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de la Salle S, Piche J, Duncan B, Choueiry J, Hyde M, Aidelbaum R, Baddeley A, Impey D, Rahmani N, Ilivitsky V, Knott V. Influence of GABA A and GABA B receptor activation on auditory sensory gating and its association with anxiety in healthy volunteers. J Psychopharmacol 2024:2698811241246854. [PMID: 38647196 DOI: 10.1177/02698811241246854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
BACKGROUND Dysfunctional sensory gating in anxiety disorders, indexed by the failure to inhibit the P50 event-related potential (ERP) to repeated stimuli, has been linked to deficits in the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). AIMS/METHODS This study, conducted in 30 healthy volunteers, examined the acute effects of GABAA (lorazepam: 1 mg) and GABAB receptor (baclofen: 10 mg) agonists on P50 measures of auditory sensory gating within a paired-stimulus (S1-S2) paradigm and assessed changes in gating in relation to self-ratings of anxiety. RESULTS Compared to placebo, lorazepam reduced ERP indices of sensory gating by attenuating response to S1. Although not directly impacting P50 inhibition, baclofen-induced changes in gating (relative to placebo) were negatively correlated with trait but not state anxiety. CONCLUSIONS These preliminary findings support the involvement of GABA in sensory gating and tentatively suggest a role for GABAB receptor signaling in anxiety-associated gating dysregulation.
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Affiliation(s)
- Sara de la Salle
- The Royal's Institute of Mental Health Research at The Royal, Ottawa, ON, Canada
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Justin Piche
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Brittany Duncan
- Department of Psychology, Carleton University, Ottawa, ON, Canada
| | - Joëlle Choueiry
- The Royal's Institute of Mental Health Research at The Royal, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Molly Hyde
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Robert Aidelbaum
- School of Psychology, University of Toronto, Toronto, ON, Canada
| | - Ashley Baddeley
- The Royal's Institute of Mental Health Research at The Royal, Ottawa, ON, Canada
| | - Danielle Impey
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Noreen Rahmani
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | | | - Verner Knott
- The Royal's Institute of Mental Health Research at The Royal, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
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Francis AM, Parks A, Choueiry J, El-Marj N, Impey D, Knott VJ, Fisher DJ. Sensory gating in tobacco-naïve cannabis users is unaffected by acute nicotine administration. Psychopharmacology (Berl) 2022; 239:1279-1288. [PMID: 33932162 DOI: 10.1007/s00213-021-05843-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/29/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Long-term cannabis use has been associated with the appearance of psychotic symptoms and schizophrenia-like cognitive impairments; however these studies may be confounded by concomitant use of tobacco by cannabis users. We aimed to determine if previously observed cannabis-associated deficits in sensory gating would be seen in cannabis users with no history of tobacco use, as evidenced by changes in the P50, N100, and P200 event-related potentials. A secondary objective of this study was to examine the effects of acute nicotine administration on cannabis users with no tobacco use history. METHODS Three components (P50, N100, P200) of the mid-latency auditory-evoked response (MLAER) were elicited by a paired-stimulus paradigm in 43 healthy, non-tobacco smoking male volunteers between the ages of 18-30. Cannabis users (CU, n = 20) were administered nicotine (6 mg) and placebo gum within a randomized, double-blind design. Non-cannabis users (NU, n = 23) did not receive nicotine. RESULTS Between-group sensory gating effects were only observed for the N100, with CUs exhibiting a smaller N100 to S1 of the paired stimulus paradigm, in addition to reduced dN100 (indicating poorer gating). Results revealed no significant sensory gating differences with acute administration of nicotine compared to placebo cannabis conditions. CONCLUSIONS These findings suggest a relationship between gating impairment and cannabis use; however, acute nicotine administration nicotine does not appear to impact sensory gating function.
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Affiliation(s)
- Ashley M Francis
- Department of Psychology, Saint Mary's University, Halifax, NS, Canada
| | - Andrea Parks
- Department of Biomedical Science, University of Ottawa, Ottawa, ON, Canada
| | - Joëlle Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada
| | - Nicole El-Marj
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Danielle Impey
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Verner J Knott
- Department of Biomedical Science, University of Ottawa, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Derek J Fisher
- Department of Psychology, Saint Mary's University, Halifax, NS, Canada.
