1
|
Lee WS, Yoon BE. Necessity of an Integrative Animal Model for a Comprehensive Study of Attention-Deficit/Hyperactivity Disorder. Biomedicines 2023; 11:biomedicines11051260. [PMID: 37238931 DOI: 10.3390/biomedicines11051260] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/13/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Animal models of attention-deficit/hyperactivity disorder (ADHD) have been used to study and understand the behavioral, neural, and physiological mechanisms underlying ADHD. These models allow researchers to conduct controlled experiments and manipulate specific brain regions or neurotransmitter systems to investigate the underlying causes of ADHD and test potential drug targets or treatments. However, it is essential to note that while these models can provide valuable insights, they do not ideally mimic the complex and heterogeneous nature of ADHD and should be interpreted cautiously. Additionally, since ADHD is a multifactorial disorder, environmental and epigenetic factors should be considered simultaneously. In this review, the animal models of ADHD reported thus far are classified into genetic, pharmacological, and environmental models, and the limitations of the representative models are discussed. Furthermore, we provide insights into a more reliable alternative model for the comprehensive study of ADHD.
Collapse
Affiliation(s)
- Won-Seok Lee
- Department of Molecular Biology, Dankook University, Cheonan 31116, Chungcheongnam-do, Republic of Korea
| | - Bo-Eun Yoon
- Department of Molecular Biology, Dankook University, Cheonan 31116, Chungcheongnam-do, Republic of Korea
| |
Collapse
|
2
|
Ptukha M, Fesenko Z, Belskaya A, Gromova A, Pelevin A, Kurzina N, Gainetdinov RR, Volnova A. Effects of Atomoxetine on Motor and Cognitive Behaviors and Brain Electrophysiological Activity of Dopamine Transporter Knockout Rats. Biomolecules 2022; 12:biom12101484. [PMID: 36291693 PMCID: PMC9599468 DOI: 10.3390/biom12101484] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 11/16/2022] Open
Abstract
Changes in dopaminergic and noradrenergic transmission are considered to be the underlying cause of attention deficit and hyperactivity disorder (ADHD). Atomoxetine (ATX) is a selective norepinephrine transporter (NET) inhibitor that is currently used for ADHD treatment. In this study, we aimed to evaluate the effect of atomoxetine on the behavior and brain activity of dopamine transporter knockout (DAT-KO) rats, which are characterized by an ADHD-like behavioral phenotype. Prepulse inhibition (PPI) was assessed in DAT-KO and wild type rats after saline and ATX injections, as well as behavioral parameters in the Hebb-Williams maze and power spectra and coherence of electrophysiological activity. DAT-KO rats demonstrated a pronounced behavioral and electrophysiological phenotype, characterized by hyperactivity, increased number of errors in the maze, repetitive behaviors and disrupted PPI, changes in cortical and striatal power spectra and interareal coherence. Atomoxetine significantly improved PPI and decreased repetitive behaviors in DAT-KO rats and influenced behavior of wild-type rats. ATX also led to significant changes in power spectra and coherence of DAT-KO and wild type rats. Assessment of noradrenergic modulation effects in DAT-KO provides insight into the intricate interplay of monoaminergic systems, although further research is still required to fully understand the complexity of this interaction.
Collapse
Affiliation(s)
- Maria Ptukha
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
- Correspondence: (M.P.); (A.V.)
| | - Zoia Fesenko
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Anastasia Belskaya
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Arina Gromova
- Faculty of Biology, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Arseniy Pelevin
- Faculty of Biology, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Natalia Kurzina
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Raul R. Gainetdinov
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
- Saint Petersburg State University Hospital, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Anna Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia
- Faculty of Biology, Saint Petersburg State University, 199034 Saint Petersburg, Russia
- Correspondence: (M.P.); (A.V.)
