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Bellozi PM, Pelição R, Santos MC, Lima IV, Saliba SW, Vieira ÉL, Campos AC, Teixeira AL, de Oliveira AC, Nakamura-Palacios EM, Rodrigues LC. URB597 ameliorates the deleterious effects induced by binge alcohol consumption in adolescent rats. Neurosci Lett 2019; 711:134408. [DOI: 10.1016/j.neulet.2019.134408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 07/16/2019] [Accepted: 07/29/2019] [Indexed: 12/22/2022]
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Borgan F, Laurikainen H, Veronese M, Marques TR, Haaparanta-Solin M, Solin O, Dahoun T, Rogdaki M, Salokangas RKR, Karukivi M, Di Forti M, Turkheimer F, Hietala J, Howes O. In Vivo Availability of Cannabinoid 1 Receptor Levels in Patients With First-Episode Psychosis. JAMA Psychiatry 2019; 76:1074-1084. [PMID: 31268519 PMCID: PMC6613300 DOI: 10.1001/jamapsychiatry.2019.1427] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
IMPORTANCE Experimental and epidemiological studies implicate the cannabinoid 1 receptor (CB1R) in the pathophysiology of psychosis. However, whether CB1R levels are altered in the early stages of psychosis and whether they are linked to cognitive function or symptom severity remain unknown. OBJECTIVE To investigate CB1R availability in first-episode psychosis (FEP) without the confounds of illness chronicity or the use of illicit substances or antipsychotics. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional, case-control study of 2 independent samples included participants receiving psychiatric early intervention services at 2 independent centers in Turku, Finland (study 1) and London, United Kingdom (study 2). Study 1 consisted of 18 volunteers, including 7 patients with affective or nonaffective psychoses taking antipsychotic medication and 11 matched controls; study 2, 40 volunteers, including 20 antipsychotic-naive or antipsychotic-free patients with schizophrenia or schizoaffective disorder and 20 matched controls. Data were collected from January 5, 2015, through September 26, 2018, and analyzed from June 20, 2016, through February 12, 2019. MAIN OUTCOMES AND MEASURES The availability of CB1R was indexed using the distribution volume (VT, in milliliters per cubic centimeter) of 2 CB1R-selective positron emission tomography radiotracers: fluoride 18-labeled FMPEP-d2 (study 1) and carbon 11-labeled MePPEP (study 2). Cognitive function was measured using the Wechsler Digit Symbol Coding Test. Symptom severity was measured using the Brief Psychiatric Rating Scale for study 1 and the Positive and Negative Syndrome Scale for study 2. RESULTS A total of 58 male individuals were included in the analyses (mean [SD] age of controls, 27.16 [5.93] years; mean [SD] age of patients, 26.96 [4.55] years). In study 1, 7 male patients with FEP (mean [SD] age, 26.80 [5.40] years) were compared with 11 matched controls (mean [SD] age, 27.18 [5.86] years); in study 2, 20 male patients with FEP (mean [SD] age, 27.00 [5.06] years) were compared with 20 matched controls (mean [SD] age, 27.15 [6.12] years). In study 1, a significant main effect of group on [18F]FMPEP-d2 VT was found in the anterior cingulate cortex (ACC) (t16 = -4.48; P < .001; Hedges g = 1.2), hippocampus (t16 = -2.98; P = .006; Hedges g = 1.4), striatum (t16 = -4.08; P = .001; Hedges g = 1.9), and thalamus (t16 = -4.67; P < .001; Hedges g = 1.4). In study 2, a significant main effect of group on [11C]MePPEP VT was found in the ACC (Hedges g = 0.8), hippocampus (Hedges g = 0.5), striatum (Hedges g = 0.4), and thalamus (Hedges g = 0.7). In patients, [11C]MePPEP VT in the ACC was positively associated with cognitive functioning (R = 0.60; P = .01), and [11C]MePPEP VT in the hippocampus was inversely associated with Positive and Negative Syndrome Scale total symptom severity (R = -0.50; P = .02). CONCLUSIONS AND RELEVANCE The availability of CB1R was lower in antipsychotic-treated and untreated cohorts relative to matched controls. Exploratory analyses indicated that greater reductions in CB1R levels were associated with greater symptom severity and poorer cognitive functioning in male patients. These findings suggest that CB1R may be a potential target for the treatment of psychotic disorders.