- School of Psychology, University of Ottawa, Ottawa, ON, Canada.
- Department of Psychology, Mount Saint Vincent University, 166 Bedford Hwy, Halifax, NS, B3M 2J6, Canada.
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Strudwick G, Sockalingam S, Kassam I, Sequeira L, Bonato S, Youssef A, Mehta R, Green N, Agic B, Soklaridis S, Impey D, Wiljer D, Crawford A. Digital Interventions to Support Population Mental Health in Canada During the COVID-19 Pandemic: Rapid Review. JMIR Ment Health 2021; 8:e26550. [PMID: 33650985 PMCID: PMC7927953 DOI: 10.2196/26550] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/18/2021] [Accepted: 02/10/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The COVID-19 pandemic has resulted in a number of negative health related consequences, including impacts on mental health. More than 22% of Canadians reported that they had felt depressed in the last week, in response to a December 2020 national survey. Given the need to physically distance during the pandemic, and the increase in demand for mental health services, digital interventions that support mental health and wellness may be beneficial. OBJECTIVE The purpose of this research was to identify digital interventions that could be used to support the mental health of the Canadian general population during the COVID-19 pandemic. The objectives were to identify (1) the populations these interventions were developed for, inclusive of exploring areas of equity such as socioeconomic status, sex/gender, race/ethnicity and culture, and relevance to Indigenous peoples and communities; (2) the effect of the interventions; and (3) any barriers or facilitators to the use of the intervention. METHODS This study was completed using a Cochrane Rapid Review methodology. A search of Embase, PsycInfo, Medline, and Web of Science, along with Google, Million Short, and popular mobile app libraries, was conducted. Two screeners were involved in applying inclusion criteria using Covidence software. Academic articles and mobile apps identified were screened using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields resource, the American Psychiatric Association App Evaluation Framework, and the Mental Health Commission of Canada's guidance on app assessment and selection. RESULTS A total of 31 mobile apps and 114 web-based resources (eg, telemedicine, virtual peer support groups, discussion forums, etc) that could be used to support the mental health of the Canadian population during the pandemic were identified. These resources have been listed on a publicly available website along with search tags that may help an individual make a suitable selection. Variability exists in the populations that the interventions were developed for, and little assessment has been done with regard to areas of equity. The effect of the interventions was not reported for all those identified in this synthesis; however, for those that did report the effect, it was shown that they were effective in the context that they were used. A number of barriers and facilitators to using these interventions were identified, such as access, cost, and connectivity. CONCLUSIONS A number of digital interventions that could support population mental health in Canada during the global COVID-19 pandemic were identified, indicating that individuals have several options to choose from. These interventions vary in their purpose, approach, design, cost, and targeted user group. While some research and digital interventions addressed equity-related considerations, more research and focused attention should be given to this area.
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Affiliation(s)
- Gillian Strudwick
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - Sanjeev Sockalingam
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
- University Health Network, Toronto, ON, Canada
| | - Iman Kassam
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Lydia Sequeira
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - Sarah Bonato
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Alaa Youssef
- University of Toronto, Toronto, ON, Canada
- University Health Network, Toronto, ON, Canada
| | - Rohan Mehta
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | | | - Branka Agic
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Sophie Soklaridis
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | | | - David Wiljer
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
- University Health Network, Toronto, ON, Canada
| | - Allison Crawford
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
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Strudwick G, Impey D, Torous J, Krausz RM, Wiljer D. Advancing E-Mental Health in Canada: Report From a Multistakeholder Meeting. JMIR Ment Health 2020; 7:e19360. [PMID: 32330114 PMCID: PMC7226031 DOI: 10.2196/19360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 01/19/2023] Open
Abstract
The need for e-mental health (electronic mental health) services in Canada is significant. The current mental health care delivery models primarily require people to access services in person with a health professional. Given the large number of people requiring mental health care in Canada, this model of care delivery is not sufficient in its current form. E-mental health technologies may offer an important solution to the problem. This topic was discussed in greater depth at the 9th Annual Canadian E-Mental Health Conference held in Toronto, Canada. Themes that emerged from the discussions at the conference include (1) the importance of trust, transparency, human centeredness, and compassion in the development and delivery of digital mental health technologies; (2) an emphasis on equity, diversity, inclusion, and access when implementing e-mental health services; (3) the need to ensure that the mental health workforce is able to engage in a digital way of working; and (4) co-production of e-mental health services among a diverse stakeholder group becoming the standard way of working.