| |
Collapse
|
3
|
Negrón-Moreno PN, Diep DT, Guoynes CD, Sidorov MS. Dissociating motor impairment from five-choice serial reaction time task performance in a mouse model of Angelman syndrome. Front Behav Neurosci 2022; 16:968159. [PMID: 36212189 PMCID: PMC9539753 DOI: 10.3389/fnbeh.2022.968159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/05/2022] [Indexed: 12/02/2022] Open
Abstract
Angelman syndrome (AS) is a single-gene neurodevelopmental disorder associated with cognitive and motor impairment, seizures, lack of speech, and disrupted sleep. AS is caused by loss-of-function mutations in the UBE3A gene, and approaches to reinstate functional UBE3A are currently in clinical trials in children. Behavioral testing in a mouse model of AS (Ube3a m-/p+ ) represents an important tool to assess the effectiveness of current and future treatments preclinically. Existing behavioral tests effectively model motor impairments, but not cognitive impairments, in Ube3a m-/p+ mice. Here we tested the hypothesis that the 5-choice serial reaction time task (5CSRTT) can be used to assess cognitive behaviors in Ube3a m-/p+ mice. Ube3a m-/p+ mice had more omissions during 5CSRTT training than wild-type littermate controls, but also showed impaired motor function including open field hypoactivity and delays in eating pellet rewards. Motor impairments thus presented an important confound for interpreting this group difference in omissions. We report that despite hypoactivity during habituation, Ube3a m-/p+ mice had normal response latencies to retrieve rewards during 5CSRTT training. We also accounted for delays in eating pellet rewards by assessing omissions solely on trials where eating delays would not impact results. Thus, the increase in omissions in Ube3a m-/p+ mice is likely not caused by concurrent motor impairments. This work underscores the importance of considering how known motor impairments in Ube3a m-/p+ mice may affect behavioral performance in other domains. Our results also provide guidance on how to design a 5CSRTT protocol that is best suited for future studies in Ube3a mutants.
Collapse
Affiliation(s)
- Paola N. Negrón-Moreno
- University of Puerto Rico-Cayey, Cayey, PR, United States
- Department of Cell Biology and Physiology, Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - David T. Diep
- University of Maryland, College Park, College Park, MD, United States
- Center for Neuroscience Research, Children’s National Medical Center, Washington, DC, United States
| | - Caleigh D. Guoynes
- Center for Neuroscience Research, Children’s National Medical Center, Washington, DC, United States
| | - Michael S. Sidorov
- Department of Cell Biology and Physiology, Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Center for Neuroscience Research, Children’s National Medical Center, Washington, DC, United States
- Departments of Pediatrics and Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| |
Collapse
|
4
|
Stanford SC. Animal Models of ADHD? Curr Top Behav Neurosci 2022; 57:363-393. [PMID: 35604570 DOI: 10.1007/7854_2022_342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
To describe animals that express abnormal behaviors as a model of Attention-Deficit Hyperactivity Disorder (ADHD) implies that the abnormalities are analogous to those expressed by ADHD patients. The diagnostic features of ADHD comprise inattentiveness, impulsivity, and hyperactivity and so these behaviors are fundamental for validation of any animal model of this disorder. Several experimental interventions such as neurotoxic lesion of neonatal rats with 6-hydroxydopamine (6-OHDA), genetic alterations, or selective inbreeding of rodents have produced animals that express each of these impairments to some extent. This article appraises the validity of claims that these procedures have produced a model of ADHD, which is essential if they are to be used to investigate the underlying cause(s) of ADHD and its abnormal neurobiology.
Collapse
Affiliation(s)
- S Clare Stanford
- Department of Neuroscience Physiology and Pharmacology, University College London, London, UK.
