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Yin F, Zhang J, Lu Y, Zhang Y, Liu J, Deji C, Qiao X, Gao K, Xu M, Lai J, Wang Y. Modafinil rescues repeated morphine-induced synaptic and behavioural impairments via activation of D1R-ERK-CREB pathway in medial prefrontal cortex. Addict Biol 2022; 27:e13103. [PMID: 34647651 DOI: 10.1111/adb.13103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/19/2021] [Accepted: 09/13/2021] [Indexed: 11/30/2022]
Abstract
Long-term opioid abuse causes a variety of long-lasting cognitive impairments such as attention, impulsivity and working memory. These cognitive impairments undermine behavioural treatment for drug abuse and lead to poor treatment retention and outcomes. Modafinil is a wake-promoting drug that shows potential in improving attention and memory in humans and animals. However, modafinil's effect on opioid-induced cognitive impairments remains unclear, and the underlying mechanism is poorly understood. This study showed that repeated morphine administration significantly impairs attention, increases impulsivity and reduces motivation to natural rewards in mice. Systemic modafinil treatment at low dose efficiently ameliorates morphine-induced attention dysfunction and improves motivation and working memory in mice. High dose of modafinil has adverse effects on impulsive action and attention. Local infusion of D1R antagonist SCH-23390 reverses the morphine-induced synaptic abnormalities and activation of the D1R-ERK-CREB pathway in medial prefrontal cortex (mPFC). This study demonstrated a protective effect of modafinil in mPFC neurons and offered a therapeutic potential for cognitive deficits in opioid abuse.
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Affiliation(s)
- Fangyuan Yin
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Jinyu Zhang
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Ye Lu
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Yulei Zhang
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Jincen Liu
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Cuola Deji
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Xiaomeng Qiao
- Department of Forensic Medicine, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Keqiang Gao
- School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Min Xu
- School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jianghua Lai
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Yunpeng Wang
- College of Forensic Science, Xi'an Jiaotong University, Xi'an, Shaanxi, China
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Cognitive profiling and proteomic analysis of the modafinil analogue S-CE-123 in experienced aged rats. Sci Rep 2021; 11:23962. [PMID: 34907284 PMCID: PMC8671572 DOI: 10.1038/s41598-021-03372-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 09/30/2021] [Indexed: 12/22/2022] Open
Abstract
The lack of novel cognitive enhancer drugs in the clinic highlights the prediction problems of animal assays. The objective of the current study was to test a putative cognitive enhancer in a rodent cognitive test system with improved translational validity and clinical predictivity. Cognitive profiling was complemented with post mortem proteomic analysis. Twenty-seven male Lister Hooded rats (26 months old) having learned several cognitive tasks were subchronically treated with S-CE-123 (CE-123) in a randomized blind experiment. Rats were sacrificed after the last behavioural procedure and plasma and brains were collected. A label-free quantification approach was used to characterize proteomic changes in the synaptosomal fraction of the prefrontal cortex. CE-123 markedly enhanced motivation which resulted in superior performance in a new-to-learn operant discrimination task and in a cooperation assay of social cognition, and mildly increased impulsivity. The compound did not affect attention, spatial and motor learning. Proteomic quantification revealed 182 protein groups significantly different between treatment groups containing several proteins associated with aging and neurodegeneration. Bioinformatic analysis showed the most relevant clusters delineating synaptic vesicle recycling, synapse organisation and antioxidant activity. The cognitive profile of CE-123 mapped by the test system resembles that of modafinil in the clinic showing the translational validity of the test system. The findings of modulated synaptic systems are paralleling behavioral results and are in line with previous evidence for the role of altered synaptosomal protein groups in mechanisms of cognitive function.
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Hersey M, Bacon AK, Bailey LG, Coggiano MA, Newman AH, Leggio L, Tanda G. Psychostimulant Use Disorder, an Unmet Therapeutic Goal: Can Modafinil Narrow the Gap? Front Neurosci 2021; 15:656475. [PMID: 34121988 PMCID: PMC8187604 DOI: 10.3389/fnins.2021.656475] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022] Open
Abstract
The number of individuals affected by psychostimulant use disorder (PSUD) has increased rapidly over the last few decades resulting in economic, emotional, and physical burdens on our society. Further compounding this issue is the current lack of clinically approved medications to treat this disorder. The dopamine transporter (DAT) is a common target of psychostimulant actions related to their use and dependence, and the recent availability of atypical DAT inhibitors as a potential therapeutic option has garnered popularity in this research field. Modafinil (MOD), which is approved for clinical use for the treatment of narcolepsy and sleep disorders, blocks DAT just like commonly abused psychostimulants. However, preclinical and clinical studies have shown that it lacks the addictive properties (in both behavioral and neurochemical studies) associated with other abused DAT inhibitors. Clinical availability of MOD has facilitated its off-label use for several psychiatric disorders related to alteration of brain dopamine (DA) systems, including PSUD. In this review, we highlight clinical and preclinical research on MOD and its R-enantiomer, R-MOD, as potential medications for PSUD. Given the complexity of PSUD, we have also reported the effects of MOD on psychostimulant-induced appearance of several symptoms that could intensify the severity of the disease (i.e., sleep disorders and impairment of cognitive functions), besides the potential therapeutic effects of MOD on PSUD.
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Affiliation(s)
- Melinda Hersey
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Amanda K. Bacon
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Lydia G. Bailey
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Mark A. Coggiano
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Amy H. Newman
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Lorenzo Leggio
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
- Clinical Psychoneuroendo- crinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
- National Institute on Alcohol Abuse and Alcoholism, Division of Intramural Clinical and Biological Research, National Institutes of Health, Bethesda, MD, United States
| | - Gianluigi Tanda
- Medication Development Program, Molecular Targets and Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
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Heyer-Osorno R, Juárez J. Modafinil reduces choice impulsivity while increasing motor activity in preadolescent rats treated prenatally with alcohol. Pharmacol Biochem Behav 2020; 194:172936. [PMID: 32360693 DOI: 10.1016/j.pbb.2020.172936] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 04/02/2020] [Accepted: 04/27/2020] [Indexed: 02/08/2023]
Abstract
Rats exposed prenatally to alcohol show a reduction in the spontaneous activity of dopaminergic neurons of the ventral tegmental area (VTA), as well as greater impulsive behavior and motor activity, behavioral alterations that have been related to dopaminergic dysfunction. Modafinil (MOD) is a dopamine (DA) reuptake blocker prescribed to treat sleep disorders; however, in recent years it has been used for the treatment of ADHD with positive results. Also, studies in humans and rodents show beneficial effects on learning and attention; however, studies evaluating MOD effects on impulsivity are few and show contradictory results. The purpose of this work was to evaluate the effect of a daily dose of MOD (60 mg/kg i.g.) on cognitive (or choice) impulsivity and motor activity in male preadolescent rats exposed prenatally to alcohol or sucrose (isocaloric control). MOD reduced the impulsive responses in a delay discounting task (DDT) at the same time that increased the motor activity, in both healthy and prenatal alcohol treated rats; however, MOD reduced the response latency in DDT only in prenatal alcohol treated rats. This differential effect of DA activation on impulsivity and motor activity show that the MOD dose that improves the impulse control, does not necessarily decrease motor activity, and suggests a possible differential neural mechanism underlying the expression of these behaviors. On the other hand, the changes in the response latency, only in prenatal alcohol treated groups, suggest that decision-making in animals with a dopaminergic dysfunction is more susceptible to be affected by MOD action.
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Affiliation(s)
- Rocio Heyer-Osorno
- Laboratorio de Farmacología y Conducta, Instituto de Neurociencias, CUCBA, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico
| | - Jorge Juárez
- Laboratorio de Farmacología y Conducta, Instituto de Neurociencias, CUCBA, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
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Kumar M, Maqbool S. Memory improvement by modafinil at cost of metabolic hazards? A study to decipher the benefits and risks of modafinil in rats. Neurotoxicology 2020; 78:106-115. [PMID: 32126242 DOI: 10.1016/j.neuro.2020.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Modafinil is approved for narcolepsy and achieved high success in off-label indications in memory-related disorders. However, chronic indiscriminate use of modafinil imposes several health hazards like hyperglycaemia, obesity and metabolic syndrome, owing to impairment of sleep-wake cycle, circadian-rhythm, and neurotransmission. The present protocol elucidates the effects of modafinil per se and diabetic complications apropos. METHODS Modafinil (100 and 200 mg/kg) was administered in rats from day 5-26. To induce type-2 diabetes, streptozotocin (STZ) was given on day 1, and blood glucose assessed on day 5. CPP (combination propranolol and phentolamine) was administered to antagonize sympathetic activity. After evaluation of cognitive functions, serum lipid profile, and biomarkers of oxidative stress and acetylcholinesterase (AChE) activity were assessed. RESULTS Subacute dosing of modafinil significantly elevated blood glucose levels, albeit considerably less than diabetic group, and attenuated brain oxidative stress and AChE activity. Modafinil caused significant dyslipidaemia, increased body weight, whereas modestly altered abdominal circumference (AC) and thoracic circumference (TC) in rats. Significant hyperglycaemia, derangement of serum lipid-profile, brain lipid peroxidation, cholinergic hypofunction, and decrease in body weight and ACTC was noted in diabetic rats. Modafinil (100 mg/kg) significantly potentiated the hyperglycaemia and dyslipidaemia, however, attenuated oxidative stress and AChE activity in diabetic rats. Modafinil increased short-term (working) memory but not long-term spatial memory in normal and diabetic rats. CPP infusion attenuated these effects of modafinil. CONCLUSION Subacute dosing of modafinil differentially modulates long-term and short-term memory subtypes, and also predisposes towards metabolic derangements.
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Affiliation(s)
- Manish Kumar
- Department of Pharmacology, Swift School of Pharmacy, Ghaggar Sarai (Rajpura), Punjab, 140401, India.
| | - Shahnawaz Maqbool
- Department of Pharmacology, Swift School of Pharmacy, Ghaggar Sarai (Rajpura), Punjab, 140401, India
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Differential effect of modafinil on impulsivity, attention and motor activity in preadolescent rats prenatally treated with alcohol. Brain Res 2019; 1722:146395. [DOI: 10.1016/j.brainres.2019.146395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
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Effect of ADHD medication in male C57BL/6J mice performing the rodent Continuous Performance Test. Psychopharmacology (Berl) 2019; 236:1839-1851. [PMID: 30656365 DOI: 10.1007/s00213-019-5167-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 01/07/2019] [Indexed: 12/15/2022]
Abstract
RATIONALE The rodent Continuous Performance Test (rCPT) is a novel rodent paradigm to assess attention and impulsivity that resembles the human CPT. This task measures the rodents' ability to discriminate between target and non-target stimuli. The effect of attention-deficit/hyperactivity disorder (ADHD) medication on rCPT performance in mice remains to be fully characterized. OBJECTIVE To investigate the predictive validity of the mouse rCPT by studying the effects of ADHD medication methylphenidate, atomoxetine, amphetamine, guanfacine, and modafinil in four behavioral subgroups based on performance and impulsivity levels. METHODS Two cohorts of male C57BL/6J mice were used, and the effect of treatment was tested in a variable stimulus duration probe. Performance and impulsive subgroups were made based on discriminability and percentage premature responses, respectively. RESULTS Methylphenidate, atomoxetine, and amphetamine improved performance in the low-performing animals, with no effect in the high-performers. These improvements were a result of increased hit rate and/or decreased false-alarm rate. Furthermore, these drugs decreased percentage premature responses in the high-impulsive group. Methylphenidate, guanfacine, and modafinil increased premature responses in the low-impulsive group. Modafinil impaired performance in the high-performers by increasing false-alarm rate. CONCLUSION The effect of ADHD treatment was dependent on baseline, as seen by increases in performance for the low-performers and decreases in impulsivity for the high-impulsive animals. These results agree with clinical data and may support the inverted U-shaped arousal-performance theory. The rCPT combined with behavioral separation into subgroups has high predictive validity, and our study is a step forward towards establishing the clinical translatability of the rCPT.
