16
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Atomoxetine affects transcription/translation of the NMDA receptor and the norepinephrine transporter in the rat brain – an in vivo study

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Attention-deficit/hyperactivity disorder (ADHD) is the most frequently diagnosed neurodevelopmental disorder. The norepinephrine transporter (NET) inhibitor atomoxetine, the first nonstimulant drug licensed for ADHD treatment, also acts as an N-methyl- D-aspartate receptor (NMDAR) antagonist. The compound’s effects on gene expression and protein levels of NET and NMDAR subunits (1, 2A, and 2B) are unknown. Therefore, adolescent Sprague Dawley rats were treated with atomoxetine (3 mg/kg, intraperitoneal injection [ip]) or saline (0.9%, ip) for 21 consecutive days on postnatal days (PND) 21–41. In humans, atomoxetine’s earliest clinical therapeutic effects emerge after 2–3 weeks. Material from prefrontal cortex, striatum (STR), mesencephalon (MES), and hippocampus (HC) was analyzed either directly after treatment (PND 42) or 2 months after termination of treatment (PND 101) to assess the compound’s long-term effects. In rat brains analyzed immediately after treatment, protein analysis exhibited decreased levels of the NET in HC, and NMDAR subunit 2B in both STR and HC; the transcript levels were unaltered. In rat brains probed 2 months after final atomoxetine exposure, messenger RNA analysis also revealed significantly reduced levels of genes coding for NMDAR subunits in MES and STR. NMDAR protein levels were reduced in STR and HC. Furthermore, the levels of two SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, synaptophysin and synaptosomal-associated protein 25, were also significantly altered in both treatment groups. This in vivo study detected atomoxetine’s effects beyond NET inhibition. Taken together, these data reveal that atomoxetine seems to decrease glutamatergic transmission in a brain region-specific manner. Long-term data show that the compound’s impact is not due to an acute pharmacological effect but lasts or even amplifies after a drug-free period of 2 months, leading to altered development of synaptic composition. These alterations might contribute to atomoxetine’s clinical effects in the treatment of ADHD, a neurodevelopmental disorder in which synaptic processes and especially a dysregulated glutamatergic metabolism seem to be involved.

          Related collections

          Most cited references 76

          • Record: found
          • Abstract: found
          • Article: not found

          Developmental and regional expression in the rat brain and functional properties of four NMDA receptors.

          An in situ study of mRNAs encoding NMDA receptor subunits in the developing rat CNS revealed that, at all stages, the NR1 gene is expressed in virtually all neurons, whereas the four NR2 transcripts display distinct expression patterns. NR2B and NR2D mRNAs occur prenatally, whereas NR2A and NR2C mRNAs are first detected near birth. All transcripts except NR2D peak around P20. NR2D mRNA, present mainly in midbrain structures, peaks around P7 and thereafter decreases to adult levels. Postnatally, NR2B and NR2C transcript levels change in opposite directions in the cerebellar internal granule cell layer. In the adult hippocampus, NR2A and NR2B mRNAs are prominent in CA1 and CA3 pyramidal cells, but NR2C and NR2D mRNAs occur in different subsets of interneurons. Recombinant binary NR1-NR2 channels show comparable Ca2+ permeabilities, but marked differences in voltage-dependent Mg2+ block and in offset decay time constants. Thus, the distinct expression profiles and functional properties of NR2 subunits provide a basis for NMDA channel heterogeneity in the brain.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Attention-deficit hyperactivity disorder.

            Attention-deficit hyperactivity disorder (ADHD) is a disorder of inattention, impulsivity, and hyperactivity that affects 8-12% of children worldwide. Although the rate of ADHD falls with age, at least half of children with the disorder will have impairing symptoms in adulthood. Twin, adoption, and molecular genetic studies show ADHD to be highly heritable, and other findings have recorded obstetric complications and psychosocial adversity as predisposing risk factors. Converging evidence from animal and human studies implicates the dysregulation of frontal-subcortical-cerebellar catecholaminergic circuits in the pathophysiology of ADHD, and molecular imaging studies suggest that abnormalities of the dopamine transporter lead to impaired neurotransmission. Studies during the past decade have shown the safety and effectiveness of new non-stimulant drugs and long-acting formulations of methylphenidate and amfetamine. Other investigations have also clarified the appropriate role of targeted psychosocial treatments in the context of ongoing pharmacotherapy.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              NMDA receptor subunits: diversity, development and disease

              Current Opinion in Neurobiology, 11(3), 327-335
                Bookmark

                Author and article information

                Journal
                Drug Des Devel Ther
                Drug Des Devel Ther
                Drug Design, Development and Therapy
                Dove Medical Press
                1177-8881
                2013
                04 December 2013
                : 7
                : 1433-1446
                Affiliations
                [1 ]Department of Child and Adolescent Psychiatry and Psychotherapy, University of Ulm, Ulm, Germany
                [2 ]Institute of Anatomy and Cell Biology, University of Ulm, Ulm, Germany
                [3 ]Department of Anaesthesiology, University of Ulm, Ulm, Germany
                [4 ]Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany
                Author notes
                Correspondence: Andrea G Ludolph, Department of Child and Adolescent Psychiatry and Psychotherapy, University of Ulm, Steinhoevelstr 5, D-89075 Ulm, Germany, Tel +49 731 5006 1601, Fax +49 731 5006 1662, Email andrea.ludolph@ 123456uni-ulm.de
                Article
                dddt-7-1433
                10.2147/DDDT.S50448
                3857115
                © 2013 Udvardi et al. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License

                The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

                Categories
                Original Research

                Comments

                Comment on this article