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Sultana OF, Bandaru M, Islam MA, Reddy PH. Unraveling the complexity of human brain: Structure, function in healthy and disease states. Ageing Res Rev 2024; 100:102414. [PMID: 39002647 DOI: 10.1016/j.arr.2024.102414] [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: 05/23/2024] [Revised: 06/29/2024] [Accepted: 07/05/2024] [Indexed: 07/15/2024]
Abstract
The human brain stands as an intricate organ, embodying a nexus of structure, function, development, and diversity. This review delves into the multifaceted landscape of the brain, spanning its anatomical intricacies, diverse functional capacities, dynamic developmental trajectories, and inherent variability across individuals. The dynamic process of brain development, from early embryonic stages to adulthood, highlights the nuanced changes that occur throughout the lifespan. The brain, a remarkably complex organ, is composed of various anatomical regions, each contributing uniquely to its overall functionality. Through an exploration of neuroanatomy, neurophysiology, and electrophysiology, this review elucidates how different brain structures interact to support a wide array of cognitive processes, sensory perception, motor control, and emotional regulation. Moreover, it addresses the impact of age, sex, and ethnic background on brain structure and function, and gender differences profoundly influence the onset, progression, and manifestation of brain disorders shaped by genetic, hormonal, environmental, and social factors. Delving into the complexities of the human brain, it investigates how variations in anatomical configuration correspond to diverse functional capacities across individuals. Furthermore, it examines the impact of neurodegenerative diseases on the structural and functional integrity of the brain. Specifically, our article explores the pathological processes underlying neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases, shedding light on the structural alterations and functional impairments that accompany these conditions. We will also explore the current research trends in neurodegenerative diseases and identify the existing gaps in the literature. Overall, this article deepens our understanding of the fundamental principles governing brain structure and function and paves the way for a deeper understanding of individual differences and tailored approaches in neuroscience and clinical practice-additionally, a comprehensive understanding of structural and functional changes that manifest in neurodegenerative diseases.
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Affiliation(s)
- Omme Fatema Sultana
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Madhuri Bandaru
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Md Ariful Islam
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Nutritional Sciences Department, College of Human Sciences, Texas Tech University, Lubbock, TX 79409, USA; Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Neurology, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA 5. Department of Public Health, Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Department of Speech, Language, and Hearing Sciences, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
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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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3
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Limón-Morales O, Morales-Quintero K, Arteaga-Silva M, Molina-Jiménez T, Cerbón M, Bonilla-Jaime H. Alterations of learning and memory are accompanied by alterations in the expression of 5-HT receptors, glucocorticoid receptor and brain-derived neurotrophic factor in different brain regions of an animal model of depression generated by neonatally male treatment with clomipramine in male rats. Behav Brain Res 2023; 455:114664. [PMID: 37714467 DOI: 10.1016/j.bbr.2023.114664] [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] [Received: 06/21/2023] [Revised: 09/02/2023] [Accepted: 09/09/2023] [Indexed: 09/17/2023]
Abstract
Depressive illness has been associated with impaired cognitive processes accompanied by reduced neurotrophin levels, especially brain-derived neurotrophic factor (BDNF), and dysfunctions in the hypothalamic-pituitary-adrenal (HPA) axis. In addition, depression is characterized by a decreased functioning of the serotonergic system due to changes in the activity or expression of its receptors including, most significantly, 5-HT1A, 5-HT2A, and 5-HT3 in brain regions that regulate mood, emotions, and memory, such as the prefrontal cortex, hippocampus, and amygdala. In this regard, rats treated with clomipramine (CMI) in the neonatal stage show depression-like behaviors that persist into adulthood; hence, this constitutes an adequate model of depression for exploring various molecular aspects associated with the etiology of this disorder. This, study, then, was designed to analyze the long-term effects of early postnatal exposure to CMI on the expression of 5-HT1A, 5-HT2A, and 5-HT3 receptors, as well as BDNF and GR in the following brain regions: PFC, amygdala, hippocampus, and hypothalamus, which could be related to alterations in memory and learning, as evaluated using the novel object recognition (NOR) and Morris water maze (MWM). Expression of the 5-HT1A, 5-HT2A, and 5-HT3 receptors, BDNF, and the glucocorticoid receptor (GR) was assessed by RT-qPCR in the four aforementioned brain regions, all of which play important roles in the control of memory and mood. Findings show that neonatal treatment with CMI causes alterations in memory and learning, as indicated by alterations in the results of the MWM and NOR tests. Expression of the 5-HT1A receptor increased in the hippocampus, amygdala, and hypothalamus, but decreased in the PFC, while the 5-HT2A and BDNF receptors decreased their expression in the PFC, amygdala, and hippocampus. There was no change in the expression of the 5-HT3 receptor. In addition, expression of GR in the hippocampus and PFC was low, but increased in the hypothalamus. Taken together, these data show that neonatal CMI treatment produces permanent molecular changes in brain regions related to learning and memory that could contribute to explaining the behavioral alterations observed in this model.
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Affiliation(s)
- Ofelia Limón-Morales
- Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, C.P 09340 CDMX, Mexico; Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México, CDMX, Mexico.
| | - Kenia Morales-Quintero
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México, CDMX, Mexico
| | - Marcela Arteaga-Silva
- Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, C.P 09340 CDMX, Mexico
| | - Tania Molina-Jiménez
- Facultad de Química Farmacéutica Biológica, Universidad Veracruzana, Circuito Gonzalo Aguirre Beltrán s/n, Zona Universitaria Xalapa, Veracruz, Mexico
| | - Marco Cerbón
- Unidad de Investigación en Reproducción Humana Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México, CDMX, Mexico
| | - Herlinda Bonilla-Jaime
- Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana-Iztapalapa, C.P 09340 CDMX, Mexico
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4
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Zhang X, An H, Chen Y, Shu N. Neurobiological Mechanisms of Cognitive Decline Correlated with Brain Aging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1419:127-146. [PMID: 37418211 DOI: 10.1007/978-981-99-1627-6_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Cognitive decline has emerged as one of the greatest health threats of old age. Meanwhile, aging is the primary risk factor for Alzheimer's disease (AD) and other prevalent neurodegenerative disorders. Developing therapeutic interventions for such conditions demands a greater understanding of the processes underlying normal and pathological brain aging. Despite playing an important role in the pathogenesis and incidence of disease, brain aging has not been well understood at a molecular level. Recent advances in the biology of aging in model organisms, together with molecular- and systems-level studies of the brain, are beginning to shed light on these mechanisms and their potential roles in cognitive decline. This chapter seeks to integrate the knowledge about the neurological mechanisms of age-related cognitive changes that underlie aging.
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Affiliation(s)
- Xiaxia Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, China
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Centre, Beijing Normal University, Beijing, China
| | - Haiting An
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Centre, Beijing Normal University, Beijing, China
- Beijing Neurosurgical Institute, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China
| | - Yuan Chen
- State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, China
- Beijing Aging Brain Rejuvenation Initiative (BABRI) Centre, Beijing Normal University, Beijing, China
| | - Ni Shu
- State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, China.
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Alberts T, Antipova V, Holzmann C, Hawlitschka A, Schmitt O, Kurth J, Stenzel J, Lindner T, Krause BJ, Wree A, Witt M. Olfactory Bulb D 2/D 3 Receptor Availability after Intrastriatal Botulinum Neurotoxin-A Injection in a Unilateral 6-OHDA Rat Model of Parkinson's Disease. Toxins (Basel) 2022; 14:94. [PMID: 35202123 PMCID: PMC8879205 DOI: 10.3390/toxins14020094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 11/16/2022] Open
Abstract
Olfactory deficits occur as early non-motor symptoms of idiopathic Parkinson's disease (PD) in humans. The first central relay of the olfactory pathway, the olfactory bulb (OB), depends, among other things, on an intact, functional crosstalk between dopaminergic interneurons and dopamine receptors (D2/D3R). In rats, hemiparkinsonism (hemi-PD) can be induced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle (MFB), disrupting dopaminergic neurons of the substantia nigra pars compacta (SNpc). In a previous study, we showed that subsequent injection of botulinum neurotoxin-A (BoNT-A) into the striatum can reverse most of the pathological motor symptoms and normalize the D2/D3R availability. To determine whether this rat model is suitable to explain olfactory deficits that occur in humans with PD, we examined the availability of D2/D3R by longitudinal [18F]fallypride-PET/CT, the density of tyrosine hydroxylase immunoreactivity in the OB, olfactory performance by an orienting odor identification test adapted for rats, and a connectome analysis. PET/CT and immunohistochemical data remained largely unchanged after 6-OHDA lesion in experimental animals, suggesting that outcomes of the 6-OHDA hemi-PD rat model do not completely explain olfactory deficits in humans. However, after subsequent ipsilateral BoNT-A injection into the striatum, a significant 8.5% increase of the D2/D3R availability in the ipsilateral OB and concomitant improvement of olfactory performance were detectable. Based on tract-tracing meta-analysis, we speculate that this may be due to indirect connections between the striatum and the OB.