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Nilsson SRO, Heath CJ, Takillah S, Didienne S, Fejgin K, Nielsen V, Nielsen J, Saksida LM, Mariani J, Faure P, Didriksen M, Robbins TW, Bussey TJ, Mar AC. Continuous performance test impairment in a 22q11.2 microdeletion mouse model: improvement by amphetamine. Transl Psychiatry 2018; 8:247. [PMID: 30429456 PMCID: PMC6235862 DOI: 10.1038/s41398-018-0295-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 08/21/2018] [Accepted: 10/05/2018] [Indexed: 02/03/2023] Open
Abstract
The 22q11.2 deletion syndrome (22q11.2DS) confers high risk of neurodevelopmental disorders such as schizophrenia and attention-deficit hyperactivity disorder. These disorders are associated with attentional impairment, the remediation of which is important for successful therapeutic intervention. We assessed a 22q11.2DS mouse model (Df(h22q11)/+) on a touchscreen rodent continuous performance test (rCPT) of attention and executive function that is analogous to human CPT procedures. Relative to wild-type littermates, Df(h22q11)/+ male mice showed impaired attentional performance as shown by decreased correct response ratio (hit rate) and a reduced ability to discriminate target stimuli from non-target stimuli (discrimination sensitivity, or d'). The Df(h22q11)/+ model exhibited decreased prefrontal cortical-hippocampal oscillatory synchrony within multiple frequency ranges during quiet wakefulness, which may represent a biomarker of cognitive dysfunction. The stimulant amphetamine (0-1.0 mg/kg, i.p.) dose-dependently improved d' in Df(h22q11)/+ mice whereas the highest dose of modafinil (40 mg/kg, i.p.) exacerbated their d' impairment. This is the first report to directly implicate attentional impairment in a 22q11.2DS mouse model, mirroring a key endophenotype of the human disorder. The capacity of the rCPT to detect performance impairments in the 22q11.2DS mouse model, and improvement following psychostimulant-treatment, highlights the utility and translational potential of the Df(h22q11)/+ model and this automated behavioral procedure.
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Affiliation(s)
- Simon R. O. Nilsson
- 0000000121885934grid.5335.0Department of Psychology, University of Cambridge, Cambridge, UK ,0000000121885934grid.5335.0MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK ,0000 0001 2109 4251grid.240324.3Neuroscience Institute, New York University Medical Center, New York, NY USA ,0000 0004 1936 8753grid.137628.9Department of Neuroscience and Physiology, School of Medicine, New York University, New York, NY USA
| | - Christopher J. Heath
- 0000000096069301grid.10837.3dSchool of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - Samir Takillah
- Fatigue and Vigilance team, Neuroscience and Operational Constraints Department, French Armed Forces Biomedical Research Institute (IRBA), Brétigny-sur-Orge, France ,0000 0001 2188 0914grid.10992.33VIFASOM team (EA 7330), Paris Descartes University, Sorbonne Paris Cité, Hôtel Dieu, Paris, France ,0000 0001 2097 0141grid.121334.6Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, INSERM, U1130, Institut de Biologie Paris Seine (IBPS), UMR 8246 Neuroscience Paris Seine (NPS), Team Neurophysiology and Behavior, Paris, France ,Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris Seine (IBPS), UMR 8256 Biological adaptation and ageing (B2A), Team Brain Development, Repair and Ageing, Paris, France ,APHP Hôpital, DHU Fast, Institut de la Longévité, Ivry-Sur-Seine, France
| | - Steve Didienne
- 0000 0001 2097 0141grid.121334.6Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, INSERM, U1130, Institut de Biologie Paris Seine (IBPS), UMR 8246 Neuroscience Paris Seine (NPS), Team Neurophysiology and Behavior, Paris, France
| | - Kim Fejgin
- 0000 0004 0476 7612grid.424580.fH. Lundbeck A/S, Synaptic Transmission, Neuroscience Research DK, Copenhagen, Denmark
| | - Vibeke Nielsen
- 0000 0004 0476 7612grid.424580.fH. Lundbeck A/S, Synaptic Transmission, Neuroscience Research DK, Copenhagen, Denmark
| | - Jacob Nielsen
- 0000 0004 0476 7612grid.424580.fH. Lundbeck A/S, Synaptic Transmission, Neuroscience Research DK, Copenhagen, Denmark
| | - Lisa M. Saksida
- 0000000121885934grid.5335.0Department of Psychology, University of Cambridge, Cambridge, UK ,0000000121885934grid.5335.0MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK ,0000 0004 1936 8884grid.39381.30Molecular Medicine Research Group, Robarts Research Institute & Department of Physiology, Western University, London, ON Canada ,0000 0004 1936 8884grid.39381.30Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON Canada ,0000 0004 1936 8884grid.39381.30The Brain and Mind Institute, Western University, London, ON Canada
| | - Jean Mariani
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC), CNRS, Institut de Biologie Paris Seine (IBPS), UMR 8256 Biological adaptation and ageing (B2A), Team Brain Development, Repair and Ageing, Paris, France ,APHP Hôpital, DHU Fast, Institut de la Longévité, Ivry-Sur-Seine, France
| | - Philippe Faure
- 0000 0001 2188 0914grid.10992.33VIFASOM team (EA 7330), Paris Descartes University, Sorbonne Paris Cité, Hôtel Dieu, Paris, France
| | - Michael Didriksen
- 0000 0004 0476 7612grid.424580.fH. Lundbeck A/S, Synaptic Transmission, Neuroscience Research DK, Copenhagen, Denmark
| | - Trevor W. Robbins
- 0000000121885934grid.5335.0Department of Psychology, University of Cambridge, Cambridge, UK ,0000000121885934grid.5335.0MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Timothy J. Bussey
- 0000000121885934grid.5335.0Department of Psychology, University of Cambridge, Cambridge, UK ,0000000121885934grid.5335.0MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK ,0000 0004 1936 8884grid.39381.30Molecular Medicine Research Group, Robarts Research Institute & Department of Physiology, Western University, London, ON Canada ,0000 0004 1936 8884grid.39381.30Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON Canada ,0000 0004 1936 8884grid.39381.30The Brain and Mind Institute, Western University, London, ON Canada
| | - Adam C. Mar
- 0000 0001 2109 4251grid.240324.3Neuroscience Institute, New York University Medical Center, New York, NY USA ,0000 0004 1936 8753grid.137628.9Department of Neuroscience and Physiology, School of Medicine, New York University, New York, NY USA
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Ding Z, Brown JW, Rueter LE, Mohler EG. Profiling attention and cognition enhancing drugs in a rat touchscreen-based continuous performance test. Psychopharmacology (Berl) 2018; 235:1093-1105. [PMID: 29332255 DOI: 10.1007/s00213-017-4827-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/29/2017] [Indexed: 11/25/2022]
Abstract
RATIONALE A novel rodent continuous performance test (CPT) was developed as one of the goals of the NEWMEDS (Novel Methods leading to New Medications in Depression and Schizophrenia) consortium to improve its translatability to the CPT test used in human subjects. OBJECTIVES The objective of the study is to investigate the effects of attention and cognition enhancing drugs in rodent CPT. METHODS A single cohort of rats were trained to asymptotic performance in the test. Pharmacological test sessions were then performed twice per week in a full crossover design with the following drugs tested: methylphenidate (0.3, 1, and 3 mg/kg), the α4β2 nicotinic agonist ABT-594 (0.0023, 0.007 and 0.023 mg/kg), modafinil (8, 16, and 32 mg/kg), atomoxetine (0.3, 1, and 3 mg/kg), donepezil (0.1, 0.3, and 1 mg/kg), and memantine (1.25, 2.5, and 5 mg/kg). RESULTS The stimulant-like drugs methylphenidate, ABT-594, and modafinil were found to increase measures of impulsivity and overall responding with generally no positive effects on d', a putative measure of attention, with the exception of ABT-594 which improved d' at the highest dose tested. Atomoxetine and the memory-enhancing drugs donepezil and memantine, on the other hand, were found to reduce measures of impulsivity and responding and had either negligible or worsening effects on d'. CONCLUSIONS Our results suggest rodent CPT can detect changes in impulsivity resulting from drugs known to improve attention in rodents and humans. However, additional work is needed to assess the sensitivity and validity of this assay for assessing effects on attention.
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Affiliation(s)
- Zhiyong Ding
- Neuroscience Drug Discovery, AbbVie, 1 N. Waukegan Rd, North Chicago, IL, 60046, USA
| | - Jordan W Brown
- Neuroscience Drug Discovery, AbbVie, 1 N. Waukegan Rd, North Chicago, IL, 60046, USA
| | - Lynne E Rueter
- Neuroscience Drug Discovery, AbbVie, 1 N. Waukegan Rd, North Chicago, IL, 60046, USA
| | - Eric G Mohler
- Neuroscience Drug Discovery, AbbVie, 1 N. Waukegan Rd, North Chicago, IL, 60046, USA.
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10
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Dhawan SS, Xia S, Tait DS, Bundgaard C, Bowman E, Brown VJ. Oral dosing of rodents using a palatable tablet. Psychopharmacology (Berl) 2018; 235:1527-1532. [PMID: 29511808 PMCID: PMC5919998 DOI: 10.1007/s00213-018-4863-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/15/2018] [Indexed: 12/20/2022]
Abstract
RATIONALE Delivering orally bioavailable drugs to rodents is an important component to investigating that route of administration in novel treatments for humans. However, the traditional method of oral gavage requires training, is stressful, and can induce oesophageal damage in rodents. OBJECTIVES To demonstrate a novel administrative technique-palatable gelatine tablets-as a stress-free route of oral delivery. METHODS Twenty-four male Lister hooded rats were sacrificed for brain tissue analysis at varying time-points after jelly administration of 30 mg/kg of the wake-promoting drug modafinil. A second group of 22 female rats were tested on locomotor activity after 30 mg/kg modafinil, or after vehicle jellies, with the locomotor data compared to the brain tissue concentrations at the corresponding times. RESULTS Modafinil was present in the brain tissue at all time-points, reducing in concentration over time. The pattern of brain tissue modafinil concentration is comparable to previously reported results following oral gavage. Modafinil-treated rats were more active than control rats, with greater activity during the later time-periods-similar to that previously reported following intraperitoneal injection of 40 mg/kg modafinil. CONCLUSIONS Palatable jelly tablets are an effective route of administration of thermally stable orally bioavailable compounds, eliminating the stress/discomfort and health risk of oral gavage and presenting as an alternative to previously reported palatable routes of administration where high protein and fat levels may adversely affect appetite for food reward, and uptake rate in the gastrointestinal tract.
