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Ding Y, Tian Q, Hou W, Chen Z, Mao Z, Bo Q, Dong F, Wang C. Core of sensory gating deficits in first-episode schizophrenia: attention dysfunction. Front Psychiatry 2023; 14:1160715. [PMID: 37181885 PMCID: PMC10169682 DOI: 10.3389/fpsyt.2023.1160715] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Background Sensory gating deficits are a common feature of schizophrenia and may be indicative of higher-order psychopathological impairments. It has been proposed that incorporating subjective attention components into prepulse inhibition (PPI) measures may improve the accuracy of assessing these deficits. This study aimed to investigate the relationship between modified PPI and cognitive function, with a specific focus on subjective attention, to gain a better understanding of the underlying mechanisms of sensory processing deficits in schizophrenia. Methods Fifty-four unmedicated first-episode schizophrenia (UMFE) patients and 53 healthy controls participated in this study. The modified Prepulse Inhibition paradigm, including Perceived Spatial Separation PPI (PSSPPI) and Perceived Spatial Colocation PPI (PSCPPI), was used to evaluate sensorimotor gating deficits. Cognitive function was assessed in all participants using the Chinese version of the MATRICS Consensus Cognitive Suite Test (MCCB). Results UMFE patients had lower MCCB scores and deficient PSSPPI scores than healthy controls. PSSPPI was negatively correlated with total PANSS scores and positively correlated with the speed of processing, attention/ vigilance, and social cognition. Multiple linear regression analysis showed that the PSSPPI at 60 ms had a significant effect on attentional/ vigilance and social cognition, even after controlling for gender, age, years of education, and smoking. Conclusion The study revealed notable impairments in sensory gating and cognitive function in UMFE patients, best reflected by the PSSPPI measure. Specifically, PSSPPI at 60 ms was significantly associated with both clinical symptoms and cognitive performance, suggesting that PSSPPI at 60 ms may capture psychopathological symptoms related to psychosis.
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Affiliation(s)
- Yushen Ding
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Qing Tian
- Suzhou Guangji Hospital, The Affiliated Guangji Hospital of Soochow University, The Institute of Mental Health, Suzhou, China
| | - Wenpeng Hou
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Zhenzhu Chen
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Zhen Mao
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Qijing Bo
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Fang Dong
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Chuanyue Wang
- Beijing Key Laboratory of Mental Disorders, Beijing Institute for Brain Disorders Center of Schizophrenia, Beijing Anding Hospital, Capital Medical University, Beijing, China
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
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Myles L, Garrison J, Cheke L. Latent Inhibition in Schizophrenia and Schizotypy. SCHIZOPHRENIA BULLETIN OPEN 2023; 4:sgad026. [PMID: 39145328 PMCID: PMC11207691 DOI: 10.1093/schizbullopen/sgad026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Background The Salience Hypothesis posits that aberrations in the assignment of salience culminate in hallucinations and unusual beliefs, the "positive symptoms" of schizophrenia. Evidence for this comes from studies on latent inhibition (LI), referring to the phenomenon that prior exposure to a stimulus impedes learning about the relationship between that stimulus and an outcome. Design This article reviewed all published studies examining the relationship between LI and both schizophrenia and schizotypy. Results Contemporary literature suggests that LI is attenuated in both people with schizophrenia and those loading highly on measures of schizotypy, the multidimensional derivative of schizophrenia. This suggests that these individuals assign greater salience to stimuli than healthy controls and people scoring low on measures of schizotypy, respectively. However, several confounds limit these conclusions. Studies on people with schizophrenia are limited by the confounding effects of psychotropic medications, idiosyncratic parsing of samples, variation in dependent variables, and lack of statistical power. Moreover, LI paradigms are limited by the confounding effects of learned irrelevance, conditioned inhibition, negative priming, and novel pop-out effects. Conclusions This review concludes with the recommendation that researchers develop novel paradigms that overcome these limitations to evaluate the predictions of the Salience Hypothesis.
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Affiliation(s)
- Liam Myles
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - Jane Garrison
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - Lucy Cheke
- Department of Psychology, University of Cambridge, Cambridge, UK
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Millard SJ, Bearden CE, Karlsgodt KH, Sharpe MJ. The prediction-error hypothesis of schizophrenia: new data point to circuit-specific changes in dopamine activity. Neuropsychopharmacology 2022; 47:628-640. [PMID: 34588607 PMCID: PMC8782867 DOI: 10.1038/s41386-021-01188-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/23/2021] [Accepted: 09/07/2021] [Indexed: 02/07/2023]
Abstract
Schizophrenia is a severe psychiatric disorder affecting 21 million people worldwide. People with schizophrenia suffer from symptoms including psychosis and delusions, apathy, anhedonia, and cognitive deficits. Strikingly, schizophrenia is characterised by a learning paradox involving difficulties learning from rewarding events, whilst simultaneously 'overlearning' about irrelevant or neutral information. While dysfunction in dopaminergic signalling has long been linked to the pathophysiology of schizophrenia, a cohesive framework that accounts for this learning paradox remains elusive. Recently, there has been an explosion of new research investigating how dopamine contributes to reinforcement learning, which illustrates that midbrain dopamine contributes in complex ways to reinforcement learning, not previously envisioned. This new data brings new possibilities for how dopamine signalling contributes to the symptomatology of schizophrenia. Building on recent work, we present a new neural framework for how we might envision specific dopamine circuits contributing to this learning paradox in schizophrenia in the context of models of reinforcement learning. Further, we discuss avenues of preclinical research with the use of cutting-edge neuroscience techniques where aspects of this model may be tested. Ultimately, it is hoped that this review will spur to action more research utilising specific reinforcement learning paradigms in preclinical models of schizophrenia, to reconcile seemingly disparate symptomatology and develop more efficient therapeutics.
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Affiliation(s)
- Samuel J. Millard
- grid.19006.3e0000 0000 9632 6718Department of Psychology, University of California, Los Angeles, CA 90095 USA
| | - Carrie E. Bearden
- grid.19006.3e0000 0000 9632 6718Department of Psychology, University of California, Los Angeles, CA 90095 USA ,grid.19006.3e0000 0000 9632 6718Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095 USA
| | - Katherine H. Karlsgodt
- grid.19006.3e0000 0000 9632 6718Department of Psychology, University of California, Los Angeles, CA 90095 USA ,grid.19006.3e0000 0000 9632 6718Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA 90095 USA
| | - Melissa J. Sharpe
- grid.19006.3e0000 0000 9632 6718Department of Psychology, University of California, Los Angeles, CA 90095 USA
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Török B, Fodor A, Klausz B, Varga J, Zelena D. Ameliorating schizophrenia-like symptoms in vasopressin deficient male Brattleboro rat by chronic antipsychotic treatment. Eur J Pharmacol 2021; 909:174383. [PMID: 34332923 DOI: 10.1016/j.ejphar.2021.174383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/07/2021] [Accepted: 07/23/2021] [Indexed: 02/06/2023]
Abstract
Due to its various function vasopressin has been associated with many psychiatric disorders, including schizophrenia. Our previous study confirmed that vasopressin-deficient (di/di) Brattleboro rat can be a good genetic model for schizophrenia. Our present aim was to confirm whether the treatment effects of marketed antipsychotics are similar in di/di rats to those seen in human schizophrenic patients. Chronic subcutaneous administration of aripiprazole (5 mg/kg), clozapine (1 mg/kg), haloperidol (0.1 mg/kg), olanzapine (0.3 mg/kg) or risperidone (0.25 mg/kg) was used for 15 days in control (+/+ Brattleboro) and di/di rats. Social discrimination, social avoidance and prepulse inhibition tests were conducted on day 1, 8 and 15 of the treatment. Vasopressin-deficient rats showed social memory- and sensorimotor gating deficit. All used antipsychotics successfully normalized the reduced prepulse inhibition of di/di animals. However, most were effective only after prolonged treatment. Aripiprazole, clozapine, and olanzapine normalized the social memory deficit, while the effects of haloperidol and risperidone were not unequivocal. All drugs reduced social interest to some extent both in control and in di/di animals, aripiprazole being the less implicated in this regard during the social avoidance test. The restoration of schizophrenia-like behavior by antipsychotic treatment further support the utility of the vasopressin-deficient Brattleboro rat as a good preclinical model. Reduced social interest might be a general side-effect of antipsychotics, and aripiprazole has the most favorable profile in this regard.
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Affiliation(s)
- Bibiána Török
- Institute of Experimental Medicine, Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Anna Fodor
- Institute of Experimental Medicine, Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | | | - János Varga
- Institute of Experimental Medicine, Budapest, Hungary; János Szentágothai School of Neurosciences, Semmelweis University, Budapest, Hungary
| | - Dóra Zelena
- Institute of Experimental Medicine, Budapest, Hungary; Centre for Neuroscience, Szentágothai Research Centre, Institute of Physiology, Medical School, University of Pécs, Pécs, Hungary.
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Gil-Miravet I, Fuertes-Saiz A, Benito A, Almodóvar I, Ochoa E, Haro G. Prepulse Inhibition in Cocaine Addiction and Dual Pathologies. Brain Sci 2021; 11:brainsci11020269. [PMID: 33672693 PMCID: PMC7924364 DOI: 10.3390/brainsci11020269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 12/14/2022] Open
Abstract
Cocaine addiction is frequently associated with different psychiatric disorders, especially schizophrenia and antisocial personality disorder. A small number of studies have used prepulse inhibition (PPI) as a discriminating factor between these disorders. This work evaluated PPI and the phenotype of patients with cocaine-related disorder (CRD) who presented a dual diagnosis of schizophrenia or antisocial personality disorder. A total of 74 men aged 18–60 years were recruited for this research. The sample was divided into four groups: CRD (n = 14), CRD and schizophrenia (n = 21), CRD and antisocial personality disorder (n = 16), and a control group (n = 23). We evaluated the PPI and other possible vulnerability factors in these patients by using different assessment scales. PPI was higher in the CRD group at 30 ms (F(3, 64) = 2.972, p = 0.038). Three discriminant functions were obtained which allowed us to use the overall Hare Psychopathy Checklist Revised score, reward sensitivity, and PPI at 30 ms to predict inclusion of these patients in the different groups with a success rate of 79.7% (42.9% for CRD, 76.2% for CRD and schizophrenia, 100% for CRD and antisocial personality disorder, and 91.3% in the control group). Despite the differences we observed in PPI, this factor is of little use for discriminating between the different diagnostic groups and it acts more as a non-specific endophenotype in certain mental disorders, such as in patients with a dual diagnosis.
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Affiliation(s)
- Isis Gil-Miravet
- TXP Research Group, Universidad Cardenal Herrera-CEU, CEU Universities, 12006 Castellón, Spain; (I.G.-M.); (A.B.); (I.A.); (G.H.)
- Predepartamental Unit of Medicine, Universitat Jaume I, 12071 Castellón, Spain
| | - Alejandro Fuertes-Saiz
- TXP Research Group, Universidad Cardenal Herrera-CEU, CEU Universities, 12006 Castellón, Spain; (I.G.-M.); (A.B.); (I.A.); (G.H.)
- Psychiatry Department, Consorcio Hospitalario Provincial de Castellón, 12002 Castellón, Spain
- Correspondence:
| | - Ana Benito
- TXP Research Group, Universidad Cardenal Herrera-CEU, CEU Universities, 12006 Castellón, Spain; (I.G.-M.); (A.B.); (I.A.); (G.H.)