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Affiliation(s)
- Teresa Alberts
- Department of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Veronica Antipova
- Department of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Macroscopic and Clinical Anatomy, Medical University of Graz, A-8010 Graz, Austria
| | - Carsten Holzmann
- Department of Medical Genetics, Rostock University Medical Center, D-18057 Rostock, Germany
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany
| | | | - Oliver Schmitt
- Department of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Jens Kurth
- Department of Nuclear Medicine, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Jan Stenzel
- Core Facility Small Animal Imaging, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Tobias Lindner
- Core Facility Small Animal Imaging, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Bernd J Krause
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany
- Department of Nuclear Medicine, Rostock University Medical Center, D-18057 Rostock, Germany
| | - Andreas Wree
- Department of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany
| | - Martin Witt
- Department of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany
- Center of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany
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Blümel L, Brosda J, Bert B, Hamann M, Dietz GPH. Moderately aged OFA rats as a novel model for mild age-related alterations in learning and memory. Brain Cogn 2021; 154:105799. [PMID: 34543909 DOI: 10.1016/j.bandc.2021.105799] [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: 02/09/2021] [Revised: 08/29/2021] [Accepted: 09/02/2021] [Indexed: 11/27/2022]
Abstract
Aged rodents have been used as preclinical models of age-associated cognitive decline. Most of those models displayed substantial impairments in learning and memory. The initial, more subtle changes that precede more severe losses in cognitive abilities have not been well characterized. Here, we established a model detecting initial subtle cognitive changes by comparing the performance of moderately aged Oncins France Strain A Sprague Dawley rats with young rats in the Morris water maze (MWM) and the Open Field (OF) test. Both age groups improved their performance during the training period at a similar rate; however, the older rats performed worse in several parameters measured in the MWM. Our results suggest that already at the age of 18-20 months rats show changes in their approach to solve the spatial memory task while their ability to learn is not yet diminished. The disparate spatial information processing of the moderately aged rats provides a novel animal model for early age-related cognitive alterations that could be useful to test the effect of early intervention strategies. Moreover, our results suggest that the sensitivity of cognitive tests in the elderly could be substantially enhanced if they assess both the improvement after several trials, and the strategy used to solve a certain task.
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Affiliation(s)
- Linda Blümel
- Institute of Pharmacology and Toxicology, Department of Veterinary Medicine, Freie Universität Berlin, Germany.
| | - Jan Brosda
- Institute of Pharmacology and Toxicology, Department of Veterinary Medicine, Freie Universität Berlin, Germany.
| | - Bettina Bert
- Institute of Pharmacology and Toxicology, Department of Veterinary Medicine, Freie Universität Berlin, Germany.
| | - Melanie Hamann
- Institute of Pharmacology and Toxicology, Department of Veterinary Medicine, Freie Universität Berlin, Germany.
| | - Gunnar P H Dietz
- Department of Global Medical Affairs, Dr. Willmar Schwabe GmbH & Co. KG, Karlsruhe, Germany.
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Lothmann K, Deitersen J, Zilles K, Amunts K, Herold C. New boundaries and dissociation of the mouse hippocampus along the dorsal-ventral axis based on glutamatergic, GABAergic and catecholaminergic receptor densities. Hippocampus 2020; 31:56-78. [PMID: 32986281 DOI: 10.1002/hipo.23262] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 08/31/2020] [Accepted: 09/05/2020] [Indexed: 02/01/2023]
Abstract
In rodents, gene-expression, neuronal tuning, connectivity and neurogenesis studies have postulated that the dorsal, the intermediate and the ventral hippocampal formation (HF) are distinct entities. These findings are underpinned by behavioral studies showing a dissociable role of dorsal and ventral HF in learning, memory, stress and emotional processing. However, up to now, the molecular basis of such differences in relation to discrete boundaries is largely unknown. Therefore, we analyzed binding site densities for glutamatergic AMPA, NMDA, kainate and mGluR2/3 , GABAergic GABAA (including benzodiazepine binding sites), GABAB , dopaminergic D1/5 and noradrenergic α1 and α2 receptors as key modulators for signal transmission in hippocampal functions, using quantitative in vitro receptor autoradiography along the dorsal-ventral axis of the mouse HF. Beside general different receptor profiles of the dentate gyrus (DG) and Cornu Ammonis fields (CA1, CA2, CA3, CA4/hilus), we detected substantial differences between dorsal, intermediate and ventral subdivisions and individual layers for all investigated receptor types, except GABAB . For example, striking higher densities of α2 receptors were detected in the ventral DG, while the dorsal DG possesses higher numbers of kainate, NMDA, GABAA and D1/5 receptors. CA1 dorsal and intermediate subdivisions showed higher AMPA, NMDA, mGluR2/3 , GABAA , D1/5 receptors, while kainate receptors are higher expressed in ventral CA1, and noradrenergic α1 and α2 receptors in the intermediate region of CA1. CA2 dorsal was distinguished by higher kainate, α1 and α2 receptors in the intermediate region, while CA3 showed a more complex dissociation. Our findings resulted not only in a clear segmentation of the mouse hippocampus along the dorsal-ventral axis, but also provides insights into the neurochemical basis and likely associated physiological processes in hippocampal functions. Therein, the presented data has a high impact for future studies modeling and investigating dorsal, intermediate and ventral hippocampal dysfunction in relation to neurodegenerative diseases or psychiatric disorders.
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Affiliation(s)
- Kimberley Lothmann
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Jana Deitersen
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine INM-1, Research Centre Jülich, 52425, Jülich, Germany
| | - Katrin Amunts
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany.,Institute of Neuroscience and Medicine INM-1, Research Centre Jülich, 52425, Jülich, Germany
| | - Christina Herold
- C. & O. Vogt-Institute for Brain Research, Medical Faculty, University Clinic Düsseldof, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
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Palomero-Gallagher N, Kedo O, Mohlberg H, Zilles K, Amunts K. Multimodal mapping and analysis of the cyto- and receptorarchitecture of the human hippocampus. Brain Struct Funct 2020; 225:881-907. [PMID: 31955294 PMCID: PMC7166210 DOI: 10.1007/s00429-019-02022-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 12/26/2019] [Indexed: 12/29/2022]
Abstract
The human hippocampal formation is relevant for various aspects of memory and learning, and the different hippocampal regions are differentially affected by neuropsychiatric disorders. Therefore, the hippocampal formation has been subject of numerous cytoarchitectonic and other mapping studies, which resulted in divergent parcellation schemes. To understand the principles of hippocampal architecture, it is necessary to integrate different levels of hippocampal organisation, going beyond one modality. We here applied a multimodal mapping approach combining cyto- and multi-receptorarchitectonic analyses, and generated probabilistic maps in stereotaxic space of the identified regions. Cytoarchitecture in combination with the regional and laminar distribution of 15 neurotransmitter receptors visualized by in vitro receptor autoradiography were analysed in seven hemispheres from 6 unfixed shock frozen and serially sectioned brains. Cytoarchitectonic delineations for generation of probabilistic maps were carried out on histological sections from ten fixed, paraffin embedded and serially sectioned brains. Nine cyto- and receptorarchitectonically distinct regions were identified within the hippocampal formation (i.e., fascia dentata, cornu Ammonis (CA) regions 1-4, prosubiculum, subiculum proper, presubiculum and parasubiculum), as well as the hippocampal-amygdaloid transition area and the periallocortical transsubiculum. Subsequently generated probabilistic maps quantify intersubject variability in the size and extent of these cyto- and receptorarchitectonically distinct regions. The regions did not differ in their volume between the hemispheres and gender. Receptor mapping revealed additional subdivisions which could not be detected by cytoarchitectonic analysis alone. They correspond to parcellations previously found in immunohistochemical and connectivity studies. The multimodal approach enabled the definition of regions not consistently reported, e.g., CA4 region or prosubiculum. The ensuing detailed probabilistic maps of the hippocampal formation constitute the basis for future architectonically informed analyses of in vivo neuroimaging studies.