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Affiliation(s)
- Faith Borgan
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom,MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Heikki Laurikainen
- Turku PET (Positron Emission Tomography) Centre, University of Turku and Turku University Hospital, Turku, Finland.,Department of Psychiatry, University of Turku and Turku University Hospital, Turku, Finland
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Tiago Reis Marques
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom,MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Merja Haaparanta-Solin
- Turku PET (Positron Emission Tomography) Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Olof Solin
- Turku PET (Positron Emission Tomography) Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Tarik Dahoun
- MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom,Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, United Kingdom
| | - Maria Rogdaki
- MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Raimo KR Salokangas
- Department of Psychiatry, University of Turku and Turku University Hospital, Turku, Finland
| | - Max Karukivi
- Department of Psychiatry, Turku University, Satakunta Hospital District, Turku, Finland
| | - Marta Di Forti
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Jarmo Hietala
- Turku PET (Positron Emission Tomography) Centre, University of Turku and Turku University Hospital, Turku, Finland.,Department of Psychiatry, University of Turku and Turku University Hospital, Turku, Finland
| | - Oliver Howes
- Psychosis Studies Department, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom,MRC London Institute of Medical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom,Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom
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Balmus IM, Ciobica A. Main Plant Extracts' Active Properties Effective on Scopolamine-Induced Memory Loss. Am J Alzheimers Dis Other Demen 2017; 32:418-428. [PMID: 28643520 PMCID: PMC10852862 DOI: 10.1177/1533317517715906] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease leads to progressive cognitive function loss, which may impair both intellectual capacities and psychosocial aspects. Although the current knowledge points to a multifactorial character of Alzheimer's disease, the most issued pathological hypothesis remains the cholinergic theory. The main animal model used in cholinergic theory research is the scopolamine-induced memory loss model. Although, in some cases, a temporary symptomatic relief can be obtained through targeting the cholinergic or glutamatergic neurotransmitter systems, no current treatment is able to stop or slow cognitive impairment. Many potentially successful therapies are often blocked by the blood-brain barrier since it exhibits permeability only for several classes of active molecules. However, the plant extracts' active molecules are extremely diverse and heterogeneous regarding the biochemical structure. In this way, many active compounds constituting the recently tested plant extracts may exhibit the same general effect on acetylcholine pathway, but on different molecular ground, which can be successfully used in Alzheimer's disease adjuvant therapy.
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Affiliation(s)
- Ioana-Miruna Balmus
- Department of Biology, Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania
| | - Alin Ciobica
- Department of Research, Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania
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Porritt M, Poling A. Scopolamine Effects Under a Titrating-Delayed-Nonmatching-to-Position Procedure. PSYCHOLOGICAL RECORD 2017. [DOI: 10.1007/bf03395601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gilmour G, Dix S, Fellini L, Gastambide F, Plath N, Steckler T, Talpos J, Tricklebank M. NMDA receptors, cognition and schizophrenia – Testing the validity of the NMDA receptor hypofunction hypothesis. Neuropharmacology 2012; 62:1401-12. [DOI: 10.1016/j.neuropharm.2011.03.015] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 03/10/2011] [Accepted: 03/12/2011] [Indexed: 11/25/2022]
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Deiana S, Platt B, Riedel G. The cholinergic system and spatial learning. Behav Brain Res 2011; 221:389-411. [DOI: 10.1016/j.bbr.2010.11.036] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 11/15/2010] [Indexed: 12/30/2022]
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Dix S, Gilmour G, Potts S, Smith JW, Tricklebank M. A within-subject cognitive battery in the rat: differential effects of NMDA receptor antagonists. Psychopharmacology (Berl) 2010; 212:227-42. [PMID: 20676612 DOI: 10.1007/s00213-010-1945-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 06/29/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE The range of cognitive and psychotomimetic effects produced by antagonists of the N-methyl-D-aspartate (NMDA) receptor has lead to widespread usage of these molecules as pharmacological models of cognitive impairment for drug discovery. Historically, NMDA receptor antagonists have been used interchangeably on the assumption that they produce analogous effects. OBJECTIVES To profile a subset of these antagonists across a novel within-subject cognitive battery in the rat. METHODS Naïve male Lister Hooded rats were subjected to a series of tests in which they were required to learn a simple visuo-auditory conditional discrimination. They then underwent testing in a delayed discrimination test followed by rule reversal and rule extinction tests. RESULTS All NMDA receptor antagonists tested impaired acquisition performance and, with the exception of ketamine and the GluN2A preferring antagonist, NVP-AAM077, impaired consolidation of extinction. GluN2B antagonism produced a singular profile with potentially enhanced delayed discrimination performance and reduced hit rates in the reversal phase. Only PCP (phencyclidine) and ketamine disrupted performance in the delay phase but did so in a delay-independent manner. MK-801, PCP and memantine all increased the hit rate in the reversal phase; whilst only MK-801 and PCP impaired extinction per se. CONCLUSIONS NMDA receptor-dependent mechanisms are requisite in the acquisition of a simple conditional discrimination and consolidation of extinction. Their role in working memory and reversal tasks appear to be less critical and potentially specific to the paradigm and NMDA receptor antagonist used. It is clearly misleading to generalise across NMDA antagonists with respect to their preclinical cognitive profile.