- Torrente Mental Health Centre, Hospital General Universitario, 46014 Valencia, Spain
| | - Isabel Almodóvar
- TXP Research Group, Universidad Cardenal Herrera-CEU, CEU Universities, 12006 Castellón, Spain; (I.G.-M.); (A.B.); (I.A.); (G.H.)
| | - Enrique Ochoa
- Molecular Biopathology Department, Consorcio Hospitalario Provincial de Castellón, 12002 Castellón, Spain;
| | - Gonzalo Haro
- TXP Research Group, Universidad Cardenal Herrera-CEU, CEU Universities, 12006 Castellón, Spain; (I.G.-M.); (A.B.); (I.A.); (G.H.)
- Psychiatry Department, Consorcio Hospitalario Provincial de Castellón, 12002 Castellón, Spain
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Hedberg M, Imbeault S, Erhardt S, Schwieler L. Disrupted sensorimotor gating in first-episode psychosis patients is not affected by short-term antipsychotic treatment. Schizophr Res 2021; 228:118-123. [PMID: 33434725 DOI: 10.1016/j.schres.2020.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 10/23/2020] [Accepted: 12/12/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Impaired sensorimotor gating, commonly measured as disrupted prepulse inhibition (PPI) of the acoustic startle response, has been widely observed in psychotic diseases. However, most PPI studies published so far involve patients with long illness duration and different drug treatments. Few studies have investigated untreated patients at their first episode of psychotic symptoms. METHOD PPI is an acoustic startle paradigm (30, 60-, 120-ms interstimulus intervals). Startle reactivity and habituation were succesfully assessed in 49 antipsychotic-naïve first-episode psychosis (FEP) patients and compared with 35 age- and gender-matched healthy control subjects. Mean age of patients was 28 years and 27 for controls. Patients treated with antipsychotics more than 30 days were not included in the study and twenty-three out of forty-nine patients received antipsychotic treatment with a mean treatment time of 13 days. RESULTS PPI was significantly lower in FEP patients, compared to healthy controls. The PPI deficiency found in these patients was not due to antipsychotic treatment since PPI did not differ between treated (n=23) and untreated patients n=(26). By using the latent curve modeling we identified a delayed habituation in patients treated with antipsychotics, suggesting that antipsychotic treatment should be considered as a confound when investigating habituation in schizophrenia. CONCLUSIONS Our results suggest that acute pharmacological treatment does not normalize PPI in FEP patients but should be considered as a confound when investigating habituation in these patients.
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Affiliation(s)
- Mikael Hedberg
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Sophie Imbeault
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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- Dept. of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm, Sweden
| | - Sophie Erhardt
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
| | - Lilly Schwieler
- Dept. of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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7
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San-Martin R, Castro LA, Menezes PR, Fraga FJ, Simões PW, Salum C. Meta-Analysis of Sensorimotor Gating Deficits in Patients With Schizophrenia Evaluated by Prepulse Inhibition Test. Schizophr Bull 2020; 46:1482-1497. [PMID: 32506125 PMCID: PMC8061122 DOI: 10.1093/schbul/sbaa059] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Prepulse inhibition (PPI) of startle is an operational measure of sensorimotor gating that is often impaired in patients with schizophrenia. Despite the large number of studies, there is considerable variation in PPI outcomes reported. We conducted a systematic review and meta-analysis investigating PPI impairment in patients with schizophrenia compared with healthy control subjects, and examined possible explanations for the variation in results between studies. Major databases were screened for observational studies comparing healthy subjects and patients with schizophrenia for the prepulse and pulse intervals of 60 and 120 ms as primary outcomes, ie, PPI-60 and PPI-120. Standardized mean difference (SMD) and 95% confidence intervals (CI) were extracted and pooled using random effects models. We then estimated the mean effect size of these measures with random effects meta-analyses and evaluated potential PPI heterogeneity moderators, using sensitivity analysis and meta-regressions. Sixty-seven primary studies were identified, with 3685 healthy and 4290 patients with schizophrenia. The schizophrenia group showed reduction in sensorimotor gating for both PPI-60 (SMD = -0.50, 95% CI = [-0.61, -0.39]) and PPI-120 (SMD = -0.44, 95% CI = [-0.54, -0.33]). The sensitivity and meta-regression analysis showed that sample size, gender proportion, imbalance for gender, source of control group, and study continent were sources of heterogeneity (P < .05) for both PPI-60 and PPI-120 outcomes. Our findings confirm a global sensorimotor gating deficit in schizophrenia patients, with overall moderate effect size for PPI-60 and PPI-120. Methodological consistency should decrease the high level of heterogeneity of PPI results between studies.
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Affiliation(s)
- Rodrigo San-Martin
- Center for Mathematics, Computation and Cognition, Universidade Federal do ABC, Santo André, Brazil
| | - Leonardo Andrade Castro
- Center for Mathematics, Computation and Cognition, Universidade Federal do ABC, Santo André, Brazil
| | - Paulo Rossi Menezes
- Department of Preventive Medicine, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
- Population Mental Health Research Center, Universidade de São Paulo, São Paulo, Brazil
| | - Francisco José Fraga
- Engineering, Modeling and Applied Social Sciences Center, Universidade Federal do ABC, Santo André, Brazil
| | - Priscyla Waleska Simões
- Engineering, Modeling and Applied Social Sciences Center, Universidade Federal do ABC, Santo André, Brazil
| | - Cristiane Salum
- Center for Mathematics, Computation and Cognition, Universidade Federal do ABC, Santo André, Brazil
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Kumari V, Antonova E, Geyer MA. Prepulse inhibition and “psychosis-proneness” in healthy individuals: An fMRI study. Eur Psychiatry 2020; 23:274-80. [DOI: 10.1016/j.eurpsy.2007.11.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 11/20/2007] [Accepted: 11/20/2007] [Indexed: 10/22/2022] Open
Abstract
AbstractObjectivePrepulse inhibition (PPI) of the startle response provides an operational index of sensorimotor gating that is reliably demonstrable in both human and animal subjects. Patients with schizophrenia, first-degree relatives of patients with schizophrenia, patients with schizotypal personality disorder and healthy individuals scoring high on psychometric measures of psychosis-proneness display reduced PPI. This study examined associations between individual differences in “psychosis-proneness” and brain activity during a tactile prepulse inhibition paradigm previously found to reveal activation in controls and deficient activation in schizophrenia patients in the striatum, thalamus, insula, hippocampal, temporal, inferior frontal, and inferior parietal regions.MethodsFourteen right-handed healthy men underwent psychophysiological testing and functional magnetic resonance imaging (fMRI) during a 15-min tactile PPI paradigm involving the use of tactile stimuli as both the pulse (a 40-ms presentation of 30 psi air-puff) and the prepulse (a 20-ms presentation of 6 psi air-puff presented 30-ms or 120-ms before the pulse). Individual differences in “psychosis-proneness” were assessed with Psychoticism scale of the Eysenck Personality Questionnaire-Revised (EPQ-R).ResultsHigh psychosis-proneness was associated with lower PPI and reduced activity in the inferior frontal gyrus, insula extending to putamen and thalamus, parahippocampal gyrus, and inferior parietal and middle temporal regions. No regional activity correlated positively with psychosis-proneness.ConclusionsThe present observations extend the findings observed previously in people with schizophrenia to people with high psychosis-proneness, providing support to continuum theories of psychosis with implications for understanding trait-related neural deficits in schizophrenia.
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Rydkjaer J, Jepsen JRM, Pagsberg AK, Fagerlund B, Glenthoej BY, Oranje B. Do young adolescents with first-episode psychosis or ADHD show sensorimotor gating deficits? Psychol Med 2020; 50:607-615. [PMID: 30873927 DOI: 10.1017/s0033291719000412] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Early identification is important for patients with early-onset schizophrenia (SZ). Assessment of (candidate) endophenotypic markers for SZ, such as prepulse inhibition of the startle reflex (PPI), may help distinguish between the early-onset SZ and other psychiatric disorders. We explored whether PPI deficits usually seen in adult-onset SZ are present in young adolescents with either early-onset psychosis or attention deficit/hyperactivity disorder (ADHD). METHODS Twenty-five adolescents with first-episode, non-affective psychosis (FEP), 28 adolescents with ADHD and 43 healthy controls (HC), aged 12-17 years, were assessed with an auditory PPI paradigm. RESULTS No significant group differences were found in PPI. However, when the FEP group was divided into those already diagnosed with SZ (n = 13) and those without (N-SZ) (n = 12), and all four groups (SZ, N-SZ, ADHD and HC) were compared on percentage PPI in the 85/60 trials, significantly less PPI was found in patients with SZ than in the HC as well as the ADHD group. No significant group differences were found in explorative analyses on the other trial types. Additionally, startle magnitude was significantly higher in SZ than in N-SZ patients. CONCLUSION Young adolescents with SZ showed sensorimotor gating deficits similar to those usually found in adults with SZ and had larger startle magnitude than patients with other types of non-affective early-onset psychosis. No sensorimotor gating deficits were found in adolescents with ADHD. Our findings support the theory that deficient PPI is endophenotypic for SZ.
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Affiliation(s)
- Jacob Rydkjaer
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS) and Center for Neuropsychiatric Schizophrenia Research (CNSR), Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
- Child and Adolescent Mental Health Center, Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
| | - Jens Richardt Moellegaard Jepsen
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS) and Center for Neuropsychiatric Schizophrenia Research (CNSR), Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
- Child and Adolescent Mental Health Center, Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
| | - Anne Katrine Pagsberg
- Child and Adolescent Mental Health Center, Mental Health Services, Capital Region of Denmark, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Fagerlund
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS) and Center for Neuropsychiatric Schizophrenia Research (CNSR), Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
- Department of Psychology, University of Copenhagen, Copenhagen, Denmark
| | - Birte Yding Glenthoej
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS) and Center for Neuropsychiatric Schizophrenia Research (CNSR), Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bob Oranje
- Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research (CINS) and Center for Neuropsychiatric Schizophrenia Research (CNSR), Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
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Perez SM, Donegan JJ, Boley AM, Aguilar DD, Giuffrida A, Lodge DJ. Ventral hippocampal overexpression of Cannabinoid Receptor Interacting Protein 1 (CNRIP1) produces a schizophrenia-like phenotype in the rat. Schizophr Res 2019; 206:263-270. [PMID: 30522798 PMCID: PMC6525642 DOI: 10.1016/j.schres.2018.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 11/01/2018] [Accepted: 11/04/2018] [Indexed: 12/18/2022]
Abstract
Adolescent cannabis use has been implicated as a risk factor for schizophrenia; however, it is neither necessary nor sufficient. Previous studies examining this association have focused primarily on the role of the cannabinoid receptor 1 (CB1R) with relatively little known about a key regulatory protein, the cannabinoid receptor interacting protein 1 (CNRIP1). CNRIP1 is an intracellular protein that interacts with the C-terminal tail of CB1R and regulates its intrinsic activity. Previous studies have demonstrated aberrant CNRIP1 DNA promoter methylation in post-mortem in human patients with schizophrenia, and we have recently reported decreased methylation of the CNRIP1 DNA promoter in the ventral hippocampus (vHipp) of a rodent model of schizophrenia susceptibility. To examine whether augmented CNRIP1 expression could contribute to the pathology of schizophrenia, we performed viral-mediated overexpression of CNRIP1 in the vHipp of Sprague Dawley rats. We then tested these rats for behavioral correlates of schizophrenia symptoms, followed by electrophysiology to determine the effects on the dopamine system, known to underlie psychosis. Here, we report that overexpression of vHipp CNRIP1 induces impairments in latent inhibition and social interaction, similar to those observed in individuals with schizophrenia and in rodent models of the disease. Furthermore, rats overexpressing vHipp CNRIP1 displayed a significant increase in ventral tegmental area (VTA) dopamine neuron population activity, a putative correlate of psychosis. These data provide evidence that alterations in CNRIP1 may contribute to the pathophysiology of schizophrenia, as overexpression is sufficient to produce neurophysiological and behavioral correlates consistently observed in rodent models of the disease.