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Affiliation(s)
- Nicola Palomero-Gallagher
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, 52425, Jülich, Germany.
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.
- C. & O. Vogt Institute for Brain Research, Heinrich-Heine-University, 40225, Düsseldorf, Germany.
| | - Olga Kedo
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, 52425, Jülich, Germany
| | - Hartmut Mohlberg
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, 52425, Jülich, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, 52425, Jülich, Germany
- JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich, Germany
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, 52425, Jülich, Germany
- C. & O. Vogt Institute for Brain Research, Heinrich-Heine-University, 40225, Düsseldorf, Germany
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Kumar A. Calcium Signaling During Brain Aging and Its Influence on the Hippocampal Synaptic Plasticity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:985-1012. [PMID: 31646542 DOI: 10.1007/978-3-030-12457-1_39] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Calcium (Ca2+) ions are highly versatile intracellular signaling molecules and are universal second messenger for regulating a variety of cellular and physiological functions including synaptic plasticity. Ca2+ homeostasis in the central nervous system endures subtle dysregulation with advancing age. Research has provided abundant evidence that brain aging is associated with altered neuronal Ca2+ regulation and synaptic plasticity mechanisms. Much of the work has focused on the hippocampus, a brain region critically involved in learning and memory, which is particularly susceptible to dysfunction during aging. The current chapter takes a specific perspective, assessing various Ca2+ sources and the influence of aging on Ca2+ sources and synaptic plasticity in the hippocampus. Integrating the knowledge of the complexity of age-related alterations in neuronal Ca2+ signaling and synaptic plasticity mechanisms will positively shape the development of highly effective therapeutics to treat brain disorders including cognitive impairment associated with aging and neurodegenerative disease.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA.
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10
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Temido-Ferreira M, Coelho JE, Pousinha PA, Lopes LV. Novel Players in the Aging Synapse: Impact on Cognition. J Caffeine Adenosine Res 2019; 9:104-127. [PMID: 31559391 PMCID: PMC6761599 DOI: 10.1089/caff.2019.0013] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
While neuronal loss has long been considered as the main contributor to age-related cognitive decline, these alterations are currently attributed to gradual synaptic dysfunction driven by calcium dyshomeostasis and alterations in ionotropic/metabotropic receptors. Given the key role of the hippocampus in encoding, storage, and retrieval of memory, the morpho- and electrophysiological alterations that occur in the major synapse of this network-the glutamatergic-deserve special attention. We guide you through the hippocampal anatomy, circuitry, and function in physiological context and focus on alterations in neuronal morphology, calcium dynamics, and plasticity induced by aging and Alzheimer's disease (AD). We provide state-of-the art knowledge on glutamatergic transmission and discuss implications of these novel players for intervention. A link between regular consumption of caffeine-an adenosine receptor blocker-to decreased risk of AD in humans is well established, while the mechanisms responsible have only now been uncovered. We review compelling evidence from humans and animal models that implicate adenosine A2A receptors (A2AR) upsurge as a crucial mediator of age-related synaptic dysfunction. The relevance of this mechanism in patients was very recently demonstrated in the form of a significant association of the A2AR-encoding gene with hippocampal volume (synaptic loss) in mild cognitive impairment and AD. Novel pathways implicate A2AR in the control of mGluR5-dependent NMDAR activation and subsequent Ca2+ dysfunction upon aging. The nature of this receptor makes it particularly suited for long-term therapies, as an alternative for regulating aberrant mGluR5/NMDAR signaling in aging and disease, without disrupting their crucial constitutive activity.
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Affiliation(s)
- Mariana Temido-Ferreira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Joana E. Coelho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Paula A. Pousinha
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), CNRS UMR7275, Université Côte d'Azur, Valbonne, France
| | - Luísa V. Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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Zhang Y, He F, Hua T, Sun Q. Green tea polyphenols ameliorate ethanol-induced spatial learning and memory impairments by enhancing hippocampus NMDAR1 expression and CREB activity in rats. Neuroreport 2018; 29:1564-1570. [PMID: 30371539 DOI: 10.1097/wnr.0000000000001152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The current research probed into the effects of green tea polyphenols (GTPs) on ethanol-induced spatial learning and memory impairments and inquired the potential molecular mechanism in rats. Thirty 8-week-old male Sprague-Dawley rats were randomly divided into three groups. The control group (control, n=10), ethanol group (ethanol, n=10), and GTPs intervention group (GTP, n=10) received gavage administration of saline, ethanol, and ethanol-GTP solution, respectively, for 8 weeks. Morris water maze was applied to assess the spatial learning and memory function of rats in each group at the last week of treatment. There was no dramatic change in body weight of rats in the different groups. Compared with rats in the control group, 8-week ethanol gavaged rats showed increased escape latency period and decreased time in the target quadrant. Moreover, 8-week ethanol gavage decreased the density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region. In contrast, GTP intervention decreased escape latency period and increased the time in the target quadrant, the density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region. The current findings indicated that GTP intervention can improve ethanol-induced spatial learning and memory impairments in rats after ethanol withdrawal, which is related to the upregulated density of pyramidal layer neurons, expression of NMDAR1, and CREB phosphorylation in the hippocampus region.
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Affiliation(s)
- Yong Zhang
- Physiology Laboratory of College of Life Sciences
| | - Fenfen He
- Physiology Laboratory of College of Life Sciences
| | - Tianmiao Hua
- Neurobiology Laboratory of College of Life Sciences, Anhui Normal University, Wuhu, People's Republic of China
| | - Qingyan Sun
- Physiology Laboratory of College of Life Sciences
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12
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Lester AW, Moffat SD, Wiener JM, Barnes CA, Wolbers T. The Aging Navigational System. Neuron 2017; 95:1019-1035. [PMID: 28858613 PMCID: PMC5659315 DOI: 10.1016/j.neuron.2017.06.037] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 12/17/2022]
Abstract
The discovery of neuronal systems dedicated to computing spatial information, composed of functionally distinct cell types such as place and grid cells, combined with an extensive body of human-based behavioral and neuroimaging research has provided us with a detailed understanding of the brain's navigation circuit. In this review, we discuss emerging evidence from rodents, non-human primates, and humans that demonstrates how cognitive aging affects the navigational computations supported by these systems. Critically, we show 1) that navigational deficits cannot solely be explained by general deficits in learning and memory, 2) that there is no uniform decline across different navigational computations, and 3) that navigational deficits might be sensitive markers for impending pathological decline. Following an introduction to the mechanisms underlying spatial navigation and how they relate to general processes of learning and memory, the review discusses how aging affects the perception and integration of spatial information, the creation and storage of memory traces for spatial information, and the use of spatial information during navigational behavior. The closing section highlights the clinical potential of behavioral and neural markers of spatial navigation, with a particular emphasis on neurodegenerative disorders.
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Affiliation(s)
- Adam W Lester
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, USA; Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, AZ 85721, USA
| | - Scott D Moffat
- School of Psychology, Georgia Institute of Technology, Atlanta, GA 30332 USA
| | - Jan M Wiener
- Department of Psychology, Ageing and Dementia Institute, Bournemouth University, Poole BH12 5BB, UK
| | - Carol A Barnes
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85721, USA; Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, AZ 85721, USA; Departments of Psychology, Neurology, and Neuroscience, University of Arizona, Tucson, AZ 85721, USA
| | - Thomas Wolbers
- German Center for Neurodegenerative Diseases (DZNE), Aging and Cognition Research Group, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), 39118 Magdeburg, Germany.