| |
Collapse
|
5
|
Jogamoto T, Utsunomiya R, Sato A, Kihara N, Choudhury ME, Miyanishi K, Kubo M, Nagai M, Nomoto M, Yano H, Shimizu YI, Fukuda M, Ishii E, Eguchi M, Tanaka J. Lister hooded rats as a novel animal model of attention-deficit/hyperactivity disorder. Neurochem Int 2020; 141:104857. [DOI: 10.1016/j.neuint.2020.104857] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/17/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023]
|
6
|
Leffa DT, Panzenhagen AC, Salvi AA, Bau CHD, Pires GN, Torres ILS, Rohde LA, Rovaris DL, Grevet EH. Systematic review and meta-analysis of the behavioral effects of methylphenidate in the spontaneously hypertensive rat model of attention-deficit/hyperactivity disorder. Neurosci Biobehav Rev 2019; 100:166-179. [PMID: 30826386 DOI: 10.1016/j.neubiorev.2019.02.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 02/27/2019] [Accepted: 02/27/2019] [Indexed: 12/19/2022]
Abstract
The spontaneously hypertensive rats (SHR) are the most widely used model for ADHD. While face and construct validity are consolidated, questions remain about the predictive validity of the SHR model. We aim at summarizing the evidence for the predictive validity of SHR by evaluating its ability to respond to methylphenidate (MPH), the most well documented treatment for ADHD. A systematic review was carried out to identify studies evaluating MPH effects on SHR behavior. Studies (n=36) were grouped into locomotion, attention, impulsivity or memory, and a meta-analysis was performed. Meta-regression, sensitivity, heterogeneity, and publication bias analyses were also conducted. MPH increased attentional and mnemonic performances in the SHR model and decreased impulsivity in a dose-dependent manner. However, MPH did not reduce hyperactivity in low and medium doses, while increased locomotor activity in high doses. Thus, since the paradoxical effect of stimulant in reducing hyperactivity was not observed in the SHR model, our study does not fully support the predictive validity of SHR, questioning their validity as an animal model for ADHD.
Collapse
Affiliation(s)
- Douglas T Leffa
- Post-Graduate Program in Medicine: Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Pre-clinical studies - Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alana C Panzenhagen
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil
| | - Artur A Salvi
- Laboratory of Pain Pharmacology and Neuromodulation: Pre-clinical studies - Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Claiton H D Bau
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Gabriel N Pires
- Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, Brazil; Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Iraci L S Torres
- Laboratory of Pain Pharmacology and Neuromodulation: Pre-clinical studies - Pharmacology Department, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Animal Experimentation Unit - GPPG - Hospital de Clínicas de Porto Alegre - Porto, Alegre, Brazil
| | - Luis A Rohde
- ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; National Institute of Developmental Psychiatry for Children and Adolescents, Brazil
| | - Diego L Rovaris
- Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
| | - Eugenio H Grevet
- ADHD Outpatient Program, Hospital de Clínicas de Porto Alegre, Brazil; Department of Psychiatry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| |
Collapse
|
7
|
Leffa DT, Bellaver B, Salvi AA, de Oliveira C, Caumo W, Grevet EH, Fregni F, Quincozes-Santos A, Rohde LA, Torres IL. Transcranial direct current stimulation improves long-term memory deficits in an animal model of attention-deficit/hyperactivity disorder and modulates oxidative and inflammatory parameters. Brain Stimul 2018; 11:743-751. [DOI: 10.1016/j.brs.2018.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 03/26/2018] [Accepted: 04/02/2018] [Indexed: 02/07/2023] Open
|
8
|
Rostron CL, Gaeta V, Brace LR, Dommett EJ. Instrumental conditioning for food reinforcement in the spontaneously hypertensive rat model of attention deficit hyperactivity disorder. BMC Res Notes 2017; 10:525. [PMID: 29084583 PMCID: PMC5661932 DOI: 10.1186/s13104-017-2857-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/23/2017] [Indexed: 01/17/2023] Open
Abstract
Background The spontaneously hypertensive rat is thought to show good validity as a model of attention deficit hyperactivity disorder, in part because of impaired delayed reinforcement behaviour, corresponding to the dynamic developmental theory of the disorder. However, some previous studies may have been confounded use of fluid reward. Therefore, the objective of this study was to assess the spontaneously hypertensive rat and two comparison strains (Wistar and Wistar Kyoto) using a non-delayed food reinforcement paradigm in an attempt to advance knowledge of basic learnt behaviour in this strain, without potentially confounding reward sensitivity, which could impact on motivation to learn. Rats were trained on a fixed ratio 1 two choice discrimination schedule, extinction, reacquisition and reversal. We also tested non-reinforced spontaneous alternation to facilitate data interpretation. Results The spontaneously hypertensive rat displayed slower shaping and reduced on task activity during task acquisition, contrasting with previous results which indicate either enhanced responding and an impairment only when a delay is used; we suggest several reasons for this. In line with previous work, the same strain exhibited poor extinguishing of behaviour but were not impaired to the same extent on reversal of the discrimination. Finally, non-reinforced alternations on a Y-maze were also reduced in the spontaneously hypertensive rat. Conclusions In sum, the spontaneously hypertensive rat appear to show poor response inhibition in reinforced and non-reinforced contexts. However, impaired response inhibition was reduced during reversal when an opposite response produced food reward alongside presentation of the conditioned stimulus. We discuss the possibility of enhanced attribution of incentive salience to cues in this strain and highlight several points of caution for researchers conducting behavioural assessments using the spontaneously hypertensive rat and their associated comparison strains. Electronic supplementary material The online version of this article (10.1186/s13104-017-2857-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Claire L Rostron
- Dept Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - Victoria Gaeta
- Dept Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - Louise R Brace
- Dept Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - Eleanor J Dommett
- Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Addison House, Guy's Campus, London, SE1 1UL, UK.