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Affiliation(s)
- Stephanie M Perez
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA.
| | - Jennifer J Donegan
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA
| | - Angela M Boley
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA
| | - David D Aguilar
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA; VA Boston Healthcare System and Harvard Medical School Department of Psychiatry, 1400 VFW Parkway, West Roxbury, MA 02132, USA
| | - Andrea Giuffrida
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA
| | - Daniel J Lodge
- Department of Pharmacology and Center for Biomedical Neuroscience, UT Health San Antonio, 7703 Floyd Curl Drive, MC 7764, San Antonio, TX 78229, USA
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11
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Fargotstein M, Hasenkamp W, Gross R, Cuthbert B, Green A, Swails L, Lewison B, Boshoven W, Keyes M, Duncan E. The effect of antipsychotic medications on acoustic startle latency in schizophrenia. Schizophr Res 2018; 198:28-35. [PMID: 28732798 DOI: 10.1016/j.schres.2017.07.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 10/19/2022]
Abstract
Prepulse inhibition of the acoustic startle reflex (PPI) is extensively studied as a biomarker of schizophrenia (SCZ); however, antipsychotic medication can confound the measure. Latency, the time between the startling stimulus and the reflexive eye blink, provides an index of neural processing speed and is 90% heritable. SCZ subjects have slower latency than controls (CON). This study examined the effects of antipsychotic medication on startle latency. 108 CON and 132 SCZ subjects in three medication subgroups (94 on second-generation antipsychotics (SGA), 25 on first-generation antipsychotics (FGA), 13 unmedicated (NoMed)) were tested on a standard acoustic startle paradigm designed to measure startle magnitude, PPI, and latency. Latency was slower in SCZ compared to CON subjects (p=0.005). Latency did not differ between the three SCZ medication groups. When CON were added to that model, both the NoMed subjects (p=0.04) and the SGA subjects (p=0.003) were slower than CON subjects. For PPI, CON did not differ from SCZ analyzed as a single group. When SCZ subjects were divided into medication groups, PPI was lower in NoMed subjects than the CON group (p=0.03), the SGA group (p=0.02) and the FGA group (p=0.05). SCZ subjects on any medication did not differ from CON. Thus, latency was partially normalized by antipsychotic medication, but this did not obscure the slower latency in SCZ compared to CON. Therefore latency is both trait and state related, whereas medication normalized PPI and obscured any difference between SCZ and CON.
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Affiliation(s)
- Molly Fargotstein
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA
| | - Wendy Hasenkamp
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA
| | - Robin Gross
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 12 Executive Park Drive Northeast #200, Atlanta, GA 30329, USA
| | - Bruce Cuthbert
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 12 Executive Park Drive Northeast #200, Atlanta, GA 30329, USA
| | - Amanda Green
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA
| | - Lisette Swails
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA
| | - Barbara Lewison
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 12 Executive Park Drive Northeast #200, Atlanta, GA 30329, USA
| | - William Boshoven
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 12 Executive Park Drive Northeast #200, Atlanta, GA 30329, USA
| | - Megan Keyes
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA
| | - Erica Duncan
- Atlanta Veterans Affairs Medical Center, 1670 Clairmont Road, Decatur, GA 30033, USA; Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, 12 Executive Park Drive Northeast #200, Atlanta, GA 30329, USA.
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12
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The role of N-methyl-d-aspartate receptors and metabotropic glutamate receptor 5 in the prepulse inhibition paradigms for studying schizophrenia: pharmacology, neurodevelopment, and genetics. Behav Pharmacol 2018; 29:13-27. [DOI: 10.1097/fbp.0000000000000352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Tarland E, Franke RT, Fink H, Pertz HH, Brosda J. Effects of 2-bromoterguride, a dopamine D 2 receptor partial agonist, on cognitive dysfunction and social aversion in rats. Psychopharmacology (Berl) 2018; 235:99-108. [PMID: 28971230 PMCID: PMC5748440 DOI: 10.1007/s00213-017-4747-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/19/2017] [Indexed: 12/31/2022]
Abstract
RATIONALE 2-Bromoterguride, a dopamine D2 receptor partial agonist with antagonist properties at serotonin 5-HT2A receptors and α2C-adrenoceptors, meets the prerequisites of a putative atypical antipsychotic drug (APD). We recently showed that 2-bromoterguride is effective in tests of positive symptoms of schizophrenia in rats without inducing extrapyramidal side effects or metabolic changes. OBJECTIVE In continuation of our recent work, we now investigated the effect of 2-bromoterguride on apomorphine and phencyclidine (PCP)-induced disruptions of prepulse inhibition (PPI) of the acoustic startle response, a measure of sensory gating. In addition, we used subchronic PCP treatment to produce cognitive deficits and social aversion, and assessed the effect of 2-bromoterguride on the performance in the novel object recognition (NOR) task (model for studying cognitive deficit symptoms of schizophrenia) and the social interaction test (model for studying negative symptoms of schizophrenia). Finally, we extended the side effect profile of 2-bromoterguride by measuring the prolactin response to systemic administration of the drug in rats. RESULTS Treatment with 2-bromoterguride (0.1 and 0.3 mg/kg) reversed PPI deficits induced by apomorphine and PCP, respectively. Subchronic PCP induced impairments in object memory and social interaction behavior which were ameliorated by 2-bromoterguride but not by clozapine and aripiprazole, respectively. Prolactin concentration in blood serum was not elevated at 1, 2, or 4 h post-2-bromoterguride treatment, which further supports the safe and effective use of this drug. CONCLUSIONS Our data support 2-bromoterguride as a promising APD candidate due to its beneficial effect on cognitive impairments and negative symptoms of schizophrenia.
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Affiliation(s)
- Emilia Tarland
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, 14195 Berlin, Germany
| | - Robert T. Franke
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, 14195 Berlin, Germany
| | - Heidrun Fink
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, 14195 Berlin, Germany
| | - Heinz H. Pertz
- Institute of Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Jan Brosda
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, 14195, Berlin, Germany. .,Bundesamt für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589, Berlin, Germany.
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14
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Buhusi M, Brown CK, Buhusi CV. Impaired Latent Inhibition in GDNF-Deficient Mice Exposed to Chronic Stress. Front Behav Neurosci 2017; 11:177. [PMID: 29066960 PMCID: PMC5641315 DOI: 10.3389/fnbeh.2017.00177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/07/2017] [Indexed: 12/14/2022] Open
Abstract
Increased reactivity to stress is maladaptive and linked to abnormal behaviors and psychopathology. Chronic unpredictable stress (CUS) alters catecholaminergic neurotransmission and remodels neuronal circuits involved in learning, attention and decision making. Glial-derived neurotrophic factor (GDNF) is essential for the physiology and survival of dopaminergic neurons in substantia nigra and of noradrenergic neurons in the locus coeruleus. Up-regulation of GDNF expression during stress is linked to resilience; on the other hand, the inability to up-regulate GDNF in response to stress, as a result of either genetic or epigenetic modifications, induces behavioral alterations. For example, GDNF-deficient mice exposed to chronic stress exhibit alterations of executive function, such as increased temporal discounting. Here we investigated the effects of CUS on latent inhibition (LI), a measure of selective attention and learning, in GDNF-heterozygous (HET) mice and their wild-type (WT) littermate controls. No differences in LI were found between GDNF HET and WT mice under baseline experimental conditions. However, following CUS, GDNF-deficient mice failed to express LI. Moreover, stressed GDNF-HET mice, but not their WT controls, showed decreased neuronal activation (number of c-Fos positive neurons) in the nucleus accumbens shell and increased activation in the nucleus accumbens core, both key regions in the expression of LI. Our results add LI to the list of behaviors affected by chronic stress and support a role for GDNF deficits in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.
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Affiliation(s)
- Mona Buhusi
- Interdisciplinary Program in Neuroscience, Department of Psychology, Utah State University, Logan, UT, United States
| | - Colten K Brown
- Interdisciplinary Program in Neuroscience, Department of Psychology, Utah State University, Logan, UT, United States
| | - Catalin V Buhusi
- Interdisciplinary Program in Neuroscience, Department of Psychology, Utah State University, Logan, UT, United States
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Smith AK, Jovanovic T, Kilaru V, Lori A, Gensler L, Lee SS, Norrholm SD, Massa N, Cuthbert B, Bradley B, Ressler KJ, Duncan E. A Gene-Based Analysis of Acoustic Startle Latency. Front Psychiatry 2017; 8:117. [PMID: 28729842 PMCID: PMC5498475 DOI: 10.3389/fpsyt.2017.00117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/19/2017] [Indexed: 12/16/2022] Open
Abstract
Latency of the acoustic startle response is the time required from the presentation of startling auditory stimulus until the startle response is elicited and provides an index of neural processing speed. Latency is prolonged in subjects with schizophrenia compared to controls in some but not all studies and is 68-90% heritable in baseline startle trials. In order to determine the genetic association with latency as a potential inroad into genetically based vulnerability to psychosis, we conducted a gene-based study of latency followed by an independent replication study of significant gene findings with a single-nucleotide polymorphism (SNP)-based analysis of schizophrenia and control subjects. 313 subjects from an urban population of low socioeconomic status with mixed psychiatric diagnoses were included in the gene-based study. Startle testing was conducted using a Biopac M150 system according to our published methods. Genotyping was performed with the Omni-Quad 1M or the Omni Express BeadChip. The replication study was conducted on 154 schizophrenia subjects and 123 psychiatric controls. Genetic analyses were conducted with Illumina Human Omni1-Quad and OmniExpress BeadChips. Twenty-nine SNPs were selected from four genes that were significant in the gene-based analysis and also associated with startle and/or schizophrenia in the literature. Linear regressions on latency were conducted, controlling for age, race, and diagnosis as a dichotomous variable. In the gene-based study, 2,870 genes demonstrated the evidence of association after correction for multiple comparisons (false discovery rate < 0.05). Pathway analysis of these genes revealed enrichment for relevant biological processes including neural transmission (p = 0.0029), synaptic transmission (p = 0.0032), and neuronal development (p = 0.024). The subsequent SNP-based replication analysis revealed a strong association of onset latency with the SNP rs901561 on the neuregulin gene (NRG1) in an additive model (beta = 0.21, p = 0.001), indicating that subjects with the AA and AG genotypes had slower mean latency than subjects with GG genotype. In conclusion, startle latency, a highly heritable measure that is slowed in schizophrenia, may be a useful biological probe for genetic contributions to psychotic disorders. Our analyses in two independent populations point to a significant prediction of startle latency by genetic variation in NRG1.