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13
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Sexual dimorphisms in swimming behavior, cerebral metabolic activity and adrenoceptors in adult zebrafish (Danio rerio). Behav Brain Res 2016; 312:385-93. [PMID: 27363927 DOI: 10.1016/j.bbr.2016.06.047] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Revised: 06/13/2016] [Accepted: 06/26/2016] [Indexed: 02/06/2023]
Abstract
Sexually dimorphic behaviors and brain sex differences, not only restricted to reproduction, are considered to be evolutionary preserved. Specifically, anxiety related behavioral repertoire is suggested to exhibit sex-specific characteristics in rodents and primates. The present study investigated whether behavioral responses to novelty, have sex-specific characteristics in the neurogenetic model organism zebrafish (Danio rerio), lacking chromosomal sex determination. For this, aspects of anxiety-like behavior (including reduced exploration, increased freezing behavior and erratic movement) of male and female adult zebrafish were tested in a novel tank paradigm and after habituation. Male and female zebrafish showed significant differences in their swimming activity in response to novelty, with females showing less anxiety spending more time in the upper tank level. When fish have habituated, regional cerebral glucose uptake, an index of neuronal activity, and brain adrenoceptors' (ARs) expression (α2-ARs and β-ARs) were determined using in vivo 2-[(14)C]-deoxyglucose methodology and in vitro neurotransmitter receptors quantitative autoradiography, respectively. Intriguingly, females exhibited higher glucose utilization than males in hypothalamic brain areas. Adrenoceptor's expression pattern was dimorphic in zebrafish telencephalic, preoptic, hypothalamic nuclei, central gray, and cerebellum, similarly to birds and mammals. Specifically, the lateral zone of dorsal telencephalon (Dl), an area related to spatial cognition, homologous to the mammalian hippocampus, showed higher α2-AR densities in females. In contrast, male cerebellum included higher densities of β-ARs in comparison to female. Taken together, our data demonstrate a well-defined sex discriminant cerebral metabolic activity and ARs' pattern in zebrafish, possibly contributing to male-female differences in the swimming behavior.
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14
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Kumar A. NMDA Receptor Function During Senescence: Implication on Cognitive Performance. Front Neurosci 2015; 9:473. [PMID: 26732087 PMCID: PMC4679982 DOI: 10.3389/fnins.2015.00473] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/25/2015] [Indexed: 12/13/2022] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors, a family of L-glutamate receptors, play an important role in learning and memory, and are critical for spatial memory. These receptors are tetrameric ion channels composed of a family of related subunits. One of the hallmarks of the aging human population is a decline in cognitive function; studies in the past couple of years have demonstrated deterioration in NMDA receptor subunit expression and function with advancing age. However, a direct relationship between impaired memory function and a decline in NMDA receptors is still ambiguous. Recent studies indicate a link between an age-associated NMDA receptor hypofunction and memory impairment and provide evidence that age-associated enhanced oxidative stress might be contributing to the alterations associated with senescence. However, clear evidence is still deficient in demonstrating the underlying mechanisms and a relationship between age-associated impaired cognitive faculties and NMDA receptor hypofunction. The current review intends to present an overview of the research findings regarding changes in expression of various NMDA receptor subunits and deficits in NMDA receptor function during senescence and its implication in age-associated impaired hippocampal-dependent memory function.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, Evelyn F. and William L. McKnight Brain Institute, University of Florida Gainesville, FL, USA
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15
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Kouvaros S, Kotzadimitriou D, Papatheodoropoulos C. Hippocampal sharp waves and ripples: Effects of aging and modulation by NMDA receptors and L-type Ca2+ channels. Neuroscience 2015; 298:26-41. [PMID: 25869622 DOI: 10.1016/j.neuroscience.2015.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/02/2015] [Accepted: 04/06/2015] [Indexed: 12/19/2022]
Abstract
Aging is accompanied by a complicated pattern of changes in the brain organization and often by alterations in specific memory functions. One of the brain activities with important role in the process of memory consolidation is thought to be the hippocampus activity of sharp waves and ripple oscillation (SWRs). Using field recordings from the CA1 area of hippocampal slices we compared SWRs as well as single pyramidal cell activity between adult (3-6-month old) and old (24-34-month old) Wistar rats. The slices from old rats displayed ripple oscillation with a significantly less number of ripples and lower frequency compared with those from adult animals. However, the hippocampus from old rats had significantly higher propensity to organized SWRs in long sequences. Furthermore, the bursts recorded from complex spike cells in slices from old compared with adult rats displayed higher number of spikes and longer mean inter-spike interval. Blockade of N-methyl-D-aspartic acid (NMDA) receptors by 3-((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) increased the amplitude of both sharp waves and ripples and increased the interval between events of SWRs in both age groups. On the contrary, CPP reduced the probability of occurrence of sequences of SWRs more strongly in slices from adult than old rats. Blockade of L-type voltage-dependent calcium channels by nifedipine only enhanced the amplitude of sharp waves in slices from adult rats. CPP increased the postsynaptic excitability and the paired-pulse inhibition in slices from both adult and old rats similarly while nifedipine increased the postsynaptic excitability only in slices from adult rats. We propose that the tendency of the aged hippocampus to generate long sequences of SWR events might represent the consequence of homeostatic mechanisms that adaptively try to compensate the impairment in the ripple oscillation in order to maintain the behavioral outcome efficient in the old individuals. The age-dependent alterations in the firing mode of pyramidal cells might underlie to some extent the changes in ripples that occur in old animals.
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Affiliation(s)
- S Kouvaros
- Laboratory of Physiology, Department of Medicine, University of Patras, 26504 Rion, Greece
| | - D Kotzadimitriou
- Laboratory of Physiology, Department of Medicine, University of Patras, 26504 Rion, Greece
| | - C Papatheodoropoulos
- Laboratory of Physiology, Department of Medicine, University of Patras, 26504 Rion, Greece.
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16
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Herold C, Bingman VP, Ströckens F, Letzner S, Sauvage M, Palomero-Gallagher N, Zilles K, Güntürkün O. Distribution of neurotransmitter receptors and zinc in the pigeon (Columba livia) hippocampal formation: A basis for further comparison with the mammalian hippocampus. J Comp Neurol 2015; 522:2553-75. [PMID: 24477871 DOI: 10.1002/cne.23549] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 01/17/2014] [Accepted: 01/21/2014] [Indexed: 12/29/2022]
Abstract
The avian hippocampal formation (HF) and mammalian hippocampus share a similar functional role in spatial cognition, but the underlying neuronal mechanisms allowing the functional similarity are incompletely understood. To understand better the organization of the avian HF and its transmitter receptors, we analyzed binding site densities for glutamatergic AMPA, NMDA, and kainate receptors; GABAA receptors; muscarinic M1 , M2 and nicotinic (nACh) acetylcholine receptors; noradrenergic α1 and α2 receptors; serotonergic 5-HT1A receptors; dopaminergic D1/5 receptors by using quantitative in vitro receptor autoradiography. Additionally, we performed a modified Timm staining procedure to label zinc. The regionally different receptor densities mapped well onto seven HF subdivisions previously described. Several differences in receptor expression highlighted distinct HF subdivisions. Notable examples include 1) high GABAA and α1 receptor expression, which rendered distinctive ventral subdivisions; 2) high α2 receptor expression, which rendered distinctive a dorsomedial subdivision; 3) distinct kainate, α2 , and muscarinic receptor densities that rendered distinctive the two dorsolateral subdivisions; and 4) a dorsomedial region characterized by high kainate receptor density. We further observed similarities in receptor binding densities between subdivisions of the avian and mammalian HF. Despite the similarities, we propose that 300 hundred million years of independent evolution has led to a mosaic of similarities and differences in the organization of the avian HF and mammalian hippocampus and that thinking about the avian HF in terms of the strict organization of the mammalian hippocampus is likely insufficient to understand the HF of birds.
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Affiliation(s)
- Christina Herold
- C. & O. Vogt Institute of Brain Research, University of Düsseldorf, 40225, Düsseldorf, Germany
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17
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Saroja SR, Kim EJ, Shanmugasundaram B, Höger H, Lubec G. Hippocampal monoamine receptor complex levels linked to spatial memory decline in the aging C57BL/6J. Behav Brain Res 2014; 264:1-8. [PMID: 24508236 DOI: 10.1016/j.bbr.2014.01.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/25/2014] [Accepted: 01/28/2014] [Indexed: 01/09/2023]
Abstract
Although a large series of reports on monoamine receptor (MAR) biochemistry and pharmacology in aging are available, work on MAR complexes rather than subunits is limited. It was the aim of the study to determine MAR complexes in hippocampi of three different age groups (3-12 and 18 months) in the mouse and to link MAR changes to spatial memory retrieval in the Morris water maze (MWM). MAR complexes were separated by blue native electrophoresis. Immunohistochemistry was performed in order to show the pattern of dopamine receptors and its colocalizations. D1R, D2R and 5-HT7R containing receptor complex levels were decreasing with age while 5-HT1AR-containing complex levels were increasing with age. D1R, 5-HT7R and 5-HT1AR were significantly correlating with the time spent in the target quadrant, representing retrieval in the MWM. D1R and D2R immunoreactivity was decreasing in an area-dependent pattern and D1R and D2R were colocalized. Individual monoamine receptors are linked to spatial memory retrieval and are modulated by age. The findings are relevant for interpretation of previous and design of future work on brain receptors, spatial memory and aging.