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Affiliation(s)
- Sandeep S. Dhawan
- School of Psychology and Neuroscience, University of St Andrews, St Mary’s Quad, South Street, St Andrews, Fife, KY16 9JP UK
| | - Shuang Xia
- School of Psychology and Neuroscience, University of St Andrews, St Mary’s Quad, South Street, St Andrews, Fife, KY16 9JP UK
| | - David S. Tait
- School of Psychology and Neuroscience, University of St Andrews, St Mary’s Quad, South Street, St Andrews, Fife, KY16 9JP UK
| | | | - Ellen Bowman
- School of Psychology and Neuroscience, University of St Andrews, St Mary’s Quad, South Street, St Andrews, Fife, KY16 9JP UK
| | - Verity J. Brown
- School of Psychology and Neuroscience, University of St Andrews, St Mary’s Quad, South Street, St Andrews, Fife, KY16 9JP UK
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Nikiforuk A, Kalaba P, Ilic M, Korz V, Dragačević V, Wackerlig J, Langer T, Höger H, Golebiowska J, Popik P, Lubec G. A Novel Dopamine Transporter Inhibitor CE-123 Improves Cognitive Flexibility and Maintains Impulsivity in Healthy Male Rats. Front Behav Neurosci 2017; 11:222. [PMID: 29230168 PMCID: PMC5711856 DOI: 10.3389/fnbeh.2017.00222] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/24/2017] [Indexed: 11/24/2022] Open
Abstract
Reduced cognitive abilities are often characterized by an impairment of flexibility, i.e., the ability to switch from learned rules or categories that were important in certain contexts to different new modalities that rule the task. Drugs targeting the dopamine transporter (DAT) are widely used for their potential to enhance cognitive abilities. However, commercially available drugs are of limited specificity for DAT, blocking also noradrenaline and serotonine transporters, that can lead to unwanted side effects in healthy subjects. Therefore, we tested a newly synthetized compound (CE-123) with higher specificity for DAT in male rats in an attentional set-shifting task (ASST), that proves for cognitive flexibility and a 5-choice serial-reaction time task (5-CSRTT) assessing visuospatial attention and impulsivity. Treated rats at a dose of 0.3 and 1.0 but not 0.1 mg/kg bodyweight showed reduced extra-dimensional shifts in the ASST compared to controls indicating increased cognitive flexibility. Rats treated with R-Modafinil, a commercially available DAT inhibitor at a dose of 10 mg/kg bodyweight showed increased premature responses, an indicator of increased impulsivity, during a 10 s but not a 2.5, 5, or 7.5 s intertrial interval when compared to vehicle-treated rats in the 5-CSRTT. This was not found in rats treated with CE-123 at the same dose as for R-Modafinil. Visuospatial attention, except premature responses, did not differ between R-Modafinil and CE-123-treated rats and their respective controls. Thus, CE-123 increased cognitive flexibility with diminished impulsivity.
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Affiliation(s)
- Agnieszka Nikiforuk
- Department of Behavioral Neuroscience and Drug Development, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Predrag Kalaba
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Marija Ilic
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Volker Korz
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Vladimir Dragačević
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Judith Wackerlig
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Vienna, Austria
| | - Joanna Golebiowska
- Department of Behavioral Neuroscience and Drug Development, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Piotr Popik
- Department of Behavioral Neuroscience and Drug Development, Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland
| | - Gert Lubec
- Paracelsus Medical University, Salzburg, Austria
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Mar AC, Nilsson SRO, Gamallo-Lana B, Lei M, Dourado T, Alsiö J, Saksida LM, Bussey TJ, Robbins TW. MAM-E17 rat model impairments on a novel continuous performance task: effects of potential cognitive enhancing drugs. Psychopharmacology (Berl) 2017; 234:2837-2857. [PMID: 28744563 PMCID: PMC5591806 DOI: 10.1007/s00213-017-4679-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/18/2017] [Indexed: 12/02/2022]
Abstract
RATIONALE Impairments in attention and inhibitory control are endophenotypic markers of neuropsychiatric disorders such as schizophrenia and represent key targets for therapeutic management. Robust preclinical models and assays sensitive to clinically relevant treatments are crucial for improving cognitive enhancement strategies. OBJECTIVES We assessed a rodent model with neural and behavioral features relevant to schizophrenia (gestational day 17 methylazoxymethanol acetate treatment (MAM-E17)) on a novel test of attention and executive function, and examined the impact of putative nootropic drugs. METHODS MAM-E17 and sham control rats were trained on a novel touchscreen-based rodent continuous performance test (rCPT) designed to closely mimic the human CPT paradigm. Performance following acute, systemic treatment with an array of pharmacological compounds was investigated. RESULTS Two cohorts of MAM-E17 rats were impaired on rCPT performance including deficits in sensitivity (d') and increased false alarm rates (FARs). Sulpiride (0-30 mg/kg) dose-dependently reduced elevated FAR in MAM-E17 rats whereas low-dose modafinil (8 mg/kg) only improved d' in sham controls. ABT-594 (5.9-19.4 μg/kg) and modafinil (64 mg/kg) showed expected stimulant-like effects, while LSN2463359 (5 mg/kg), RO493858 (10 mg/kg), atomoxetine (0.3-1 mg/kg), and sulpiride (30 mg/kg) showed expected suppressant effects on performance across all animals. Donepezil (0.1-1 mg/kg) showed near-significant enhancements in d', and EVP-6124 (0.3-3 mg/kg) exerted no effects in the rCPT paradigm. CONCLUSION The MAM-E17 model exhibits robust and replicable impairments in rCPT performance that resemble attention and inhibitory control deficits seen in schizophrenia. Pharmacological profiles were highly consistent with known drug effects on cognition in preclinical and clinical studies. The rCPT is a sensitive and reliable tool with high translational potential for understanding the etiology and treatment of disorders affecting attention and executive dysfunction.
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Affiliation(s)
- Adam C Mar
- Neuroscience Institute, New York University Medical Center, New York, NY, 10016, USA.
- Department of Neuroscience and Physiology, New York University Medical Center, New York, NY, USA.
- Department of Psychology, University of Cambridge, Cambridge, UK.
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
| | - Simon R O Nilsson
- Neuroscience Institute, New York University Medical Center, New York, NY, 10016, USA
- Department of Neuroscience and Physiology, New York University Medical Center, New York, NY, USA
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Begoña Gamallo-Lana
- Neuroscience Institute, New York University Medical Center, New York, NY, 10016, USA
- Department of Neuroscience and Physiology, New York University Medical Center, New York, NY, USA
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Ming Lei
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Health Industry Management, Beijing International Studies University, 1 Dingfuzhuang Nanli, Beijing, China
| | - Theda Dourado
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
| | - Johan Alsiö
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Department of Neuroscience, Unit of Functional Neurobiology, University of Uppsala, Uppsala, Sweden
| | - Lisa M Saksida
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Molecular Medicine Research Group, Robarts Research Institute, Western University, London, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
- The Brain and Mind Institute, Western University, London, ON, Canada
| | - Timothy J Bussey
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
- Molecular Medicine Research Group, Robarts Research Institute, Western University, London, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
- The Brain and Mind Institute, Western University, London, ON, Canada
| | - Trevor W Robbins
- Department of Psychology, University of Cambridge, Cambridge, UK
- MRC and Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK
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Higgins GA, Silenieks LB. Rodent Test of Attention and Impulsivity: The 5-Choice Serial Reaction Time Task. ACTA ACUST UNITED AC 2017; 78:5.49.1-5.49.34. [PMID: 28892143 DOI: 10.1002/cpph.27] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The 5-choice serial reaction time task (5-CSRTT) is employed extensively to measure attention in rodents. The assay involves animals trained to respond to a brief, unpredictable visual stimulus presented in one of five locations. The effects of experimental manipulations on response speed and choice accuracy are measured, and each related to attentional performance. The 5-CSRTT is also used to measure motor impulsivity. Adapted from a human task, the 5-CSRTT can be employed with rodents or primates, highlighting its translational value. Another strength of this procedure is its adaptability to task modification. An example is the 5-choice continuous performance task, which has both target and non-target trial types. Overall, the 5-CSRTT has proven to be valuable for drug discovery efforts aimed at identifying new agents for the treatment of central nervous system disorders and for further understanding the neurobiological processes of attention and impulsivity. Its flexibility offers considerable scope to the experimenter, and in this respect the task continues to evolve. © 2017 by John Wiley & Sons, Inc.
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Affiliation(s)
- Guy A Higgins
- InterVivoSolutions Inc, Toronto, Ontario, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
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Shanmugasundaram B, Aher YD, Aradska J, Ilic M, Daba Feyissa D, Kalaba P, Aher NY, Dragacevic V, Saber Marouf B, Langer T, Sitte HH, Hoeger H, Lubec G, Korz V. R-Modafinil exerts weak effects on spatial memory acquisition and dentate gyrus synaptic plasticity. PLoS One 2017. [PMID: 28644892 PMCID: PMC5482457 DOI: 10.1371/journal.pone.0179675] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Modafinil is a wake promoting drug approved for clinical use and also has cognitive enhancing properties. Its enantiomer R-Modafinil (R-MO) is not well studied in regard to cognitive enhancing properties. Hence we studied its effect in a spatial memory paradigm and its possible effects on dentate gyrus long-term potentiation (DG-LTP). Clinically relevant doses of R-MO, vehicle dimethyl sulfoxide (DMSO) or saline were administered for three days during the hole-board test and in in vivo DG-LTP. Synaptic levels of dopamine receptors D1R, D2R, dopamine transporter (DAT), and its phosphorylated form (ph-DAT) in DG tissue 4 h after LTP induction were quantified by western blot analysis. Monoamine reuptake and release assays were performed by using transfected HEK-293 cells. Possible neurotoxic side effects on general behaviour were also studied. R-MO at both doses significantly enhanced spatial reference memory during the last training session and during memory retrieval compared to DMSO vehicle but not when compared to saline treated rats. Similarly, R-MO rescues DG-LTP from impairing effects of DMSO. DMSO reduced memory performance and LTP magnitude when compared to saline treated groups. The synaptic DR1 levels in R-MO groups were significantly decreased compared to DMSO group but were comparable with saline treated animals. We found no effect of R-MO in neurotoxicity tests. Thus, our results support the notion that LTP-like synaptic plasticity processes could be one of the factors contributing to the cognitive enhancing effects of spatial memory traces. D1R may play an important regulatory role in these processes.