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Affiliation(s)
| | | | - John Torous
- Division of Digital Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States
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de la Salle S, Inyang L, Impey D, Smith D, Choueiry J, Nelson R, Heera J, Baddeley A, Ilivitsky V, Knott V. Acute separate and combined effects of cannabinoid and nicotinic receptor agonists on MMN-indexed auditory deviance detection in healthy humans. Pharmacol Biochem Behav 2019; 184:172739. [PMID: 31283908 DOI: 10.1016/j.pbb.2019.172739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 12/21/2022]
Abstract
The high prevalence of concomitant cannabis and nicotine use has implications for sensory and cognitive processing. While nicotine tends to enhance function in these domains, cannabis use has been associated with both sensory and cognitive impairments, though the underlying mechanisms are unclear. Additionally, the interaction of the nicotinic (nAChR) and cannabinoid (CB1) receptor systems has received limited study in terms of sensory/cognitive processes. This study involving healthy volunteers assessed the acute separate and combined effects of nabilone (a CB1 agonist) and nicotine on sensory processing as assessed by auditory deviance detection and indexed by the mismatch negativity (MMN) event-related potential. It was hypothesized that nabilone would impair auditory discriminability as shown by diminished MMN amplitudes, but not when administered in combination with nicotine. 20 male non-smokers and non-cannabis-users were assessed using a 5-stimulus 'optimal' multi-feature MMN paradigm within a randomized, placebo controlled design (placebo; nabilone [0.5 mg]; nicotine [6 mg]; and nicotine + nabilone). Treatment effects were region- and deviant-dependent. At the temporal regions (mastoid sites), MMN was reduced by nabilone and nicotine separately, whereas co-administration resulted in no impairment. At the frontal region, MMN was enhanced by co-administration of nicotine and nabilone, with no MMN effects being found with separate treatment. These neural effects have relevance for sensory/cognitive processes influenced by separate and simultaneous use of cannabis and tobacco and may have treatment implications for disorders associated with sensory dysfunction and impairments in endocannabinoid and nicotinic cholinergic neurotransmission.
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Affiliation(s)
- Sara de la Salle
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Lawrence Inyang
- Interdisciplinary Sciences, Carleton University, Ottawa, ON, Canada
| | - Danielle Impey
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Dylan Smith
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Joelle Choueiry
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Renee Nelson
- Biomedical Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Jasmit Heera
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Ashley Baddeley
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada
| | - Vadim Ilivitsky
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
| | - Verner Knott
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada.
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Impey D, de la Salle S, Baddeley A, Knott V. Effects of an NMDA antagonist on the auditory mismatch negativity response to transcranial direct current stimulation. J Psychopharmacol 2017; 31:614-624. [PMID: 27624152 DOI: 10.1177/0269881116665336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive form of brain stimulation which uses a weak constant current to alter cortical excitability and activity temporarily. tDCS-induced increases in neuronal excitability and performance improvements have been observed following anodal stimulation of brain regions associated with visual and motor functions, but relatively little research has been conducted with respect to auditory processing. Recently, pilot study results indicate that anodal tDCS can increase auditory deviance detection, whereas cathodal tDCS decreases auditory processing, as measured by a brain-based event-related potential (ERP), mismatch negativity (MMN). As evidence has shown that tDCS lasting effects may be dependent on N-methyl-D-aspartate (NMDA) receptor activity, the current study investigated the use of dextromethorphan (DMO), an NMDA antagonist, to assess possible modulation of tDCS's effects on both MMN and working memory performance. The study, conducted in 12 healthy volunteers, involved four laboratory test sessions within a randomised, placebo and sham-controlled crossover design that compared pre- and post-anodal tDCS over the auditory cortex (2 mA for 20 minutes to excite cortical activity temporarily and locally) and sham stimulation (i.e. device is turned off) during both DMO (50 mL) and placebo administration. Anodal tDCS increased MMN amplitudes with placebo administration. Significant increases were not seen with sham stimulation or with anodal stimulation during DMO administration. With sham stimulation (i.e. no stimulation), DMO decreased MMN amplitudes. Findings from this study contribute to the understanding of underlying neurobiological mechanisms mediating tDCS sensory and memory improvements.