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Affiliation(s)
- Sivaprakasam R Saroja
- Department of Paediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | - Eun-Jung Kim
- Department of Paediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria
| | | | - Harald Höger
- Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Brauhausgasse 34, A-2325 Himberg, Austria
| | - Gert Lubec
- Department of Paediatrics, Medical University of Vienna, Währinger Gürtel 18, 1090 Vienna, Austria.
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18
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Khan ZU, Martín-Montañez E, Navarro-Lobato I, Muly EC. Memory deficits in aging and neurological diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 122:1-29. [PMID: 24484696 DOI: 10.1016/b978-0-12-420170-5.00001-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Memory is central to our ability to perform daily life activities and correctly function in society. Improvements in public health and medical treatment for a variety of diseases have resulted in longer life spans; however, age-related memory impairments have been significant sources of morbidity. Loss in memory function is not only associated with aging population but is also a feature of neurodegenerative diseases such as Alzheimer's disease and other psychiatric and neurological disorders. Here, we focus on current understanding of the impact of normal aging on memory and what is known about its mechanisms, and further review pathological mechanisms behind the cause of dementia in Alzheimer's disease. Finally, we discuss schizophrenia and look into abnormalities in circuit function and neurotransmitter systems that contribute to memory impairment in this illness.
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Affiliation(s)
- Zafar U Khan
- Laboratory of Neurobiology at CIMES, University of Málaga, Málaga, Spain; Department of Medicine at Faculty of Medicine, University of Málaga, Málaga, Spain
| | - Elisa Martín-Montañez
- Laboratory of Neurobiology at CIMES, University of Málaga, Málaga, Spain; Department of Pharmacology at Faculty of Medicine, University of Málaga, Málaga, Spain
| | - Irene Navarro-Lobato
- Laboratory of Neurobiology at CIMES, University of Málaga, Málaga, Spain; Department of Medicine at Faculty of Medicine, University of Málaga, Málaga, Spain
| | - E Chris Muly
- Atlanta Department of Veterans Affairs Medical Center, Decatur, Georgia, USA; Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, Georgia, USA; Division of Neuropharmacology and Neurological Diseases, Yerkes National Primate Research Center, Atlanta, Georgia, USA
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19
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Ottis P, Topic B, Loos M, Li KW, de Souza A, Schulz D, Smit AB, Huston JP, Korth C. Aging-induced proteostatic changes in the rat hippocampus identify ARP3, NEB2 and BRAG2 as a molecular circuitry for cognitive impairment. PLoS One 2013; 8:e75112. [PMID: 24069387 PMCID: PMC3777897 DOI: 10.1371/journal.pone.0075112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 08/10/2013] [Indexed: 11/28/2022] Open
Abstract
Disturbed proteostasis as a particular phenotype of the aging organism has been advanced in C. elegans experiments and is also conceived to underlie neurodegenerative diseases in humans. Here, we investigated whether particular changes in non-disease related proteostasis can be identified in the aged mammalian brain, and whether a particular signature of aberrant proteostasis is related to behavioral performance of learning and memory. Young (adult, n = 30) and aged (2 years, n = 50) Wistar rats were tested in the Morris Water Maze (MWM) to distinguish superior and inferior performers. For both young and old rats, the best and worst performers in the MWM were selected and the insoluble proteome, termed aggregome, was purified from the hippocampus as evidence for aberrant proteostasis. Quantitative proteomics (iTRAQ) was performed. The aged inferior performers were considered as a model for spontaneous, age-associated cognitive impairment. Whereas variability of the insoluble proteome increased with age, absolute changes in the levels of insoluble proteins were small compared to the findings in the whole C. elegans insoluble proteome. However, we identified proteins with aberrant proteostasis in aging. For the cognitively impaired rats, we identified a changed molecular circuitry of proteins selectively involved in F-actin remodeling, synapse building and long-term depression: actin related protein 3 (ARP3), neurabin II (NEB2) and IQ motif and SEC7 domain-containing protein 1 (BRAG2). We demonstrate that aberrant proteostasis is a specific phenotype of brain aging in mammals. We identify a distinct molecular circuitry where changes in proteostasis are characteristic for poor learning and memory performance in the wild type, aged rat. Our findings 1. establish the search for aberrant proteostasis as a successful strategy to identify neuronal dysfunction in deficient cognitive behavior, 2. reveal a previously unknown functional network of proteins (ARP3, NEB2, BRAG2) involved in age-associated cognitive dysfunction.
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Affiliation(s)
- Philipp Ottis
- Department of Neuropathology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Bianca Topic
- Center for Behavioral Neuroscience, Department Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Maarten Loos
- Department of Molecular and Cellular Neurobiology, Faculty of Earth and Life Sciences, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, The Netherlands
- Synaptologics B.V., Amsterdam, The Netherlands
| | - Ka Wan Li
- Department of Molecular and Cellular Neurobiology, Faculty of Earth and Life Sciences, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, The Netherlands
| | - Angelica de Souza
- Center for Behavioral Neuroscience, Department Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Daniela Schulz
- Center for Behavioral Neuroscience, Department Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - August B. Smit
- Department of Molecular and Cellular Neurobiology, Faculty of Earth and Life Sciences, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, The Netherlands
| | - Joseph P. Huston
- Center for Behavioral Neuroscience, Department Experimental Psychology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Carsten Korth
- Department of Neuropathology, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
- * E-mail:
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20
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Senescent-induced dysregulation of cAMP/CREB signaling and correlations with cognitive decline. Brain Res 2013; 1516:93-109. [PMID: 23623816 DOI: 10.1016/j.brainres.2013.04.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 04/12/2013] [Accepted: 04/13/2013] [Indexed: 11/20/2022]
Abstract
It is well known that alongside senescence there is a gradual decline in cognitive ability, most noticeably certain kinds of memory such as working, episodic, spatial, and long term memory. However, until recently, not much has been known regarding the specific mechanisms responsible for the decline in cognitive ability with age. Over the past decades, researchers have become more interested in cAMP signaling, and its downstream transcription factor cAMP response element binding protein (CREB) in the context of senescence. However, there is still a lack of understanding on what ultimately causes the cognitive deficits observed with senescence. This review will focus on the changes in intracellular signaling in the brain, more specifically, alterations in cAMP/CREB signaling in aging. In addition, the downstream effects of altered cAMP signaling on cognitive ability with age will be further discussed. Overall, understanding the senescent-related changes that occur in cAMP/CREB signaling could be important for the development of novel drug targets for both healthy aging, and pathological aging such as Alzheimer's disease.
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21
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Frauenknecht K, Katzav A, Grimm C, Chapman J, Sommer CJ. Neurological impairment in experimental antiphospholipid syndrome is associated with increased ligand binding to hippocampal and cortical serotonergic 5-HT1A receptors. Immunobiology 2012; 218:517-26. [PMID: 22884359 DOI: 10.1016/j.imbio.2012.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 06/20/2012] [Indexed: 12/30/2022]
Abstract
The antiphospholipid syndrome (APS) is an autoimmune disease where the presence of high titers of circulating autoantibodies causes thrombosis with consecutive infarcts. In experimental APS (eAPS), a mouse model of APS, behavioral abnormalities develop in the absence of vessel occlusion or infarcts. Using brain hemispheres of control and eAPS mice with documented neurological and cognitive deficits, we checked for lymphocytic infiltration, activation of glia and macrophages, as well as alterations of ligand binding densities of various neurotransmitter receptors to unravel the molecular basis of this abnormal behavior. Lymphocytic infiltrates were immunohistochemically characterized using antibodies against CD3, CD4, CD8 and forkhead box P3 (Foxp3), respectively. GFAP, Iba1 and CD68-immunohistochemistry was performed, to check for activation of astrocytes, microglia and macrophages. Ligand binding densities of NMDA, AMPA, GABAA and 5-HT1A receptors were analyzed by in vitro receptor autoradiography. No significant inflammatory reaction occurred in eAPS mice. There was neither activation of astrocytes or microglia nor accumulation of macrophages. Binding values of excitatory and inhibitory neurotransmitter receptors were largely unchanged. However, ligand binding densities of the modulatory serotonergic 5-HT1A receptors in the hippocampus and in the primary somatosensory cortex of eAPS mice were significantly upregulated which is suggested to induce the behavioral abnormalities observed.
