuse and increased susceptibility of developing schizophrenia spectrum disorders.
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Affiliation(s)
- Mihály Hajós
- Department of Neuroscience, Pfizer Global Research and Development, Groton, CT 06340, USA.
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Atkinson R, Migues PV, Cammarota M, Kavanagh JM, Hunter M, Rostas JAP. Biochemical, behavioural and electrophysiological investigations of brain maturation in chickens. Brain Res Bull 2008; 76:217-23. [PMID: 18498934 DOI: 10.1016/j.brainresbull.2008.02.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 02/26/2008] [Accepted: 02/26/2008] [Indexed: 11/28/2022]
Abstract
It is convenient to divide the development of synaptic networks into two phases: synapse formation during which synaptic contacts are established, and a subsequent maturation phase during which synaptic circuits are fine tuned and the properties of individual synapses are modified. Understanding the complex factors that control the protracted maturation process in humans is likely to be important for understanding a variety of neurological and psychiatric disorders. Chickens provide an ideal experimental model in which maturation specific changes can be identified and the mechanisms controlling them can be elucidated because the maturation phase is protracted and temporally separated from the formation phase. This paper reviews the knowledge about the biological mechanisms involved in the maturation phase of brain development in chickens and presents some new data. Studies of synaptic physiology suggest that maturation may alter the basal set point for stimulus induced synaptic plasticity. Biochemical and pharmacological studies of N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and metabotropic glutamate receptors (mGluRs) revealed major changes in receptor regulation and the intracellular signalling pathways linked to receptor activation. Not surprisingly, therefore, when immature or mature chickens learn the same behavioural task the learning induced molecular events at the synapse are different. Changes in the features of auditory event related potentials and the basal EEG provide non-invasive techniques for monitoring maturation changes in chicken brain but prepulse inhibition (PPI) is too small and variable in chickens to be useful. Experimentally induced mild late-onset hypothyroidism retards some aspects of brain maturation and may help identify some of the mechanisms controlling maturation.
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Affiliation(s)
- Rebbekah Atkinson
- School of Psychology and the Hunter Medical Research Institute, University of Newcastle, Callaghan, NSW 2308, Australia
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Effects of prenatal infection on prepulse inhibition in the rat depend on the nature of the infectious agent and the stage of pregnancy. Behav Brain Res 2007; 181:270-7. [PMID: 17553574 DOI: 10.1016/j.bbr.2007.04.016] [Citation(s) in RCA: 183] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 03/06/2007] [Accepted: 04/25/2007] [Indexed: 02/02/2023]
Abstract
Maternal infection during pregnancy is a risk factor for some psychiatric illnesses of neurodevelopmental origin such as schizophrenia and autism. In experimental animals, behavioral and neuropathological outcomes relevant to schizophrenia have been observed in offspring of infected dams. However, the type of infectious agent used and gestational age at time of administration have varied. The objective of the present study was to compare the effects of prenatal challenge with different immune agents given at different time windows during gestation on behavioral outcomes in offspring. For this, pregnant rats were administered bacterial endotoxin (lipopolysaccharide, LPS), the viral mimic polyinosinic: polycytidylic acid (poly I:C), or turpentine, an inducer of local inflammation, at doses known to produce fever, at three different stages in pregnancy: embryonic day (E)10-11, E15-16 and E18-19. Prepulse inhibition of acoustic startle (PPI) was later measured in male adult offspring. PPI was significantly decreased in offspring after prenatal LPS treatment at E15-16 and E18-19. Intramuscular injection of pregnant dams with turpentine at E15-16 also decreased PPI in adult offspring. Maternal poly I:C administration had no significant effect on PPI in offspring. In contrast to prenatal LPS exposure, acute LPS administration to naive adult males had no effect on PPI. Thus, prenatal exposure both to a systemic immunogen and to local inflammation at brief periods during later pregnancy produced lasting deficits in PPI in rat offspring. These findings support the idea that maternal infection during critical windows of pregnancy could contribute to sensorimotor gating deficits in schizophrenia.
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Anstrom KK, Cromwell HC, Woodward DJ. Effects of restraint and haloperidol on sensory gating in the midbrain of awake rats. Neuroscience 2007; 146:515-24. [PMID: 17360124 DOI: 10.1016/j.neuroscience.2007.01.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 01/10/2007] [Accepted: 01/21/2007] [Indexed: 10/23/2022]
Abstract
Deficits in sensory processing have been reported to be associated with an array of neuropsychiatric disorders including schizophrenia. Auditory sensory gating paradigms have been routinely used to test the integrity of inhibitory circuits hypothesized to filter sensory information. Abnormal dopaminergic neurotransmission has been implicated in the expression of schizophrenic symptoms. The aim of this study was to determine if inhibitory gating in response to paired auditory stimuli would occur in putative dopaminergic and non-dopaminergic midbrain neurons. A further goal of this study was to determine if restraint, a classic model of stress known to increase extracellular dopamine levels, and systemic haloperidol injections affected inhibitory mechanisms involved in sensory gating. Neural activity in the rat midbrain was recorded across paired auditory stimuli (first auditory stimulus (S1) and second auditory stimulus (S2)) under resting conditions, during restraint and after systemic haloperidol injections. Under resting conditions, a subset of putative GABA neurons showed fast, gated, short latency responses while putative dopamine neurons showed long, slow responses that were inhibitory and ungated. During restraint, gated responses in putative GABAergic neurons were decreased (increased S2/S1 or ratio of test to conditioning (T/C)) by reducing the response amplitude to S1. Systemic haloperidol decreased the T/C ratio by preferentially increasing response amplitude to S1. The results from this study suggest that individual neurons encode discrete components of the auditory sensory gating paradigm, that phasic midbrain GABAergic responses to S1 may trigger subsequent inhibitory filtering processes, and that these GABAergic responses are sensitive to restraint and systemic haloperidol.
