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Vorhees CV, Williams MT. Tests for learning and memory in rodent regulatory studies. Curr Res Toxicol 2024; 6:100151. [PMID: 38304257 PMCID: PMC10832385 DOI: 10.1016/j.crtox.2024.100151] [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: 08/07/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 02/03/2024] Open
Abstract
For decades, regulatory guidelines for safety assessment in rodents for drugs, chemicals, pesticides, and food additives with developmental neurotoxic potential have recommended a single test of learning and memory (L&M). In recent years some agencies have requested two such tests. Given the importance of higher cognitive function to health, and the fact that different types of L&M are mediated by different brain regions assessing higher functions represents a step forward in providing better evidence-based protection against adverse brain effects. Given the myriad of tests available for assessing L&M in rodents this leads to the question of which tests best fit regulatory guidelines. To address this question, we begin by describing the central role of two types of L&M essential to all mammalian species and the regions/networks that mediate them. We suggest that the tests recommended possess characteristics that make them well suited to the needs in regulatory safety studies. By brain region, these are (1) the hippocampus and entorhinal cortex for spatial navigation, which assesses explicit L&M for reference and episodic memory and (2) the striatum and related structures for egocentric navigation, which assesses implicit or procedural memory and path integration. Of the tests available, we suggest that in this context, the evidence supports the use of water mazes, specifically, the Morris water maze (MWM) for spatial L&M and the Cincinnati water maze (CWM) for egocentric/procedural L&M. We review the evidentiary basis for these tests, describe their use, and explain procedures that optimize their sensitivity.
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Affiliation(s)
- Charles V. Vorhees
- Corresponding author at: Div. of Neurology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA.
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Schmitz F, Ferreira FS, Silveira JS, V. R. Júnior O, T. S. Wyse A. Effects of methylphenidate after a long period of discontinuation include changes in exploratory behavior and increases brain activities of Na+,K+-ATPase and acetylcholinesterase. Neurobiol Learn Mem 2022; 192:107637. [DOI: 10.1016/j.nlm.2022.107637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/04/2022] [Accepted: 05/13/2022] [Indexed: 11/28/2022]
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Miguel PM, Deniz BF, Confortim HD, de Almeida W, Bronauth LP, Vieira MC, Bertoldi K, Siqueira IR, Silveira PP, Pereira LO. Methylphenidate treatment increases hippocampal BDNF levels but does not improve memory deficits in hypoxic-ischemic rats. J Psychopharmacol 2020; 34:750-758. [PMID: 32255391 DOI: 10.1177/0269881120913153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Methylphenidate (MPH) is a stimulant drug mainly prescribed to treat cognitive impairments in attention-deficit/hyperactivity disorder (ADHD). We demonstrated that neonatal hypoxia-ischemia (HI) induced attentional deficits in rats and MPH administration reversed these deficits. However, MPH effects on memory deficits after the HI procedure have not been evaluated yet. AIMS We aimed to analyze learning and memory performance of young hypoxic-ischemic rats after MPH administration and associate their performance with brain-derived neurotrophic factor (BDNF) levels in the prefrontal cortex and hippocampus. METHODS Male Wistar rats were divided into four groups (n=11-13/group): control saline (CTS), control MPH (CTMPH), HI saline (HIS) and HIMPH. The HI procedure was conducted at post-natal day (PND) 7 and memory tasks between PND 30 and 45. MPH administration (2.5 mg/kg, i.p.) occurred 30 min prior to each behavioral session and daily, for 15 days, for the BDNF assay (n=5-7/group). RESULTS As expected, hypoxic-ischemic animals demonstrated learning and memory deficits in the novel-object recognition (NOR) and Morris water maze (MWM) tasks. However, MPH treatment did not improve learning and memory deficits of these animals in the MWM-and even disrupted the animals' performance in the NOR task. Increased BDNF levels were found in the hippocampus of HIMPH animals, which seem to have been insufficient to improve memory deficits observed in this group. CONCLUSIONS The MPH treatment was not able to improve memory deficits resulting from the HI procedure considering a dose of 2.5 mg/kg. Further studies investigating different MPH doses would be necessary to determine a dose-response relationship in this model.