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Affiliation(s)
- Katrin Frauenknecht
- Department of Neuropathology, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany.
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22
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Harris MA, Wolbers T. Ageing effects on path integration and landmark navigation. Hippocampus 2012; 22:1770-80. [PMID: 22431367 DOI: 10.1002/hipo.22011] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2012] [Indexed: 11/10/2022]
Abstract
Navigation abilities show marked decline in both normal ageing and dementia. Path integration may be particularly affected, as it is supported by the hippocampus and entorhinal cortex, both of which show severe degeneration with ageing. Age differences in path integration based on kinaesthetic and vestibular cues have been clearly demonstrated, but very little research has focused on visual path integration, based only on optic flow. Path integration is complemented by landmark navigation, which may also show age differences, but has not been well studied either. Here we present a study using several simple virtual navigation tasks to explore age differences in path integration both with and without landmark information. We report that, within a virtual environment that provided only optic flow information, older participants exhibited deficits in path integration in terms of distance reproduction, rotation reproduction, and triangle completion. We also report age differences in triangle completion within an environment that provided landmark information. In all tasks, we observed a more restricted range of responses in the older participants, which we discuss in terms of a leaky integrator model, as older participants showed greater leak than younger participants. Our findings begin to explain the mechanisms underlying age differences in path integration, and thus contribute to an understanding of the substantial decline in navigation abilities observed in ageing.
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Affiliation(s)
- Mathew A Harris
- Centre for Cognitive and Neural Systems, University of Edinburgh, Edinburgh, United Kingdom.
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23
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Serotonin 5-HT1A receptor binding sites in the brain of the pigeon (Columba livia). Neuroscience 2012; 200:1-12. [DOI: 10.1016/j.neuroscience.2011.10.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 10/25/2011] [Accepted: 10/26/2011] [Indexed: 01/18/2023]
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24
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Besnard S, Machado ML, Vignaux G, Boulouard M, Coquerel A, Bouet V, Freret T, Denise P, Lelong-Boulouard V. Influence of vestibular input on spatial and nonspatial memory and on hippocampal NMDA receptors. Hippocampus 2011; 22:814-26. [PMID: 21538662 DOI: 10.1002/hipo.20942] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 01/20/2011] [Accepted: 02/04/2011] [Indexed: 11/07/2022]
Abstract
It has recently been shown that a lack of vestibular sensory information decreases spatial memory performance and induces biochemical changes in the hippocampus in rodents. After vestibular neurectomy, patients display spatial memory deficit and hippocampal atrophy. Our objectives were to explore: (a) spatial (Y maze, radial-arm maze), and non-spatial (object recognition) memory performance, (b) modulation of NMDA receptors within the hippocampus using radioligand binding, and (c) hippocampal atrophy, using MRI, in a rat model of bilateral labyrinthectomy realized in two operations. Chemical vestibular lesions (VLs) were induced in 24 animals by transtympanic injections of sodium arsanilate (30 mg/0.1 ml/ear), one side being lesioned 3 weeks after the other. The control group received transtympanic saline solution (0.1 ml/ear) (n = 24). Spatial memory performance (Y maze and radial maze) decreased after VL. Conversely, non-spatial memory performance (object recognition) was not affected by VL. No hippocampal atrophy was observed with MRI, but density of NMDA receptors were increased in the hippocampus after VL. These findings show that the lack of vestibular information induced specific deficits in spatial memory. Additionally, quantitative autoradiographic data suggest the involvement of the glutamatergic system in spatial memory processes related to vestibular information. When studying spatial memory performances in the presence of vestibular syndrome, two-step labyrinthectomy is a suitable procedure for distinguishing between the roles of the specific components of vestibular input loss and those of impaired locomotor activity.
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Affiliation(s)
- S Besnard
- INSERM, ERI 27, Caen, F-14000 France, Univ Caen, Caen, F-14000 France.
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25
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Das SR, Magnusson KR. Changes in expression of splice cassettes of NMDA receptor GluN1 subunits within the frontal lobe and memory in mice during aging. Behav Brain Res 2011; 222:122-33. [PMID: 21443909 DOI: 10.1016/j.bbr.2011.03.045] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 03/12/2011] [Accepted: 03/18/2011] [Indexed: 11/25/2022]
Abstract
Age-related decline in memory has been associated with changes in mRNA and protein expression of different NMDA receptor subunits. The NMDA receptor GluN1 subunit appears to be necessary and sufficient for receptor function. There is evidence that the mRNA expressions of some splice forms of the subunit are influenced by aging and/or behavioral testing experience in old mice. The present study explored the relationships between behavioral testing experience and protein expression of different GluN1 subunit isoforms in the prefrontal/frontal cortex of the brain during aging. Aged C57BL/6 mice with behavioral testing experience showed declines in performance in both spatial working and reference memory tasks. Protein expression of GluN1 C-terminal cassettes C2 and C2', but not the C1 or N1 cassettes, was observed to decline with increasing age, regardless of experience. In middle-age animals, higher expressions of the GluN1 subunit and C2' cassette proteins were associated with good reference memory on initial search. Aged animals with a higher protein expression of GluN1 subunits containing C1 cassettes and the whole population of GluN1 subunits exhibited a closer proximity to the former platform location within the final phase of probe trials. However, the old mice with high expression of the C1 cassette did not show an accurate search during this phase. The old mice with lower expression of the C1 cassette protein more closely mimicked the performances of the young and middle-aged mice. These results indicate that there was heterogeneity in the effect of aging on the expression of the GluN1 subunits containing different splice cassettes. It also suggests that the GluN1 subunit might be most important for good reference memory during middle age, but this relationship may not be maintained into old age.
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Affiliation(s)
- Siba R Das
- Molecular and Cellular Biology Program & Dept. of Biomedical Science, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331, USA
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Seidler RD, Bernard JA, Burutolu TB, Fling BW, Gordon MT, Gwin JT, Kwak Y, Lipps DB. Motor control and aging: links to age-related brain structural, functional, and biochemical effects. Neurosci Biobehav Rev 2010; 34:721-33. [PMID: 19850077 PMCID: PMC2838968 DOI: 10.1016/j.neubiorev.2009.10.005] [Citation(s) in RCA: 1027] [Impact Index Per Article: 73.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 10/12/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
Abstract
Although connections between cognitive deficits and age-associated brain differences have been elucidated, relationships with motor performance are less well understood. Here, we broadly review age-related brain differences and motor deficits in older adults in addition to cognition-action theories. Age-related atrophy of the motor cortical regions and corpus callosum may precipitate or coincide with motor declines such as balance and gait deficits, coordination deficits, and movement slowing. Correspondingly, degeneration of neurotransmitter systems-primarily the dopaminergic system-may contribute to age-related gross and fine motor declines, as well as to higher cognitive deficits. In general, older adults exhibit involvement of more widespread brain regions for motor control than young adults, particularly the prefrontal cortex and basal ganglia networks. Unfortunately these same regions are the most vulnerable to age-related effects, resulting in an imbalance of "supply and demand". Existing exercise, pharmaceutical, and motor training interventions may ameliorate motor deficits in older adults.
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Affiliation(s)
- Rachael D Seidler
- School of Kinesiology, University of Michigan, 401 Washtenaw Avenue, Ann Arbor, MI 48109-2214, USA.
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Magnusson KR, Brim BL, Das SR. Selective Vulnerabilities of N-methyl-D-aspartate (NMDA) Receptors During Brain Aging. Front Aging Neurosci 2010; 2:11. [PMID: 20552049 PMCID: PMC2874396 DOI: 10.3389/fnagi.2010.00011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 03/02/2010] [Indexed: 01/07/2023] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors are present in high density within the cerebral cortex and hippocampus and play an important role in learning and memory. NMDA receptors are negatively affected by aging, but these effects are not uniform in many different ways. This review discusses the selective age-related vulnerabilities of different binding sites of the NMDA receptor complex, different subunits that comprise the complex, and the expression and functions of the receptor within different brain regions. Spatial reference, passive avoidance, and working memory, as well as place field stability and expansion all involve NMDA receptors. Aged animals show deficiencies in these functions, as compared to young, and some studies have identified an association between age-associated changes in the expression of NMDA receptors and poor memory performance. A number of diet and drug interventions have shown potential for reversing or slowing the effects of aging on the NMDA receptor. On the other hand, there is mounting evidence that the NMDA receptors that remain within aged individuals are not always associated with good cognitive functioning. This may be due to a compensatory response of neurons to the decline in NMDA receptor expression or a change in the subunit composition of the remaining receptors. These studies suggest that developing treatments that are aimed at preventing or reversing the effects of aging on the NMDA receptor may aid in ameliorating the memory declines that are associated with aging. However, we need to be mindful of the possibility that there may also be negative consequences in aged individuals.
