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Zheng Y, Liu Q, Zhao Y, Qi Y, Dong L. Design of a 1 × 4 micro-magnetic stimulation device and its targeted, coordinated regulation on LTP of Schaffer-CA1 in the hippocampus of rats. Methods 2024; 229:49-60. [PMID: 38880432 DOI: 10.1016/j.ymeth.2024.06.004] [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: 02/20/2024] [Revised: 05/29/2024] [Accepted: 06/12/2024] [Indexed: 06/18/2024] Open
Abstract
Magnetic technology has been a hotspot of neuromodulation research in recent years. However, magnetic coil is limited by their size, and it is impossible to realize precise targeted magnetic stimulation to the target area at the cellular scale. To this end, this study designs a 1 × 4 array micro-magnetic stimulation (μMS) device with four sub-millimeter-sized elements, enabling precise magnetic stimulation of the CA1-CA3-DG tri-synaptic positions in the rat hippocampal region. First, it is determined that 70 KHz/2 mT/1 min magnetic stimulation parameter has a modulatory effect on the long-term potentiation (LTP) of Schaffer-CA1 in rat hippocampus. Then, a 1 × 4 array μMS device is used to perform magnetic stimulation at 70 KHz/2 mT/1 min, targeting the CA1, CA3, and DG regions individually with single-point magnetic stimulation; and multi-region magnetic stimulation is applied to the double-point targeting regions of CA1-CA3, CA1-DG, and CA3-DG, as well as the triple-point targeting region of CA1-CA3-DG, so as to investigate the regulation of LTP by single-region magnetic stimulation and multi-region magnetic stimulation. The experimental results indicate that, in the case of single-region magnetic stimulation, the magnitude of the increase in LTP in the CA1 region is the greatest, followed by the CA3 region, while the effect of magnetic stimulation on the DG region is less pronounced. In multi-region magnetic stimulation, synergistic magnetic stimulation of the three-point CA1-CA3-DG results in a greater increase in LTP compared to stimulation of two individual areas, and the enhancement of LTP induction with multi-region magnetic stimulation surpasses that of single-region stimulation. This study has implications for the collaborative targeted magnetic stimulation application of arrayed micro-magnetic devices.
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Affiliation(s)
- Yu Zheng
- School of Life Sciences, Tiangong University, Tianjin, China.
| | - Qiwen Liu
- School of Control Science and Engineering, Tiangong University, Tianjin, China
| | - Yuhang Zhao
- School of Life Sciences, Tiangong University, Tianjin, China
| | - Yenan Qi
- School of Life Sciences, Tiangong University, Tianjin, China
| | - Lei Dong
- School of Life Sciences, Tiangong University, Tianjin, China; Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, China.
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2
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Tan JW, An JJ, Deane H, Xu H, Liao GY, Xu B. Neurotrophin-3 from the dentate gyrus supports postsynaptic sites of mossy fiber-CA3 synapses and hippocampus-dependent cognitive functions. Mol Psychiatry 2024; 29:1192-1204. [PMID: 38212372 PMCID: PMC11176039 DOI: 10.1038/s41380-023-02404-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/13/2024]
Abstract
At the center of the hippocampal tri-synaptic loop are synapses formed between mossy fiber (MF) terminals from granule cells in the dentate gyrus (DG) and proximal dendrites of CA3 pyramidal neurons. However, the molecular mechanism regulating the development and function of these synapses is poorly understood. In this study, we showed that neurotrophin-3 (NT3) was expressed in nearly all mature granule cells but not CA3 cells. We selectively deleted the NT3-encoding Ntf3 gene in the DG during the first two postnatal weeks to generate a Ntf3 conditional knockout (Ntf3-cKO). Ntf3-cKO mice of both sexes had normal hippocampal cytoarchitecture but displayed impairments in contextual memory, spatial reference memory, and nest building. Furthermore, male Ntf3-cKO mice exhibited anxiety-like behaviors, whereas female Ntf3-cKO showed some mild depressive symptoms. As MF-CA3 synapses are essential for encoding of contextual memory, we examined synaptic transmission at these synapses using ex vivo electrophysiological recordings. We found that Ntf3-cKO mice had impaired basal synaptic transmission due to deficits in excitatory postsynaptic currents mediated by AMPA receptors but normal presynaptic function and intrinsic excitability of CA3 pyramidal neurons. Consistent with this selective postsynaptic deficit, Ntf3-cKO mice had fewer and smaller thorny excrescences on proximal apical dendrites of CA3 neurons and lower GluR1 levels in the stratum lucidum area where MF-CA3 synapses reside but normal MF terminals, compared with control mice. Thus, our study indicates that NT3 expressed in the dentate gyrus is crucial for the postsynaptic structure and function of MF-CA3 synapses and hippocampal-dependent memory.
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Affiliation(s)
- Ji-Wei Tan
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA
| | - Juan Ji An
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA
| | - Hannah Deane
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA
- Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Haifei Xu
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA
| | - Guey-Ying Liao
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA
| | - Baoji Xu
- Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, 33458, USA.
- Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, Jupiter, FL, 33458, USA.
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Robles-Gómez ÁA, Ordaz B, Lorea-Hernández JJ, Peña-Ortega F. Deleterious and protective effects of epothilone-D alone and in the context of amyloid β- and tau-induced alterations. Front Mol Neurosci 2023; 16:1198299. [PMID: 37900942 PMCID: PMC10603193 DOI: 10.3389/fnmol.2023.1198299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 09/20/2023] [Indexed: 10/31/2023] Open
Abstract
Amyloid-β (Aβ) and hyperphosphorylated tau (P-tau) are Alzheimer's disease (AD) biomarkers that interact in a complex manner to induce most of the cognitive and brain alterations observed in this disease. Since the neuronal cytoskeleton is a common downstream pathological target of tau and Aβ, which mostly lead to augmented microtubule instability, the administration of microtubule stabilizing agents (MSAs) can protect against their pathological actions. However, the effectiveness of MSAs is still uncertain due to their state-dependent negative effects; thus, evaluating their specific actions in different pathological or physiological conditions is required. We evaluated whether epothilone-D (Epo-D), a clinically used MSA, rescues from the functional and behavioral alterations produced by intracerebroventricular injection of Aβ, the presence of P-tau, or their combination in rTg4510 mice. We also explored the side effects of Epo-D. To do so, we evaluated hippocampal-dependent spatial memory with the Hebb-Williams maze, hippocampal CA1 integrity and the intrinsic and synaptic properties of CA1 pyramidal neurons with the patch-clamp technique. Aβ and P-tau mildly impaired memory retrieval, but produced contrasting effects on intrinsic excitability. When Aβ and P-tau were combined, the alterations in excitability and spatial reversal learning (i.e., cognitive flexibility) were exacerbated. Interestingly, Epo-D prevented most of the impairments induced Aβ and P-tau alone and combined. However, Epo-D also exhibited some side effects depending on the prevailing pathological or physiological condition, which should be considered in future preclinical and translational studies. Although we did not perform extensive histopathological evaluations or measured microtubule stability, our findings show that MSAs can rescue the consequences of AD-like conditions but otherwise be harmful if administered at a prodromal stage of the disease.