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Affiliation(s)
- Alicia K. Smith
- Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, GA, United States
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Tanja Jovanovic
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Varun Kilaru
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Adriana Lori
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Lauren Gensler
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
| | - Samuel S. Lee
- Department of Emergency Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Seth Davin Norrholm
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Mental Health Service Line, Atlanta Veterans Affairs Medical Center, Decatur, GA, United States
| | - Nicholas Massa
- Mental Health Service Line, Atlanta Veterans Affairs Medical Center, Decatur, GA, United States
| | - Bruce Cuthbert
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Mental Health Service Line, Atlanta Veterans Affairs Medical Center, Decatur, GA, United States
| | - Bekh Bradley
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Mental Health Service Line, Atlanta Veterans Affairs Medical Center, Decatur, GA, United States
| | - Kerry J. Ressler
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
| | - Erica Duncan
- Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, United States
- Mental Health Service Line, Atlanta Veterans Affairs Medical Center, Decatur, GA, United States
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16
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Yang NB, Tian Q, Fan Y, Bo QJ, Zhang L, Li L, Wang CY. Deficits of perceived spatial separation induced prepulse inhibition in patients with schizophrenia: relationships to symptoms and neurocognition. BMC Psychiatry 2017; 17:135. [PMID: 28399842 PMCID: PMC5387250 DOI: 10.1186/s12888-017-1276-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 03/18/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Prepulse inhibition (PPI) and attention were impaired, which may cause psychotic symptoms and (or) hinder the cognitive functions in schizophrenia. However, due to the measurement methods of PPI, findings about the relationship between PPI and clinical symptoms, cognitive performances have been equivocal. METHODS Seventy-five schizophrenia patients (SZ) and 50 healthy controls (HC) were assessed in a modified acoustic PPI paradigm, named perceived spatial separation-induced PPI (PSS-PPI), compared to perceived spatial co-location PPI (PSC-PPI) with inter-stimulus interval (ISI) of 120 ms. Repeatable Battery for the Assessment of Neuropsychological Status and the Stroop Color-Word Test were administered to all subjects. RESULTS Significant decrease in the modified PPI was found in the patients as compared to the controls, and effect sizes (Cohen'd) for patients vs. HCs % PPI levels achieved a significant level (PSC-PPI d = 0.84, PSS-PPI d = 1.27). A logistic regression model based on PSS-PPI significantly represented the diagnostic grouping (χ2= 29.3; p < 0 .001), with 85.2% area under ROC curve in predicting group membership. In addition, patients exhibited deficits in neurocognition. Among patients of "non-remission", after controlling for gender, age, education, duration, recurrence times, onset age, cigarettes per day and chlorpromazine equivalent dosage, PSS-PPI levels were associated with positive and negative symptoms, PANSS total and thought disorder (P1, P6, P7, N5, N7, G9). In multiple linear regression analyses, male and higher attention scores contributed to better PSC-PPI and PSS-PPI in controls group, while larger amount of smoke and longer word-color interfere time contributed to poor PSS-PPI. In patients' group, higher education and attention scores contributed to better PSS-PPI, while repeated relapse contributed to poor PSS-PPI. CONCLUSIONS The acoustic perceived spatial separation-induced PPIs may bring to light the psychopathological symptoms, especially for thought disorder, and the mechanism(s) of the novel PPI paradigm was associated with attention function.
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Affiliation(s)
- Ning-Bo Yang
- grid.24696.3fDepartment of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China
| | - Qing Tian
- grid.24696.3fDepartment of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China
| | - Yu Fan
- grid.24696.3fDepartment of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China
| | - Qi-Jing Bo
- grid.24696.3fDepartment of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China
| | - Liang Zhang
- grid.24696.3fDepartment of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China ,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088 China
| | - Liang Li
- grid.11135.37Department of Psychology, Peking University, Beijing, 100871 China ,grid.419897.aKey Laboratory on Machine Perception (Ministry of Education), Beijing, 100871 China ,McGovern Institute for Brain Research, Beijing, 100871 China
| | - Chuan-Yue Wang
- Department of Psychiatry, Beijing Anding Hospital, Capital Medical University, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088, China. .,Beijing Key Laboratory of Mental Disorders, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088, China. .,Beijing Institute for Brain Disorders Center of Schizophrenia, No.5 Ankang Lane, Dewai Avenue, Xicheng District, Beijing, 100088, China.
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17
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Matsuo J, Ota M, Hori H, Hidese S, Teraishi T, Ishida I, Hiraishi M, Kunugi H. A large single ethnicity study of prepulse inhibition in schizophrenia: Separate analysis by sex focusing on effect of symptoms. J Psychiatr Res 2016; 82:155-62. [PMID: 27505440 DOI: 10.1016/j.jpsychires.2016.07.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/13/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
Abstract
Deficits in sensorimotor gating, as measured with prepulse inhibition (PPI), have been considered an endophenotype of schizophrenia. However, the question remains whether these deficits are related to current symptoms. This single site study aimed to explore clinical features related to the modulation of startle reflex in a large sample of Japanese patients with schizophrenia (DSM-IV). The subjects comprised 181 patients and 250 healthy controls matched for age and sex. Schizophrenia symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Startle reflex to acoustic stimuli was recorded using a startle stimulus of 115 dB and a prepulse of four different conditions (intensity: 86 dB or 90 dB; lead interval: 60 ms or 120 ms). Patients exhibited significantly reduced startle magnitude (p < 0.001), habituation (p = 0.001), and PPI (90 dB, 60 ms, p = 0.016; 90 dB, 120 ms, p = 0.001) compared with controls. Patients of both sexes exhibited significantly lower habituation and PPI (90 dB, 120 ms) compared with the same sex controls. We could not detect a significant correlation with any clinical variable in the entire patients, however, when men and women were examined separately, there was a negative correlation with the PANSS cognitive domain (ρ = -0.33, p = 0.008) in men, but not in women. Moreover, when patients were subdivided into four clusters, two clusters with high positive symptoms showed significant PPI deficits in men. Our results suggest that sensorimotor gating is impaired in schizophrenia of both sexes, and PPI deficits may be related to thought disturbance and disorganization in male patients with schizophrenia.
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Affiliation(s)
- Junko Matsuo
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Miho Ota
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Hiroaki Hori
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Shinsuke Hidese
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Toshiya Teraishi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Ikki Ishida
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Moeko Hiraishi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Hiroshi Kunugi
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
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18
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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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19
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Peres FF, Levin R, Almeida V, Zuardi AW, Hallak JE, Crippa JA, Abilio VC. Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy. Front Pharmacol 2016; 7:303. [PMID: 27667973 PMCID: PMC5016523 DOI: 10.3389/fphar.2016.00303] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/26/2016] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings.
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Affiliation(s)
- Fernanda F Peres
- Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil; Department of Pharmacology, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil
| | - Raquel Levin
- Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil; Department of Pharmacology, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil
| | - Valéria Almeida
- Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil; Department of Pharmacology, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil
| | - Antonio W Zuardi
- Department of Neuroscience and Behavior, University of São PauloRibeirão Preto, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq)Ribeirão Preto, Brazil
| | - Jaime E Hallak
- Department of Neuroscience and Behavior, University of São PauloRibeirão Preto, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq)Ribeirão Preto, Brazil
| | - José A Crippa
- Department of Neuroscience and Behavior, University of São PauloRibeirão Preto, Brazil; National Institute for Translational Medicine (INCT-TM, CNPq)Ribeirão Preto, Brazil
| | - Vanessa C Abilio
- Interdisciplinary Laboratory of Clinical Neurosciences, Department of Psychiatry, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil; Department of Pharmacology, Escola Paulista De Medicina, Federal University of São PauloSão Paulo, Brazil
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20
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Feifel D, Shilling PD, Fazlinejad AA, Melendez G. Antipsychotic drug-like facilitation of latent inhibition by a brain-penetrating neurotensin-1 receptor agonist. J Psychopharmacol 2016; 30:312-7. [PMID: 26783230 DOI: 10.1177/0269881115625360] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Latent inhibition (LI) is a measure of cognitive gating and refers to reduced conditioned learning when there is pre-exposure to the conditioned stimulus (CS) before it is paired with the unconditioned stimulus (US). Dysregulation of LI is associated with some neuropsychiatric disorders, including schizophrenia, and the ability to facilitate LI in rodents is a reasonably good predictive test for antipsychotic drugs. Converging evidence supports neurotensin-1 receptor (NTS1) agonists as novel drugs for schizophrenia. Therefore, we investigated the ability of a brain-penetrating, selective NTS1 agonist, PD149163, to facilitate LI in heterozygous Brattleboro rats, a strain that exhibits naturally low LI. Conditioned taste aversion to flavored water (FW; 0.1% saccharin) was induced by pairing it with malaise-inducing injections of lithium chloride (LiCl). Prior to LiCl-FW pairing, rats received subcutaneous injections of saline, or PD149163 (100 µg/kg or 200 µg/kg). Half the rats in each drug group had been allowed to drink FW the day before the LiCl-FW pairing (pre-exposed rats). Two days after pairing, the amount of FW each rat consumed was recorded. LI, defined as significantly greater FW drinking in the pre-exposed group compared with the non pre-exposed group, was exhibited only among rats that received 200 µg/kg of PD149163. These results further support NTS1 agonists as potentially novel drugs for the treatment of schizophrenia.
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Affiliation(s)
- D Feifel
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - P D Shilling
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - A A Fazlinejad
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - G Melendez
- Department of Psychiatry, University of California, San Diego, CA, USA
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Mohr C, Ettinger U. An Overview of the Association between Schizotypy and Dopamine. Front Psychiatry 2014; 5:184. [PMID: 25566103 PMCID: PMC4271513 DOI: 10.3389/fpsyt.2014.00184] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 12/05/2014] [Indexed: 12/31/2022] Open
Abstract
Schizotypy refers to a constellation of personality traits that are believed to mirror the subclinical expression of schizophrenia in the general population. Evidence from pharmacological studies indicates that dopamine (DA) is involved in the etiology of schizophrenia. Based on the assumption of a continuum between schizophrenia and schizotypy, researchers have begun investigating the association between DA and schizotypy using a wide range of methods. In this article, we review published studies on this association from the following areas of work: (1) experimental investigations of the interactive effects of dopaminergic challenges and schizotypy on cognition, motor control, and behavior (2), dopaminergically supported cognitive functions (3), studies of associations between schizotypy and polymorphisms in genes involved in dopaminergic neurotransmission, and (4) molecular imaging studies of the association between schizotypy and markers of the DA system. Together, data from these lines of evidence suggest that DA is important to the expression and experience of schizotypy and associated behavioral biases. An important observation is that the experimental designs, methods, and manipulations used in this research are highly heterogeneous. Future studies are required to replicate individual observations, to enlighten the link between DA and different schizotypy dimensions (positive, negative, cognitive disorganization), and to guide the search for solid DA-sensitive behavioral markers. Such studies are important in order to clarify inconsistencies between studies. More work is also needed to identify differences between dopaminergic alterations in schizotypy compared to the dysfunctions observed in schizophrenia.
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Affiliation(s)
- Christine Mohr
- Institute of Psychology, University of Lausanne , Lausanne , Switzerland
| | - Ulrich Ettinger
- Department of Psychology, University of Bonn , Bonn , Germany
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22
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Liu X, Hong X, Chan RCK, Kong F, Peng Z, Wan X, Wang C, Cheng L. Association study of polymorphisms in the alpha 7 nicotinic acetylcholine receptor subunit and catechol-o-methyl transferase genes with sensory gating in first-episode schizophrenia. Psychiatry Res 2013; 209:431-8. [PMID: 23598060 DOI: 10.1016/j.psychres.2013.03.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Revised: 03/02/2013] [Accepted: 03/26/2013] [Indexed: 11/15/2022]
Abstract
The purpose of the current study was to explore the association of auditory P50 sensory gating (P50) and prepulse inhibition (PPI) of schizophrenia with polymorphisms in the CHRNA7 and COMT genes. One hundred and fourty patients with schizophrenia participated in this study. They were administered the tests P50 and PPI. Moreover, three single nucleotide polymorphisms (SNPs) (rs2337980, rs1909884 and rs883473) in CHRNA7 and three SNPs (rs4680, rs737865 and rs165599) in COMT were selected to be genotyped by polyacrylamide gel microarray techniques. P50 index showed significant reduction in S2 amplitude between wild-type and mutation groups in the COMT rs4680. S1 amplitude of mutation group in the COMT rs737865 was also lower compared to wild-type group. PPI index revealed a shorter pulse latency of mutation group in the rs4680. The suppression ratio of mutation group was lower in COMT rs165599. Negative findings were shown between comparisons in all the CHRNA7 SNPs. We find that P50 and PPI may be influenced by COMT rs4680 polymorphisms in schizophrenia; more excitingly, we find that P50 might be influenced by COMT rs737865 polymorphisms and PPI may be influenced by COMT rs165599 polymorphisms in schizophrenia, and their mutations are associated with the reduction of the risk of P50 or PPI defects in schizophrenia. Futher studies with a larger number of subjects are needed to verify the present findings.