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Affiliation(s)
- Danielle Impey
- 1 Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, Canada.,2 School of Psychology, University of Ottawa, Ottawa, Canada
| | - Sara de la Salle
- 1 Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, Canada.,2 School of Psychology, University of Ottawa, Ottawa, Canada
| | - Ashley Baddeley
- 1 Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, Canada
| | - Verner Knott
- 1 Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, Canada.,2 School of Psychology, University of Ottawa, Ottawa, Canada
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Impey D, de la Salle S, Knott V. Assessment of anodal and cathodal transcranial direct current stimulation (tDCS) on MMN-indexed auditory sensory processing. Brain Cogn 2016; 105:46-54. [DOI: 10.1016/j.bandc.2016.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 03/04/2016] [Accepted: 03/23/2016] [Indexed: 12/20/2022]
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Knott V, Impey D, Fisher D, Delpero E, Fedoroff P. Pedophilic brain potential responses to adult erotic stimuli. Brain Res 2015; 1632:127-40. [PMID: 26683083 DOI: 10.1016/j.brainres.2015.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 11/27/2015] [Accepted: 12/02/2015] [Indexed: 11/24/2022]
Abstract
Cognitive mechanisms associated with the relative lack of sexual interest in adults by pedophiles are poorly understood and may benefit from investigations examining how the brain processes adult erotic stimuli. The current study used event-related brain potentials (ERP) to investigate the time course of the explicit processing of erotic, emotional, and neutral pictures in 22 pedophilic patients and 22 healthy controls. Consistent with previous studies, early latency anterior ERP components were highly selective for erotic pictures. Although the ERPs elicited by emotional stimuli were similar in patients and controls, an early frontal positive (P2) component starting as early as 185 ms was significantly attenuated and slow to onset in pedophilia, and correlated with a clinical measure of cognitive distortions. Failure of rapid attentional capture by erotic stimuli suggests a relative reduction in early processing in pedophilic patients which may be associated with relatively diminished sexual interest in adults.
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Affiliation(s)
- Verner Knott
- Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada.
| | - Danielle Impey
- Clinical Neuroelectrophysiology and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Derek Fisher
- Department of Psychology, Mount Saint Vincent University, Halifax, NS, Canada
| | - Emily Delpero
- Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Paul Fedoroff
- Forensic Research Unit, University of Ottawa, Institute of Mental Health Research, Ottawa, ON, Canada
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Impey D, El-Marj N, Parks A, Choueiry J, Fisher D, Knott VJ. Mismatch negativity in tobacco-naïve cannabis users and its alteration with acute nicotine administration. Pharmacol Biochem Behav 2015; 136:73-81. [PMID: 26188167 DOI: 10.1016/j.pbb.2015.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 06/30/2015] [Accepted: 07/03/2015] [Indexed: 11/29/2022]
Abstract
Chronic cannabis use may interact with factors, such as age of onset of cannabis use, family history, and genetic factors, to elicit schizophrenia (SZ)-like symptoms, including sensory and cognitive deficits. However, evidence of a relationship between cannabis use and cognitive impairment is confounded by concomitant use of tobacco. The objective of this study was to compare tobacco-naïve cannabis users with individuals without a history of tobacco/cannabis use on the auditory mismatch negativity (MMN) event-related potential (ERP), a neural measure of auditory deviance detection which is diminished in SZ. An exploratory arm of the study, conducted within a randomized, double-blind, placebo controlled design, examined the acute effects of nicotine gum (6mg) on MMN in cannabis users. MMN was recorded in response to 5 deviant stimuli within an optimal MMN paradigm in 44 healthy, non-tobacco smoking volunteers aged 18-26. Cannabis users (n=21) started smoking cannabis prior to age 17, at least 1 joint per month. To examine the effects of chronicity, users were grouped into relatively heavy long-term (HLT; n=11) users and light short-term (LST; n=10) users. Impaired deviance detection was shown in cannabis users vs. nonusers as reflected by a smaller MMN to duration deviants. Chronicity of use was also associated with MMN alterations, as HLTs displayed a reduced duration and gap MMN vs. LSTs. Compared with placebo, nicotine treatment enhanced select MMN deviants in cannabis user subgroups. As deficits associated with early and persistent cannabis use are similar to those seen in SZ, these dose-dependant disturbances in early sensory processing with cannabis use may be one cognitive pathway which mediates an increased risk for SZ in vulnerable youth, and be influenced by concurrent cigarette smoking behavior.