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Affiliation(s)
| | - Yogesh D. Aher
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Jana Aradska
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
| | - Marija Ilic
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | | | - Predrag Kalaba
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Nilima Y. Aher
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Vladimir Dragacevic
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Babak Saber Marouf
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Harald H. Sitte
- Centre for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Vienna, Austria
- Center for Addiction Research and Science, Medical University Vienna, Vienna, Austria
| | - Harald Hoeger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Himberg, Austria
| | - Gert Lubec
- Neuroproteomics Laboratory, Science Park, Bratislava, Slowakia
- * E-mail: (GL); (VK)
| | - Volker Korz
- Department of Pediatrics, Medical University of Vienna, Vienna, Austria
- * E-mail: (GL); (VK)
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15
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Roschlau C, Votteler A, Hauber W. Stimulant drug effects on touchscreen automated paired-associates learning (PAL) in rats. ACTA ACUST UNITED AC 2016; 23:422-6. [PMID: 27421894 PMCID: PMC4947238 DOI: 10.1101/lm.040345.115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 05/09/2016] [Indexed: 11/25/2022]
Abstract
Here we tested in rats effects of the procognitive drugs modafinil and methylphenidate on post-acquisition performance in an object–location paired-associates learning (PAL) task. Modafinil (32; 64 mg/kg) was without effect, while higher (9 mg/kg) but not lower (4.5 mg/kg) doses of methylphenidate impaired PAL performance. Likewise, higher but not lower doses of amphetamine (0.4; 0.8 mg/kg) and MK-801 (0.08; 0.12 mg/kg) decreased PAL performance. Impaired PAL performance induced by methylphenidate, amphetamine, and MK801 most likely reflects compromised cognitive function, e.g., retrieval of learned paired associates. Our data suggest that stimulant drugs such as methylphenidate and modafinil might not facilitate performance in hippocampus-related cognitive tasks.
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Affiliation(s)
- Corinna Roschlau
- Department Animal Physiology, University of Stuttgart, D-70550 Stuttgart, Germany
| | - Angeline Votteler
- Department Animal Physiology, University of Stuttgart, D-70550 Stuttgart, Germany
| | - Wolfgang Hauber
- Department Animal Physiology, University of Stuttgart, D-70550 Stuttgart, Germany
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16
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Aher YD, Subramaniyan S, Shanmugasundaram B, Sase A, Saroja SR, Holy M, Höger H, Beryozkina T, Sitte HH, Leban JJ, Lubec G. A Novel Heterocyclic Compound CE-104 Enhances Spatial Working Memory in the Radial Arm Maze in Rats and Modulates the Dopaminergic System. Front Behav Neurosci 2016; 10:20. [PMID: 26941626 PMCID: PMC4761905 DOI: 10.3389/fnbeh.2016.00020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 02/01/2016] [Indexed: 12/13/2022] Open
Abstract
Various psychostimulants targeting monoamine neurotransmitter transporters (MATs) have been shown to rescue cognition in patients with neurological disorders and improve cognitive abilities in healthy subjects at low doses. Here, we examined the effects upon cognition of a chemically synthesized novel MAT inhibiting compound 2-(benzhydrylsulfinylmethyl)-4-methylthiazole (named as CE-104). The efficacy of CE-104 in blocking MAT [dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter] was determined using in vitro neurotransmitter uptake assay. The effect of the drug at low doses (1 and 10 mg/kg) on spatial memory was studied in male rats in the radial arm maze (RAM). Furthermore, the dopamine receptor and transporter complex levels of frontal cortex (FC) tissue of trained and untrained animals treated either with the drug or vehicle were quantified on blue native PAGE (BN-PAGE). The drug inhibited dopamine (IC50: 27.88 μM) and norepinephrine uptake (IC50: 160.40 μM), but had a negligible effect on SERT. In the RAM, both drug-dose groups improved spatial working memory during the performance phase of RAM as compared to vehicle. BN-PAGE Western blot quantification of dopamine receptor and transporter complexes revealed that D1, D2, D3, and DAT complexes were modulated due to training and by drug effects. The drug’s ability to block DAT and its influence on DAT and receptor complex levels in the FC is proposed as a possible mechanism for the observed learning and memory enhancement in the RAM.
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Affiliation(s)
- Yogesh D Aher
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | | | | | - Ajinkya Sase
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | | | - Marion Holy
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna Vienna, Austria
| | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna Himberg, Austria
| | | | - Harald H Sitte
- Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna Vienna, Austria
| | - Johann J Leban
- Department of Pediatrics, Medical University of Vienna Vienna, Austria
| | - Gert Lubec
- Department of Pharmaceutical Chemistry, University of Vienna Vienna, Austria
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17
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Modafinil as a cognitive enhancer of spatial working memory in rats. Physiol Behav 2015; 142:126-30. [DOI: 10.1016/j.physbeh.2015.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/01/2015] [Accepted: 02/02/2015] [Indexed: 11/19/2022]
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Abstract
The ability to focus one's attention on important environmental stimuli while ignoring irrelevant stimuli is fundamental to human cognition and intellectual function. Attention is inextricably linked to perception, learning and memory, and executive function; however, it is often impaired in a variety of neuropsychiatric disorders, including Alzheimer's disease, schizophrenia, depression, and attention deficit hyperactivity disorder (ADHD). Accordingly, attention is considered as an important therapeutic target in these disorders. The purpose of this chapter is to provide an overview of the most common behavioral paradigms of attention that have been used in animals (particularly rodents) and to review the literature where these tasks have been employed to elucidate neurobiological substrates of attention as well as to evaluate novel pharmacological agents for their potential as treatments for disorders of attention. These paradigms include two tasks of sustained attention that were developed as rodent analogues of the human Continuous Performance Task (CPT), the Five-Choice Serial Reaction Time Task (5-CSRTT) and the more recently introduced Five-Choice Continuous Performance Task (5C-CPT), and the Signal Detection Task (SDT) which was designed to emphasize temporal components of attention.
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Affiliation(s)
- Patrick M Callahan
- Department of Pharmacology and Toxicology, CB-3545, Georgia Regents University, 1120 Fifteenth Street, Augusta, GA, 30912-2450, USA
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Loomis S, McCarthy A, Baxter C, Kellett DO, Edgar DM, Tricklebank M, Gilmour G. Distinct pro-vigilant profile induced in rats by the mGluR5 potentiator LSN2814617. Psychopharmacology (Berl) 2015; 232:3977-89. [PMID: 25902875 PMCID: PMC4600478 DOI: 10.1007/s00213-015-3936-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/02/2015] [Indexed: 12/30/2022]
Abstract
While treatment options are available, excessive daytime sleepiness (EDS) remains a significant unmet medical need for many patients. Relatively little rodent behavioural pharmacology has been conducted in this context to assess potential pro-vigilant compounds for their ability to restore functional capacity following experimentally induced sleep loss. Male Wistar rats were prepared for electroencephalographic (EEG) recording and subject to 11 h of sleep restriction using a biofeedback-induced cage rotation protocol. A simple response latency task (SRLT) was used to behaviourally index sleep restriction and the effects of pro-vigilant compounds: modafinil, D-amphetamine, caffeine, and the mGlu5-positive allosteric modulator LSN2814617. Sleep restriction resulted in a consistent, quantified loss of non-rapid eye movement (NREM) and REM sleep that impaired SRLT performance in a manner suggestive of progressive task disengagement. In terms of EEG parameters, all compounds induced wakefulness. Amphetamine treatment further decreased SRLT performance capacity, whereas the other three compounds decreased omissions and allowed animals to re-engage in the task. Caffeine and modafinil also significantly increased premature responses during this period, an effect not observed for LSN2814617. While all compounds caused compensatory sleep responses, the magnitude of compensation observed for LSN2814617 was much smaller than would be predicted to result from the prolongation of wakefulness exhibited. Using simple response latencies to index performance, an mGlu5 PAM dramatically increased wakefulness and improved functional capacity of sleep-restricted animals, without eliciting a proportionate compensatory sleep response. This effect was qualitatively distinct from that of amphetamine, caffeine and modafinil.
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Affiliation(s)
- Sally Loomis
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Andrew McCarthy
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Christopher Baxter
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Daniel O. Kellett
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Dale M. Edgar
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Mark Tricklebank
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH England UK
| | - Gary Gilmour
- Lilly Research Laboratories, Eli Lilly & Co. Ltd, Erl Wood Manor, Sunninghill Road, Windlesham, Surrey, GU20 6PH, England, UK.
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20
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D'Amour-Horvat V, Leyton M. Impulsive actions and choices in laboratory animals and humans: effects of high vs. low dopamine states produced by systemic treatments given to neurologically intact subjects. Front Behav Neurosci 2014; 8:432. [PMID: 25566001 PMCID: PMC4274964 DOI: 10.3389/fnbeh.2014.00432] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/26/2014] [Indexed: 11/13/2022] Open
Abstract
Increases and decreases in dopamine (DA) transmission have both been suggested to influence reward-related impulse-control. The present literature review suggests that, in laboratory animals, the systemic administration of DA augmenters preferentially increases susceptibility to premature responding; with continued DA transmission, reward approach behaviors are sustained. Decreases in DA transmission, in comparison, diminish the appeal of distal and difficult to obtain rewards, thereby increasing susceptibility to temporal discounting and other forms of impulsive choice. The evidence available in humans is not incompatible with this model but is less extensive.