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Affiliation(s)
- Kathy R Magnusson
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University Corvallis, OR, USA
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Segu L, Lecomte MJ, Wolff M, Santamaria J, Hen R, Dumuis A, Berrard S, Bockaert J, Buhot MC, Compan V. Hyperfunction of muscarinic receptor maintains long-term memory in 5-HT4 receptor knock-out mice. PLoS One 2010; 5:e9529. [PMID: 20209108 PMCID: PMC2832007 DOI: 10.1371/journal.pone.0009529] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 02/11/2010] [Indexed: 11/18/2022] Open
Abstract
Patients suffering from dementia of Alzheimer's type express less serotonin 4 receptors (5-HTR4), but whether an absence of these receptors modifies learning and memory is unexplored. In the spatial version of the Morris water maze, we show that 5-HTR4 knock-out (KO) and wild-type (WT) mice performed similarly for spatial learning, short- and long-term retention. Since 5-HTR4 control mnesic abilities, we tested whether cholinergic system had circumvented the absence of 5-HTR4. Inactivating muscarinic receptor with scopolamine, at an ineffective dose (0.8 mg/kg) to alter memory in WT mice, decreased long-term but not short-term memory of 5-HTR4 KO mice. Other changes included decreases in the activity of choline acetyltransferase (ChAT), the required enzyme for acetylcholine synthesis, in the septum and the dorsal hippocampus in 5-HTR4 KO under baseline conditions. Training- and scopolamine-induced increase and decrease, respectively in ChAT activity in the septum in WT mice were not detected in the 5-HTR4 KO animals. Findings suggest that adaptive changes in cholinergic systems may circumvent the absence of 5-HTR4 to maintain long-term memory under baseline conditions. In contrast, despite adaptive mechanisms, the absence of 5-HTR4 aggravates scopolamine-induced memory impairments. The mechanisms whereby 5-HTR4 mediate a tonic influence on ChAT activity and muscarinic receptors remain to be determined.
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Affiliation(s)
- Luis Segu
- Centre de Neurosciences Intégratives et Cognitives, CNRS UMR5228, Bordeaux University, Talence, France
| | - Marie-José Lecomte
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, CNRS UMR7225 INSERM UMR S975, Paris, France
| | - Mathieu Wolff
- Centre de Neurosciences Intégratives et Cognitives, CNRS UMR5228, Bordeaux University, Talence, France
| | - Julie Santamaria
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, CNRS UMR7225 INSERM UMR S975, Paris, France
| | - René Hen
- Center for Neurobiology and Behavior, Columbia University, New York, New York, United States of America
| | - Aline Dumuis
- Institut de Génomique Fonctionnelle, Neurobiology, CNRS UMR5203 INSERM U661 Montpellier I & II University, Nîmes University, Montpellier, France
| | - Sylvie Berrard
- Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, CNRS UMR7225 INSERM UMR S975, Paris, France
| | - Joël Bockaert
- Institut de Génomique Fonctionnelle, Neurobiology, CNRS UMR5203 INSERM U661 Montpellier I & II University, Nîmes University, Montpellier, France
| | - Marie-Christine Buhot
- Centre de Neurosciences Intégratives et Cognitives, CNRS UMR5228, Bordeaux University, Talence, France
| | - Valérie Compan
- Institut de Génomique Fonctionnelle, Neurobiology, CNRS UMR5203 INSERM U661 Montpellier I & II University, Nîmes University, Montpellier, France
- * E-mail:
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Campeau S, Nyhuis TJ, Kryskow EM, Masini CV, Babb JA, Sasse SK, Greenwood BN, Fleshner M, Day HEW. Stress rapidly increases alpha 1d adrenergic receptor mRNA in the rat dentate gyrus. Brain Res 2010; 1323:109-18. [PMID: 20138850 DOI: 10.1016/j.brainres.2010.01.084] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 01/26/2010] [Accepted: 01/28/2010] [Indexed: 01/30/2023]
Abstract
The hippocampal formation is a highly plastic brain region that is sensitive to stress. It receives extensive noradrenergic projections, and noradrenaline is released in the hippocampus in response to stressor exposure. The hippocampus expresses particularly high levels of the alpha(1D) adrenergic receptor (ADR) and we have previously demonstrated that alpha(1d) ADR mRNA expression in the rat hippocampus is modulated by corticosterone. One of the defining features of a stress response is activation of the hypothalamic pituitary adrenal (HPA) axis, resulting in the release of corticosterone from the adrenal glands. However, the effect of stress on hippocampal expression of alpha(1d) ADR mRNA has not been determined. In this study, male rats were exposed to inescapable tail shock, loud noise or restraint, and the effect on alpha(1d) ADR mRNA expression in the hippocampus was determined by semi-quantitative in situ hybridization. All three stressors resulted in a rapid upregulation of alpha(1d) ADR mRNA in the dentate gyrus, with expression peaking at approximately 90min after the start of the stressor. Physical activity has previously been reported to counteract some of the effects of stress that occur within the dentate gyrus. However, 6weeks of voluntary wheel running in rats did not prevent the restraint stress-induced increase in alpha(1d) ADR mRNA expression in the dentate gyrus. Although the function of the alpha(1D) ADR in the dentate gyrus is not known, these data provide further evidence for a close interaction between stress and the noradrenergic system in the hippocampus.
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Affiliation(s)
- Serge Campeau
- Department of Psychology and Neuroscience, University of Colorado, Boulder, USA
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Kumar A, Bodhinathan K, Foster TC. Susceptibility to Calcium Dysregulation during Brain Aging. Front Aging Neurosci 2009; 1:2. [PMID: 20552053 PMCID: PMC2874411 DOI: 10.3389/neuro.24.002.2009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Accepted: 10/27/2009] [Indexed: 01/06/2023] Open
Abstract
Calcium (Ca(2+)) is a highly versatile intracellular signaling molecule that is essential for regulating a variety of cellular and physiological processes ranging from fertilization to programmed cell death. Research has provided ample evidence that brain aging is associated with altered Ca(2+) homeostasis. Much of the work has focused on the hippocampus, a brain region critically involved in learning and memory, which is particularly susceptible to dysfunction during senescence. The current review takes a broader perspective, assessing age-related changes in Ca(2+) sources, Ca(2+) sequestration, and Ca(2+) binding proteins throughout the nervous system. The nature of altered Ca(2+) homeostasis is cell specific and may represent a deficit or a compensatory mechanism, producing complex patterns of impaired cellular function. Incorporating the knowledge of the complexity of age-related alterations in Ca(2+) homeostasis will positively shape the development of highly effective therapeutics to treat brain disorders.
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Affiliation(s)
- Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
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The N-methyl-D-aspartate receptor modulator GLYX-13 enhances learning and memory, in young adult and learning impaired aging rats. Neurobiol Aging 2009; 32:698-706. [PMID: 19446371 DOI: 10.1016/j.neurobiolaging.2009.04.012] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 04/03/2009] [Accepted: 04/12/2009] [Indexed: 11/21/2022]
Abstract
NMDA receptor (NMDAR) activity has been strongly implicated in both in vitro and in vivo learning models and the decline in cognitive function associated with aging and is linked to a decrease in NMDAR functional expression. GLYX-13 is a tetrapeptide (Thr-Pro-Pro-Thr) which acts as a NMDAR receptor partial agonist at the glycine site. GLYX-13 was administered to young adult (3 months old) and aged (27-32 months old) Fischer 344 X Brown Norway F1 rats (FBNF1), and behavioral learning tested in trace eye blink conditioning (tEBC), a movable platform version of the Morris water maze (MWM), and alternating t-maze tasks. GLYX-13 (1mg/kg, i.v.) enhanced learning in both young adult and aging animals for MWM and alternating t-maze, and increased tEBC in aging rats. We previously showed optimal enhancement of tEBC in young adult rats given GLYX-13 at the same dose. Of these learning tasks, the MWM showed the most robust age related deficit in learning. In the MWM, GLYX-13 enhancement of learning was greater in the old compared to the young adult animals. Examination of the induction of long-term potentiation (LTP) and depression (LTD) at Schaffer collateral-CA1 synapses in hippocampal slices showed that aged rats showed marked, selective impairment in the magnitude of LTP evoked by a sub-maximal tetanus, and that GLYX-13 significantly enhanced the magnitude of LTP in slices from both young adult and aged rats without affecting LTD. These data, combined with the observation that the GLYX-13 enhancement of learning was greater in old than in young adult animals, suggest that GLYX-13 may be a promising treatment for deficits in cognitive function associated with aging.