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Affiliation(s)
- Patrícia Maidana Miguel
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Bruna Ferrary Deniz
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Heloísa Deola Confortim
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Wellington de Almeida
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Loise Peres Bronauth
- Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Milene Cardoso Vieira
- Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Karine Bertoldi
- Departamento de Farmacologia, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ionara Rodrigues Siqueira
- Departamento de Farmacologia, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-Graduação em Ciências Biológicas, Fisiologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Patrícia Pelufo Silveira
- Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Canada.,Department of Psychiatry, Faculty of Medicine, McGill University, Montreal, Canada.,Sackler Program for Epigenetics & Psychobiology at McGill University, Montreal, Canada
| | - Lenir Orlandi Pereira
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Morfológicas, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Cross-disorder genetic analyses implicate dopaminergic signaling as a biological link between Attention-Deficit/Hyperactivity Disorder and obesity measures. Neuropsychopharmacology 2020; 45:1188-1195. [PMID: 31896117 PMCID: PMC7234984 DOI: 10.1038/s41386-019-0592-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 11/25/2019] [Accepted: 11/27/2019] [Indexed: 11/09/2022]
Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) and obesity are frequently comorbid, genetically correlated, and share brain substrates. The biological mechanisms driving this association are unclear, but candidate systems, like dopaminergic neurotransmission and circadian rhythm, have been suggested. Our aim was to identify the biological mechanisms underpinning the genetic link between ADHD and obesity measures and investigate associations of overlapping genes with brain volumes. We tested the association of dopaminergic and circadian rhythm gene sets with ADHD, body mass index (BMI), and obesity (using GWAS data of N = 53,293, N = 681,275, and N = 98,697, respectively). We then conducted genome-wide ADHD-BMI and ADHD-obesity gene-based meta-analyses, followed by pathway enrichment analyses. Finally, we tested the association of ADHD-BMI overlapping genes with brain volumes (primary GWAS data N = 10,720-10,928; replication data N = 9428). The dopaminergic gene set was associated with both ADHD (P = 5.81 × 10-3) and BMI (P = 1.63 × 10-5); the circadian rhythm was associated with BMI (P = 1.28 × 10-3). The genome-wide approach also implicated the dopaminergic system, as the Dopamine-DARPP32 Feedback in cAMP Signaling pathway was enriched in both ADHD-BMI and ADHD-obesity results. The ADHD-BMI overlapping genes were associated with putamen volume (P = 7.7 × 10-3; replication data P = 3.9 × 10-2)-a brain region with volumetric reductions in ADHD and BMI and linked to inhibitory control. Our findings suggest that dopaminergic neurotransmission, partially through DARPP-32-dependent signaling and involving the putamen, is a key player underlying the genetic overlap between ADHD and obesity measures. Uncovering shared etiological factors underlying the frequently observed ADHD-obesity comorbidity may have important implications in terms of prevention and/or efficient treatment of these conditions.
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PharmGKB summary: methylphenidate pathway, pharmacokinetics/pharmacodynamics. Pharmacogenet Genomics 2019; 29:136-154. [PMID: 30950912 DOI: 10.1097/fpc.0000000000000376] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Custodio RJP, Botanas CJ, de la Peña JB, Dela Peña IJ, Kim M, Sayson LV, Abiero A, Ryoo ZY, Kim BN, Kim HJ, Cheong JH. Overexpression of the Thyroid Hormone-Responsive (THRSP) Gene in the Striatum Leads to the Development of Inattentive-like Phenotype in Mice. Neuroscience 2018; 390:141-150. [PMID: 30138648 DOI: 10.1016/j.neuroscience.2018.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/03/2018] [Accepted: 08/07/2018] [Indexed: 12/13/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects 8-12% of children globally. Factor analyses have divided ADHD symptoms into two domains: inattention and a combination of hyperactivity and impulsivity. The identification of domain-specific genetic risk variants may help uncover potential genetic mechanisms underlying ADHD. We have previously identified that thyroid hormone-responsive (THRSP) gene expression is upregulated in spontaneously hypertensive rats (SHR/NCrl) and Wistar-Kyoto (WKY/NCrl) rats which exhibited inattention behavior. Thus, we established a line of THRSP overexpressing (OE) mice and assessed their behavior through an array of behavioral tests. The gene and protein overexpression of THRSP in the striatum (STR) was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. The THRSP OE mice exhibited inattention in the novel-object recognition and Y-maze test, but not hyperactivity in the open-field test and impulsivity in the cliff-avoidance and delay-discounting task. We have also found that expression of dopamine-related genes (dopamine transporter, tyrosine hydroxylase, and dopamine D1 and D2 receptors) in the STR increased. Treatment with methylphenidate (5 mg/kg), the most commonly used medication for ADHD, improved attention and normalized expression levels of dopamine-related genes in THRSP OE mice. Our findings suggest that THRSP plays a role in the inattention phenotype of ADHD and that the THRSP OE mice may be used as an animal model to elucidate the genetic mechanisms of the disorder.