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Affiliation(s)
| | - Marco Leyton
- Department of Psychology, McGill University Montreal, QC, Canada ; Department of Psychiatry, McGill University Montreal, QC, Canada ; Center for Studies in Behavioral Neurobiology, Concordia University Montreal, QC, Canada
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Mohamed AD, Lewis CR. Modafinil increases the latency of response in the Hayling Sentence Completion Test in healthy volunteers: a randomised controlled trial. PLoS One 2014; 9:e110639. [PMID: 25391155 PMCID: PMC4229110 DOI: 10.1371/journal.pone.0110639] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 09/07/2014] [Indexed: 11/24/2022] Open
Abstract
Background Modafinil is a medication licensed for the treatment of narcolepsy. However, it has been reported that healthy individuals without wakefulness disorders are using modafinil off-label to enhance cognitive functioning. Although some studies have reported that modafinil improves cognitive task performance in healthy volunteers, numerous other studies have failed to detect cognitive enhancing effects of modafinil on several well-established neuropsychological tasks. Interestingly, several clinical and preclinical studies have found that improved cognitive task performance by modafinil is accompanied by slower response times. This observation raises the question as to whether this slowing of response time in healthy volunteers is a necessary and sufficient condition for cognitive enhancement with modafinil. The aim of the current experiment was to explore this question by investigating the effects of modafinil on the Hayling Sentence Completion Test (HSCT). Methodology Sixty-four healthy volunteers received either a single dose (200 mg) of modafinil (n = 32) or placebo (n = 32) in a randomized, double-blind, placebo-controlled, parallel group study in which the principal outcome measures were response latencies on the response initiation and response inhibition sections of the HSCT. Principal Findings Participants dosed with modafinil had significantly longer mean response latencies on the HSCT for both the response initiation and response inhibition compared to participants dosed with placebo. However, participants in both groups made a similar number of errors on each of these measures, indicating that modafinil did not enhance the accuracy of performance of the task relative to placebo. Conclusions This study demonstrated that administration of single 200 mg doses of modafinil to healthy individuals increased the latency of responses in the performance of the HSCT, a task that is highly sensitive to prefrontal executive function, without enhancing accuracy of performance. This finding may provide important clues to defining the limitations of modafinil as a putative cognitive enhancer. Trial Registration ClinicalTrials.gov NCT02051153
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Affiliation(s)
- Ahmed Dahir Mohamed
- Department of Psychiatry, School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
- The School of Psychology, Cognitive and Sensory Systems Group, Faculty of Science, University of Nottingham Malaysia Campus, Selangor, Malaysia
- Clare Hall College, Cambridge, United Kingdom
- * E-mail:
| | - Chris Roberts Lewis
- Department of Psychology, Towson University, 8000 York Road, Towson, Maryland, 21252-0001, United States of America
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Davis CM, DeCicco-Skinner KL, Roma PG, Hienz RD. Individual Differences in Attentional Deficits and Dopaminergic Protein Levels following Exposure to Proton Radiation. Radiat Res 2014; 181:258-71. [DOI: 10.1667/rr13359.1] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Grupe M, Grunnet M, Laursen B, Bastlund JF. Neuropharmacological modulation of the P3-like event-related potential in a rat two-tone auditory discrimination task with modafinil and NS9283, a positive allosteric modulator of α4β2 nAChRs. Neuropharmacology 2013; 79:444-55. [PMID: 24361451 DOI: 10.1016/j.neuropharm.2013.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/05/2013] [Accepted: 12/06/2013] [Indexed: 11/19/2022]
Abstract
The P300 (P3) event-related potential (ERP) is a neurophysiological signal believed to reflect cognitive processing of salient cues, and is thus used as a measure of attention and working memory. Additionally, P3 amplitude and latency is altered in neurological diseases and can be pharmacologically modulated. As P3-like ERPs can be recorded in rodents, it may serve as a potential translational biomarker of value for drug discovery. Here we investigated whether a positive allosteric modulator of α4β2 nicotinic acetylcholine receptors, NS9283, and the psychostimulant modafinil could modulate P3-like ERPs in healthy adult rats performing an auditory oddball discrimination task. ERPs were recorded with electroencephalography electrodes implanted into mediodorsal (MD) thalamus, medial prefrontal cortex, hippocampus and auditory cortex (AC). P3-like ERPs were detected in all brain regions, displaying larger amplitudes in target trials compared to non-target trials. Administration of modafinil (64 mg/kg) decreased P3-like ERP latency in MD thalamus and AC, whereas NS9283 augmented P3-like ERP amplitude in MD thalamus at 0.3 mg/kg and in AC at 3.0 mg/kg. Additionally, N1 pre-attention peak amplitude in MD thalamus was increased with 0.3 mg/kg NS9283. Neither of the compounds enhanced task performance. Rather, modafinil lowered correct rejections in non-target trials. In summary, our findings reveal pharmacological modulation of the rat P3-like ERP in cortical and subcortical regions by modafinil and NS9283. These findings encourage further exploration of the rat P3-like ERP in order to promote the understanding of its meaning within cognition, as well as its applicability as a translatable biomarker in drug development.
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Affiliation(s)
- Morten Grupe
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark; Synaptic Transmission 1, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
| | - Morten Grunnet
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark; Synaptic Transmission 1, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
| | - Bettina Laursen
- Synaptic Transmission 1, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark; Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Moelleparkvej 4, 9100 Aalborg, Denmark.
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Wood S, Sage JR, Shuman T, Anagnostaras SG. Psychostimulants and cognition: a continuum of behavioral and cognitive activation. Pharmacol Rev 2013; 66:193-221. [PMID: 24344115 PMCID: PMC3880463 DOI: 10.1124/pr.112.007054] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Psychostimulants such as cocaine have been used as performance enhancers throughout recorded history. Although psychostimulants are commonly prescribed to improve attention and cognition, a great deal of literature has described their ability to induce cognitive deficits, as well as addiction. How can a single drug class be known to produce both cognitive enhancement and impairment? Properties of the particular stimulant drug itself and individual differences between users have both been suggested to dictate the outcome of stimulant use. A more parsimonious alternative, which we endorse, is that dose is the critical determining factor in cognitive effects of stimulant drugs. Herein, we review several popular stimulants (cocaine, amphetamine, methylphenidate, modafinil, and caffeine), outlining their history of use, mechanism of action, and use and abuse today. One common graphic depiction of the cognitive effects of psychostimulants is an inverted U-shaped dose-effect curve. Moderate arousal is beneficial to cognition, whereas too much activation leads to cognitive impairment. In parallel to this schematic, we propose a continuum of psychostimulant activation that covers the transition from one drug effect to another as stimulant intake is increased. Low doses of stimulants effect increased arousal, attention, and cognitive enhancement; moderate doses can lead to feelings of euphoria and power, as well as addiction and cognitive impairment; and very high doses lead to psychosis and circulatory collapse. This continuum helps account for the seemingly disparate effects of stimulant drugs, with the same drug being associated with cognitive enhancement and impairment.
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Affiliation(s)
- Suzanne Wood
- 9500 Gilman Dr MC 0109, La Jolla, CA 92093-0109.
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Mereu M, Bonci A, Newman AH, Tanda G. The neurobiology of modafinil as an enhancer of cognitive performance and a potential treatment for substance use disorders. Psychopharmacology (Berl) 2013; 229:415-34. [PMID: 23934211 PMCID: PMC3800148 DOI: 10.1007/s00213-013-3232-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/28/2013] [Indexed: 12/31/2022]
Abstract
RATIONALE AND OBJECTIVES Modafinil (MOD) and its R-enantiomer (R-MOD) are approved medications for narcolepsy and other sleep disorders. They have also been used, off-label, as cognitive enhancers in populations of patients with mental disorders, including substance abusers that demonstrate impaired cognitive function. A debated nonmedical use of MOD in healthy individuals to improve intellectual performance is raising questions about its potential abuse liability in this population. RESULTS AND CONCLUSIONS MOD has low micromolar affinity for the dopamine transporter (DAT). Inhibition of dopamine (DA) reuptake via the DAT explains the enhancement of DA levels in several brain areas, an effect shared with psychostimulants like cocaine, methylphenidate, and the amphetamines. However, its neurochemical effects and anatomical pattern of brain area activation differ from typical psychostimulants and are consistent with its beneficial effects on cognitive performance processes such as attention, learning, and memory. At variance with typical psychostimulants, MOD shows very low, if any, abuse liability, in spite of its use as a cognitive enhancer by otherwise healthy individuals. Finally, recent clinical studies have focused on the potential use of MOD as a medication for treatment of drug abuse, but have not shown consistent outcomes. However, positive trends in several result measures suggest that medications that improve cognitive function, like MOD or R-MOD, may be beneficial for the treatment of substance use disorders in certain patient populations.
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Affiliation(s)
- Maddalena Mereu
- Molecular Targets & Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, DHHS; 251 Bayview Blvd., NIDA suite 200, Baltimore, MD, 21224
| | - Antonello Bonci
- Synaptic Plasticity Section, Cellular Neurobiology Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, DHHS; 251 Bayview Blvd., NIDA suite 200, Baltimore, MD, 21224
| | - Amy Hauck Newman
- Molecular Targets & Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, DHHS; 251 Bayview Blvd., NIDA suite 200, Baltimore, MD, 21224
| | - Gianluigi Tanda
- Molecular Targets & Medication Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, DHHS; 251 Bayview Blvd., NIDA suite 200, Baltimore, MD, 21224
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Geng JJ, Soosman S, Sun Y, DiQuattro NE, Stankevitch B, Minzenberg MJ. A Match Made by Modafinil: Probability Matching in Choice Decisions and Spatial Attention. J Cogn Neurosci 2013. [DOI: 10.1162/jocn_a_00333] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
When predicting where a target or reward will be, participants tend to choose each location commensurate with the true underlying probability (i.e., probability match). The strategy of probability matching involves independent sampling of high and low probability locations on separate trials. In contrast, models of probabilistic spatial attention hypothesize that on any given trial attention will either be weighted toward the high probability location or be distributed equally across all locations. Thus, the strategies of probabilistic sampling by choice decisions and spatial attention appear to differ with regard to low-probability events. This distinction is somewhat surprising because similar brain mechanisms (e.g., pFC-mediated cognitive control) are thought to be important in both functions. Thus, the goal of the current study was to examine the relationship between choice decisions and attentional selection within single trials to test for any strategic differences, then to determine whether that relationship is malleable to manipulations of catecholamine-modulated cognitive control with the drug modafinil. Our results demonstrate that spatial attention and choice decisions followed different strategies of probabilistic information selection on placebo, but that modafinil brought the pattern of spatial attention into alignment with that of predictive choices. Modafinil also produced earlier learning of the probability distribution. Together, these results suggest that enhancing cognitive control mechanisms (e.g., through prefrontal cortical function) leads spatial attention to follow choice decisions in selecting information according to rule-based expectations.
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van Enkhuizen J, Geyer MA, Young JW. Differential effects of dopamine transporter inhibitors in the rodent Iowa gambling task: relevance to mania. Psychopharmacology (Berl) 2013; 225:661-74. [PMID: 22945515 PMCID: PMC3537839 DOI: 10.1007/s00213-012-2854-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 08/17/2012] [Indexed: 01/05/2023]
Abstract
RATIONALE The Iowa Gambling Task (IGT) can be used to quantify impulsive and risky choice behaviors in psychiatric patients, e.g., bipolar disorder (BD) sufferers. Although developing treatments for these behaviors is important, few predictive animal models exist. Inhibition of the dopamine transporter (DAT) can model profiles of altered motor activity and exploration seen in patients with BD. The effect of DAT inhibition on impulsive choices related to BD has received limited study however. We used a rodent IGT to elucidate the effects of similarly acting drugs on risky choice behavior. OBJECTIVES We hypothesized that (1) C57BL/6 mice could adopt the "safe" choice options in the IGT and (2) DAT inhibition would alter risk preference. METHODS Mice were trained in the IGT to a stable risk-preference and then administered the norepinephrine/DAT inhibitor amphetamine, or the more selective DAT inhibitors modafinil or GBR12909. RESULTS Mice developed a preference for the "safe" option, which was potentiated by amphetamine administration. GBR12909 or modafinil administration increased motor impulsivity, motivation significantly, and risk preference subtly. CONCLUSIONS The rodent IGT can measure different impulse-related behaviors and differentiate similarly acting BD-related drugs. The contrasting effects of amphetamine and modafinil in mice are similar to effects in rats and humans in corresponding IGT tasks, supporting the translational validity of the task. GBR12909 and modafinil elicited similar behaviors in the IGT, likely through a shared mechanism. Future studies using a within-session IGT are warranted to confirm the suitability of DAT inhibitors to model risk-preference in BD.