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Affiliation(s)
- K K Anstrom
- Department of Physiology and Pharmacology, Wake Forest University Baptist Medical Center, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
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de Bruin N, Mahieu M, Patel T, Willems R, Lesage A, Megens A. Performance of F2 B6x129 hybrid mice in the Morris water maze, latent inhibition and prepulse inhibition paradigms: Comparison with C57Bl/6J and 129sv inbred mice. Behav Brain Res 2006; 172:122-34. [PMID: 16764948 DOI: 10.1016/j.bbr.2006.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 04/23/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
Assessment of cognition and information processing in mice is an important tool in preclinical research that focuses on the development of cognitive enhancing drugs. Analysis of transgenic (TG) and knockout (KO) mice is usually performed on a F2 B6x 129 background. In the present study, we have compared performance of F2 B6x 129 hybrid mice (F2 mice) with that of the two parental inbred strains (C57Bl/6J and 129sv mice), and a wild-type (WT) strain (with a combined B6x 129 background) in three cognitive/information processing paradigms. It was found that the F2 mice outperformed either of the parental strains and provide a control sample with good baseline performance in the Morris water maze (MWM). Reliable deficits could be obtained in learning and memory in this paradigm following injections with scopolamine (0.16 mg/kg) in the F2 mice, which can potentially be used to test effects of reference and novel compounds in order to develop cognitive enhancing drugs. Furthermore, it was shown that the four genotypes showed normal latent inhibition (LI) using the conditioned taste aversion (CTA) paradigm and exhibited no differences in prepulse inhibition (PPI) levels. Following the setup of these procedures in mice, we are now able to compare the effects of gene knockout/mutations used for target validation with results in the present study as a frame of reference.
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Affiliation(s)
- Natasja de Bruin
- Johnson and Johnson, Pharmaceutical Research and Development (J and J PRD), CNS Discovery Research, Beerse, Belgium.
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Radek RJ, Miner HM, Bratcher NA, Decker MW, Gopalakrishnan M, Bitner RS. Alpha4beta2 nicotinic receptor stimulation contributes to the effects of nicotine in the DBA/2 mouse model of sensory gating. Psychopharmacology (Berl) 2006; 187:47-55. [PMID: 16767415 DOI: 10.1007/s00213-006-0394-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 03/22/2006] [Indexed: 10/24/2022]
Abstract
RATIONALE Nicotine improves the deficiencies of sensory gating function in schizophrenic patients and in dilute brown non-Agouti (DBA/2) mice. This effect of nicotine has been attributed to activation of the alpha7 nicotinic acetylcholine receptor (nAChR) subtype. OBJECTIVE The aim of this study was to determine whether the activation of another nAChR subtype, the central nervous system (CNS) prominent alpha4beta2 receptor, also contributes to the effects of nicotine on sensory gating in DBA/2 mice. METHODS Unanesthetized DBA/2 mice were treated either with nicotine, the alpha4beta2 antagonist dihydro-beta-erythroidine, the noncompetitive nAChR antagonist mecamylamine, or a combination of an antagonist and nicotine. Thereafter, gating was assessed by recording hippocampal evoked potentials (EP), which were elicited by pairs of auditory clicks. The EP response to the second click, or test amplitude (TAMP), was divided by the EP response to the first click, or condition amplitude (CAMP), to derive gating T:C ratios. RESULTS Nicotine significantly (p<0.05) lowered T:C ratios by 42%, while significantly increasing CAMP by 55%. After a pretreatment with dihydro-beta-erythroidine, nicotine still significantly lowered T:C ratios by 28%; however, the nicotine-induced increase of CAMP was blocked. Mecamylamine blocked the effect of nicotine on both T:C ratios and CAMP. CONCLUSIONS Activation of alpha4beta2 receptors by nicotine increases CAMP. However, under conditions where alpha4beta2 receptors are blocked, nicotine still lowers T:C ratios and may improve sensory gating, possibly through the activation of other nAChR subtypes such as alpha7. These effects of nicotine on auditory EPs may be indicative of a profile that would improve information processing in schizophrenia and other CNS diseases.
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Affiliation(s)
- Richard J Radek
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Dept. R4N5, AP9A/LL, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
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5-HT6 Receptors as Targets for the Treatment of Cognitive Deficits in Schizophrenia. THE SEROTONIN RECEPTORS 2006. [DOI: 10.1007/978-1-59745-080-5_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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