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Affiliation(s)
- Danielle Impey
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada.
| | - Nicole El-Marj
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Andrea Parks
- Department of Biomedical Science, University of Ottawa, Ottawa, ON, Canada
| | - Joelle Choueiry
- Department of Cellular and Molecular Medicine, Neuroscience Program, University of Ottawa, Ottawa, ON, Canada
| | - Derek Fisher
- Department of Psychology, Mount Saint Vincent University, Halifax, Nova Scotia, Canada
| | - Verner J Knott
- University of Ottawa Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada; Department of Biomedical Science, University of Ottawa, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, Neuroscience Program, University of Ottawa, Ottawa, ON, Canada
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Bowers H, Smith D, de la Salle S, Choueiry J, Impey D, Philippe T, Dort H, Millar A, Daigle M, Albert PR, Beaudoin A, Knott V. COMT polymorphism modulates the resting-state EEG alpha oscillatory response to acute nicotine in male non-smokers. Genes Brain Behav 2015; 14:466-76. [PMID: 26096691 PMCID: PMC4514526 DOI: 10.1111/gbb.12226] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 11/28/2022]
Abstract
Performance improvements in cognitive tasks requiring executive functions are evident with nicotinic acetylcholine receptor (nAChR) agonists, and activation of the underlying neural circuitry supporting these cognitive effects is thought to involve dopamine neurotransmission. As individual difference in response to nicotine may be related to a functional polymorphism in the gene encoding catechol-O-methyltransferase (COMT), an enzyme that strongly influences cortical dopamine metabolism, this study examined the modulatory effects of the COMT Val158Met polymorphism on the neural response to acute nicotine as measured with resting-state electroencephalographic (EEG) oscillations. In a sample of 62 healthy non-smoking adult males, a single dose (6 mg) of nicotine gum administered in a randomized, double-blind, placebo-controlled design was shown to affect α oscillatory activity, increasing power of upper α oscillations in frontocentral regions of Met/Met homozygotes and in parietal/occipital regions of Val/Met heterozygotes. Peak α frequency was also found to be faster with nicotine (vs. placebo) treatment in Val/Met heterozygotes, who exhibited a slower α frequency compared to Val/Val homozygotes. The data tentatively suggest that interindividual differences in brain α oscillations and their response to nicotinic agonist treatment are influenced by genetic mechanisms involving COMT.