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Affiliation(s)
- Jordy van Enkhuizen
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
| | - Mark A. Geyer
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804
- Research Service, VA San Diego Healthcare System, San Diego, CA
| | - Jared W. Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804
- Research Service, VA San Diego Healthcare System, San Diego, CA
- Correspondence: Jared W. Young, Ph.D., Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, California, 92093-0804, Tel: +1 619 543 3582, Fax: +1 619 735 9205,
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Dawson N, Xiao X, McDonald M, Higham DJ, Morris BJ, Pratt JA. Sustained NMDA receptor hypofunction induces compromised neural systems integration and schizophrenia-like alterations in functional brain networks. ACTA ACUST UNITED AC 2012; 24:452-64. [PMID: 23081884 DOI: 10.1093/cercor/bhs322] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Compromised functional integration between cerebral subsystems and dysfunctional brain network organization may underlie the neurocognitive deficits seen in psychiatric disorders. Applying topological measures from network science to brain imaging data allows the quantification of complex brain network connectivity. While this approach has recently been used to further elucidate the nature of brain dysfunction in schizophrenia, the value of applying this approach in preclinical models of psychiatric disease has not been recognized. For the first time, we apply both established and recently derived algorithms from network science (graph theory) to functional brain imaging data from rats treated subchronically with the N-methyl-D-aspartic acid (NMDA) receptor antagonist phencyclidine (PCP). We show that subchronic PCP treatment induces alterations in the global properties of functional brain networks akin to those reported in schizophrenia. Furthermore, we show that subchronic PCP treatment induces compromised functional integration between distributed neural systems, including between the prefrontal cortex and hippocampus, that have established roles in cognition through, in part, the promotion of thalamic dysconnectivity. We also show that subchronic PCP treatment promotes the functional disintegration of discrete cerebral subsystems and also alters the connectivity of neurotransmitter systems strongly implicated in schizophrenia. Therefore, we propose that sustained NMDA receptor hypofunction contributes to the pathophysiology of dysfunctional brain network organization in schizophrenia.
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Affiliation(s)
- Neil Dawson
- Psychiatric Research Institute of Neuroscience in Glasgow (PsyRING), Glasgow, UK
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Fernandes HA, Zanin KA, Patti CL, Wuo-Silva R, Carvalho RC, Fernandes-Santos L, Bittencourt LRA, Tufik S, Frussa-Filho R. Inhibitory effects of modafinil on emotional memory in mice. Neuropharmacology 2012; 64:365-70. [PMID: 22771974 DOI: 10.1016/j.neuropharm.2012.06.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/05/2012] [Accepted: 06/27/2012] [Indexed: 11/30/2022]
Abstract
Modafinil (MOD), a psychostimulant used to treat narcolepsy, excessive daytime sleepiness, and sleepiness due to obstructive sleep apnea, appears to promote a possible facilitatory effect on cognitive function. In the present study, we investigated the effects of the acute administration of MOD on the different steps of emotional memory formation and usage (acquisition, consolidation and retrieval) as well as the possible participation of the state-dependency phenomenon on the cognitive effects of this compound. Mice were acutely treated with 32, 64 or 128 mg/kg MOD before training or testing or immediately after training and were subjected to the plus-maze discriminative avoidance task. The results showed that although pre-training MOD administration did not exert any effects on learning, the doses of 32 or 64 mg/kg induced emotional memory deficits during testing. Still, the post-training acute administration of the higher doses of MOD (64 and 128 mg/kg) impaired associative memory consolidation. When the drug was administered pre-test, only the 32 mg/kg dose impaired the task retrieval. Importantly, the cognitive impairing effects induced by 32 mg/kg MOD were not related to the phenomenon of state-dependency. In all, our findings provide pre-clinical evidence of potential emotional memory amnesia induced by MOD. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Helaine A Fernandes
- Departamento de Psicobiologia, Universidade Federal de São Paulo, R. Napoleão de Barros 925, São Paulo, SP, Brazil
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Redrobe JP, Elster L, Frederiksen K, Bundgaard C, de Jong IEM, Smith GP, Bruun AT, Larsen PH, Didriksen M. Negative modulation of GABAA α5 receptors by RO4938581 attenuates discrete sub-chronic and early postnatal phencyclidine (PCP)-induced cognitive deficits in rats. Psychopharmacology (Berl) 2012; 221:451-68. [PMID: 22124672 DOI: 10.1007/s00213-011-2593-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 11/15/2011] [Indexed: 11/29/2022]
Abstract
RATIONALE A growing body of evidence suggests that negative modulation of γ-aminobutyric acid (GABA) GABA(A) α5 receptors may be a promising strategy for the treatment of certain facets of cognitive impairment; however, selective modulators of GABA(A) α5 receptors have not yet been tested in "schizophrenia-relevant" cognitive assay/model systems in animals. OBJECTIVES The objectives of this study were to investigate the potential of RO4938581, a negative modulator of GABA(A) α5 receptors, and to attenuate cognitive impairments induced following sub-chronic (sub-PCP) and early postnatal PCP (neo-PCP) administration in the novel object recognition (NOR) and intra-extradimensional shift (ID/ED) paradigms in rats. Complementary in vitro, ex vivo and in vivo studies were performed to confirm negative modulatory activity of RO4938581 and to investigate animal model validity, concept validity and potential side effect issues, respectively. RESULTS In vitro studies confirmed the reported negative modulatory activity of RO4938581, whilst immunohistochemical analyses revealed significantly reduced parvalbumin-positive cells in the prefrontal cortex of sub-PCP- and neo-PCP-treated rats. RO4938581 (1 mg/kg) ameliorated both sub-PCP- and neo-PCP-induced cognitive deficits in NOR and ID/ED performance, respectively. In contrast, QH-II-066 (1 and 3 mg/kg), a GABA(A) α5 receptor positive modulator, impaired cognitive performance in the NOR task when administered to vehicle-treated animals. Additional studies revealed that both RO4938581 (1 mg/kg) and QH-II-066 (1 and 3 mg/kg) attenuated amphetamine-induced hyperactivity in rats. CONCLUSIONS Taken together, these novel findings suggest that negative modulation of GABA(A) α5 receptors may represent an attractive treatment option for the cognitive impairments, and potentially positive symptoms, associated with schizophrenia.
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Affiliation(s)
- John P Redrobe
- Synaptic Transmission I, Neuroscience Research DK, H Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
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Dawson N, Thompson RJ, McVie A, Thomson DM, Morris BJ, Pratt JA. Modafinil reverses phencyclidine-induced deficits in cognitive flexibility, cerebral metabolism, and functional brain connectivity. Schizophr Bull 2012; 38:457-74. [PMID: 20810469 PMCID: PMC3329989 DOI: 10.1093/schbul/sbq090] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE In the present study, we employ mathematical modeling (partial least squares regression, PLSR) to elucidate the functional connectivity signatures of discrete brain regions in order to identify the functional networks subserving PCP-induced disruption of distinct cognitive functions and their restoration by the procognitive drug modafinil. METHODS We examine the functional connectivity signatures of discrete brain regions that show overt alterations in metabolism, as measured by semiquantitative 2-deoxyglucose autoradiography, in an animal model (subchronic phencyclidine [PCP] treatment), which shows cognitive inflexibility with relevance to the cognitive deficits seen in schizophrenia. RESULTS We identify the specific components of functional connectivity that contribute to the rescue of this cognitive inflexibility and to the restoration of overt cerebral metabolism by modafinil. We demonstrate that modafinil reversed both the PCP-induced deficit in the ability to switch attentional set and the PCP-induced hypometabolism in the prefrontal (anterior prelimbic) and retrosplenial cortices. Furthermore, modafinil selectively enhanced metabolism in the medial prelimbic cortex. The functional connectivity signatures of these regions identified a unifying functional subsystem underlying the influence of modafinil on cerebral metabolism and cognitive flexibility that included the nucleus accumbens core and locus coeruleus. In addition, these functional connectivity signatures identified coupling events specific to each brain region, which relate to known anatomical connectivity. CONCLUSIONS These data support clinical evidence that modafinil may alleviate cognitive deficits in schizophrenia and also demonstrate the benefit of applying PLSR modeling to characterize functional brain networks in translational models relevant to central nervous system dysfunction.
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Affiliation(s)
- Neil Dawson
- Psychiatric Research Institute of Neuroscience in Glasgow (PsyRING), University of Glasgow, G12 8QQ, UK.
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Winstanley CA. The utility of rat models of impulsivity in developing pharmacotherapies for impulse control disorders. Br J Pharmacol 2012; 164:1301-21. [PMID: 21410459 DOI: 10.1111/j.1476-5381.2011.01323.x] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
High levels of impulsive behaviours are a clinically significant symptom in a range of psychiatric disorders, such as attention deficit hyperactivity disorder, bipolar disorder, personality disorders, pathological gambling and substance abuse. Although often measured using questionnaire assessments, levels of different types of impulsivity can also be determined using behavioural tests. Rodent analogues of these paradigms have been developed, and similar neural circuitry has been implicated in their performance in both humans and rats. In the current review, the methodology underlying the measurement of different aspects of impulsive action and choice are considered from the viewpoint of drug development, with a focus on the continuous performance task (CPT), stop-signal task (SST), go/no-go and delay-discounting paradigms. Current issues impeding translation between animal and human studies are identified, and comparisons drawn between the acute effects of dopaminergic, noradrenergic and serotonergic compounds across species. Although the field could benefit from a more systematic determination of different pharmacological agents across paradigms, there are signs of strong concordance between the animal and human data. However, the type of impulsivity measured appears to play a significant role, with the SST and delay discounting providing more consistent effects for dopaminergic drugs, while the CPT and SST show better predictive validity so far for serotonergic and noradrenergic compounds. Based on the available data, it would appear that these impulsivity models could be used more widely to identify potential pharmacotherapies for impulse control disorders. Novel targets within the glutamatergic and serotonergic system are also suggested.
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Lynch G, Palmer LC, Gall CM. The likelihood of cognitive enhancement. Pharmacol Biochem Behav 2011; 99:116-29. [PMID: 21215768 PMCID: PMC3114293 DOI: 10.1016/j.pbb.2010.12.024] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/10/2010] [Accepted: 12/16/2010] [Indexed: 12/29/2022]
Abstract
Whether drugs that enhance cognition in healthy individuals will appear in the near future has become a topic of considerable interest. We address this possibility using a three variable system (psychological effect, neurobiological mechanism, and efficiency vs. capabilities) for classifying candidates. Ritalin and modafinil, two currently available compounds, operate on primary psychological states that in turn affect cognitive operations (attention and memory), but there is little evidence that these effects translate into improvements in complex cognitive processing. A second category of potential enhancers includes agents that improve memory encoding, generally without large changes in primary psychological states. Unfortunately, there is little information on how these compounds affect cognitive performance in standard psychological tests. Recent experiments have identified a number of sites at which memory drugs could, in principle, manipulate the cell biological systems underlying the learning-related long-term potentiation (LTP) effect; this may explain the remarkable diversity of memory promoting compounds. Indeed, many of these agents are known to have positive effects on LTP. A possible third category of enhancement drugs directed specifically at integrated cognitive operations is nearly empty. From a neurobiological perspective, two plausible candidate classes have emerged that both target the fast excitatory transmission responsible for communication within cortical networks. One acts on nicotinic receptors (alpha7 and alpha4) that regulate release of the neurotransmitter glutamate while the other ('ampakines') allosterically modulates the glutamate receptors mediating the post-synaptic response (EPSCs). Brain imaging in primates has shown that ampakines expand cortical networks engaged by a complex task; coupled with behavioral data, these findings provide evidence for the possibility of generating new cognitive capabilities. Finally, we suggest that continuing advances in behavioral sciences provide new opportunities for translational work, and that discussions of the social impact of cognitive enhancers have failed to consider the distinction between effects on efficiency vs. new capabilities.
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Affiliation(s)
- Gary Lynch
- Department of Psychiatry and Human Behavior, University of California, Irvine CA 92697-4291, USA.