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Affiliation(s)
- Xia Liu
- Mental Health Center, Medical College of Shantou University, Shantou, China; Mental health Hospital of Jining, Jining, China
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23
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Alba-Ferrara L, de Erausquin GA, Hirnstein M, Weis S, Hausmann M. Emotional prosody modulates attention in schizophrenia patients with hallucinations. Front Hum Neurosci 2013; 7:59. [PMID: 23459397 PMCID: PMC3586698 DOI: 10.3389/fnhum.2013.00059] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 02/14/2013] [Indexed: 11/13/2022] Open
Abstract
Recent findings have demonstrated that emotional prosody (EP) attracts attention involuntarily (Grandjean et al., 2008). The automat shift of attention toward emotionally salient stimuli can be overcome by attentional control (Hahn et al., 2010). Attentional control is impaired in schizophrenia, especially in schizophrenic patients with hallucinations because the "voices" capture attention increasing the processing load and competing for top-down resources. The present study investigates how involuntary attention is driven by implicit EP in schizophrenia with auditory verbal hallucinations (AVH) and without (NAVH). Fifteen AVH patients, 12 NAVH patients and 16 healthy controls (HC) completed a dual-task dichotic listening paradigm, in which an emotional vocal outburst was paired with a neutral vocalization spoken in male and female voices. Participants were asked to report the speaker's gender while attending to either the left or right ear. NAVH patients and HC revealed shorter response times for stimuli presented to the attended left ear than the attended right ear. This laterality effect was not present in AVH patients. In addition, NAVH patients and HC showed faster responses when the EP stimulus was presented to the unattended ear, probably because of less interference between the attention-controlled gender voice identification task and involuntary EP processing. AVH patients did not benefit from presenting emotional stimuli to the unattended ear. The findings suggest that similar to HC, NAVH patients show a right hemispheric bias for EP processing. AVH patients seem to be less lateralized for EP and therefore might be more susceptible to interfering involuntary EP processing; regardless which ear/hemisphere receives the bottom up input.
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Affiliation(s)
- L. Alba-Ferrara
- Department of Psychiatry and Neurosciences, Roskamp Laboratory of Brain Development, Modulation and Repair, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Psychology, Durham UniversityDurham, UK
| | - G. A. de Erausquin
- Department of Psychiatry and Neurosciences, Roskamp Laboratory of Brain Development, Modulation and Repair, Morsani College of Medicine, University of South FloridaTampa, FL, USA
| | - M. Hirnstein
- Department of Psychology, Durham UniversityDurham, UK
- Department of Biological and Medical Psychology, University of BergenBergen, Norway
| | - S. Weis
- Department of Psychology, Durham UniversityDurham, UK
| | - M. Hausmann
- Department of Psychology, Durham UniversityDurham, UK
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Xue YY, Wang HN, Xue F, Tan QR. Atypical antipsychotics do not reverse prepulse inhibition deficits in acutely psychotic schizophrenia. J Int Med Res 2013; 40:1467-75. [PMID: 22971498 DOI: 10.1177/147323001204000425] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES To investigate the effects of atypical antipsychotics on prepulse inhibition, startle response and habituation in acutely psychotic patients with schizophrenia, and investigate whether prepulse inhibition deficit improvements are a result of the direct impact of atypical antipsychotics or improvements in antipsychotic-related symptoms. METHODS Prepulse inhibition, habituation and acoustic startle response were evaluated in healthy control subjects and patients with schizophrenia (either unmedicated with antipsychotics at the time of hospitalization or medicated with atypical antipsychotics for ≥1 month before hospitalization). RESULTS Data were analysed for 26 patients in the unmedicated group, 20 patients in the medicated group and 31 control subjects. Compared with controls, both medicated and unmedicated patients showed prepulse inhibition deficits; however, there were no significant differences between the two patient groups. Lower prepulse inhibition levels were correlated with higher levels of positive, negative, general and total scores on the Positive and Negative Syndrome Scale. CONCLUSIONS These results suggest that effects of atypical antipsychotics on prepulse inhibition may not be evident when patients with schizophrenia are acutely symptomatic, and do not directly influence prepulse inhibition.
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Affiliation(s)
- Y-Y Xue
- Department of Psychiatry, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi Province, China
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25
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Ramage EM, Weintraub DM, Allen DN, Snyder JS. Evidence for stimulus-general impairments on auditory stream segregation tasks in schizophrenia. J Psychiatr Res 2012; 46:1540-5. [PMID: 23017812 PMCID: PMC3485434 DOI: 10.1016/j.jpsychires.2012.08.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 06/26/2012] [Accepted: 08/27/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Auditory impairments in schizophrenia have been demonstrated previously, especially for tasks requiring precise encoding of frequency, although it is unclear the extent to which they have difficulty using pitch information and other cues to segregate sounds. We determined the extent to which those with schizophrenia have difficulty using pitch information and other auditory cues to segregate sounds that are presented sequentially. METHODS Ten participants with schizophrenia and nine healthy/normal control participants completed a battery of tasks that tested for the ability to perform sequential auditory stream segregation using pitch, amplitude modulation, or inter-aural phase difference as cues to segregation. RESULTS All three sequential segregation tasks showed reduced tendency for those with schizophrenia to perceive segregated sounds, compared to control participants. CONCLUSIONS These findings extend prior research by demonstrating a general impairment on sequential sound segregation tasks in schizophrenia, and not just on tasks that require precise encoding of frequency. Together, the pattern of results provide evidence that auditory impairments in schizophrenia result from selective abnormalities in neural circuits that carry out specific computations necessary for stream segregation, as opposed to an impairment in processing specific cues.
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Affiliation(s)
- Erin M Ramage
- Department of Psychology, University of Nevada, Las Vegas, NV 89154-5030, USA
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26
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de Koning MB, Boot E, Bloemen OJN, van Duin EDA, Abel KM, de Haan L, Linszen DH, van Amelsvoort TAMJ. Startle reactivity and prepulse inhibition of the acoustic startle response are modulated by catechol-O-methyl-transferase Val(158) Met polymorphism in adults with 22q11 deletion syndrome. J Psychopharmacol 2012; 26:1548-60. [PMID: 22952320 DOI: 10.1177/0269881112456610] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
22q11 deletion syndrome (22q11DS) is a genetic disorder caused by a microdeletion on chromosome 22, which includes the gene coding for catechol-O-methyl-transferase (COMT). High dopamine (DA) levels due to COMT haplo-insufficiency may be associated with the increased risk of developing schizophrenia in adults with 22q11DS. Reduced prepulse inhibition (PPI) of the acoustic startle response has been associated with schizophrenia and with disrupted DAergic transmission in the prefrontal cortex (PFC). COMT Val(158)Met polymorphism has been shown to influence PPI. We report the first study in adults with 22q11DS to examine PPI of the acoustic startle response and its modulation by COMT Val(158)Met polymorphism. Startle reactivity (SR) and PPI of the acoustic startle response were measured in 23 adults with 22q11DS and 21 healthy controls. 22q11DS subjects were genotyped for the functional COMT Val(158)Met polymorphism. 22q11DS Met hemizygotes showed reduced SR and PPI compared with 22q11DS Val hemizygotes. The effect of COMT Val(158)Met polymorphism on PPI was no longer significant when controlling for baseline SR. Met hemizygosity in 22q11DS is associated with reduced SR and influences PPI indirectly. Decreased PFC functioning following excessive PFC DA levels may be one of the mechanisms by which the Met genotype in 22q11DS disrupts SR.
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Affiliation(s)
- Mariken B de Koning
- Department of Psychiatry, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands.
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Schmidt-Hansen M, Le Pelley M. The positive symptoms of acute schizophrenia and latent inhibition in humans and animals: underpinned by the same process(es)? Cogn Neuropsychiatry 2012; 17:473-505. [PMID: 22443090 DOI: 10.1080/13546805.2012.667202] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION It has been suggested that the positive symptoms of acute schizophrenia are a consequence of a disruption of the process that produces latent inhibition (slower acquisition of conditioned responding after preexposure to the conditioned stimulus) and that this effect can be modelled by pro- and antipsychotic compounds in healthy participants and in nonhuman animals. This idea assumes that latent inhibition in humans and animals is underpinned by the same process(es). METHOD First, we question the equivalence of human and animal latent inhibition. Second, we review the studies that have examined latent inhibition in populations with schizophrenia and in healthy populations after administration of amphetamine or haloperidol. RESULTS Theoretical analysis of the similarities and differences in latent inhibition effects, and the procedures used to generate them, in humans and animals renders the suggested equivalence between them unconvincing. The studies examining latent inhibition in populations with schizophrenia and in healthy populations after administration of amphetamine or haloperidol are marked by a number of methodological shortcomings and reveal discrepant results. CONCLUSIONS The theoretical and empirical analyses provide little support for a common process underlying deficits of latent inhibition in patients exhibiting positive symptoms of acute schizophrenia, and such deficits in experimental models in healthy humans and infrahumans.
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Devoto P, Frau R, Bini V, Pillolla G, Saba P, Flore G, Corona M, Marrosu F, Bortolato M. Inhibition of 5α-reductase in the nucleus accumbens counters sensorimotor gating deficits induced by dopaminergic activation. Psychoneuroendocrinology 2012; 37:1630-45. [PMID: 22029952 PMCID: PMC3432701 DOI: 10.1016/j.psyneuen.2011.09.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 11/16/2022]
Abstract
Cogent evidence highlights a key role of neurosteroids and androgens in schizophrenia. We recently reported that inhibition of steroid 5α-reductase (5αR), the rate-limiting enzyme in neurosteroid synthesis and androgen metabolism, elicits antipsychotic-like effects in humans and animal models, without inducing extrapyramidal side effects. To elucidate the anatomical substrates mediating these effects, we investigated the contribution of peripheral and neural structures to the behavioral effects of the 5αR inhibitor finasteride (FIN) on the prepulse inhibition (PPI) of the acoustic startle reflex (ASR), a rat paradigm that dependably simulates the sensorimotor gating impairments observed in schizophrenia and other neuropsychiatric disorders. The potential effect of drug-induced ASR modifications on PPI was excluded by measuring this index both as percent (%PPI) and absolute values (ΔPPI). In both orchidectomized and sham-operated rats, FIN prevented the %PPI deficits induced by the dopamine (DA) receptor agonists apomorphine (APO, 0.25mg/kg, SC) and d-amphetamine (AMPH, 2.5mg/kg, SC), although the latter effect was not corroborated by ΔPPI analysis. Conversely, APO-induced PPI deficits were countered by FIN infusions in the brain ventricles (10μg/1μl) and in the nucleus accumbens (NAc) shell and core (0.5μg/0.5μl/side). No significant PPI-ameliorating effect was observed following FIN injections in other brain regions, including dorsal caudate, basolateral amygdala, ventral hippocampus and medial prefrontal cortex, although a statistical trend was observed for the latter region. The efflux of DA in NAc was increased by systemic, but not intracerebral FIN administration. Taken together, these findings suggest that the role of 5αR in gating regulation is based on post-synaptic mechanisms in the NAc, and is not directly related to alterations in DA efflux in this region.