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Affiliation(s)
- Ángel Abdiel Robles-Gómez
- Instituto de Neurobiología, UNAM Campus Juriquilla, Querétaro, Mexico
- Posgrado en Ciencias Biológicas, UNAM, Ciudad Universitaria, México City, Mexico
| | - Benito Ordaz
- Instituto de Neurobiología, UNAM Campus Juriquilla, Querétaro, Mexico
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Tian L, Zhao T, Dong L, Liu Q, Zheng Y. Passive array micro-magnetic stimulation device based on multi-carrier wireless flexible control for magnetic neuromodulation. J Neural Eng 2023; 20:056020. [PMID: 37714145 DOI: 10.1088/1741-2552/acfa23] [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: 05/25/2023] [Accepted: 09/15/2023] [Indexed: 09/17/2023]
Abstract
Objective.The passive micro-magnetic stimulation (µMS) devices typically consist of an external transmitting coil and a single internal micro-coil, which enables a point-to-point energy supply from the external coil to the internal coil and the realization of magnetic neuromodulation via wireless energy transmission. The internal array of micro coils can achieve multi-target stimulation without movement, which improves the focus and effectiveness of magnetic stimulations. However, achieving a free selection of an appropriate external coil to deliver energy to a particular internal array of micro-coils for multiple stimulation targets has been challenging. To address this challenge, this study uses a multi-carrier modulation technique to transmit the energy of the external coil.Approach.In this study, a theoretical model of a multi-carrier resonant compensation network for the arrayµMS is established based on the principle of magnetically coupled resonance. The resonant frequency coupling parameter corresponding to each micro-coil of the arrayµMS is determined, and the magnetic field interference between the external coil and its non-resonant micro-coils is eliminated. Therefore, an effective magnetic stimulation threshold for a micro-coil corresponding to the target is determined, and wireless free control of the internal micro-coil array is achieved by using an external transmitting coil.Main results.The passiveµMS array model is designed using a multi-carrier wireless modulation method, and its synergistic modulation of the magnetic stimulation of synaptic plasticity long-term potentiation in multiple hippocampal regions is investigated using hippocampal isolated brain slices.Significance.The results presented in this study could provide theoretical and experimental bases for implantable micro-magnetic device-targeted therapy, introducing an efficient method for diagnosis and treatment of neurological diseases and providing innovative ideas for in-depth application of micro-magnetic stimulation in the neuroscience field.
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Affiliation(s)
- Lei Tian
- Department of Biomedical Engineering, Tiangong University, Tian Jin, People's Republic of China
| | - Tong Zhao
- Department of Biomedical Engineering, Tiangong University, Tian Jin, People's Republic of China
| | - Lei Dong
- Department of Biomedical Engineering, Tiangong University, Tian Jin, People's Republic of China
| | - Qiwen Liu
- Department of Biomedical Engineering, Tiangong University, Tian Jin, People's Republic of China
| | - Yu Zheng
- Department of Biomedical Engineering, Tiangong University, Tian Jin, People's Republic of China
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5
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Poon CH, Liu Y, Pak S, Zhao RC, Aquili L, Tipoe GL, Leung GKK, Chan YS, Yang S, Fung ML, Wu EX, Lim LW. Prelimbic Cortical Stimulation with L-methionine Enhances Cognition through Hippocampal DNA Methylation and Neuroplasticity Mechanisms. Aging Dis 2023; 14:112-135. [PMID: 36818556 PMCID: PMC9937711 DOI: 10.14336/ad.2022.0706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 07/06/2022] [Indexed: 11/18/2022] Open
Abstract
Declining global DNA methylation and cognitive impairment are reported to occur in the normal aging process. It is not known if DNA methylation plays a role in the efficacy of memory-enhancing therapies. In this study, aged animals were administered prelimbic cortical deep brain stimulation (PrL DBS) and/or L-methionine (MET) treatment. We found that PrL DBS and MET (MET-PrL DBS) co-administration resulted in hippocampal-dependent spatial memory enhancements in aged animals. Molecular data suggested MET-PrL DBS induced DNA methyltransferase DNMT3a-dependent methylation, robust synergistic upregulation of neuroplasticity-related genes, and simultaneous inhibition of the memory-suppressing gene calcineurin in the hippocampus. We further found that MET-PrL DBS also activated the PKA-CaMKIIα-BDNF pathway, increased hippocampal neurogenesis, and enhanced dopaminergic and serotonergic neurotransmission. We next inhibited the activity of DNA methyltransferase (DNMT) by RG108 infusion in the hippocampus of young animals to establish a causal relationship between DNMT activity and the effects of PrL DBS. Hippocampal DNMT inhibition in young animals was sufficient to recapitulate the behavioral deficits observed in aged animals and abolished the memory-enhancing and molecular effects of PrL DBS. Our findings implicate hippocampal DNMT as a therapeutic target for PrL DBS and pave way for the potential use of non-invasive neuromodulation modalities against dementia.
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Affiliation(s)
- Chi Him Poon
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Yanzhi Liu
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Sojeong Pak
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong, China.
| | | | - Luca Aquili
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,College of Science, Health, Engineering and Education, Discipline of Psychology, Murdoch University, Perth, Australia.
| | - George Lim Tipoe
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Gilberto Ka-Kit Leung
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
| | - Ying-Shing Chan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Sungchil Yang
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong, China.
| | - Man-Lung Fung
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Ed Xuekui Wu
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Correspondence should be addressed to: Dr. Lee Wei LIM, Neuromodulation Laboratory, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China. .
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6
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Méndez-Salcido FA, Torres-Flores MI, Ordaz B, Peña-Ortega F. Abnormal innate and learned behavior induced by neuron-microglia miscommunication is related to CA3 reconfiguration. Glia 2022; 70:1630-1651. [PMID: 35535571 DOI: 10.1002/glia.24185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 12/15/2022]
Abstract
Neuron-microglia communication through the Cx3cr1-Cx3cl1 axis is essential for the development and refinement of neural circuits, which determine their function into adulthood. In the present work we set out to extend the behavioral characterization of Cx3cr1-/- mice evaluating innate behaviors and spatial navigation, both dependent on hippocampal function. Our results show that Cx3cr1-deficient mice, which show some changes in microglial and synaptic terminals morphology and density, exhibit alterations in activities of daily living and in the rapid encoding of novel spatial information that, nonetheless, improves with training. A neural substrate for these cognitive deficiencies was found in the form of synaptic dysfunction in the CA3 region of the hippocampus, with a marked impact on the mossy fiber (MF) pathway. A network analysis of the CA3 microcircuit reveals the effect of these synaptic alterations on the functional connectivity among CA3 neurons with diminished strength and topological reorganization in Cx3cr1-deficient mice. Neonatal population activity of the CA3 region in Cx3cr1-deficient mice shows a marked reorganization around the giant depolarizing potentials, the first form of network-driven activity of the hippocampus, suggesting that alterations found in adult subjects arise early on in postnatal development, a critical period of microglia-dependent neural circuit refinement. Our results show that interruption of the Cx3cr1-Cx3cl1/neuron-microglia axis leads to changes in CA3 configuration that affect innate and learned behaviors.
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Affiliation(s)
- Felipe Antonio Méndez-Salcido
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, México
| | - Mayra Itzel Torres-Flores
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, México
| | - Benito Ordaz
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, México
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Yang Q, Song D, Xie Z, He G, Zhao J, Wang Z, Dong Z, Zhang H, Yang L, Jiang M, Wu Y, Shi Q, Li J, Yang J, Bai Z, Quan Z, Qing H. Optogenetic stimulation of CA3 pyramidal neurons restores synaptic deficits to improve spatial short-term memory in APP/PS1 mice. Prog Neurobiol 2021; 209:102209. [PMID: 34953962 DOI: 10.1016/j.pneurobio.2021.102209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 12/11/2021] [Accepted: 12/20/2021] [Indexed: 12/26/2022]
Abstract
The hippocampal CA3 region, that is involved in the encoding and retrieval of spatial memory, is found to be synaptically impaired in the early-onset of Alzheimer's disease (AD). It is reported optogenetic manipulation of DG or CA1 can rescue the memory impairment of APP/PS1 mice, however, how CA3 region contributes to AD-related deficits in cognitive function is still unknown. Our work shows optogenetic stimulation of CA3 pyramidal neurons (PNs) significantly restores the impaired spatial short-term memory of APP/PS1 mice. This enhances the anatomical synaptic density/strength and synaptic plasticity as well as activates astrocytes. Chemogenetic inhibiting the activity of CA3 astrocytes reverses the effect of optogenetic stimulation of CA3 PNs that leads to reduced anatomical synaptic density/strength, decreased synaptic protein and AMPA receptors GluA3/4, thus disrupting the cognitive restoration of APP/PS1 mice. These results reveal the molecular mechanism of optogenetic activation of CA3 PNs on restoration of the spatial short-term memory of APP/PS1 mice and unveil a potential strategy of manipulating CA3 for AD treatment.