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Bobo WV, Woodward ND, Sim MY, Jayathilake K, Meltzer HY. The effect of adjunctive armodafinil on cognitive performance and psychopathology in antipsychotic-treated patients with schizophrenia/schizoaffective disorder: a randomized, double-blind, placebo-controlled trial. Schizophr Res 2011; 130:106-13. [PMID: 21641776 DOI: 10.1016/j.schres.2011.05.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/17/2011] [Accepted: 05/19/2011] [Indexed: 11/25/2022]
Abstract
BACKGROUND The efficacy, safety and tolerability of adjunctive armodafinil for cognitive performance, and negative and affective symptoms, were examined in 60 patients with schizophrenia or schizoaffective disorder. METHOD This was a 6-week, double-blind, placebo-controlled, fixed dose trial of armodafinil (150 mg/d) augmentation in patients with clinically stable schizophrenia or schizoaffective disorder. Cognition, psychopathology, alertness/wakefulness and adverse effects were assessed with standardized rating instruments. The primary endpoint was performance on measures of attention/vigilance. RESULTS Patients were randomly allocated to adjunctive armodafinil or placebo. There was a significant Drug×Time interaction effect for attention/vigilance, due to modest non-significant worsening in the armodafinil group and improvement in the armodafinil group [CPT-Pairs d', F(1,40)=6.2, p=0.017]. However, it became non-significant after correction for multiple comparisons. There were no differences between armodafinil and placebo in other cognitive domains or psychopathology measures. However, armodafinil was associated with significant improvement in the Scale for the Assessment of Negative Symptoms (SANS) anhedonia-asociality [F(1,41)=4.1, p=0.05]. CONCLUSIONS There were no significant differences in neurocognitive measures between adjunctive armodafinil and placebo in this 6-week study. Armodafinil improved anhedonia-asociality, but not other negative symptom domains.
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Affiliation(s)
- William V Bobo
- Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA.
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Mouse pharmacological models of cognitive disruption relevant to schizophrenia. Neuropharmacology 2011; 62:1381-90. [PMID: 21726569 DOI: 10.1016/j.neuropharm.2011.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 06/14/2011] [Accepted: 06/17/2011] [Indexed: 01/25/2023]
Abstract
Schizophrenia is a debilitating cognitive disorder. The link between cognitive debilitation and functional outcome in patients with schizophrenia has prompted research to develop procognitive therapies. It is hoped that by improving cognition in these patients, their functional outcome will also improve. Although no established treatments exist as yet, progress has been made toward understanding how to evaluate putative compounds in the clinic. Genetic mouse models and pharmacological rat models of cognitive disruption are being developed that may help to evaluate these putative compounds preclinically. Considering the increased number of genetic mouse models relevant to schizophrenia, there is a need to evaluate pharmacological manipulations on cognition in mice. Here we review the current literature on mouse pharmacological models relevant to schizophrenia. In this review, we discuss where different pharmacological effects between rats and mice on cognitive tasks are observed and assess the validity offered by these models. We conclude that the predictive validity of these models is currently difficult to assess and that much more needs to be done to develop useful mouse pharmacological models of cognitive disruption in schizophrenia.
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Wake-promoting agent modafinil worsened attentional performance following REM sleep deprivation in a young-adult rat model of 5-choice serial reaction time task. Psychopharmacology (Berl) 2011; 213:155-66. [PMID: 20865249 DOI: 10.1007/s00213-010-2019-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 09/07/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE Individuals who experience sleep loss may exhibit certain physiological abnormalities. Central stimulant drugs have been studied in sleep-loss conditions, and some of them might be therapeutically beneficial. Modafinil (diphenyl-methyl-sulfinyl-2-acetamide, MOD) has been increasingly employed for elevating alertness and vigilance in recent years, yet the underlying mechanism of actions for MOD is not fully understood. OBJECTIVES To examine the behavioral effect of MOD following rapid eye movement sleep deprivation (REMD) in rats. A five-choice serial reaction time task (5-CSRTT) was employed to investigate animals' attentional performance and impulsive reactivity. MATERIALS AND METHODS Rats of different ages were trained to learn the 5-CSRTT. REMD with the water platform method was applied for 96 h. The impacts of REMD on 5-CSRTT in middle-age (32-weeks-old) and young-adult (12-week-old) rats were compared with baseline or a condition with shorter visual stimulus duration. RESULTS The results revealed that following REMD, young-adult but not middle-age rats were liable to be affected in their performances of the 5-CSRTT. In young-adult rats, while MOD had no contributions to the effect of REMD, it worsened rats' performance following REMD when the stimulus duration was shortened, as shown by the reduced number of correct responses and prolonged magazine latency. CONCLUSIONS These results suggest that aging might be a crucial factor for the physiological impact following REMD. MOD should be used cautiously, particularly, in conditions that require REM sleep.
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Floresco SB, Jentsch JD. Pharmacological enhancement of memory and executive functioning in laboratory animals. Neuropsychopharmacology 2011; 36:227-50. [PMID: 20844477 PMCID: PMC3055518 DOI: 10.1038/npp.2010.158] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Investigating how different pharmacological compounds may enhance learning, memory, and higher-order cognitive functions in laboratory animals is the first critical step toward the development of cognitive enhancers that may be used to ameliorate impairments in these functions in patients suffering from neuropsychiatric disorders. Rather than focus on one aspect of cognition, or class of drug, in this review we provide a broad overview of how distinct classes of pharmacological compounds may enhance different types of memory and executive functioning, particularly those mediated by the prefrontal cortex. These include recognition memory, attention, working memory, and different components of behavioral flexibility. A key emphasis is placed on comparing and contrasting the effects of certain drugs on different cognitive and mnemonic functions, highlighting methodological issues associated with this type of research, tasks used to investigate these functions, and avenues for future research. Viewed collectively, studies of the neuropharmacological basis of cognition in rodents and non-human primates have identified targets that will hopefully open new avenues for the treatment of cognitive disabilities in persons affected by mental disorders.
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Affiliation(s)
- Stan B Floresco
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
| | - James D Jentsch
- Departments of Psychology and Psychiatry & Bio-behavioral Sciences, University of California, Los Angeles, CA, USA
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Pierard C, Liscia P, Chauveau F, Coutan M, Corio M, Krazem A, Beracochea D. Differential effects of total sleep deprivation on contextual and spatial memory: Modulatory effects of modafinil. Pharmacol Biochem Behav 2011; 97:399-405. [DOI: 10.1016/j.pbb.2010.09.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/21/2010] [Accepted: 09/21/2010] [Indexed: 10/19/2022]
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Liu YP, Tung CS, Chuang CH, Lo SM, Ku YC. Tail-pinch stress and REM sleep deprivation differentially affect sensorimotor gating function in modafinil-treated rats. Behav Brain Res 2010; 219:98-104. [PMID: 21167213 DOI: 10.1016/j.bbr.2010.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/04/2010] [Accepted: 12/08/2010] [Indexed: 10/18/2022]
Abstract
Prepulse inhibition (PPI) is a phenomenon in which a mild stimulus attenuates a cross-modality startle response to later intense stimulation. PPI is thought to index the central inhibitory mechanism through which behavioural responses are filtered. The present study compared the effects of two stress paradigms on the acoustic startle response (ASR) and on PPI in a rat model. The tail-pinch (TP) method produces an acute and immediate stressful condition, whereas rapid eye movement (REM) sleep deprivation (REMSD) leads to a more persistent and long-term stress. Our results demonstrated that in rats, TP stress reduced the size of the ASR, and REMSD impaired PPI. The wake-promoting agent modafinil (MOD) had no effect on PPI if given alone. However, MOD reduced the ASR and PPI under TP stress, whereas only PPI was reduced by MOD after 96 h of REMSD. These results suggest that distinct stress paradigms differentially mediated sensorimotor gating abilities in terms of either responsiveness to the stimulus or information-filtering capabilities.
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Affiliation(s)
- Yia-Ping Liu
- Department of Physiology and Biophysics, National Defence Medical Centre, Taipei, Taiwan, ROC.
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Goetghebeur PJD, Lerdrup L, Sylvest A, Dias R. Erythropoietin reverses the attentional set-shifting impairment in a rodent schizophrenia disease-like model. Psychopharmacology (Berl) 2010; 212:635-42. [PMID: 20734030 DOI: 10.1007/s00213-010-1990-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 08/04/2010] [Indexed: 12/11/2022]
Abstract
RATIONALE Executive function impairment, as classically assessed using the Wisconsin Card Sort Test or intradimensional/extradimensional tests, is a key feature of schizophrenia but remains inadequately treated by existing therapies. Recently, however, erythropoietin has been shown to improve attentional set-shifting performance in schizophrenic patients. OBJECTIVE The present study utilized the rat intradimensional/extradimensional task to investigate the potential of erythropoietin to reverse a phencyclidine-induced extradimensional shift impairment when given alone or in combination with subchronic haloperidol treatment. METHODS Rats were subjected to a subchronic systemic administration (7 days, b.i.d) of either saline vehicle or phencyclidine (5 mg/kg) followed by a 7-day washout period during which haloperidol was given. Subsequently, rats were trained to dig in baited bowls for a food reward and to discriminate on the basis of digging media or bowl odor. In experiment 1, rats performed a series of discriminations following acute administration of vehicle, erythropoietin, or modafinil. In a second experiment, rats receiving either haloperidol in the drinking water or just normal drinking water were run in the attentional set-shifting task after acute administration of erythropoietin (1,000 or 10,000 IU/ml i.p., selected from experiment 1). RESULTS The subchronic phencyclidine-induced extradimensional deficit was ameliorated by both erythropoietin and modafinil. When combined with subchronic haloperidol, the higher dose of erythropoietin tested was able to reverse the extradimensional shift impairment. CONCLUSIONS Overall, these findings further support the use of erythropoietin as an adjunct to antipsychotic therapy in order to address, at least part of, the cognitive dysfunction associated with schizophrenia.
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Burgos H, Castillo A, Flores O, Puentes G, Morgan C, Gatica A, Cofré C, Hernández A, Laurido C, Constandil L. Effect of modafinil on learning performance and neocortical long-term potentiation in rats. Brain Res Bull 2010; 83:238-44. [PMID: 20800665 DOI: 10.1016/j.brainresbull.2010.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 08/16/2010] [Accepted: 08/18/2010] [Indexed: 11/19/2022]
Abstract
Modafinil is a novel wake-promoting agent whose effects on cognitive performance have begun to be addressed at both preclinical and clinical level. The present study was designed to investigate in rats the effects of chronic modafinil administration on cognitive performance by evaluating: (i) working and reference memories in an Olton 4×4 maze, and (ii) learning of a complex operant conditioning task in a Skinner box. In addition, the effect of modafinil on the ability of the rat frontal cortex to develop long-term potentiation (LTP) was also studied. Chronic modafinil did not significantly modify working memory errors but decreased long-term memory errors on the Olton 4×4 maze, meaning that the drug may have a favourable profile on performance of visuo-spatial tasks (typically, a hippocampus-dependent task) when chronically administered. On the other hand, chronic modafinil resulted in a marked decrease of successful responses in a complex operant conditioning learning, which means that repeated administration of the drug influences negatively problem-solving abilities when confronting the rat to a sequencing task (typically, a prefrontal cortex-dependent task). In addition, in vivo electrophysiology showed that modafinil resulted in impaired capacity of the rat prefrontal cortex to develop LTP following tetanization. It is concluded that modafinil can improve the performance of spatial tasks that depend almost exclusively on hippocampal functioning, but not the performance in tasks including a temporal factor where the prefrontal cortex plays an important role. The fact that modafinil together with preventing operant conditioning learning was also able to block LTP induction in the prefrontal cortex, suggests that the drug could interfere some critical component required for LTP can be developed, thereby altering neuroplastic capabilities of the prefrontal cortex.