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Affiliation(s)
- Raly James Perez Custodio
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Chrislean Jun Botanas
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - June Bryan de la Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea; Department of Biological Sciences, University of Texas Dallas, Richardson, TX 75080, United States
| | - Irene Joy Dela Peña
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Mikyung Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Leandro Val Sayson
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Arvie Abiero
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea
| | - Zae Young Ryoo
- School of Life Science, BK21 Plus KNU Creative Bio Research Group, College of Natural Sciences, Kyungpook National University, Buk-ku, Daegu 41566, Republic of Korea
| | - Bung-Nyun Kim
- Department of Research Planning, Mental Health Research Institute, National Center for Mental Health, Seoul, Republic of Korea
| | - Hee Jin Kim
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea.
| | - Jae Hoon Cheong
- Uimyung Research Institute for Neuroscience, Department of Pharmacy, Sahmyook University, 815 Hwarangro, Nowon-gu, Seoul 01795, Republic of Korea.
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Phenotypic variability between Social Dominance Ranks in laboratory mice. Sci Rep 2018; 8:6593. [PMID: 29700322 PMCID: PMC5920077 DOI: 10.1038/s41598-018-24624-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 04/04/2018] [Indexed: 01/21/2023] Open
Abstract
The laboratory mouse is the most prevalent animal used in experimental procedures in the biomedical and behavioural sciences. Yet, many scientists fail to consider the animals’ social context. Within a cage, mice may differ in their behaviour and physiology depending on their dominance relationships. Therefore, dominance relationships may be a confounding factor in animal experiments. The current study housed male and female C57BL/6ByJ mice in same-sex groups of 5 in standard laboratory conditions and investigated whether dominance hierarchies were present and stable across three weeks, and whether mice of different dominance ranks varied consistently in behaviour and physiology. We found that dominance ranks of most mice changed with time, but were most stable between the 2nd and 3rd week of testing. Phenotypic measures were also highly variable, and we found no relation between dominance rank and phenotype. Further, we found limited evidence that variation in measures of phenotype was associated with cage assignment for either males or females. Taken together, these findings do not lend support to the general assumption that individual variation among mice is larger between cages than within cages.