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Affiliation(s)
- Qinghu Yang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China; College of Life Sciences & Research Center for Resource Peptide Drugs, Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, YananUniversity, Yanan, 716000, China
| | - Da Song
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China
| | - Zhen Xie
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China
| | - Guiqiong He
- Institute of Neuroscience, Chongqing Medical University, Chongqing, 400016, China; Department of Anatomy, Chongqing Medical University, Chongqing, 400016, China
| | - Juan Zhao
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China
| | - Zhe Wang
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China; The National Clinical Research Center for Geriatric Disease, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhifang Dong
- Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China; Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
| | - Heao Zhang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China
| | - Liang Yang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China; College of Life Sciences & Research Center for Resource Peptide Drugs, Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, YananUniversity, Yanan, 716000, China
| | - Ming Jiang
- College of Life Sciences & Research Center for Resource Peptide Drugs, Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, YananUniversity, Yanan, 716000, China
| | - Yili Wu
- Shandong Collaborative Innovation Center for Diagnosis, Treatment and Behavioral Interventions of mental disorders, Institute of Mental Health, Jining Medical University, 133 Hehua Road, Taibaihu New District, Jining, Shandong, 272067, China; Shandong Key Laboratory of Behavioral Medicine, Institute of Mental Health, Jining Medical University, 133 Hehua Road, Taibaihu New District, Jining, Shandong, 272067, China
| | - Qing Shi
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing, 100081, China; Key Laboratory of Biomimetic Robots and Systems (Beijing Institute of Technology), Ministry of Education, Beijing, 100081, China
| | - Junjie Li
- Ministry of Education Key Laboratory of Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China; Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China
| | - Jun Yang
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, 100875, China
| | - Zhantao Bai
- College of Life Sciences & Research Center for Resource Peptide Drugs, Shaanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, YananUniversity, Yanan, 716000, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China.
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, 10008, China.
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Pofahl M, Nikbakht N, Haubrich AN, Nguyen T, Masala N, Distler F, Braganza O, Macke JH, Ewell LA, Golcuk K, Beck H. Synchronous activity patterns in the dentate gyrus during immobility. eLife 2021; 10:65786. [PMID: 33709911 PMCID: PMC7987346 DOI: 10.7554/elife.65786] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/11/2021] [Indexed: 01/25/2023] Open
Abstract
The hippocampal dentate gyrus is an important relay conveying sensory information from the entorhinal cortex to the hippocampus proper. During exploration, the dentate gyrus has been proposed to act as a pattern separator. However, the dentate gyrus also shows structured activity during immobility and sleep. The properties of these activity patterns at cellular resolution, and their role in hippocampal-dependent memory processes have remained unclear. Using dual-color in vivo two-photon Ca2+ imaging, we show that in immobile mice dentate granule cells generate sparse, synchronized activity patterns associated with entorhinal cortex activation. These population events are structured and modified by changes in the environment; and they incorporate place- and speed cells. Importantly, they are more similar than expected by chance to population patterns evoked during self-motion. Using optogenetic inhibition, we show that granule cell activity is not only required during exploration, but also during immobility in order to form dentate gyrus-dependent spatial memories.
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Affiliation(s)
- Martin Pofahl
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Negar Nikbakht
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - André N Haubrich
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Theresa Nguyen
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Nicola Masala
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Fabian Distler
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Oliver Braganza
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Jakob H Macke
- Machine Learning in Science, Cluster of Excellence "Machine Learning", University of Tübingen, Germany & Department Empirical Inference, Max Planck Institute for Intelligent Systems, Tübingen, Germany
| | - Laura A Ewell
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Kurtulus Golcuk
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Heinz Beck
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen e.V, Bonn, Germany
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Farokhi-Sisakht F, Farhoudi M, Sadigh-Eteghad S, Mahmoudi J, Mohaddes G. Cognitive Rehabilitation Improves Ischemic Stroke-Induced Cognitive Impairment: Role of Growth Factors. J Stroke Cerebrovasc Dis 2019; 28:104299. [DOI: 10.1016/j.jstrokecerebrovasdis.2019.07.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/24/2019] [Accepted: 07/13/2019] [Indexed: 12/20/2022] Open
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10
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Bayati M, Neher T, Melchior J, Diba K, Wiskott L, Cheng S. Storage fidelity for sequence memory in the hippocampal circuit. PLoS One 2018; 13:e0204685. [PMID: 30286147 PMCID: PMC6171846 DOI: 10.1371/journal.pone.0204685] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022] Open
Abstract
Episodic memories have been suggested to be represented by neuronal sequences, which are stored and retrieved from the hippocampal circuit. A special difficulty is that realistic neuronal sequences are strongly correlated with each other since computational memory models generally perform poorly when correlated patterns are stored. Here, we study in a computational model under which conditions the hippocampal circuit can perform this function robustly. During memory encoding, CA3 sequences in our model are driven by intrinsic dynamics, entorhinal inputs, or a combination of both. These CA3 sequences are hetero-associated with the input sequences, so that the network can retrieve entire sequences based on a single cue pattern. We find that overall memory performance depends on two factors: the robustness of sequence retrieval from CA3 and the circuit's ability to perform pattern completion through the feedforward connectivity, including CA3, CA1 and EC. The two factors, in turn, depend on the relative contribution of the external inputs and recurrent drive on CA3 activity. In conclusion, memory performance in our network model critically depends on the network architecture and dynamics in CA3.
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Affiliation(s)
- Mehdi Bayati
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Torsten Neher
- Mental Health Research and Treatment Center, Department of Clinical Child and Adolescent Psychology, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany
| | - Jan Melchior
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Kamran Diba
- Department of Anesthesiology, University of Michigan, Ann Arbor, United States of America
| | - Laurenz Wiskott
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
| | - Sen Cheng
- Institut für Neuroinformatik, Ruhr-University Bochum, Bochum, Germany
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11
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Long J, Feng Y, Liao H, Zhou Q, Urbin MA. Motor Sequence Learning Is Associated With Hippocampal Subfield Volume in Humans With Medial Temporal Lobe Epilepsy. Front Hum Neurosci 2018; 12:367. [PMID: 30319375 PMCID: PMC6168622 DOI: 10.3389/fnhum.2018.00367] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/28/2018] [Indexed: 01/07/2023] Open
Abstract
Objectives: Medial temporal lobe epilepsy (mTLE) is characterized by decreased hippocampal volume, which results in motor memory consolidation impairments. However, the extent to which motor memory acquisition are affected in humans with mTLE remains poorly understood. We therefore examined the extent to which learning of a motor tapping sequence task is affected by mTLE. Methods: MRI volumetric analysis was performed using a T1-weighted three-dimensional gradient echo sequence in 15 patients with right mTLE and 15 control subjects. Subjects trained on a motor sequence tapping task with the left hand in right mTLE and non-dominant hand in neurologically-intact controls. Results: The number of correct sequences performed by the mTLE patient group increased after training, albeit to a lesser extent than the control group. Although hippocampal subfield volume was reduced in mTLE relative to controls, no differences were observed in the volumes of other brain areas including thalamus, caudate, putamen and amygdala. Correlations between hippocampal subfield volumes and the change in pre- to post-training performance indicated that the volume of hippocampal subfield CA2–3 was associated with motor sequence learning in patients with mTLE. Significance: These results provide evidence that individuals with mTLE exhibit learning on a motor sequence task. Learning is linked to the volume of hippocampal subfield CA2–3, supporting a role of the hippocampus in motor memory acquisition. HighlightsHumans with mTLE exhibit learning on a motor tapping sequence task but not to the same extent as neurologically-intact controls. Hippocampal subfield volumes are significantly reduced after mTLE. Surrounding brain area volumes do not show abnormalities. Hippocampal subfield CA2–3 volume is associated with motor sequence learning in humans with mTLE.