| |
Collapse
|
9
|
Brace LR, Kraev I, Rostron CL, Stewart MG, Overton PG, Dommett EJ. Auditory responses in a rodent model of Attention Deficit Hyperactivity Disorder. Brain Res 2015; 1629:10-25. [PMID: 26453290 DOI: 10.1016/j.brainres.2015.09.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 01/30/2023]
Abstract
A central component of Attention Deficit Hyperactivity Disorder (ADHD) is increased distractibility in response to visual and auditory stimuli, which is linked to the superior colliculus (SC). Furthermore, there is now mounting evidence of altered collicular functioning in ADHD and it is proposed that a hyper-responsive SC could mediate symptoms of ADHD, including distractibility. In the present study we conducted a systematic characterisation of the intermediate and deep layers of the SC in the most commonly used and well-validated model of ADHD, the spontaneously hypertensive rat (SHR), building on prior work showing increased distractible behaviour in this strain using visual distractors. We examined collicular-dependent orienting behaviour, local field potential (LFP) and multiunit activity (MUA) in response to auditory stimuli in the anaesthetised rat, and morphological measures, in the SHR in comparison to the Wistar Kyoto (WKY) and Wistar (WIS). We found no evidence of increased distractibility in the behavioural data but suggest that this may arise due to cochlear hearing loss in the SHR. Furthermore, the electrophysiology data indicate that the SC in the SHR may still be hyper-responsive, normalising the amplitude of auditory responses that would otherwise be reduced due to the hearing impairment. The morphological measures of collicular volume, cell density and ratios did not indicate this potential hyper-responsiveness had a basis at the structural level examined. These findings have implications for future use of the SHR in auditory processing studies and may represent a limitation to the validity of this animal model.
Collapse
Affiliation(s)
- Louise R Brace
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Igor Kraev
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Claire L Rostron
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Michael G Stewart
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Paul G Overton
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Eleanor J Dommett
- Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes MK7 6AA, UK; Department of Psychology, Institute of Psychiatry, Psychology and Neuroscience, King׳s College London, London SE1 3QD, UK.
| |
Collapse
|
10
|
Feja M, Lang M, Deppermann L, Yüksel A, Wischhof L. High levels of impulsivity in rats are not accompanied by sensorimotor gating deficits and locomotor hyperactivity. Behav Processes 2015; 121:13-20. [PMID: 26484709 DOI: 10.1016/j.beproc.2015.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 10/04/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
High levels of impulsivity have been linked to a number of psychiatric disorders, including attention-deficit/hyperactivity disorder, drug abuse and schizophrenia. Additionally, schizophrenia patients commonly show deficits in another rather preattentive form of response inhibition, called sensorimotor gating. Given that higher-order functions, such as impulse control, are protected by early and preattentive processes, disturbed gating mechanisms may hamper more complex cognitive-executive functions. In the present study, we therefore tested whether high levels of impulsivity are accompanied by impaired sensorimotor gating in rats. High (HI) and low impulsive (LI) rats were identified based on the number of premature responses in the 5-choice serial reaction time task. Here, LI rats showed higher numbers of omission errors which may suggest attentional deficits while HI rats completed significantly less trials which could indicate a decrease in motivation. However, HI and LI rats did not differ in terms of impulsive decision-making in a delay-based decision-making T-maze task, prepulse inhibition of the acoustic startle response (a measure of sensorimotor gating mechanisms) or locomotor activity levels. Overall, our data indicate that high motor impulsivity is not a suitable predictor of deficient sensorimotor gating and is further not necessarily associated with attentional deficits and/or locomotor hyperactivity in rats.