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Robison LS, Michaelos M, Gandhi J, Fricke D, Miao E, Lam CY, Mauceri A, Vitale M, Lee J, Paeng S, Komatsu DE, Hadjiargyrou M, Thanos PK. Sex Differences in the Physiological and Behavioral Effects of Chronic Oral Methylphenidate Treatment in Rats. Front Behav Neurosci 2017; 11:53. [PMID: 28400722 PMCID: PMC5368228 DOI: 10.3389/fnbeh.2017.00053] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 03/10/2017] [Indexed: 11/13/2022] Open
Abstract
Methylphenidate (MP) is a psychostimulant prescribed for Attention Deficit Hyperactivity Disorder. Previously, we developed a dual bottle 8-h-limited-access-drinking-paradigm for oral MP treatment of rats that mimics the pharmacokinetic profile of treated patients. This study assessed sex differences in response to this treatment. Male and female Sprague Dawley rats were assigned to one of three treatment groups at 4 weeks of age (n = 12/group): Control (water), low dose (LD) MP, and high dose (HD) MP. Rats drank 4 mg/kg MP (LD) or 30 mg/kg MP (HD) during the first hour, and 10 mg/kg (LD) or 60 mg/kg MP (HD) for the remaining 7 h each day. Throughout 3 months of treatment, rats were monitored for body weight, food intake, and fluid intake; as well as tested for open field behavior, circadian activity, novel object recognition, and social interaction. Chronic MP treated rats exhibited reduced fluid intake during distinct treatment weeks to a greater extent in males, and reduced total fluid intake in males only. HD MP treatment decreased body weight in both sexes, while HD MP increased total food intake in females only, likely to offset energy deficits resulting from MP-induced hyperactivity. LD and HD MP increased locomotor activity in the open field, particularly in females and during later treatment weeks. MP dose-dependently increased activity during the dark cycle of circadian testing in females, while in males hyperactivity was only exhibited by HD rats. HD MP increased center activity to a greater extent in males, while MP increased rearing behavior in females only. MP had no effect on social behavior or novel object recognition in either sex. This study concludes that chronic oral MP treatment at clinically-relevant dosages has significant effects on food intake, body weight, open field behavior, and wake cycle activity. Particularly marked sex differences were apparent for locomotor activity, with females being significantly more sensitive to the hyperactivating effects of the drug. These findings suggest that chronic MP exposure beginning in adolescence can have significant behavioral effects that are both dose- and sex-dependent, and raise concerns regarding the reversibility of these effects post-discontinuation of treatment.
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Affiliation(s)
- Lisa S Robison
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | | | - Jason Gandhi
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Dennis Fricke
- Research Institute on Addictions, University at Buffalo Buffalo, NY, USA
| | - Erick Miao
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Chiu-Yim Lam
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Anthony Mauceri
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Melissa Vitale
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Junho Lee
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - Soyeh Paeng
- Department of Psychology, Stony Brook University Stony Brook, NY, USA
| | - David E Komatsu
- Department of Orthopedics, Stony Brook University Stony Brook, NY, USA
| | - Michael Hadjiargyrou
- Department of Life Sciences, New York Institute of Technology Old Westbury, NY, USA
| | - Panayotis K Thanos
- Research Institute on Addictions, University at Buffalo Buffalo, NY, USA
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Pulga A, Porte Y, Morel JL. Changes in C57BL6 Mouse Hippocampal Transcriptome Induced by Hypergravity Mimic Acute Corticosterone-Induced Stress. Front Mol Neurosci 2016; 9:153. [PMID: 28082866 PMCID: PMC5183579 DOI: 10.3389/fnmol.2016.00153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 12/06/2016] [Indexed: 02/05/2023] Open
Abstract
Centrifugation is a widely used procedure to study the impact of altered gravity on Earth, as observed during spaceflights, allowing us to understand how a long-term physical constraint can condition the mammalian physiology. It is known that mice, placed in classical cages and maintained during 21 days in a centrifuge at 3G gravity level, undergo physiological adaptations due to hypergravity, and/or stress. Indeed, an increase of corticosterone levels has been previously measured in the plasma of 3G-exposed mice. Corticosterone is known to modify neuronal activity during memory processes. Although learning and memory performances cannot be assessed during the centrifugation, literature largely described a large panel of proteins (channels, second messengers, transcription factors, structural proteins) which expressions are modified during memory processing. Thus, we used the Illumina technology to compare the whole hippocampal transcriptome of three groups of C57Bl6/J mice, in order to gain insights into the effects of hypergravity on cerebral functions. Namely, a group of 21 days 3G-centrifuged mice was compared to (1) a group subjected to an acute corticosterone injection, (2) a group receiving a transdermal chronic administration of corticosterone during 21 days, and (3) aged mice because aging could be characterized by a decrease of hippocampus functions and memory impairment. Our results suggest that hypergravity stress induced by corticosterone administration and aging modulate the expression of genes in the hippocampus. However, the modulations of the transcriptome observed in these conditions are not identical. Hypergravity affects per-se the hippocampus transcriptome and probably modifies its activity. Hypergravity induced changes in hippocampal transcriptome were more similar to acute injection than chronic diffusion of corticosterone or aging.