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Affiliation(s)
- Jinyi Long
- College of Information Science and Technology, Jinan University, Guangzhou, China
| | - Yanyun Feng
- Department of Radiology, The First People's Hospital of Foshan, Foshan, China
| | - HongPeng Liao
- School of Automation Science and Engineering, South China University of Technology, Guangzhou, China
| | - Quan Zhou
- Department of Neurology, The First People's Hospital of Foshan, Foshan, China
| | - M A Urbin
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
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12
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Al-Amin M, Bradford D, Sullivan RKP, Kurniawan ND, Moon Y, Han SH, Zalesky A, Burne THJ. Vitamin D deficiency is associated with reduced hippocampal volume and disrupted structural connectivity in patients with mild cognitive impairment. Hum Brain Mapp 2018; 40:394-406. [PMID: 30251770 DOI: 10.1002/hbm.24380] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 12/16/2022] Open
Abstract
Vitamin D deficiency may exacerbate adverse neurocognitive outcomes in the progression of diseases such as Parkinson's, Alzheimer's, and other dementias. Mild cognitive impairment (MCI) is prodromal for these neurocognitive disorders and neuroimaging studies suggest that, in the elderly, this cognitive impairment is associated with a reduction in hippocampal volume and white matter structural integrity. To test whether vitamin D is associated with neuroanatomical correlates of MCI, we analyzed an existing structural and diffusion MRI dataset of elderly patients with MCI. Based on serum 25-OHD levels, patients were categorized into serum 25-OHD deficient (<12 ng/mL, n = 27) or not-deficient (>12 ng/mL, n = 29). Freesurfer 6.0 was used to parcellate the whole brain into 164 structures and segment the hippocampal subfields. Whole-brain structural connectomes were generated using probabilistic tractography with MRtrix. The network-based statistic (NBS) was used to identify subnetworks of connections that significantly differed between the groups. We found a significant reduction in total hippocampal volume in the serum 25-OHD deficient group especially in the CA1, molecular layer, dentate gyrus, and fimbria. We observed a connection deficit in 13 regions with the right hippocampus at the center of the disrupted network. Our results demonstrate that low vitamin D is associated with reduced volumes of hippocampal subfields and connection deficits in elderly people with MCI, which may exacerbate neurocognitive outcomes. Longitudinal studies are now required to determine if vitamin D can serve as a biomarker for Alzheimer's disease and if intervention can prevent the progression from MCI to major cognitive disorders.
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Affiliation(s)
- Mamun Al-Amin
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - DanaKai Bradford
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia.,Australian e-Health Research Centre, CSIRO, Brisbane, Australia
| | - Robert K P Sullivan
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Nyoman D Kurniawan
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Yeonsil Moon
- Department of Neurology, Konkuk University Medical Center, Seoul, Republic of Korea
| | - Seol-Heui Han
- Department of Neurology, Konkuk University Medical Center, Seoul, Republic of Korea
| | - Andrew Zalesky
- Melbourne Neuropsychiatry Centre and Melbourne School of Engineering, The University of Melbourne, Parkville, Victoria, Australia
| | - Thomas H J Burne
- Queensland Brain Institute, The University of Queensland, Brisbane, Australia.,Queensland Centre for Mental Health Research, Wacol, Australia
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13
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A behavioral task with more opportunities for memory acquisition promotes the survival of new neurons in the adult dentate gyrus. Sci Rep 2018; 8:7369. [PMID: 29743494 PMCID: PMC5943398 DOI: 10.1038/s41598-018-25331-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/29/2018] [Indexed: 12/14/2022] Open
Abstract
It has been suggested that the dentate gyrus, particularly its new neurons generated via adult neurogenesis, is involved in memory acquisition and recall. Here, we trained rats in two types of Morris water maze tasks that are differentially associated with these two memory processes, and examined whether new neurons are differently affected by the two tasks performed during the second week of neuronal birth. Our results indicate that the task involving more opportunities to acquire new information better supports the survival of new neurons. Further, we assessed whether the two tasks differentially induce the expression of an immediate early gene, Zif268, which is known to be induced by neuronal activation. While the two tasks differentially induce Zif268 expression in the dentate gyrus, the proportions of new neurons activated were similar between the two tasks. Thus, we conclude that while the two tasks differentially activate the dentate gyrus, the task involving more opportunities for memory acquisition during the second week of the birth of new neurons better promotes the survival of the new neurons.
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14
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Weng FJ, Garcia RI, Lutzu S, Alviña K, Zhang Y, Dushko M, Ku T, Zemoura K, Rich D, Garcia-Dominguez D, Hung M, Yelhekar TD, Sørensen AT, Xu W, Chung K, Castillo PE, Lin Y. Npas4 Is a Critical Regulator of Learning-Induced Plasticity at Mossy Fiber-CA3 Synapses during Contextual Memory Formation. Neuron 2018; 97:1137-1152.e5. [PMID: 29429933 PMCID: PMC5843542 DOI: 10.1016/j.neuron.2018.01.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 11/26/2017] [Accepted: 01/11/2018] [Indexed: 11/18/2022]
Abstract
Synaptic connections between hippocampal mossy fibers (MFs) and CA3 pyramidal neurons are essential for contextual memory encoding, but the molecular mechanisms regulating MF-CA3 synapses during memory formation and the exact nature of this regulation are poorly understood. Here we report that the activity-dependent transcription factor Npas4 selectively regulates the structure and strength of MF-CA3 synapses by restricting the number of their functional synaptic contacts without affecting the other synaptic inputs onto CA3 pyramidal neurons. Using an activity-dependent reporter, we identified CA3 pyramidal cells that were activated by contextual learning and found that MF inputs on these cells were selectively strengthened. Deletion of Npas4 prevented both contextual memory formation and this learning-induced synaptic modification. We further show that Npas4 regulates MF-CA3 synapses by controlling the expression of the polo-like kinase Plk2. Thus, Npas4 is a critical regulator of experience-dependent, structural, and functional plasticity at MF-CA3 synapses during contextual memory formation.