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Affiliation(s)
- H. Bowers
- Department of Psychology, University of Guelph, Guelph, ON, Canada
| | - D. Smith
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - S. de la Salle
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - J. Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - D. Impey
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - T. Philippe
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - H. Dort
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - A. Millar
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - M. Daigle
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - P. R. Albert
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Hospital Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - A. Beaudoin
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
| | - V. Knott
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Care Centre, Ottawa, ON, Canada
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Knott V, Impey D, Choueiry J, Smith D, de la Salle S, Saghir S, Smith M, Beaudry E, Ilivitsky V, Labelle A. An acute dose, randomized trial of the effects of CDP-Choline on Mismatch Negativity (MMN) in healthy volunteers stratified by deviance detection level. ACTA ACUST UNITED AC 2015. [DOI: 10.1186/s40810-014-0002-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Knott V, Salle SDL, Smith D, Choueiry J, Impey D, Smith M, Beaudry E, Saghir S, Ilivitsky V, Labelle A. Effects of acute CDP-choline treatment on resting state brain oscillations in healthy volunteers. Neurosci Lett 2015; 591:121-125. [PMID: 25700947 DOI: 10.1016/j.neulet.2015.02.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/03/2015] [Accepted: 02/13/2015] [Indexed: 11/16/2022]
Abstract
CDP-choline (cytidine-5'-diphosphocholine) is a phospholipid used to treat cognitive disorders, presumably repairing and maintaining brain cell membranes. Additional mechanisms may include enhanced cholinergic neurotransmission as the α7 nicotinic receptor actions of choline and increased acetylcholine synthesis accompanying CDP-choline administration may modulate brain oscillations underlying cognitive processes. This study utilizes electroencephalographic (EEG) recordings in healthy volunteers to evaluate CDP-choline induction of an oscillatory response profile associated with nicotinic stimulation. Resting state EEG was acquired in 24 male volunteers administered low (500mg) and moderate (1000mg) doses of CDP-choline in a randomized placebo-controlled, crossover trial. Consistent with nicotinic agonist treatment, spectral analysis showed dose-dependent reductions in delta and increases in alpha oscillations, which were also accompanied by decreases in beta and gamma oscillatory activity. These findings support the posit that CDP-choline cognitive enhancement involves multiple mechanisms including facilitated nicotinic cholinergic action.
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Affiliation(s)
- Verner Knott
- University of Ottawa, Institute of Mental Health Research, Ottawa, ON, Canada; School of Psychology, University of Ottawa, Ottawa, ON, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada; Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada.
| | | | - Dylan Smith
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Joelle Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Danielle Impey
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Meaghan Smith
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Elise Beaudry
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Salman Saghir
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Vadim Ilivitsky
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
| | - Alain Labelle
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
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Knott V, Smith D, de la Salle S, Impey D, Choueiry J, Beaudry E, Smith M, Saghir S, Ilivitsky V, Labelle A. CDP-choline: effects of the procholine supplement on sensory gating and executive function in healthy volunteers stratified for low, medium and high P50 suppression. J Psychopharmacol 2014; 28:1095-108. [PMID: 25315828 DOI: 10.1177/0269881114553254] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diminished auditory sensory gating and associated neurocognitive deficits in schizophrenia have been linked to altered expression and function of the alpha-7 nicotinic acetycholinergic receptor (α7 nAChR), the targeting of which may have treatment potential. Choline is a selective α7 nAChR agonist and the aim of this study was to determine whether cytidine 5'-diphosphocholine (CDP-choline), or citicoline, a dietary source of choline, increases sensory gating and cognition in healthy volunteers stratified for gating level. In a randomized, placebo-controlled, double-blind design involving acute administration of low, moderate doses (500 mg, 1000 mg) of CDP-choline, 24 healthy volunteers were assessed for auditory gating as indexed by suppression of the P50 event-related potential (ERP) in a paired-stimulus (S1, S2) paradigm, and for executive function as measured by the Groton Maze Learning Task (GMLT) of the CogState Schizophrenia Battery. CDP-choline improved gating (1000 mg) and suppression of the S2 P50 response (500 mg, 1000 mg), with the effects being selective for individuals with low gating (suppression) levels. Tentative support was also shown for increased GMLT performance (500 mg) in low suppressors. These preliminary findings with CDP-choline in a healthy, schizophrenia-like surrogate sample are consistent with a α7 nAChR mechanism and support further trials with choline as a pro-cognitive strategy.