Collapse
Affiliation(s)
- M Feja
- Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - M Lang
- Department of Neuropharmacology, Center for Cognitive Science, University of Bremen, Bremen, Germany
| | - L Deppermann
- Department of Neuropharmacology, Center for Cognitive Science, University of Bremen, Bremen, Germany
| | - A Yüksel
- Department of Neuropharmacology, Center for Cognitive Science, University of Bremen, Bremen, Germany
| | - L Wischhof
- Department of Neuropharmacology, Center for Cognitive Science, University of Bremen, Bremen, Germany.
| |
Collapse
|
11
|
D-amphetamine improves attention performance in adolescent Wistar, but not in SHR rats, in a two-choice visual discrimination task. Psychopharmacology (Berl) 2015; 232:3269-86. [PMID: 26037943 DOI: 10.1007/s00213-015-3974-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 05/24/2015] [Indexed: 01/30/2023]
Abstract
The validity of spontaneous hypertensive rat (SHR) as a model of attention deficit hyperactivity disorder (ADHD) has been explored by comparing SHR with Wistar rats in a test of attention, the two-choice visual discrimination task (2-CVDT). Animals were 4-5 weeks old during the training phase of the experiment and 6-7 weeks old during the testing phase in which they were tested with D-amphetamine, a stimulant drug used for the treatment of ADHD. As compared to Wistar, SHR showed a slightly better attention performance, a slightly lower impulsivity level, and a lower general activity during the training phase, but these differences disappeared or lessened thereafter, during the testing phase. D-amphetamine (0.5, 1 mg/kg) improved attention performance in Wistar, but not in SHR, and did not modify impulsivity and activity in the two strains. In conclusion, the present study did not demonstrate that SHR represents a valid model of ADHD, since it did not show face validity regarding the behavioral symptoms of ADHD and predictive validity regarding the effect of a compound used for the treatment of ADHD. On the other hand, this study showed that the 2-CVDT may represent a suitable tool for evaluating in adolescent Wistar rats the effect on attention of compounds intended for the treatment of ADHD.
Collapse
|
12
|
Atomoxetine reduces hyperactive/impulsive behaviours in neurokinin-1 receptor 'knockout' mice. Pharmacol Biochem Behav 2014; 127:56-61. [PMID: 25450119 PMCID: PMC4258612 DOI: 10.1016/j.pbb.2014.10.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/09/2014] [Accepted: 10/19/2014] [Indexed: 01/23/2023]
Abstract
Background Mice with functional ablation of the neurokinin-1 receptor gene (NK1R−/−) display behavioural abnormalities which resemble the hyperactivity, inattention and impulsivity seen in Attention Deficit Hyperactivity Disorder (ADHD). Here, we investigated whether the established ADHD treatment, atomoxetine, alleviates these abnormalities when tested in the light/dark exploration box (LDEB) and 5-Choice Serial Reaction-Time Task (5-CSRTT). Methods Separate cohorts of mice were tested in the 5-CSRTT and LDEB after treatment with no injection, vehicle or atomoxetine (5-CSRTT: 0.3, 3 or 10 mg/kg; LDEB: 1, 3 or 10 mg/kg). Results Atomoxetine reduced the hyperactivity displayed by NK1R−/− mice in the LDEB at a dose (3 mg/kg) which did not affect the locomotor activity of wildtypes. Atomoxetine (10 mg/kg) also reduced impulsivity in NK1R−/− mice, but not wildtypes, in the 5-CSRTT. No dose of drug affected attention in either genotype. Conclusions This evidence that atomoxetine reduces hyperactive/impulsive behaviours in NK1R−/− mice consolidates the validity of using NK1R−/− mice in research of the aetiology and treatment of ADHD. We compared the behavioural response to atomoxetine in NK1R−/− and wildtype mice. Atomoxetine reduced hyperactivity and impulsivity in NK1R−/− mice but not wildtypes. This was not explained by changes in animals' emotional status or motor motivation. NK1R−/− mice are more sensitive to atomoxetine (an ADHD treatment) than wildtypes. These findings consolidate the NK1R−/− mouse model of ADHD.
Collapse
|