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Affiliation(s)
- Feng-Ju Weng
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Rodrigo I Garcia
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Stefano Lutzu
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Karina Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yuxiang Zhang
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Margaret Dushko
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Taeyun Ku
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA; Institute for Medical Engineering and Science, MIT, Cambridge, MA, USA
| | - Khaled Zemoura
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA
| | - David Rich
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Dario Garcia-Dominguez
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Matthew Hung
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Tushar D Yelhekar
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Andreas Toft Sørensen
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Weifeng Xu
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA
| | - Kwanghun Chung
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, USA; Institute for Medical Engineering and Science, MIT, Cambridge, MA, USA; Department of Chemical Engineering, MIT, Cambridge, MA, USA; Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, USA
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Yingxi Lin
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
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15
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Unfolding the cognitive map: The role of hippocampal and extra-hippocampal substrates based on a systems analysis of spatial processing. Neurobiol Learn Mem 2018; 147:90-119. [DOI: 10.1016/j.nlm.2017.11.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/17/2017] [Accepted: 11/21/2017] [Indexed: 01/03/2023]
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16
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Sharma A, Kesari KK, Saxena VK, Sisodia R. Ten gigahertz microwave radiation impairs spatial memory, enzymes activity, and histopathology of developing mice brain. Mol Cell Biochem 2017; 435:1-13. [DOI: 10.1007/s11010-017-3051-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/27/2017] [Indexed: 12/13/2022]
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17
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Mathew RS, Tatarakis A, Rudenko A, Johnson-Venkatesh EM, Yang YJ, Murphy EA, Todd TP, Schepers ST, Siuti N, Martorell AJ, Falls WA, Hammack SE, Walsh CA, Tsai LH, Umemori H, Bouton ME, Moazed D. A microRNA negative feedback loop downregulates vesicle transport and inhibits fear memory. eLife 2016; 5. [PMID: 28001126 PMCID: PMC5293492 DOI: 10.7554/elife.22467] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 12/20/2016] [Indexed: 12/16/2022] Open
Abstract
The SNARE-mediated vesicular transport pathway plays major roles in synaptic remodeling associated with formation of long-term memories, but the mechanisms that regulate this pathway during memory acquisition are not fully understood. Here we identify miRNAs that are up-regulated in the rodent hippocampus upon contextual fear-conditioning and identify the vesicular transport and synaptogenesis pathways as the major targets of the fear-induced miRNAs. We demonstrate that miR-153, a member of this group, inhibits the expression of key components of the vesicular transport machinery, and down-regulates Glutamate receptor A1 trafficking and neurotransmitter release. MiR-153 expression is specifically induced during LTP induction in hippocampal slices and its knockdown in the hippocampus of adult mice results in enhanced fear memory. Our results suggest that miR-153, and possibly other fear-induced miRNAs, act as components of a negative feedback loop that blocks neuronal hyperactivity at least partly through the inhibition of the vesicular transport pathway. DOI:http://dx.doi.org/10.7554/eLife.22467.001
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Affiliation(s)
- Rebecca S Mathew
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Antonis Tatarakis
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Andrii Rudenko
- Department of Brain and Cognitive Sciences Massachusetts Institute of Technology, The Picower Institute for Learning and Memory, Cambridge, United States
| | - Erin M Johnson-Venkatesh
- Department of Neurology, FM Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Yawei J Yang
- Division of Genetics, Howard Hughes Medical Institute, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, United States.,Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, United States.,Harvard-MIT Division of Health Sciences and Technology, Harvard Medical School, Boston, United States
| | - Elisabeth A Murphy
- Division of Genetics, Howard Hughes Medical Institute, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, United States
| | - Travis P Todd
- Department of Psychology, University of Vermont, Burlington, United States
| | - Scott T Schepers
- Department of Psychology, University of Vermont, Burlington, United States
| | - Nertila Siuti
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Anthony J Martorell
- Department of Brain and Cognitive Sciences Massachusetts Institute of Technology, The Picower Institute for Learning and Memory, Cambridge, United States
| | - William A Falls
- Department of Psychology, University of Vermont, Burlington, United States
| | | | - Christopher A Walsh
- Division of Genetics, Howard Hughes Medical Institute, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, United States.,Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Li-Huei Tsai
- Department of Brain and Cognitive Sciences Massachusetts Institute of Technology, The Picower Institute for Learning and Memory, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Hisashi Umemori
- Department of Neurology, FM Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, United States
| | - Mark E Bouton
- Department of Psychology, University of Vermont, Burlington, United States
| | - Danesh Moazed
- Department of Cell Biology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
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18
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Prince LY, Bacon TJ, Tigaret CM, Mellor JR. Neuromodulation of the Feedforward Dentate Gyrus-CA3 Microcircuit. Front Synaptic Neurosci 2016; 8:32. [PMID: 27799909 PMCID: PMC5065980 DOI: 10.3389/fnsyn.2016.00032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 09/20/2016] [Indexed: 12/16/2022] Open
Abstract
The feedforward dentate gyrus-CA3 microcircuit in the hippocampus is thought to activate ensembles of CA3 pyramidal cells and interneurons to encode and retrieve episodic memories. The creation of these CA3 ensembles depends on neuromodulatory input and synaptic plasticity within this microcircuit. Here we review the mechanisms by which the neuromodulators aceylcholine, noradrenaline, dopamine, and serotonin reconfigure this microcircuit and thereby infer the net effect of these modulators on the processes of episodic memory encoding and retrieval.
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Affiliation(s)
- Luke Y Prince
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
| | - Travis J Bacon
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
| | - Cezar M Tigaret
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
| | - Jack R Mellor
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol Bristol, UK
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19
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Benito N, Martín-Vázquez G, Makarova J, Makarov VA, Herreras O. The right hippocampus leads the bilateral integration of gamma-parsed lateralized information. eLife 2016; 5. [PMID: 27599221 PMCID: PMC5050016 DOI: 10.7554/elife.16658] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/05/2016] [Indexed: 12/26/2022] Open
Abstract
It is unclear whether the two hippocampal lobes convey similar or different activities and how they cooperate. Spatial discrimination of electric fields in anesthetized rats allowed us to compare the pathway-specific field potentials corresponding to the gamma-paced CA3 output (CA1 Schaffer potentials) and CA3 somatic inhibition within and between sides. Bilateral excitatory Schaffer gamma waves are generally larger and lead from the right hemisphere with only moderate covariation of amplitude, and drive CA1 pyramidal units more strongly than unilateral waves. CA3 waves lock to the ipsilateral Schaffer potentials, although bilateral coherence was weak. Notably, Schaffer activity may run laterally, as seen after the disruption of the connecting pathways. Thus, asymmetric operations promote the entrainment of CA3-autonomous gamma oscillators bilaterally, synchronizing lateralized gamma strings to converge optimally on CA1 targets. The findings support the view that interhippocampal connections integrate different aspects of information that flow through the left and right lobes. DOI:http://dx.doi.org/10.7554/eLife.16658.001 In humans and other backboned animals, the brain is divided into the left and right hemispheres, which are connected by several large bundles of nerve fibers. Thanks to these fiber tracts, sensory information from each side of the body can reach both sides of the brain. However, although many areas of the brain work with a counterpart on the opposite hemisphere to process this sensory information, they do not necessarily perform the same tasks, or perform them at the same time as their partner. The hippocampus is a brain region that helps to support navigation, to detect novelty, and to produce memories. In fact, our brains contain two hippocampi – one in each hemisphere. Previous studies of the hippocampus have tended to record from only one side of the brain. Benito, Martín-Vázquez, Makarova et al. now compare the activity of the left and right hippocampi, and consider how the two structures might work together. Recordings of the electrical activity of the hippocampi of anesthetized rats show that different groups of neurons fire in rhythmic sequence, forming waves called gamma waves. Successive waves have different amplitudes, and can be thought to form ‘strings’. The recordings made by Benito et al. show that the two hippocampi produce parallel strings of waves, although the waves that originate in the right hemisphere are generally larger than those that originate in the left. Right-hemisphere waves also tend to begin slightly earlier than their left-hemisphere counterparts. Further experiments revealed that disrupting the fiber tracts between the hemispheres uncouples the waves that no longer occur at the same time, and the strings of waves may remain constrained to one side of the brain. In healthy animals, however, the right-hand dominance acts as a master-slave device, and makes the waves from the two hemispheres pair up and merge in the neurons that receive them both. Thus the information running in both hippocampi can be integrated or compared before sending to the cortex for task execution or storage. Overall, the findings reported by Benito et al. suggest that different types of information flow through the left and right hemispheres, and that the brain integrates these two streams using asymmetric connections. The next challenge is to identify how the information in the two streams differs: whether each stream reflects different sensory stimuli, different features of a scene, or the difference between recalled and perceived information. DOI:http://dx.doi.org/10.7554/eLife.16658.002