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The effects of aging on N-methyl-D-aspartate receptor subunits in the synaptic membrane and relationships to long-term spatial memory. Neuroscience 2009; 162:933-45. [PMID: 19446010 DOI: 10.1016/j.neuroscience.2009.05.018] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 04/22/2009] [Accepted: 05/08/2009] [Indexed: 11/23/2022]
Abstract
There are declines in the protein expression of the NR2B (mouse epsilon2) and NR1 (mouse zeta1) subunits of the N-methyl-D-aspartate (NMDA) receptor in the cerebral cortex and hippocampus during aging in C57BL/6 mice. This study was designed to determine if there is a greater effect of aging on subunit expression and a stronger relationship between long-term spatial memory and subunit expression within the synaptic membrane than in the cell as a whole. Male, C57BL/6JNIA mice (4, 11 and 26 months old) were tested for long-term spatial memory in the Morris water maze. Frontal cortex, including prefrontal regions, and hippocampus were homogenized and fractionated into light and synaptosomal membrane fractions. Western blots were used to analyze protein expression of NR2B and NR1 subunits of the NMDA receptor. Old mice performed significantly worse than other ages in the spatial task. In the frontal cortex, the protein levels of the NR2B subunit showed a greater decline with aging in the synaptic membrane fraction than in the whole homogenate, while in the hippocampus a similar age-related decline was observed in both fractions. There were no significant effects of aging on the expression of the NR1 subunit. Within the middle-aged mouse group, higher expression of both NR2B and NR1 subunits in the synaptic membrane of the hippocampus was associated with better memory. In the aged mice, however, higher expression of both subunits was associated with poorer memory. These results indicate that aging could be altering the localization of the NR2B subunit to the synaptic membrane within the frontal cortex. The correlational results suggest that NMDA receptor functions, receptor subunit composition, and/or the environment in which the receptor interacted in the hippocampus were not the same in the old animals as in younger mice and this may have contributed to memory declines during aging.
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Zhao H, Li Q, Pei X, Zhang Z, Yang R, Wang J, Li Y. Long-term ginsenoside administration prevents memory impairment in aged C57BL/6J mice by up-regulating the synaptic plasticity-related proteins in hippocampus. Behav Brain Res 2009; 201:311-7. [PMID: 19428650 DOI: 10.1016/j.bbr.2009.03.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Revised: 02/27/2009] [Accepted: 03/04/2009] [Indexed: 01/10/2023]
Abstract
Memory impairment is considered to be one of the most prominent consequences of aging. Deterioration of memory begins in advance of old age in animals, including humans. Thus, it is extremely important to prevent memory decline for increasing healthy aging. Ginsenoside, the effective ingredient of ginseng, has been reported to have a neuron beneficial effect, but the preventive role on memory impairment and the underlying mechanisms have not been well determined. In the present study, C57BL/6J mice aged 12 months were chronically treated with ginsenoside 100mg/kg per day for 8 months. Placebo-treated aged mice, young and adult ones (4- and 8-month-old, respectively) were used as controls. The efficacious effect of ginsenoside was manifested in the amelioration of memory impairment in aged mice by Morris water maze and step-down tests. Compared with aged control group, the plasticity-related proteins including phospho-N-methyl-d-aspartate receptor1 (NMDAR1), phospho-calcium-calmodulin dependent kinase II (CaMK II), phospho-PKA catalytic beta subunit (PKA Cbeta), phospho-cAMP-response element binding protein (CREB) and brain derived neurotrophic factor (BDNF) in hippocampus significantly increased in ginsenoside treated group. These findings suggest that ginsenoside is effective on the prevention of age-related memory impairment, and the up-regulation of plasticity-related proteins in hippocampus may be one of the mechanisms.
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Affiliation(s)
- Haifeng Zhao
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Xueyuan Road 38, Beijing 100191, PR China
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Bert B, Voigt JP, Kusserow H, Theuring F, Rex A, Fink H. Increasing the number of 5-HT1A-receptors in cortex and hippocampus does not induce mnemonic deficits in mice. Pharmacol Biochem Behav 2009; 92:76-81. [DOI: 10.1016/j.pbb.2008.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 10/09/2008] [Accepted: 10/21/2008] [Indexed: 11/29/2022]
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Perez-Garcia G, Meneses A. Memory formation, amnesia, improved memory and reversed amnesia: 5-HT role. Behav Brain Res 2008; 195:17-29. [DOI: 10.1016/j.bbr.2007.11.027] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2007] [Revised: 11/27/2007] [Accepted: 11/27/2007] [Indexed: 11/16/2022]
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Abstract
+/-3,4-Methylenedioxymethamphetamine (MDMA) is a chemical derivative of amphetamine that has become a popular drug of abuse and has been shown to deplete serotonin in the brains of users and animals exposed to it. To date, most studies have investigated the effects of MDMA on adult animals. With a majority of users of MDMA being young adults, the chances of the users becoming pregnant and exposing the fetuses to MDMA are also a concern. Evidence to date has shown that developmental exposure to MDMA results in learning and memory impairments in the Morris water maze, a task known to be sensitive to hippocampal disruption, when the animals are tested as adults. Developmental MDMA exposure leads to hypoactivity in the offspring as adults but does not affect outcome on tests of anxiety. MDMA administration decreases pup weight, increases corticosterone and brain-derived neurotrophic factor levels during treatment while decreasing brain levels of serotonin; a decrease that initially dissipates and then reappears in adulthood. Neonatal MDMA exposure increases the sensitivity of the serotonin 1A receptor, a possible mechanism underlying the learning and memory deficits seen. Taken together, the evidence shows that MDMA exposure has adverse effects on the developing brain and behavior. The animal and human data on developmental MDMA exposure are reviewed and their public health implications discussed.
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Meneses A, Perez-Garcia G. 5-HT1A receptors and memory. Neurosci Biobehav Rev 2007; 31:705-27. [PMID: 17418894 DOI: 10.1016/j.neubiorev.2007.02.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2006] [Revised: 01/03/2007] [Accepted: 02/13/2007] [Indexed: 11/19/2022]
Abstract
The study of 5-hydroxytryptamine (5-HT) systems has benefited from the identification, classification and cloning of multiple 5-HT receptors (5-HT(1)-5-HT(7)). Increasing evidence suggests that 5-HT pathways, reuptake site/transporter complex and 5-HT receptors represent a strategic distribution for learning and memory. A key question still remaining is whether 5-HT markers (e.g., receptors) are directly or indirectly contributing to the physiological and pharmacological basis of memory and its pathogenesis or, rather, if they represent protective or adaptable mechanisms (at least in initial stages). In the current paper, the major aim is to revise recent advances regarding mammalian 5-HT(1A) receptors in light of their physiological, pathophysiological and therapeutic implications in memory. An attempt is made to identify and discuss sources of discrepancies by employing an analytic approach to examine the nature and degree of difficulty of behavioral tasks used, as well as implicating other factors (for example, brain areas, training time or duration, and drug administration) which might offer new insights into the understanding and interpretation of these data. In this context, 8-OH-DPAT deserves special attention since for many years it has been the more selective 5-HT drug and, hence, more frequently used. As 5-HT(1A) receptors are key components of serotonergic signaling, investigation of their memory mechanisms and action sites and the conditions under which they might operate, could yield valuable insights. Moreover, selective drugs with agonists, neutral antagonists or inverse agonist properties for 5-HT(1A) (and 5-HT(7)) receptors may constitute a new therapeutic opportunity for learning and memory disorders.
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Affiliation(s)
- Alfredo Meneses
- Department de Farmacobiologia, CINVESTAV-IPN, Tenorios 235, Granjas Coapa, México.
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