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Affiliation(s)
- Verner Knott
- Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada School of Psychology, University of Ottawa, Ottawa, ON, Canada Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
| | - Dylan Smith
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | | | - Danielle Impey
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Joelle Choueiry
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Elise Beaudry
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Meaghan Smith
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Salman Saghir
- School of Psychology, University of Ottawa, Ottawa, ON, Canada
| | - Vadim Ilivitsky
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
| | - Alain Labelle
- Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada
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Knott V, Impey D, Philippe T, Smith D, Choueiry J, de la Salle S, Dort H. Modulation of auditory deviance detection by acute nicotine is baseline and deviant dependent in healthy nonsmokers: a mismatch negativity study. Hum Psychopharmacol 2014; 29:446-58. [PMID: 25196041 DOI: 10.1002/hup.2418] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 03/19/2014] [Accepted: 05/19/2014] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Cognitive enhancement resulting from nicotinic acetylcholine receptor stimulation may be evidenced by increased efficiency of the auditory-frontal cortex network of auditory discrimination, which is impaired in schizophrenia, a cognitive disorder associated with excessive tobacco use. Investigating automatic (preattentive) detection of acoustic change with the mismatch negativity (MMN) brain event-related potential in response to nicotine in individuals with varying baseline levels of auditory discrimination may provide useful insight into the cholinergic regulation of this neural network and its potential amelioration with novel nicotinic agents. METHODS Sixty healthy, non-smoking male volunteers were presented with an 'optimal' multi-feature MMN paradigm in a randomized, placebo controlled double-blind design with 6 mg of nicotine gum. RESULTS Participants with low, medium, and high baseline amplitudes responded differently to nicotine (vs. placebo), and nicotine response was feature specific. Whereas MMN in individuals with high amplitudes was diminished by nicotine, MMN increased in those with low amplitudes. Nicotine effects were not shown in medium amplitude participants. CONCLUSIONS These findings provide preliminary support for the role of nicotinic neurotransmission in sensory memory processing of auditory change and suggest that nicotinic receptor modulation can both enhance and diminish change detection, depending on baseline MMN and its eliciting stimulus feature.
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Affiliation(s)
- Verner Knott
- University of Ottawa Institute of Mental Health Research, Ottawa, Ontario, Canada; School of Psychology, University of Ottawa, Ottawa, Ontario, Canada; Neuroscience Program, Department of Cellular and Molecular Medicine, University of Ottawa, Ontario, Canada
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Knott V, Choueiry J, Dort H, Smith D, Impey D, de la Salle S, Philippe T. Baseline-dependent modulating effects of nicotine on voluntary and involuntary attention measured with brain event-related P3 potentials. Pharmacol Biochem Behav 2014; 122:107-17. [DOI: 10.1016/j.pbb.2014.03.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 03/17/2014] [Accepted: 03/23/2014] [Indexed: 11/16/2022]
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Knott V, de la Salle S, Smith D, Phillipe T, Dort H, Choueiry J, Impey D. Baseline dependency of nicotine's sensory gating actions: similarities and differences in low, medium and high P50 suppressors. J Psychopharmacol 2013; 27:790-800. [PMID: 23744798 DOI: 10.1177/0269881113490449] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Reduced suppression of the P50 auditory event-related potential in schizophrenia patients relative to normal controls is indicative of a sensory gating deficit and is one of the most robust findings reported for functional brain abnormalities in this disorder. However, there is considerable gating variability in patients and controls and there is little understanding as to how inter-individual differences moderate gating responses to drugs and nicotinic agonists in particular, which have shown potential to reverse gating deficits. In this study the effects of acutely administered nicotine (gum, 6 mg) on sensory gating in a paired (S₁-S₂) auditory stimulus paradigm were investigated in 57 healthy, non-smoking volunteers stratified as low (n = 19), medium (n = 19) and high (n = 19) P50 suppressors on the basis of three separate baseline derived gating indices, P50 ratios, P50 difference scores, and gating difference waveforms. Relative to placebo, nicotine consistently improved gating in low suppressors as stratified with all three gating indices, exerted no effects in medium suppressors and reduced gating in high suppressors. Analysis of individual stimulus (S₂, S₂) amplitudes showed distinctly different mechanisms of action underlying nicotine effects in individuals with low and high baseline suppression. The results parallel similar findings of baseline-dependency in the gating effects of several antipsychotic drugs in healthy volunteers and support the use of group segmentation as a translational model in novel cognitive drug development for schizophrenia.
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Affiliation(s)
- Verner Knott
- University of Ottawa Institute of Mental Health Research, Ottawa, Canada.