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Affiliation(s)
- Nuria Benito
- Department of Translational Neuroscience, Cajal Institute - CSIC, Madrid, Spain
| | | | - Julia Makarova
- Department of Translational Neuroscience, Cajal Institute - CSIC, Madrid, Spain.,N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Valeri A Makarov
- N.I. Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Department of Applied Mathematics, Faculty of Mathematics, Universidad Complutense de Madrid, Madrid, Spain
| | - Oscar Herreras
- Department of Translational Neuroscience, Cajal Institute - CSIC, Madrid, Spain
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20
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Hu F, Ge MM, Chen WH. Effects of lead exposure on dendrite and spine development in hippocampal dentate gyrus areas of rats. Synapse 2016; 70:87-97. [DOI: 10.1002/syn.21873] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Fan Hu
- School of Biotechnology and Food Engineering; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Meng-Meng Ge
- School of Biotechnology and Food Engineering; Hefei University of Technology; Hefei Anhui 230009 People's Republic of China
| | - Wei-Heng Chen
- School of Life Sciences; University of Science and Technology of China; Hefei Anhui 230027 People's Republic of China
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21
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A computational theory of hippocampal function, and tests of the theory: New developments. Neurosci Biobehav Rev 2015; 48:92-147. [DOI: 10.1016/j.neubiorev.2014.11.009] [Citation(s) in RCA: 226] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/24/2014] [Accepted: 11/12/2014] [Indexed: 01/01/2023]
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22
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Paleja M, Girard TA, Herdman KA, Christensen BK. Two distinct neural networks functionally connected to the human hippocampus during pattern separation tasks. Brain Cogn 2014; 92C:101-111. [DOI: 10.1016/j.bandc.2014.10.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 10/20/2014] [Accepted: 10/23/2014] [Indexed: 01/03/2023]
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23
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Abstract
Left-right asymmetries have likely evolved to make optimal use of bilaterian nervous systems; however, little is known about the synaptic and circuit mechanisms that support divergence of function between equivalent structures in each hemisphere. Here we examined whether lateralized hippocampal memory processing is present in mice, where hemispheric asymmetry at the CA3-CA1 pyramidal neuron synapse has recently been demonstrated, with different spine morphology, glutamate receptor content, and synaptic plasticity, depending on whether afferents originate in the left or right CA3. To address this question, we used optogenetics to acutely silence CA3 pyramidal neurons in either the left or right dorsal hippocampus while mice performed hippocampus-dependent memory tasks. We found that unilateral silencing of either the left or right CA3 was sufficient to impair short-term memory. However, a striking asymmetry emerged in long-term memory, wherein only left CA3 silencing impaired performance on an associative spatial long-term memory task, whereas right CA3 silencing had no effect. To explore whether synaptic properties intrinsic to the hippocampus might contribute to this left-right behavioral asymmetry, we investigated the expression of hippocampal long-term potentiation. Following the induction of long-term potentiation by high-frequency electrical stimulation, synapses between CA3 and CA1 pyramidal neurons were strengthened only when presynaptic input originated in the left CA3, confirming an asymmetry in synaptic properties. The dissociation of hippocampal long-term memory function between hemispheres suggests that memory is routed via distinct left-right pathways within the mouse hippocampus, and provides a promising approach to help elucidate the synaptic basis of long-term memory.
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24
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O'Reilly KC, Alarcon JM, Ferbinteanu J. Relative contributions of CA3 and medial entorhinal cortex to memory in rats. Front Behav Neurosci 2014; 8:292. [PMID: 25221487 PMCID: PMC4148030 DOI: 10.3389/fnbeh.2014.00292] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 08/10/2014] [Indexed: 01/03/2023] Open
Abstract
The hippocampal CA1 field processes spatial information, but the relative importance of intra- vs. extra-hippocampal sources of input into CA1 for spatial behavior is unclear. To characterize the relative roles of these two sources of input, originating in the hippocampal field CA3 and in the medial entorhinal cortex (MEC), we studied effects of discrete neurotoxic lesions of CA3 or MEC on concurrent spatial and nonspatial navigation tasks, and on synaptic transmission in afferents to CA1. Lesions in CA3 or MEC regions that abolished CA3-CA1, or reduced MEC-CA1 synaptic transmission, respectively, impaired spatial navigation and unexpectedly interfered with cue response, suggesting that in certain conditions of training regimen, hippocampal activity may influence behavior otherwise supported by nonhippocampal neural networks. MEC lesions had milder and temporary behavioral effects, but also markedly amplified transmission in the CA3-CA1 pathway. Extensive behavioral training had a similar, but more modest effect on CA3-CA1 transmission. Thus, cortical input to the hippocampus modulates CA1 activity both directly and indirectly, through heterosynaptic interaction, to control information flow in the hippocampal loop. Following damage to hippocampal cortical input, the functional coupling of separate intra- and extra-hippocampal inputs to CA1 involved in normal learning may initiate processes that support recovery of behavioral function. Such a process may explain how CA3 lesions, which do not significantly modify the basic features of CA1 neural activity, nonetheless impair spatial recall, whereas lesions of EC input to CA1, which reduce the spatial selectivity of CA1 firing in foraging rats, have only mild effects on spatial navigation.
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Affiliation(s)
- Kally C O'Reilly
- Center for Neural Science, New York University New York, NY, USA
| | - Juan M Alarcon
- Department of Pathology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center Brooklyn, NY, USA
| | - Janina Ferbinteanu
- Division of Neuroscience, Department of Physiology and Pharmacology, SUNY Downstate Medical Center Brooklyn, NY, USA
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25
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Lu B, Ma Z, Cheng F, Zhao Y, Zhang X, Mao H, Shen X, Liu S. Effects of electroacupuncture on ethanol-induced impairments of spatial learning and memory and Fos expression in the hippocampus in rats. Neurosci Lett 2014; 576:62-7. [PMID: 24923763 DOI: 10.1016/j.neulet.2014.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/26/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
Abstract
It is well established that alcohol impairs spatial learning and memory. Here, we investigated the effects of electroacupuncture (EA) at ST36 or nonacupoint on ethanol-induced learning and memory impairment and the expression of Fos in the hippocampus. Ethanol (5g/kg) was administered intragastrically once a day for 5 consecutive days; 2Hz EA was administered immediately after ethanol exposure. After a 2-day ethanol abstinence, for 6 consecutive days, the rats were submitted to Morris water maze training. Probe trials were performed on 1 day after the final training session. We also applied immunohistochemistry to detect Fos-positive nuclei in the hippocampus. We found that 5-day ethanol exposure markedly decreased spatial learning and memory abilities in the Morris water maze task as indicated by escape latency and time in the target quadrant. EA treatment shortened the time of reaching platform and increased times traveled in the target quadrant (P<0.05). Animals administered with ethanol emitted significantly fewer Fos expression in the hippocampal CA1 area. EA increased Fos expression in the hippocampal CA1 area. Significant correlations were obtained between Fos protein expression in CA1 and time in the target quadrant. Altogether, these results suggest that EA protects against ethanol-induced impairments of spatial learning and memory, which may be involved in the hippocampal CA1 area. EA treatment may provide a novel nonpharmacological strategy for ethanol-induced learning and memory impairment.