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Affiliation(s)
- Sophie Dix
- Lilly Centre for Cognitive Neuroscience, Eli Lilly and Co Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey GU20 6PH, UK.
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Antiamnesic Effect of B. monniera on L-NNA Induced Amnesia Involves Calmodulin. Neurochem Res 2010; 35:1172-81. [DOI: 10.1007/s11064-010-0171-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2010] [Indexed: 10/19/2022]
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Saraf M, Prabhakar S, Anand A. Bacopa monniera alleviates Nω-nitro-l-arginine-induced but not MK-801-induced amnesia: A mouse Morris water maze study. Neuroscience 2009; 160:149-55. [DOI: 10.1016/j.neuroscience.2009.02.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 02/03/2009] [Accepted: 02/04/2009] [Indexed: 11/28/2022]
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Deiana S, Harrington CR, Wischik CM, Riedel G. Methylthioninium chloride reverses cognitive deficits induced by scopolamine: comparison with rivastigmine. Psychopharmacology (Berl) 2009; 202:53-65. [PMID: 19005644 DOI: 10.1007/s00213-008-1394-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
Abstract
RATIONALE The cholinergic system is involved in cognition as well as in age-related cognitive decline and Alzheimer disease (AD). Cholinergic enhancers ameliorate AD symptoms and represent the main current therapy for AD. MTC (Methylthioninium chloride), an antioxidant with metabolism-enhancing properties may be a novel candidate with pro-cognitive capacities. OBJECTIVES This study was performed: (1) to assess the pro-cognitive efficacy of MTC and establish its dose-response; (2) to compare the efficacy of MTC with rivastigmine and (3) to determine the potential for combination therapy by co-administration of MTC and rivastigmine. METHODS Spatial cognition of female NMRI mice was tested in a reference memory water maze task. Subjects received intra-peritoneal injections of scopolamine (0.5 mg/kg) followed by vehicle, and/or MTC and/or rivastigmine (0.15-4 mg/kg MTC; 0.1-0.5 mg/kg rivastigmine) in mono or combination treatment. RESULTS Scopolamine treatment prevented spatial learning in NMRI female mice and the deficit was reversed by both rivastigmine and MTC in a dose-dependent manner. Mono-therapy with high doses of rivastigmine (>0.5 mg/kg) caused severe side effects but MTC was safe up to 4 mg/kg. Co-administration of sub-effective doses of both drugs acted synergistically in reversing learning deficits and scopolamine-induced memory impairments. CONCLUSIONS In our model, MTC reversed the spatial learning impairment. When combined with the ChEI rivastigmine, the effect of MTC appeared to be amplified indicating that combination therapy could potentially improve not only symptoms but also contribute beneficially to neuronal metabolism by minimising side effects at lower doses.
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Affiliation(s)
- Serena Deiana
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB252ZD, Scotland
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Kueh D, Iwamoto K, Poling A, Baker LE. Effects of gamma-hydroxybutyrate (GHB) and its metabolic precursors on delayed-matching-to-position performance in rats. Pharmacol Biochem Behav 2007; 89:179-87. [PMID: 18201754 DOI: 10.1016/j.pbb.2007.12.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 11/21/2007] [Accepted: 12/05/2007] [Indexed: 10/22/2022]
Abstract
The purpose of the present study was to provide further information about the effects of gamma-hydroxybutyrate (GHB) on memory. Initially, the acute effects of gamma-butyrolactone (GBL, 75-200 mg/kg IP), 1,4-butanediol (1,4-BD, 100-300 mg/kg IP), and ethanol (1.0-3.0 g/kg, oral), as well as GHB (100-300 mg/kg IP), were examined in rats responding under a delayed-matching-to-position (DMTP) procedure with delays from 0 to 32 s. Acute administration of all four drugs reduced the number of trials completed and also reduced accuracy during delay trials, but not during trials without a delay. Some tolerance developed to the disruptive effects of GHB following exposure to 300 mg/kg/day for 29 consecutive days. These data indicate that GHB can disrupt working memory and speed of responding, and that tolerance can develop to these effects. Moreover, the acute effects of GHB under the DMTP procedure resemble those of its metabolic precursors, GBL and 1,4-BD, and of the prototypical CNS depressant drug, ethanol.