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Affiliation(s)
- Paola Devoto
- Tourette Syndrome Center, Laboratory “Guy Everett”, University of Cagliari, Cagliari, Italy
,Department of Neuroscience “Bernard B. Brodie”, University of Cagliari, Cagliari, Italy
| | - Roberto Frau
- Tourette Syndrome Center, Laboratory “Guy Everett”, University of Cagliari, Cagliari, Italy
,Department of Neuroscience “Bernard B. Brodie”, University of Cagliari, Cagliari, Italy
| | - Valentina Bini
- Department of Neuroscience “Bernard B. Brodie”, University of Cagliari, Cagliari, Italy
| | - Giuliano Pillolla
- Department of Neuroscience “Bernard B. Brodie”, University of Cagliari, Cagliari, Italy
| | - Pierluigi Saba
- Department of Neuroscience “Bernard B. Brodie”, University of Cagliari, Cagliari, Italy
| | - Giovanna Flore
- Department of Cardiovascular and Neurological Sciences, University of Cagliari, Italy
| | - Marta Corona
- Department of Cardiovascular and Neurological Sciences, University of Cagliari, Italy
| | - Francesco Marrosu
- Tourette Syndrome Center, Laboratory “Guy Everett”, University of Cagliari, Cagliari, Italy
,Department of Cardiovascular and Neurological Sciences, University of Cagliari, Italy
| | - Marco Bortolato
- Tourette Syndrome Center, Laboratory “Guy Everett”, University of Cagliari, Cagliari, Italy
,Department of Cardiovascular and Neurological Sciences, University of Cagliari, Italy
,Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
,Corresponding author at: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Rm. 527, PSC 1985 Zonal Avenue, Los Angeles, CA 90089, USA. Tel.: +1 323 442 3225; fax: +1 323 442 3229. (M. Bortolato)
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Early social isolation disrupts latent inhibition and increases dopamine D2 receptor expression in the medial prefrontal cortex and nucleus accumbens of adult rats. Brain Res 2012; 1447:38-43. [DOI: 10.1016/j.brainres.2012.01.058] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/15/2011] [Accepted: 01/24/2012] [Indexed: 11/20/2022]
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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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Feifel D, Shilling PD, Melendez G. Clozapine and PD149163 elevate prepulse inhibition in Brown Norway rats. Behav Neurosci 2012; 125:268-72. [PMID: 21463026 DOI: 10.1037/a0022691] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Unmedicated schizophrenia patients exhibit deficits in prepulse inhibition (PPI) of the acoustic startle response. Similar deficits can be induced in rodents via a variety of manipulations and these deficits can be reversed by antipsychotics. Brown Norway (BN) rats exhibit natural PPI deficits under certain parametric conditions. We treated BN rats with haloperidol or clozapine to determine if the BN rat is a useful animal model with predictive validity for the effects of antipsychotics. In addition, we also tested PD149163, a neurotensin-1 receptor agonist, which has been shown to exhibit antipsychotic-like effects in several other animal models. BN rats received subcutaneous injections of either saline or one of two doses of haloperidol (0.5 mg/kg, 1.0 mg/kg), clozapine (7.5 mg/kg, 10 mg/kg) or PD149163 (1.0 mg/kg, 2.0 mg/kg). PPI was measured in startle chambers 30 min after injection. Systemic clozapine and PD149163 but not haloperidol facilitated PPI in BN rats (p < .001). This drug response profile suggests that the BN rat may be useful for detecting atypical antipsychotics and antipsychotics with novel mechanisms of action. The results also add to the evidence suggesting that PD149163 may have antipsychotic properties.
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Affiliation(s)
- David Feifel
- Department of Psychiatry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-8218, USA.
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Wang Z, Tan Y, Yang F, Zhang W, Zou Y, Song C, Zhou Y, Li Y, Zhang X, Zhou D. The study of acoustic startle reflex in male patients with chronic schizophrenia. Asian J Psychiatr 2012; 5:54-7. [PMID: 26878949 DOI: 10.1016/j.ajp.2011.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 12/04/2011] [Accepted: 12/19/2011] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To explore the deficits of acoustic startle reflex (ASR) that might exist in Chinese patients with schizophrenia and the effects of antipsychotics on ASR. METHODS Participants included 25 male patients with chronic schizophrenia treated with typical antipsychotics (typical group), 25 who were treated with atypical antipsychotic clozapine (clozapine group) and 25 healthy male subjects (control group) matched for age and years of education. Startle reflex to acoustic stimuli were examined in all subjects from the three groups. At the same day of startle testing, psychopathological symptoms of the patients were assessed with the Positive and Negative Syndrome Scale (PANSS). RESULTS (1) Startle response (SR) was significantly reduced in typical group as compared to control group [(553.6±516.9)mV vs. (942.0±447.3)mV, P=0.009]. SR of clozapine group [(755.9±439.4)mV] was greater than that of typical group and less than that of control group, but there was no significant difference between the clozapine group and the other two. (2) Habituation (HAB) of startle reflex in typical group was significantly lower than in control group [(17.8±35.8)% vs. (44.9±28.9)%, P=0.027]. HAB of clozapine group [(22.9±34.1)%] was higher than that of typical group and less than that of control group, but there was no significant difference between clozapine group and the other groups. (3) Compared with healthy controls, patients of typical group exhibited the significant reduction in prepulse inhibition (PPI) of startle reflex (P=0.024) when prepulse interval (LI) was 120ms. PPI of clozapine group was higher than typical group and less than control group, but no significant differences in PPI were found between clozapine group and the other groups. While LI was 30- or 120-ms, PPI among the three groups showed not significantly different (P>0.05). (4) No significant relationship was found between PPI of different LIs and symptom scores assessed with PANSS in patients with schizophrenia (P>0.05). CONCLUSION Our findings suggest impaired PPI in Chinese patients with schizophrenia; Atypical antipsychotic clozapine might partly improve disinhibition of startle reflex in schizophrenic patients.
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Affiliation(s)
- Zhiren Wang
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Yunlong Tan
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Fude Yang
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Wufang Zhang
- Institute of Mental Health, Peking University, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, PR China
| | - Yizhuang Zou
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Chongsheng Song
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Yu Zhou
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Yingli Li
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China
| | - Xiangyang Zhang
- Center for Biological Psychiatry, Beijing Hui-Long-Guan Hospital, Beijing 100096, PR China; Menninger Department of Psychiatry, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dongfeng Zhou
- Institute of Mental Health, Peking University, Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing 100191, PR China
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Takahashi H, Hashimoto R, Iwase M, Ishii R, Kamio Y, Takeda M. Prepulse inhibition of startle response: recent advances in human studies of psychiatric disease. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2011; 9:102-10. [PMID: 23429840 PMCID: PMC3569113 DOI: 10.9758/cpn.2011.9.3.102] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 11/18/2011] [Accepted: 11/21/2011] [Indexed: 12/04/2022]
Abstract
Prepulse inhibition (PPI) is considered to be one of the most promising neurophysiological indexes for translational research in psychiatry. Impairment of PPI has been reported in several psychiatric diseases, particularly schizophrenia, where PPI is considered a candidate intermediate phenotype (endophenotype) of the disease. Recent findings from a variety of research areas have provided important evidence regarding PPI impairment. Human brain imaging studies have demonstrated the involvement of the striatum, hippocampus, thalamus and frontal and parietal cortical regions in PPI. In addition, several genetic polymorphisms, including variations in the genes coding for Catechol O-methyltransferase, Neuregulin 1, nuclear factor kappa-B subunit 3 and serotonin-2A receptor were related to PPI; and these findings support PPI as a polygenetic trait that involves several neurotransmitter pathways. Early psychosis studies suggest that PPI disruption is present before the onset of psychosis. Also, discrepancy of PPI impairment between children and adults can be found in other psychiatric diseases, such as autistic spectrum disorders and posttraumatic stress disorder, and comprehensive investigation of startle response might contribute to understand the impairment of the neural circuitry in psychiatric diseases. Finally, recent studies with both Asian and Caucasian subjects indicate that patients with schizophrenia exhibit impaired PPI, and impaired sensorimotor gating might be a global common psychophysiological feature of schizophrenia. In conclusion, studies of PPI have successfully contributed to a better understanding of the fundamental neural mechanisms underlying sensorimotor gating and will certainly be most valuable in devising future approaches that aim to investigate the complex pathogenesis of psychiatric diseases.
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Affiliation(s)
- Hidetoshi Takahashi
- Department of Child and Adolescent Mental Health, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan. ; Department of Psychiatry, Osaka University Graduate School of Medicine, Osaka, Japan
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Holstein DH, Csomor PA, Geyer MA, Huber T, Brugger N, Studerus E, Vollenweider FX. The effects of sertindole on sensory gating, sensorimotor gating, and cognition in healthy volunteers. J Psychopharmacol 2011; 25:1600-13. [PMID: 21890590 DOI: 10.1177/0269881111415734] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sensory gating, indexed by P50 suppression, and sensorimotor gating, indexed by prepulse inhibition (PPI), are impaired in schizophrenia spectrum disorders. There is considerable evidence that schizophrenia patients treated with atypical antipsychotics exhibit relatively less gating deficits than do other patients with schizophrenia. Some recent studies have investigated the effects of antipsychotic medications on gating in healthy volunteers exhibiting low levels of gating, rather than in patients. Therefore, the current study investigated the influence of sertindole versus placebo in two separate experimental sessions, on PPI, P50 suppression, and cognition in 30 male volunteers stratified for low and high baseline gating levels. Sertindole increased PPI and P50 suppression in healthy subjects exhibiting low baseline PPI and low baseline P50 suppression, respectively, while sertindole attenuated gating in subjects exhibiting high baseline gating. Furthermore, subjects exhibiting low PPI chose worse strategies in a spatial working memory task. These findings suggest that mixed D(2)/5-HT(2) receptor antagonists enhance both PPI and P50 suppression in a way that enhances it in healthy subjects exhibiting low baseline gating. Furthermore, the results militate in favor of the concomitant assessment of PPI, P50 suppression and cognitive measures while investigating the effect of antipsychotic medication in healthy subjects.
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Consequences of early life MK-801 administration: long-term behavioural effects and relevance to schizophrenia research. Behav Brain Res 2011; 227:276-86. [PMID: 22085878 DOI: 10.1016/j.bbr.2011.10.052] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 10/31/2011] [Indexed: 12/13/2022]
Abstract
Animal models contribute significantly to advancing the understanding of schizophrenia neurobiology, in addition to being an important tool for the screening of antipsychotic potential of new compounds. However, the entire spectrum or all the symptoms manifested in schizophrenia cannot be straightforwardly reproduced in animals due to the complexity of the disorder, difference in mental capacities and behaviours, and the ability to quantify or measure the changes. Blockade of the NMDA receptor by the use of MK-801, a non-competitive NMDA receptor antagonist, during the early postnatal period has been proposed to be an experimental model which induces behavioural changes that mimic several aspects of the disorder. The long term behavioural profile arising from this early life manipulation is reviewed herein, with a specific focus on behaviours relevant to a schizophrenia-like condition. Some of the reported neurochemical changes are also compiled. Although this method may be suitable to model some aspects of schizophrenia in rodents, there are unmet areas which need to be addressed, notably the characterisation of its predictive value.