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Affiliation(s)
- Bin Lu
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Zhao Ma
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Fei Cheng
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Yan Zhao
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Xin Zhang
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Huijuan Mao
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Xueyong Shen
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China
| | - Sheng Liu
- Shanghai University of Traditional Chinese Medicine, 1200 Cailun Rd, Shanghai 200032, China.
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Inoue N, Watanabe S. Effects of reversible deactivation of mossy fibers in the dentate-CA3 system on geometric center detection task in mice: Functional separation of spatial learning and its generalization to new environment. Physiol Behav 2014; 131:75-80. [PMID: 24732418 DOI: 10.1016/j.physbeh.2014.04.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 02/28/2014] [Accepted: 04/04/2014] [Indexed: 11/19/2022]
Abstract
Using diethyldithiocarbamate (DEDTC), a zinc chelator, we deactivated the mossy fibers that project from the dentate gyrus (DG) to the CA3 during acquisition and testing of a center detection task in mice. The mice were trained to find a food pellet at the center of four objects in a circular area. DEDTC injection just before the training sessions impaired this learning, whereas DEDTC injection before the probe test did not impair recall of the memory. DEDTC injection before a pattern completion test in which only one of the four objects was presented did not cause deficits in this test. DEDTC injection did, however, cause severe deficits in an array shift test in which all four objects were moved to new positions. These results demonstrated that 1) the DG-CA3 system plays a crucial role in the learning of geometric center detection task but not in its recall or pattern completion, and 2) the DG-CA3 system is involved in generalization to a new environment but is not crucial for pattern completion.
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Affiliation(s)
- Naomi Inoue
- Department of Psychology, Keio University, 2-2-24 Mita, Minato-ku, Tokyo 108-8345, Japan
| | - Shigeru Watanabe
- Department of Psychology, Keio University, 2-2-24 Mita, Minato-ku, Tokyo 108-8345, Japan.
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Morris AM, Curtis BJ, Churchwell JC, Maasberg DW, Kesner RP. Temporal associations for spatial events: the role of the dentate gyrus. Behav Brain Res 2013; 256:250-6. [PMID: 23973766 DOI: 10.1016/j.bbr.2013.08.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 08/12/2013] [Accepted: 08/14/2013] [Indexed: 12/30/2022]
Abstract
Previous research suggests that the dorsal dentate gyrus (DG) hippocampal subregion mediates spatial processing functions. However, a novel role for the DG in temporal processing for spatial information has begun to emerge based on the development of a computational model of neurogenesis. According to this model, adult born granule cells in the DG contribute to a temporal associative integration process for events presented closer in time. Currently, there is a paucity of behavioral evidence to support the temporal integration theory. Therefore, we developed a novel behavioral paradigm to investigate the role of the dDG in temporal integration for proximal and distal spatial events. Male Long-Evans rats were randomly assigned to a control group or to receive bilateral intracranial infusions of colchicine into the dDG. Following recovery from surgery, each rat was tested on a cued-recall of sequence paradigm. In this task, animals were allowed to explore identical objects placed in designated spatial locations on a cheeseboard maze across 2 days (e.g., Day 1: A and B; Day 2: C and D). One week later, animals were given a brief cue (A or C) followed by a preference test between spatial location B and D. Control animals had a significant preference for the spatial location previously paired with the cue (the temporal associate) whereas dDG lesioned animals failed to show a preference. These findings suggest that selective colchicine-induced dDG lesions are capable of disrupting the formation of temporal associations between spatial events presented close in time.
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Affiliation(s)
- Andrea M Morris
- Department of Psychology, University of Utah, Salt Lake City, UT, USA
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Gould TJ, Leach PT. Cellular, molecular, and genetic substrates underlying the impact of nicotine on learning. Neurobiol Learn Mem 2013; 107:108-32. [PMID: 23973448 DOI: 10.1016/j.nlm.2013.08.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 08/13/2013] [Accepted: 08/13/2013] [Indexed: 12/27/2022]
Abstract
Addiction is a chronic disorder marked by long-lasting maladaptive changes in behavior and in reward system function. However, the factors that contribute to the behavioral and biological changes that occur with addiction are complex and go beyond reward. Addiction involves changes in cognitive control and the development of disruptive drug-stimuli associations that can drive behavior. A reason for the strong influence drugs of abuse can exert on cognition may be the striking overlap between the neurobiological substrates of addiction and of learning and memory, especially areas involved in declarative memory. Declarative memories are critically involved in the formation of autobiographical memories, and the ability of drugs of abuse to alter these memories could be particularly detrimental. A key structure in this memory system is the hippocampus, which is critically involved in binding multimodal stimuli together to form complex long-term memories. While all drugs of abuse can alter hippocampal function, this review focuses on nicotine. Addiction to tobacco products is insidious, with the majority of smokers wanting to quit; yet the majority of those that attempt to quit fail. Nicotine addiction is associated with the presence of drug-context and drug-cue associations that trigger drug seeking behavior and altered cognition during periods of abstinence, which contributes to relapse. This suggests that understanding the effects of nicotine on learning and memory will advance understanding and potentially facilitate treating nicotine addiction. The following sections examine: (1) how the effects of nicotine on hippocampus-dependent learning change as nicotine administration transitions from acute to chronic and then to withdrawal from chronic treatment and the potential impact of these changes on addiction, (2) how nicotine usurps the cellular mechanisms of synaptic plasticity, (3) the physiological changes in the hippocampus that may contribute to nicotine withdrawal deficits in learning, and (4) the role of genetics and developmental stage (i.e., adolescence) in these effects.
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Affiliation(s)
- Thomas J Gould
- Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, United States.
| | - Prescott T Leach
- Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
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29
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Conejo NM, Cimadevilla JM, González-Pardo H, Méndez-Couz M, Arias JL. Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity. PLoS One 2013; 8:e64749. [PMID: 23724089 PMCID: PMC3665627 DOI: 10.1371/journal.pone.0064749] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 04/16/2013] [Indexed: 01/16/2023] Open
Abstract
Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions.
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Affiliation(s)
- Nélida María Conejo
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Oviedo, Spain.
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30
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Kesner RP. A process analysis of the CA3 subregion of the hippocampus. Front Cell Neurosci 2013; 7:78. [PMID: 23750126 PMCID: PMC3664330 DOI: 10.3389/fncel.2013.00078] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 05/08/2013] [Indexed: 12/30/2022] Open
Abstract
From a behavioral perspective, the CA3a,b subregion of the hippocampus plays an important role in the encoding of new spatial information within short-term memory with a duration of seconds and minutes. This can easily be observed in tasks that require rapid encoding, novelty detection, one-trial short-term or working memory, and one-trial cued recall primarily for spatial information. These are tasks that have been assumed to reflect the operations of episodic memory and require interactions between CA3a,b and the dentate gyrus (DG) via mossy fiber inputs into the CA3a,b. The CA3a,b is also important for encoding of spatial information requiring the acquisition of arbitrary and relational associations. All these tasks are assumed to operate within an autoassociative network function of the CA3 region. The CA3a,b also supports retrieval of short-term memory information based on a spatial pattern completion process. Based on afferent inputs into CA3a,b from the DG via mossy fibers and afferents from the entorhinal cortex into CA3a,b as well as reciprocal connections with the septum, CA3a,b can bias the process of encoding utilizing the operation of spatial pattern separation and the process of retrieval utilizing the operation of pattern completion. The CA3a,b also supports sequential processing of information in cooperation with CA1 based on the Schaffer collateral output from CA3a,b to CA1. The CA3c function is in part based on modulation of the DG in supporting pattern separation processes.