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Affiliation(s)
- Daniel Kueh
- Department of Psychology, Western Michigan University, Kalamazoo, MI 49008-5439, USA
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McQuail JA, Burk JA. Evaluation of muscarinic and nicotinic receptor antagonists on attention and working memory. Pharmacol Biochem Behav 2006; 85:796-803. [PMID: 17196638 DOI: 10.1016/j.pbb.2006.11.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 11/09/2006] [Accepted: 11/21/2006] [Indexed: 02/05/2023]
Abstract
Cholinergic receptor antagonists are commonly used to model attentional and mnemonic impairments associated with neuropsychiatric disorders such as Alzheimer's disease. However, few studies have systematically assessed the effects of these drugs following manipulations that affect attention or working memory within the same task. In the present experiment, rats were trained to discriminate visual signals from "blank" trials when no signal was presented. This task was modified to include retention intervals on some trials to tax working memory. During standard task performance, rats received systemic injections of the muscarinic receptor antagonist, scopolamine, or of the nicotinic receptor antagonist, mecamylamine. A second experiment tested the effects on this task of co-administering doses of scopolamine and mecamylamine that, when administered alone, did not significantly affect task performance. Scopolamine (0.3 and 1.0 mg/kg) decreased detection of 500 ms signals but did not affect accurate identification of non-signals. Scopolamine did not differentially affect performance across the retention interval. Elevated omission rates were associated with high doses of scopolamine or mecamylamine. Combination drug treatment was associated with decreased signal detection and elevated omission rates. Collectively, the data suggest that muscarinic and nicotinic receptor antagonists do not exclusively impair working memory.
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Affiliation(s)
- Joseph A McQuail
- Department of Psychology, College of William and Mary, P.O. Box 8795, Williamsburg, VA 23187, USA
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Abstract
Marijuana and its psychoactive constituents induce a multitude of effects on brain function. These include deficits in memory formation, but care needs to be exercised since many human studies are flawed by multiple drug abuse, small sample sizes, sample selection and sensitivity of psychological tests for subtle differences. The most robust finding with respect to memory is a deficit in working and short-term memory. This requires intact hippocampus and prefrontal cortex, two brain regions richly expressing CB1 receptors. Animal studies, which enable a more controlled drug regime and more constant behavioural testing, have confirmed human results and suggest, with respect to hippocampus, that exogenous cannabinoid treatment selectively affects encoding processes. This may be different in other brain areas, for instance the amygdala, where a predominant involvement in memory consolidation and forgetting has been firmly established. While cannabinoid receptor agonists impair memory formation, antagonists reverse these deficits or act as memory enhancers. These results are in good agreement with data obtained from electrophysiological recordings, which reveal reduction in neural plasticity following cannabinoid treatment, and increased plasticity following antagonist exposure. The mixed receptor properties of the pharmacological tool, however, make it difficult to define the exact role of any CB1 receptor population in memory processes with any certainty. This makes it all the more important that behavioural studies use selective administration of drugs to specific brain areas, rather than global administration to whole animals. The emerging role of the endogenous cannabinoid system in the hippocampus may be to facilitate the induction of long-term potentiation/the encoding of information. Administration of exogenous selective CB1 agonists may therefore disrupt hippocampus-dependent learning and memory by 'increasing the noise', rather than 'decreasing the signal' at potentiated inputs.
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Affiliation(s)
- G Riedel
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK.