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Orosz AT, Feldon J, Simon AE, Hilti LM, Gruber K, Yee BK, Cattapan-Ludewig K. Learned irrelevance and associative learning is attenuated in individuals at risk for psychosis but not in asymptomatic first-degree relatives of schizophrenia patients: translational state markers of psychosis? Schizophr Bull 2011; 37:973-81. [PMID: 20080901 PMCID: PMC3160228 DOI: 10.1093/schbul/sbp165] [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] [Indexed: 11/13/2022]
Abstract
Learned irrelevance (LIrr) refers to a form of selective learning that develops as a result of prior noncorrelated exposures of the predicted and predictor stimuli. In learning situations that depend on the associative link between the predicted and predictor stimuli, LIrr is expressed as a retardation of learning. It represents a form of modulation of learning by selective attention. Given the relevance of selective attention impairment to both positive and cognitive schizophrenia symptoms, the question remains whether LIrr impairment represents a state (relating to symptom manifestation) or trait (relating to schizophrenia endophenotypes) marker of human psychosis. We examined this by evaluating the expression of LIrr in an associative learning paradigm in (1) asymptomatic first-degree relatives of schizophrenia patients (SZ-relatives) and in (2) individuals exhibiting prodromal signs of psychosis ("ultrahigh risk" [UHR] patients) in each case relative to demographically matched healthy control subjects. There was no evidence for aberrant LIrr in SZ-relatives, but LIrr as well as associative learning were attenuated in UHR patients. It is concluded that LIrr deficiency in conjunction with a learning impairment might be a useful state marker predictive of psychotic state but a relatively weak link to a potential schizophrenia endophenotype.
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Affiliation(s)
- Ariane T. Orosz
- Laboratory of Behavioural Biology, Swiss Federal Institute of Technology Zürich, Zurich, Switzerland,Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, Bern, Switzerland,To whom correspondence should be addressed; tel: +41-31-932-83-52, fax: +41-31-930-99-61, e-mail:
| | - Joram Feldon
- Laboratory of Behavioural Biology, Swiss Federal Institute of Technology Zürich, Zurich, Switzerland
| | - Andor E. Simon
- Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, Bern, Switzerland,Specialised Outpatient Service for Early Psychosis, Department of Psychiatric Neurophysiology, Bruderholz, Switzerland
| | - Leonie M. Hilti
- Institute of Psychology, University of Bern, Bern, Switzerland,Neuropsychology Unit, Department of Neurology, University Hospital Zurich, Zurich, Switzerland
| | - Kerstin Gruber
- Specialised Outpatient Service for Early Psychosis, Department of Psychiatric Neurophysiology, Bruderholz, Switzerland
| | - Benjamin K. Yee
- Laboratory of Behavioural Biology, Swiss Federal Institute of Technology Zürich, Zurich, Switzerland
| | - Katja Cattapan-Ludewig
- Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, Bern, Switzerland,Sanatorium Kilchberg, Switzerland
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Stability of prepulse inhibition and habituation of the startle reflex in schizophrenia: a 6-year follow-up study of initially antipsychotic-naive, first-episode schizophrenia patients. Int J Neuropsychopharmacol 2011; 14:913-25. [PMID: 21294942 DOI: 10.1017/s1461145711000034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Deficits in information processing appear to be core features in the pathogenesis of schizophrenia. Prepulse inhibition (PPI) and habituation of the startle reflex are operational measures of early information processing. Impaired PPI in schizophrenia has been replicated in many studies and is regarded as an endophenotype for schizophrenia. However, reports on the stability of PPI over a longer period of time are lacking, both for patients with schizophrenia and for healthy subjects. The current study examined 25 initially drug-naive, first-episode schizophrenia patients and 23 healthy matched controls. Three PPI measures [stimulus onset asynchrony (SOA) 30, 60, 120 ms] and habituation were assessed at baseline, and again after 6 yr. Sixteen patients and 17 healthy controls completed the study, and 13 patients and 17 healthy controls were included in the final analysis. The schizophrenia patients had PPI deficits compared to controls at baseline. After 6 yr, no significant group differences were found. PPI had increased significantly in the patients and had decreased significantly in controls. In addition, patients showed significantly less habituation than controls while habituation did not change in patients or controls. The present results show that PPI in drug-naive, first-episode schizophrenia patients can improve significantly over time. As PPI increased in patients over the same period that it decreased in controls, it is likely that the increase was caused by disease-related factors such as disease process, clinical state, or medication.
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Hasenkamp W, Kelley M, Egan G, Green A, Wilcox L, Boshoven W, Lewison B, Duncan E. Lack of relationship between acoustic startle and cognitive variables in schizophrenia and control subjects. Psychiatry Res 2011; 187:324-8. [PMID: 21397338 PMCID: PMC3078961 DOI: 10.1016/j.psychres.2011.02.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 02/07/2011] [Accepted: 02/08/2011] [Indexed: 11/19/2022]
Abstract
Measures of acoustic startle such as prepulse inhibition (PPI) and startle latency have been found to be impaired in schizophrenia, and are commonly thought to be related to cognitive deficits in this disease. However, findings about the relationship between startle variables and cognitive performance have been equivocal. In this study, we examined correlations between startle measures (baseline startle magnitude, latency, habituation and PPI) and cognitive performance (using the Benton Visual Retention Test, Conner's Continuous Performance Test, California Verbal Learning Test, Finger Tapping Test, and Wisconsin Card Sort Test) in 107 schizophrenia patients and 94 healthy controls. Overall, there was a lack of any significant relationship between these constructs in both populations when correcting for multiple comparisons. This suggests that alterations in startle measures seen in schizophrenia may not reflect elements of information processing that cause cognitive deficits in the disease.
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Affiliation(s)
- Wendy Hasenkamp
- Mental Health Service, Atlanta Veterans Affairs Medical Center, Decatur, GA 30033, USA.
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Heritability of acoustic startle magnitude, prepulse inhibition, and startle latency in schizophrenia and control families. Psychiatry Res 2010; 178:236-43. [PMID: 20483176 PMCID: PMC2902662 DOI: 10.1016/j.psychres.2009.11.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 10/29/2009] [Accepted: 11/09/2009] [Indexed: 11/20/2022]
Abstract
Prepulse inhibition (PPI) is an acoustic startle paradigm that has been used as an operational measure of sensorimotor gating. Many patients with schizophrenia have impaired PPI, and several lines of evidence suggest that PPI may represent a heritable endophenotype in this disease. We examined startle magnitude and latencies in 40 schizophrenia patients, 58 first-degree relatives of these patients, and 100 healthy controls. After removing low-startlers, we investigated PPI and startle habituation in 34 schizophrenia patients, 43 relatives, and 86 control subjects. Heritability analyses were conducted using a variance-component approach. We found significant heritability of 45% for PPI at the 60-ms interval and 67% for startle magnitude. Onset latency heritability estimates ranged between 39% and 90% across trial types, and those for peak latency ranged from 29% to 68%. Heritability of startle habituation trended toward significance at 31%. We did not detect differences between controls and either schizophrenia patients or their family members for PPI, startle magnitude, or habituation. Startle latencies were generally longer in schizophrenia patients than controls. The heritability findings give impetus to applying genetic analyses to PPI variables, and suggest that startle latency may also be a useful measure in the study of potential endophenotypes for schizophrenia.
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40
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Chow VW, Savonenko AV, Melnikova T, Kim H, Price DL, Li T, Wong PC. Modeling an anti-amyloid combination therapy for Alzheimer's disease. Sci Transl Med 2010; 2:13ra1. [PMID: 20371462 DOI: 10.1126/scitranslmed.3000337] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
As only symptomatic treatments are now available for Alzheimer's disease (AD), safe and effective mechanism-based therapies remain a great unmet need for patients with this neurodegenerative disease. Although gamma-secretase and BACE1 [beta-site beta-amyloid (Abeta) precursor protein (APP) cleaving enzyme 1] are well-recognized therapeutic targets for AD, untoward side effects associated with strong inhibition or reductions in amounts of these aspartyl proteases have raised concerns regarding their therapeutic potential. Although moderate decreases of either gamma-secretase or BACE1 are not associated with mechanism-based toxicities, they provide only modest benefits in reducing Abeta in the brains of APPswe/PS1DeltaE9 mice. Because the processing of APP to generate Abeta requires both gamma-secretase and BACE1, it is possible that moderate reductions of both enzymes would provide additive and significant protection against Abeta amyloidosis. Here, we test this hypothesis and assess the value of this novel anti-amyloid combination therapy in mutant mice. We demonstrate that genetic reductions of both BACE1 and gamma-secretase additively attenuate the amyloid burden and ameliorate cognitive deficits occurring in aged APPswe/PS1DeltaE9 animals. No evidence of mechanism-based toxicities was associated with such decreases in amounts of both enzymes. Thus, we propose that targeting both gamma-secretase and BACE1 may be an effective and safe treatment strategy for AD.
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Affiliation(s)
- Vivian W Chow
- Department of Pathology, Johns Hopkins University School of Medicine, 558 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Prepulse inhibition of the startle reflex in schizophrenia remains stable with short-term quetiapine. Eur Psychiatry 2010; 26:271-5. [PMID: 20542668 DOI: 10.1016/j.eurpsy.2010.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/18/2010] [Accepted: 03/04/2010] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To study the short-term effect of treatment with quetiapine on prepulse inhibition (PPI) deficits of the startle reflex in schizophrenia patients. SUBJECTS AND METHODS Using PPI, we studied a group of 21 schizophrenia patients and 16 controls. Seventeen of the patients were re-tested with PPI after 21 days of treatment with quetiapine. RESULTS At baseline, an almost significant decrease in PPI was found in the patients as compared to the controls. PPI measurements did not change in the patients after 21 days of treatment with quetiapine, despite their clinical improvement. CONCLUSION Our results suggest that short-term quetiapine treatment may not modify PPI measures in schizophrenia patients.
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Martinez-Gras I, Rubio G, del Manzano BA, Rodriguez-Jimenez R, Garcia-Sanchez F, Bagney A, Leza JC, Borrell J. The relationship between prepulse inhibition and general psychopathology in patients with schizophrenia treated with long-acting risperidone. Schizophr Res 2009; 115:215-21. [PMID: 19846280 DOI: 10.1016/j.schres.2009.09.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 09/12/2009] [Accepted: 09/27/2009] [Indexed: 11/17/2022]
Abstract
Patients with schizophrenia exhibit impairments in prepulse inhibition (PPI) of the startle response. Available data suggest that atypical antipsychotics may be more effective than typical antipsychotics in improving PPI deficits in schizophrenia. However, previous studies have used between-subjects rather than longitudinal within-subjects designs to demonstrate superiority of particular atypical antipsychotics over typical antipsychotics in improving PPI in patients with schizophrenia. This longitudinal within-subjects test-retest study was designed to evaluate changes in PPI and clinical symptoms in patients with schizophrenia after switching from the conventional antipsychotic zuclopenthixol to long-acting injectable risperidone. PPI was measured in 45 chronic male patients with schizophrenia treated with zuclophentixol depot (session T1), and 12 weeks after switching to long-acting injectable risperidone (session T2). Thirty-six healthy control subjects were also evaluated. Patients with schizophrenia showed a significant improvement in PPI after changing to long-acting risperidone. Improvement of PPI deficits between T1 and T2 assessments correlated significantly with improvements in PANSS general psychopathology subscale scores. Our findings indicate that long-acting risperidone improves PPI deficits in subjects with chronic schizophrenia. These results also suggest that the PPI-restoring effect of risperidone may be related to improvement in symptoms other than positive and negative symptoms.