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de la Salle S, Smith D, Choueiry J, Impey D, Philippe T, Dort H, Millar A, Albert P, Knott V. Effects of COMT genotype on sensory gating and its modulation by nicotine: Differences in low and high P50 suppressors. Neuroscience 2013; 241:147-56. [PMID: 23535252 DOI: 10.1016/j.neuroscience.2013.03.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 02/06/2023]
Abstract
Elevated smoking rates seen in schizophrenia populations may be an attempt to correct neuropathologies associated with deficient nicotinic acetylcholine receptors and/or dopaminergic systems using exogenous nicotine. However, nicotine's effects on cognitive processing and sensory gating have been shown to be baseline-dependent. Evidence of a restorative effect on sensory gating deficits by nicotine-like agonists has been demonstrated, however, its underlying mechanisms in the context of dopamine dysregulation are unclear. Catechol-O-methyltransferase (COMT), a key dopamine regulator in the brain, contains a co-dominant allele in which a valine-to-methionine substitution causes variations in enzymatic activity leading to reduced synaptic dopamine levels in the Val/Val genotype. Using a randomized, double-blind, placebo-controlled design with 57 non-smokers, this study examined the effects of COMT genotype on sensory gating and its modulation by nicotine in low vs. high suppressors. The results were consistent with the hypothesis that increased dopamine resulting from nicotine stimulation or Met allelic activity would benefit gating in low suppressors and impair gating in high suppressors, and that this gating improvement with nicotine would be more evident in Val carriers who were low suppressors, while the gating impairment would be more evident in Met carriers who were high suppressors. These findings reaffirm the importance of baseline-dependency and suggest a subtle relationship between COMT genotype and baseline-stratified levels of sensory gating, which may help to explain the variability of cognitive abilities in schizophrenia populations.
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Affiliation(s)
- S de la Salle
- University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Centre, Ottawa, ON, Canada K1Z 7K4
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Impey D, Chique-Alfonzo M, Shah D, Fisher DJ, Knott VJ. Effects of nicotine on visuospatial attentional orienting in non-smokers. Pharmacol Biochem Behav 2013; 106:1-7. [PMID: 23470330 DOI: 10.1016/j.pbb.2013.02.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 02/16/2013] [Accepted: 02/20/2013] [Indexed: 10/27/2022]
Abstract
Nicotine is a highly addictive substance, suggested to be in part due to its cognitive enhancing effects in the attentional domain. Improvements in stimulus selection with nicotine have been reported but its effects on visual-spatial selective attention are unclear. This study utilized event-related potentials (ERPs) to examine the acute effects of nicotine on selective attention in non-smokers performing a Posner-type visuo-spatial task. The attentional processing of visual-spatial locations is reflected in the P1 ERP component, which represents earlier stages of visual analysis. 24 non-smokers received nicotine gum (6 mg) in a randomized, double-blind, placebo-controlled, repeated measures design. Behavioral performance and ERPs were assessed in response to target locations preceded by valid, invalid and neutral cues. Nicotine did not affect behavioral performance indices. P1 amplitudes were greater in valid and neutral cue trials compared to invalid cue trials and acute nicotine administration (vs. placebo) was found to increase P1 amplitudes in the right hemisphere, particularly in valid cue trials. In addition, in high symptomatic subjects (as indexed by greater increases in heart rate post-administration), nicotine (vs. placebo) produced greater P1 amplitudes in valid cue trials. The study concludes that nicotine enhanced visuospatial selective attention with regards to early visual encoding and analysis. These results demonstrate support in general for the attentional effects of nicotine and nicotinic agonists and they specifically extend these effects to include orienting of visual-spatial attention.
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Affiliation(s)
- D Impey
- University of Ottawa Institute of Mental Health Research, 1145 Carling Ave, Ottawa, ON K1Z 7K4, Canada.
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Blais C, Smith D, Choueiry J, Impey D, Phillips T, De Lasalle S, Dort H, Parks A, El Marj N, Knott V. Event-related potential and event-related oscillation correlates of sensory gating in low, medium and high suppressors. Int J Psychophysiol 2012. [DOI: 10.1016/j.ijpsycho.2012.07.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Impey D, Chique-Alfonzo M, Shah D, Fisher D, Knott V. Effects of acute nicotine administration on later visual spatial processing. Int J Psychophysiol 2010. [DOI: 10.1016/j.ijpsycho.2010.06.180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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