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Moreira KM, Ferreira TL, Hipolide DC, Fornari RV, Tufik S, Oliveira MGM. Modafinil prevents inhibitory avoidance memory deficit induced by sleep deprivation in rats. Sleep 2010; 33:990-3. [PMID: 20614860 DOI: 10.1093/sleep/33.7.990] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
STUDY OBJECTIVES Evaluation of modafinil effects on the inhibitory avoidance task (IA). DESIGN Rats were trained on a multiple trial IA task after receiving modafinil or vehicle injections. In experiment 1 they were trained with a weak protocol under baseline condition and in experiment 2, with a stronger protocol under sleep-deprivation condition. RESULTS In experiment 1 modafinil improved rats' acquisition whereas the retention test remained unaffected. In Experiment 2 modafinil did not interfere with training performance, but the lower dose prevented the retention impairment in sleep-deprived animals. CONCLUSIONS Modafinil is able to improve acquisition in normal rats and reverse the long-term memory impairment induced by sleep-deprivation.
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Tsanov M, Lyons DG, Barlow S, González Reyes RE, O’Mara SM. The psychostimulant modafinil facilitates water maze performance and augments synaptic potentiation in dentate gyrus. Neuropharmacology 2010; 59:9-19. [DOI: 10.1016/j.neuropharm.2010.03.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 02/16/2010] [Accepted: 03/19/2010] [Indexed: 10/19/2022]
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Marson L, Yu G, Farber NM. The Effects of Oral Administration of D-Modafinil on Male Rat Ejaculatory Behavior. J Sex Med 2010; 7:70-8. [DOI: 10.1111/j.1743-6109.2009.01509.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Redrobe JP, Bull S, Plath N. Translational Aspects of the Novel Object Recognition Task in Rats Abstinent Following Sub-Chronic Treatment with Phencyclidine (PCP): Effects of Modafinil and Relevance to Cognitive Deficits in Schizophrenia. Front Psychiatry 2010; 1:146. [PMID: 21423454 PMCID: PMC3059635 DOI: 10.3389/fpsyt.2010.00146] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 10/15/2010] [Indexed: 11/23/2022] Open
Abstract
Phencyclidine (PCP) induces a behavioral syndrome in rodents that bears remarkable similarities to some of the core symptoms observed in schizophrenic patients, among those cognitive deficits. The successful alleviation of cognitive impairments associated with schizophrenia (CIAS) has become a major focus of research efforts as they remain largely untreated. The aim of the present study was to investigate the effects of selected antipsychotic and cognition enhancing drugs, namely haloperidol, risperidone, donepezil, and modafinil in an animal model widely used in preclinical schizophrenia research. To this end, the novel object recognition (NOR) task was applied to rats abstinent following sub-chronic treatment with PCP. Rats were administered either PCP (5 mg/kg, i.p.) or vehicle twice a day for 7 days, followed by a 7-day washout period, before testing in NOR. Upon testing, vehicle-treated rats successfully discriminated between novel and familiar objects, an effect abolished in rats that had previously been exposed to PCP treatment. Acute treatment with modafinil (64 mg/kg, p.o.) ameliorated the PCP-induced deficit in novel object exploration, whereas haloperidol (0.1 mg/kg, s.c.), risperidone (0.2 mg/kg, i.p.), and donepezil (3 mg/kg, p.o.) were without significant effect. Given the negligible efficacy of haloperidol and risperidone, and the contradictory data with donepezil to treat CIAS in the clinic, together with the promising preliminary pro-cognitive effects of modafinil in certain subsets of schizophrenic patients, the sub-chronic PCP-NOR abstinence paradigm may represent an attractive option for the identification of potential novel treatments for CIAS.
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Abstract
Schizophrenia may well represent one of the most heterogenous mental disorders in human history. This heterogeneity encompasses (1) etiology; where numerous putative genetic and environmental factors may contribute to disease manifestation, (2) symptomatology; with symptoms characterized by group; positive--behaviors not normally present in healthy subjects (e.g. hallucinations), negative--reduced expression of normal behaviors (e.g. reduced joy), and cognitive--reduced cognitive capabilities separable from negative symptoms (e.g. impaired attention), and (3) individual response variation to treatment. The complexity of this uniquely human disorder has complicated the development of suitable animal models with which to assay putative therapeutics. Moreover, the development of animal models is further limited by a lack of positive controls because currently approved therapeutics only addresses psychotic symptoms, with minor negative symptom treatment. Despite these complexities however, many animal models of schizophrenia have been developed mainly focusing on modeling individual symptoms. Validation criteria have been established to assay the utility of these models, determining the (1) face, (2) predictive, (3) construct, and (4) etiological validities, as well as (5) reproducibility of each model. Many of these models have been created following the development of major hypotheses of schizophrenia, including the dopaminergic, glutamatergic, and neurodevelopmental hypotheses. The former two models have largely consisted of manipulating these neurotransmitter systems to produce behavioral abnormalities with some relevance to symptoms or putative etiology of schizophrenia. Given the serotonergic link to hallucinations and cholinergic link to attention, other models have manipulated these systems also. Finally, there has also been a drive toward creating mouse models of schizophrenia utilizing transgenic technology. Thus, there are opportunities to combine both environmental and genetic factors to create more suitable models of schizophrenia. More sophisticated animal tasks are also being created with which to ascertain whether these models produce behavioral abnormalities consistent with patients with schizophrenia. While animal models of schizophrenia continue to be developed, we must be cognizant that (1) validating these models are limited to the degree by which Clinicians can provide relevant information on the behavior of these patients, and (2) any putative treatments that are developed are also likely to be given with concurrent antipsychotic treatment. While our knowledge of this devastating disorder increases and our animal models and tasks with which to measure their behaviors become more sophisticated, caution must still be taken when validating these models to limit complications when introducing putative therapeutics to human trials.
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Affiliation(s)
- Jared W Young
- Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC 0804, La Jolla, CA 92093-0804, USA.
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Age-dependent effects of modafinil on acoustic startle and prepulse inhibition in rats. Behav Brain Res 2009; 208:118-23. [PMID: 19914296 DOI: 10.1016/j.bbr.2009.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/04/2009] [Accepted: 11/08/2009] [Indexed: 11/21/2022]
Abstract
Modafinil is a psychostimulant approved for treating excessive sleepiness in adults; off-label uses (e.g., treatment of cognitive impairment in schizophrenia, ADHD and age-related dementias) are currently being explored. The effects and mechanisms of action of modafinil have not been fully established. In the present study, the effects of modafinil were examined in young adult (7-month-old) and middle-aged (21-22-month-old) rats, using the acoustic startle response (ASR) and prepulse inhibition (PPI). In the control condition, middle-aged rats showed lower activity levels, significantly lower ASR amplitudes and significantly longer ASR latencies compared to young adult rats. The effects of modafinil differed by age: activity levels and ASR amplitudes were significantly increased in middle-aged rats, whereas activity levels were lower and ASR amplitude was significantly decreased in young adult rats. Modafinil did not significantly alter PPI or startle latencies relative to the control condition. Amphetamine, used as a positive control, significantly decreased ASR amplitude in young adult rats and significantly impaired PPI for both age groups. Amphetamine-induced PPI impairment was greater for young adult rats (34% reduction in ASR amplitude) than for middle-aged rats (24% reduction). The results offer new insights into the effects of modafinil and its mechanism of action, and are consistent with the idea that modafinil enhances vigilance and cognitive functioning in individuals with deficits but not in normal, healthy individuals.
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Regenthal R, Koch H, Köhler C, Preiss R, Krügel U. Depression-like deficits in rats improved by subchronic modafinil. Psychopharmacology (Berl) 2009; 204:627-39. [PMID: 19255746 DOI: 10.1007/s00213-009-1493-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 02/08/2009] [Indexed: 02/04/2023]
Abstract
RATIONALE Attentional and sensorimotor gating deficits in human depression are observed as residual symptoms irrespective of antidepressant treatment. Clinical studies point to a benefit of modafinil in depression. No data are available on modafinil effects in depression-like animal models. OBJECTIVES We investigated effects of modafinil on attention and sensorimotor gating after subchronic treatment during a restraint stress protocol inducing depression-like changes in rats. MATERIALS AND METHODS Effects of modafinil were investigated (a) acutely in the forced swim test (FST) 1 h after administration of drug or placebo and (b) in a further experiment on cognition-related behaviour in rats after induction of depression-like changes using a restraint stress protocol for 15 days. Beginning from day 10, one restrained (R) and one non-restrained (NR) group were treated with modafinil (R-M and NR-M groups) and two groups with placebo (R-P and NR-P groups). At the end of protocol, behavioural testing was performed under conditions of nearly drug-free plasma. Depression-like behaviour was examined in the FST. Selective attention and sensorimotor gating were investigated as social novelty discrimination (SND) and prepulse inhibition (PPI) of acoustic startle response. RESULTS Restraint led to reduced body weight, decreased mobility in the FST and impaired cognitive capabilities in the SND and the PPI. Subchronic modafinil treatment reversed restraint-induced deficits in the FST, the SND and PPI, whereas it was without effect on body weight. CONCLUSIONS The improvement of impaired attentional and information-processing functions under depression-like conditions suggests a benefit of modafinil in treatment of cognitive residual symptoms in affective disorders.
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Affiliation(s)
- Ralf Regenthal
- Institute of Clinical Pharmacology, University of Leipzig, Härtelstrasse 16-18, 04107, Leipzig, Germany
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Shuman T, Wood SC, Anagnostaras SG. Modafinil and memory: effects of modafinil on Morris water maze learning and Pavlovian fear conditioning. Behav Neurosci 2009; 123:257-66. [PMID: 19331449 DOI: 10.1037/a0014366] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Modafinil has been shown to promote wakefulness and some studies suggest the drug can improve cognitive function. Because of many similarities, the mechanism of action may be comparable to classical psychostimulants, although the exact mechanisms of modafinil's actions in wakefulness and cognitive enhancement are unknown. The current study aims to further examine the effects of modafinil as a cognitive enhancer on hippocampus-dependent memory in mice. A high dose of modafinil (75 mg/kg ip) given before training improved acquisition on a Morris water maze. When given only before testing, modafinil did not affect water maze performance. We also examined modafinil (0.075 to 75 mg/kg) on Pavlovian fear conditioning. A low dose of pretraining modafinil (0.75 mg/kg) enhanced memory of contextual fear conditioning (tested off-drug 1 week later) whereas a high dose (75 mg/kg) disrupted memory. Pretraining modafinil did not affect cued conditioning at any dose tested, and immediate posttraining modafinil had no effect on either cued or contextual fear. These results suggest that modafinil's effects of memory are more selective than amphetamine or cocaine and specific to hippocampus-dependent memory.
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Affiliation(s)
- Tristan Shuman
- Department of Psychology, University of California, San Diego, CA 92093-0109, USA.
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