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Affiliation(s)
- Alice Pulga
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
| | - Yves Porte
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
| | - Jean-Luc Morel
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
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Simchon Tenenbaum Y, Weizman A, Rehavi M. The Impact of Chronic Early Administration of Psychostimulants on Brain Expression of BDNF and Other Neuroplasticity-Relevant Proteins. J Mol Neurosci 2015; 57:231-42. [PMID: 26152882 DOI: 10.1007/s12031-015-0611-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 06/26/2015] [Indexed: 01/08/2023]
Abstract
ABSRACT Frequently, healthy individuals, children, and students are using stimulants to treat attention deficit hyperactivity disorder (ADHD)-like symptoms or to enhance cognitive capacity, attention and concentration. Methylphenidate, the most common treatment for ADHD, similarly to cocaine, blocks the dopamine reuptake, leading to increase in dopamine level in the synaptic cleft. Brain-derived neurotrophic factor (BDNF) and other neuroplasticity-relevant proteins have a major role in cellular plasticity during development and maturation of the brain. Young Sprague Dawley rats (postnatal days (PND) 14) were treated chronically with either cocaine or methylphenidate. The rats were examined behaviorally and biochemically at several time points (PND 35, 56, 70, and 90). We found age-dependent, but stimulant-independent, alterations in the mRNA expression levels of microtubule-associated protein tau, doublecortin, and synaptophysin. The PND 90 rats, treated with methylphenidate at an early age, exhibited increased BDNF protein levels in the prefrontal cortex compared to the saline-treated group. Despite the treatment effects at the biochemical level, cocaine and methylphenidate treatments at an early age had only minor effects on the behavioral parameters measured at older ages. The biochemical alterations may reflect neuroprotective or neuroplastic effects of chronic methylphenidate treatment at an early age.
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Affiliation(s)
- Yaarit Simchon Tenenbaum
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Tel-Aviv, Israel
| | - Abraham Weizman
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah-Tikva, Israel
| | - Moshe Rehavi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat Aviv, 69978, Tel-Aviv, Israel. .,The Dr. Miriam and Sheldon G. Adelson Chair and Center for the Biology of Addictive Diseases, Tel-Aviv, Israel.
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Schneider F, Baldauf K, Wetzel W, Reymann KG. Effects of methylphenidate on the behavior of male 5xFAD mice. Pharmacol Biochem Behav 2014; 128:68-77. [PMID: 25449360 DOI: 10.1016/j.pbb.2014.11.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 09/30/2014] [Accepted: 11/01/2014] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease is a neurodegenerative disorder characterized by a loss of memory and spatial orientation. It is also reported that the dopamine system is affected. Dopamine plays a prominent role in motor functions, motivation, emotion, arousal and reward, and it is important for learning and memory. One model that represents characteristic hallmarks of Alzheimer's disease is the 5xFAD mouse model, in which parenchymal plaque load starts at 2months of age. Transgenic 5xFAD mice show the first behavioral deficits at 6months, which are evident at 9months of age. In this study, we investigated the pharmacological influence of methylphenidate (MPH) on behavioral deficits of 5xFAD mice. Using a battery of behavioral tests, we observed no influence of MPH on anxiety in the elevated plus maze, whereas the locomotion and explorative activity in the open field was increased in transgenic and non-transgenic 5xFAD mice after the application of MPH. Further MPH inhibits habituation in the open field in healthy 5xFAD littermates after the application of 10mg/kg MPH. On the other hand, 10mg/kg MPH improved spatial memory in 6-month-old transgenic 5xFAD males, i.e., at a time point when deficits start to occur. However, in 9-month-old transgenic mice, MPH did not improve persisting learning and memory deficits. We concluded that MPH might improve the non-cognitive, apathy-like behavior (indicated by a reduced exploration), but it has no influence on sustained Alzheimer typical learning and memory deficits.
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Affiliation(s)
- F Schneider
- German Centre for Neurodegenerative Diseases (DZNE), Magdeburg D-39120, Germany.
| | - K Baldauf
- German Centre for Neurodegenerative Diseases (DZNE), Magdeburg D-39120, Germany.
| | - W Wetzel
- Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg D-39118, Germany.
| | - K G Reymann
- German Centre for Neurodegenerative Diseases (DZNE), Magdeburg D-39120, Germany; Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg D-39118, Germany.
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