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Shrira A, Tsakanikos E. Latent inhibition as a function of positive and negative schizotypal symptoms: Evidence for a bi-directional model. PERSONALITY AND INDIVIDUAL DIFFERENCES 2009. [DOI: 10.1016/j.paid.2009.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Csomor PA, Yee BK, Feldon J, Theodoridou A, Studerus E, Vollenweider FX. Impaired prepulse inhibition and prepulse-elicited reactivity but intact reflex circuit excitability in unmedicated schizophrenia patients: a comparison with healthy subjects and medicated schizophrenia patients. Schizophr Bull 2009; 35:244-55. [PMID: 18245063 PMCID: PMC2643951 DOI: 10.1093/schbul/sbm146] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Deficient sensorimotor gating as indexed by prepulse inhibition (PPI) of the startle response has been reported repeatedly in patients suffering from schizophrenia. According to the widely accepted "protective hypothesis," PPI reflects the protection of ongoing information processing against interference by other stimuli. Alternatively, it has been proposed that PPI might be regulated by startle reflex circuit excitability. In the present study, we evaluated these 2 conceptually divergent approaches underlying the regulation of PPI. To this end, we assessed sensorimotor gating as indexed by PPI, the reactivity to the prepulse-alone stimulus indexed as prepulse-elicited reactivity (PPER), and acoustic blink reflex excitability in terms of paired pulse suppression (PPS) within a single recording session in 13 unmedicated and 24 medicated (11 first break) schizophrenia patients in comparison to 43 healthy control subjects. The results showed that PPI was significantly reduced in unmedicated, but not in medicated schizophrenia patients. Furthermore, unmedicated patients could be distinguished from the medicated patients and control subjects in terms of PPER. In contrast to PPI, PPS did not differ between patients and control subjects. These findings are in line with the "protective hypothesis" of PPI and indicate that reduced sensorimotor gating in schizophrenia patients might be based on a reduced perception and/or processing of the prepulse stimulus. The extent to which PPER may or may not be causally associated with sensorimotor gating in schizophrenia has to be further investigated in human and animal studies.
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Affiliation(s)
- Philipp A. Csomor
- University Hospital of Psychiatry Zurich, PO Box 1931, CH-8032 Zurich, Switzerland,Laboratory of Behavioural Neurobiology, ETH Zurich, Schorenstrasse 16, CH-8603 Schwerzenbach, Switzerland,To whom correspondence should be addressed; tel: +41-44-3822407, fax: +41-44-384-2499, e-mail:
| | - Benjamin K. Yee
- Laboratory of Behavioural Neurobiology, ETH Zurich, Schorenstrasse 16, CH-8603 Schwerzenbach, Switzerland
| | - Joram Feldon
- Laboratory of Behavioural Neurobiology, ETH Zurich, Schorenstrasse 16, CH-8603 Schwerzenbach, Switzerland
| | | | - Erich Studerus
- Psychiatric Services of Aargau Canton, Department of Research, PO Box 298, CH-5201 Brugg, Switzerland
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Quednow BB, Frommann I, Berning J, Kühn KU, Maier W, Wagner M. Impaired sensorimotor gating of the acoustic startle response in the prodrome of schizophrenia. Biol Psychiatry 2008; 64:766-73. [PMID: 18514166 DOI: 10.1016/j.biopsych.2008.04.019] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 04/10/2008] [Accepted: 04/17/2008] [Indexed: 11/30/2022]
Abstract
BACKGROUND Schizophrenia patients exhibit impairment in prepulse inhibition (PPI) of the acoustic startle response (ASR), which is commonly interpreted as a sensorimotor gating deficit. To date, it is unclear when these gating deficits arise. Results of animal studies and some human data suggest that PPI deficits are in part genetically determined, such that gating deficits could be present before the onset of a full-blown psychosis. To test this assumption, we investigated PPI of ASR in individuals with prodromal symptoms of schizophrenia and patients with first-episode schizophrenia. METHODS Startle reactivity, habituation, and PPI of ASR, as well as a neuropsychological test battery, were assessed in 54 subjects with prodromal symptoms of schizophrenia (35 early and 19 late prodromal subjects), 31 first-episode schizophrenia patients (14 unmedicated, 17 medicated), and 28 healthy control subjects. Patients were also examined with the Positive and Negative Syndrome Scale and the Global Assessment of Functioning Scale. RESULTS Prodromal subjects and unmedicated patients with first-episode schizophrenia showed significant PPI deficits, whereas schizophrenia patients treated with risperidone had almost normal PPI. Startle reactivity decreased with greater severity of symptoms (control subjects, early prodromal group > late prodromal group > unmedicated first-episode patients) but was almost normal in the medicated patients. With respect to habituation, prodromal subjects and schizophrenia patients did not differ from healthy control subjects. CONCLUSIONS PPI disruption is already present in a prodromal state of schizophrenia, but startle reactivity deficits seem to emerge with the onset of acute psychosis.
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Affiliation(s)
- Boris B Quednow
- Department of Psychiatry, University of Bonn, Bonn, Germany.
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46
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Impaired prepulse inhibition and habituation of acoustic startle response in Japanese patients with schizophrenia. Neurosci Res 2008; 62:187-94. [DOI: 10.1016/j.neures.2008.08.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 07/18/2008] [Accepted: 08/12/2008] [Indexed: 11/23/2022]
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Sensorimotor gating and attentional set-shifting are improved by the mu-opioid receptor agonist morphine in healthy human volunteers. Int J Neuropsychopharmacol 2008; 11:655-69. [PMID: 18272020 DOI: 10.1017/s1461145707008322] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prepulse inhibition (PPI) of the acoustic startle response (ASR) has been established as an operational measure of sensorimotor gating. Animal and human studies have shown that PPI can be modulated by dopaminergic, serotonergic, and glutamatergic drugs and consequently it was proposed that impaired sensorimotor gating in schizophrenia parallels a central abnormality within the corresponding neurotransmitter systems. Recent animal studies suggest that the opioid system may also play a role in the modulation of sensorimotor gating. Thus, the present study investigated the influence of the mu-opioid receptor agonist morphine on PPI in healthy human volunteers. Eighteen male, non-smoking healthy volunteers each received placebo or 10 mg morphine sulphate (p.o.) at a 2-wk interval in a double-blind, randomized, and counterbalanced order. PPI was measured 75 min after drug/placebo intake. The effects of morphine on mood were measured by the Adjective Mood Rating Scale and side-effects were assessed by the List of Complaints. Additionally, we administered a comprehensive neuropsychological test battery consisting of tests of the Cambridge Neuropsychological Test Automated Battery and the Rey Auditory Verbal Learning Test. Morphine significantly increased PPI without affecting startle reactivity or habituation. Furthermore, morphine selectively improved the error rate in an attentional set-shifting task but did not influence vigilance, memory, or executive functions. These results imply that the opioid system is involved in the modulation of PPI and attentional set-shifting in humans and they raise the question whether the opioid system plays a crucial role also in the regulation of PPI and attentional set-shifting in schizophrenia.
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Swerdlow NR, Weber M, Qu Y, Light GA, Braff DL. Realistic expectations of prepulse inhibition in translational models for schizophrenia research. Psychopharmacology (Berl) 2008; 199:331-88. [PMID: 18568339 PMCID: PMC2771731 DOI: 10.1007/s00213-008-1072-4] [Citation(s) in RCA: 421] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 01/03/2008] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Under specific conditions, a weak lead stimulus, or "prepulse", can inhibit the startling effects of a subsequent intense abrupt stimulus. This startle-inhibiting effect of the prepulse, termed "prepulse inhibition" (PPI), is widely used in translational models to understand the biology of brainbased inhibitory mechanisms and their deficiency in neuropsychiatric disorders. In 1981, four published reports with "prepulse inhibition" as an index term were listed on Medline; over the past 5 years, new published Medline reports with "prepulse inhibition" as an index term have appeared at a rate exceeding once every 2.7 days (n=678). Most of these reports focus on the use of PPI in translational models of impaired sensorimotor gating in schizophrenia. This rapid expansion and broad application of PPI as a tool for understanding schizophrenia has, at times, outpaced critical thinking and falsifiable hypotheses about the relative strengths vs. limitations of this measure. OBJECTIVES This review enumerates the realistic expectations for PPI in translational models for schizophrenia research, and provides cautionary notes for the future applications of this important research tool. CONCLUSION In humans, PPI is not "diagnostic"; levels of PPI do not predict clinical course, specific symptoms, or individual medication responses. In preclinical studies, PPI is valuable for evaluating models or model organisms relevant to schizophrenia, "mapping" neural substrates of deficient PPI in schizophrenia, and advancing the discovery and development of novel therapeutics. Across species, PPI is a reliable, robust quantitative phenotype that is useful for probing the neurobiology and genetics of gating deficits in schizophrenia.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, 92093-0804, USA,
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Orosz AT, Feldon J, Gal G, Simon AE, Cattapan-Ludewig K. Deficient associative learning in drug-naive first-episode schizophrenia: results obtained using a new visual within-subjects learned irrelevance paradigm. Behav Brain Res 2008; 193:101-7. [PMID: 18555542 DOI: 10.1016/j.bbr.2008.04.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 04/28/2008] [Indexed: 10/22/2022]
Abstract
One of the key features of schizophrenia is the inability to filter out irrelevant stimuli which consequently leads to stimulus overload. There are different methods which aim at investigating these deficient filter mechanisms; one of these is the learned irrelevance (LIrr) paradigm. LIrr refers to the retardation of associative learning that occurs if the conditioned stimulus (CS) and the unconditioned stimulus (US) are preexposed in an explicitly unpaired manner prior to the establishment of the association between the stimuli. In the present study we used a recently developed computerized within-subject visual LIrr test. We measured 11 drug-naive first-episode schizophrenia patients and compared their performance to that of 17 healthy control subjects. LIrr was observed to be intact in normal individuals but disrupted in drug-naive first-episode schizophrenia patients. After one month elapsed, 5 of the 11 patients and 16 of the 17 control subjects were retested in a follow-up study. By this time, patients had been medicated with antipsychotic drugs for at least 3 weeks. While healthy controls exhibited a robust LIrr effect, patients still failed to show LIrr. Correlations were found between the performance of unmedicated patients and the depression component of the PANSS psychopathology scale.
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Affiliation(s)
- Ariane T Orosz
- Laboratory of Behavioural Neurobiology, Swiss Federal Institute of Technology, Zurich, Switzerland.
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Alteration of BACE1-dependent NRG1/ErbB4 signaling and schizophrenia-like phenotypes in BACE1-null mice. Proc Natl Acad Sci U S A 2008; 105:5585-90. [PMID: 18385378 DOI: 10.1073/pnas.0710373105] [Citation(s) in RCA: 241] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
beta-Site APP-cleaving enzyme 1 (BACE1) is required for the penultimate cleavage of the amyloid-beta precursor protein (APP) leading to the generation of amyloid-beta peptides that is central to the pathogenesis of Alzheimer's disease. In addition to its role in endoproteolysis of APP, BACE1 participates in the proteolytic processing of neuregulin 1 (NRG1) and influences the myelination of central and peripheral axons. Although NRG1 has been genetically linked to schizophrenia and NRG1(+/-) mice exhibit a number of schizophrenia-like behavioral traits, it is not known whether altered BACE1-dependent NRG1 signaling can cause similar behavioral abnormalities. To test this hypothesis, we analyze the behaviors considered to be rodent analogs of clinical features of schizophrenia in BACE1(-/-) mice with impaired processing of NRG1. We demonstrate that BACE1(-/-) mice exhibit deficits in prepulse inhibition, novelty-induced hyperactivity, hypersensitivity to a glutamatergic psychostimulant (MK-801), cognitive impairments, and deficits in social recognition. Importantly, some of these manifestations were responsive to treatment with clozapine, an atypical antipsychotic drug. Moreover, although the total amount of ErbB4, a receptor for NRG1 was not changed, binding of ErbB4 with postsynaptic density protein 95 (PSD95) was significantly reduced in the brains of BACE1(-/-) mice. Consistent with the role of ErbB4 in spine morphology and synaptic function, BACE1(-/-) mice displayed reduced spine density in hippocampal pyramidal neurons. Collectively, our findings suggest that alterations in BACE1-dependent NRG1/ErbB4 signaling may participate in the pathogenesis of schizophrenia and related psychiatric disorders.
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