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Arguello PA, Jentsch JD. Cannabinoid CB1 receptor-mediated impairment of visuospatial attention in the rat. Psychopharmacology (Berl) 2004; 177:141-50. [PMID: 15290005 DOI: 10.1007/s00213-004-1953-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 05/25/2004] [Indexed: 11/26/2022]
Abstract
RATIONALE CB1 receptors (CB1Rs) mediate many of the psychoactive effects of cannabinoids, and marijuana intoxication can produce neurocognitive deficits with a similarity to those seen in schizophrenia, including impairments of attention. OBJECTIVES We thus sought to characterize the effects of a CB1R-selective agonist and antagonist on attention in the rat using a lateralized reaction time task (LRT). We hypothesized that CB1R agonists would impair performance and that CB1R antagonists might improve performance. METHODS Subjects were trained to perform the LRT, a procedure that measured their ability to attend to and detect brief visual target stimuli. After training, we tested the effects of the CB1R agonist WIN55,212-2 (WIN; 0-2.5 mg/kg) or the CB1R antagonist SR141716A (SR; 0-1.0 mg/kg), administered alone or in combination, on visual attention performance using task conditions in which target stimulus salience was varied systematically across trials. RESULTS The highest dose of WIN reduced correct choices in well-trained rats, with impairment greatest at the shortest stimulus durations. The highest dose of WIN also increased omissions and slowed response times. By contrast, SR itself did not produce any measurable effects on performance but was able to prevent the impairment produced by WIN. CONCLUSIONS These results suggest that CB1Rs mediate the attentional performance impairments caused by acute administration of cannabinoid agonists and begin to unravel the possible contribution of cannabinoid systems to the pathophysiological substrates of cognitive dysfunction in schizophrenia.
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Affiliation(s)
- P Alexander Arguello
- Department of Psychology, University of California, P.O. Box 951563, Los Angeles, CA 90095-1563, USA
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Mishima K, Egashira N, Matsumoto Y, Iwasaki K, Fujiwara M. Involvement of reduced acetylcholine release in Delta9-tetrahydrocannabinol-induced impairment of spatial memory in the 8-arm radial maze. Life Sci 2002; 72:397-407. [PMID: 12467880 DOI: 10.1016/s0024-3205(02)02274-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To clarify the mechanism by which Delta9-tetrahydrocannabinol, a major psychoactive component of marijuana, impairs spatial memory in the 8-arm radial maze in rats via the cholinergic system, we used two acetylcholinesterase inhibitors, physostigmine and tetrahydroaminoacridine. Moreover, we examined the effect of Delta9-tetrahydrocannabinol on acetylcholine release in the frontal cortex and dorsal and ventral hippocampus using in vivo microdialysis. Physostigmine (0.01-0.05 mg/kg, i.p.) and tetrahydroaminoacridine (1-5 mg/kg, p.o.) improved the impairment of spatial memory induced by Delta9-tetrahydrocannabinol (6 mg/kg, i.p.) in the 8-arm radial maze. Delta9-tetrahydrocannabinol (6 mg/kg, i.p.) produced a significant decrease in acetylcholine release in the dorsal hippocampus as assessed by microdialysis. Moreover, tetrahydroaminoacridine at a dose of 1 mg/kg, which improved the impairment of spatial memory, reversed the decrease in acetylcholine release induced by Delta9-tetrahydrocannabinol in the dorsal hippocampus during 60-120 min after the Delta9-tetrahydrocannabinol injection. These findings suggest that inhibition of the cholinergic pathway by reduced acetylcholine release is one of the means by which Delta9-tetrahydrocannabinol impairs spatial memory in the 8-arm radial maze.
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Affiliation(s)
- Kenichi Mishima
- Department of Neuropharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, 814-0180, Fukuoka, Japan
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Mishima K, Egashira N, Hirosawa N, Fujii M, Matsumoto Y, Iwasaki K, Fujiwara M. Characteristics of learning and memory impairment induced by delta9-tetrahydrocannabinol in rats. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 87:297-308. [PMID: 11829149 DOI: 10.1254/jjp.87.297] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We investigated the characteristics of delta9-tetrahydrocannabinol (THC)-induced impairment of learning and memory using an 8-arm radial maze task, a water maze, a visual discrimination task with 2 figures and a passive avoidance test in rats. THC (6 mg/kg, i.p.) impaired spatial memory in the standard task of the 8-arm radial maze. THC (4-6 mg/kg, i.p.) selectively impaired working memory in a reference and working memory task of the 8-arm radial maze. Even at a dose of 10 mg/kg, THC did not impair spatial memory in the water maze. In addition, THC at a dose of 6 mg/kg, which had inhibitory effects in the 8-arm radial maze, did not affect performance in the visual discrimination task. These results indicate that at low doses (2-6 mg/kg), THC may not produce visual function abnormalities. THC impaired retrieval (6 mg/kg, i.p.) as well as acquisition (10 mg/kg, i.p.) in the passive avoidance test. The consolidation process was also impaired by i.c.v. injection (100 microg), but not i.p. injection (6-10 mg/kg) of THC. These results suggest that THC-induced impairment of spatial memory is based on the selective impairment of working memory through its effects on acquisition and retrieval processes.
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Affiliation(s)
- K Mishima
- Department of Physiology and Pharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Japan
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