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Affiliation(s)
- Raymond P Kesner
- Department of Psychology, University of Utah Salt Lake City, UT, USA
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31
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Hunsaker MR. The importance of considering all attributes of memory in behavioral endophenotyping of mouse models of genetic disease. Behav Neurosci 2013; 126:371-80. [PMID: 22642882 DOI: 10.1037/a0028453] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In order to overcome difficulties in evaluating cognitive function in mouse models of genetic disorders, it is critical to take into account the background strain of the mouse and reported phenotypes in the clinical population being studied. Recent studies have evaluated cognitive function across a number of background strains and found that spatial memory assayed by the water maze and contextual fear conditioning often does not provide optimal results. The logical extension to these results is to emphasize not only spatial, but all attributes or domains of memory function in behavioral phenotyping experiments. A careful evaluation of spatial, temporal, sensory/perceptual, affective, response, executive, proto-linguistic, and social behaviors designed to specifically evaluate the cognitive function each mouse model can be performed in a rapid, relatively high throughput manner. Such results would not only provide a more comprehensive snapshot of brain function in mouse disease models than the more common approach that approaches nonspecific spatial memory tasks to evaluate cognition, but also would better model the disorders being studied.
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Affiliation(s)
- Michael R Hunsaker
- Department of Neurological Surgery, University of California, Davis, CA 95616, USA.
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32
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Brim BL, Haskell R, Awedikian R, Ellinwood N, Jin L, Kumar A, Foster T, Magnusson K. Memory in aged mice is rescued by enhanced expression of the GluN2B subunit of the NMDA receptor. Behav Brain Res 2013; 238:211-26. [PMID: 23103326 PMCID: PMC3540206 DOI: 10.1016/j.bbr.2012.10.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 10/09/2012] [Accepted: 10/13/2012] [Indexed: 11/26/2022]
Abstract
The GluN2B subunit of the N-methyl-d-aspartate (NMDA) receptor shows age-related declines in expression across the frontal cortex and hippocampus. This decline is strongly correlated to age-related memory declines. This study was designed to determine if increasing GluN2B subunit expression in the frontal lobe or hippocampus would improve memory in aged mice. Mice were injected bilaterally with either the GluN2B vector, containing cDNA specific for the GluN2B subunit and enhanced green fluorescent protein (eGFP); a control vector or vehicle. Spatial memory, cognitive flexibility, and associative memory were assessed using the Morris water maze. Aged mice, with increased GluN2B subunit expression, exhibited improved long-term spatial memory, comparable to young mice. However, memory was rescued on different days in the Morris water maze; early for hippocampal GluN2B subunit enrichment and later for the frontal lobe. A higher concentration of the GluN2B antagonist, Ro 25-6981, was required to impair long-term spatial memory in aged mice with enhanced GluN2B expression, as compared to aged controls, suggesting there was an increase in the number of GluN2B-containing NMDA receptors. In addition, hippocampal slices from aged mice with increased GluN2B subunit expression exhibited enhanced NMDA receptor-mediated excitatory post-synaptic potentials (EPSP). Treatment with Ro 25-6981 showed that a greater proportion of the NMDA receptor-mediated EPSP was due to the GluN2B subunit in these animals, as compared to aged controls. These results suggest that increasing the production of the GluN2B subunit in aged animals enhances memory and synaptic transmission. Therapies that enhance GluN2B subunit expression within the aged brain may be useful for ameliorating age-related memory declines.
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Affiliation(s)
- B. L. Brim
- Molecular and Cellular Biosciences Program, Oregon State University, Corvallis, OR, 97331, U.S.A
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, U.S.A
- Healthy Aging Program, Linus Pauling Institute, Oregon State University, Corvallis, OR; 97331, U.S.A
| | - R. Haskell
- ViraQuest, Inc., North Liberty, IA; 52317, U.S.A
| | - R. Awedikian
- Department of Animal Sciences, Iowa State University, Ames, IA, 50011, U.S.A
| | - N.M. Ellinwood
- Department of Animal Sciences, Iowa State University, Ames, IA, 50011, U.S.A
| | - L. Jin
- Molecular and Cellular Biosciences Program, Oregon State University, Corvallis, OR, 97331, U.S.A
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, U.S.A
| | - A. Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, 32611, U.S.A
| | - T.C. Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, 32611, U.S.A
| | - K. Magnusson
- Molecular and Cellular Biosciences Program, Oregon State University, Corvallis, OR, 97331, U.S.A
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, U.S.A
- Healthy Aging Program, Linus Pauling Institute, Oregon State University, Corvallis, OR; 97331, U.S.A
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Morris AM, Weeden CS, Churchwell JC, Kesner RP. The role of the dentate gyrus in the formation of contextual representations. Hippocampus 2012; 23:162-8. [PMID: 23034739 DOI: 10.1002/hipo.22078] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2012] [Indexed: 11/06/2022]
Abstract
The hippocampus is involved in encoding and integrating contextual information. Recently, it has been suggested that the dorsal dentate gyrus (dDG) hippocampal subregion may mediate the formation of contextual representations of the spatial environment through a conjunctive encoding process whereby incoming multimodal information is integrated into a single higher-order representation. Despite anatomical evidence in support of this claim, behavioral evidence is limited. Therefore, a contextual associative learning paradigm was used to determine whether the dDG supports the formation of integrated contextual representations. Male Long-Evans rats were randomly assigned as controls or to receive bilateral intracranial infusions of colchicine into the dDG. Following recovery from surgery, each rat was tested on an appetitive task that required animals to form an association between a cue (odor) and a context to receive a food reward. Each rat received 10 trials per day and was tested for 10 consecutive days. Upon completion of testing, animals were tested on an additional two-choice olfactory and contextual discrimination task. The testing order was counterbalanced across animals. Results showed that control animals successfully acquired the contextual associative learning task for olfactory stimuli as indicated by improved performance across the 10 testing days. In contrast, animals with dDG lesions were impaired in the ability to acquire the odor-context associations. Results from follow-up odor and context discrimination tests indicated that both groups acquired the discriminations at similar rates. Therefore, it is unlikely that deficits in performance on the contextual associative learning task were due to an inability to discriminate between odors or contexts. The present findings provide further support for DG involvement in the formation of conjunctive contextual representations.
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Affiliation(s)
- Andrea M Morris
- Department of Psychology, University of Utah, Salt Lake City, Utah 84112, USA
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34
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Similarities and differences between the brain networks underlying allocentric and egocentric spatial learning in rat revealed by cytochrome oxidase histochemistry. Neuroscience 2012; 223:174-82. [DOI: 10.1016/j.neuroscience.2012.07.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 07/27/2012] [Accepted: 07/30/2012] [Indexed: 11/18/2022]
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Blueberry supplementation induces spatial memory improvements and region-specific regulation of hippocampal BDNF mRNA expression in young rats. Psychopharmacology (Berl) 2012; 223:319-30. [PMID: 22569815 DOI: 10.1007/s00213-012-2719-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 04/03/2012] [Indexed: 12/29/2022]
Abstract
RATIONALE Flavonoid-rich foods have been shown to be able to reverse age-related cognitive deficits in memory and learning in both animals and humans. However, to date, there have been only a limited number of studies investigating the effects of flavonoid-rich foods on cognition in young/healthy animals. OBJECTIVES The aim of this study was to investigate the effects of a blueberry-rich diet in young animals using a spatial working memory paradigm, the delayed non-match task, using an eight-arm radial maze. Furthermore, the mechanisms underlying such behavioural effects were investigated. RESULTS We show that a 7-week supplementation with a blueberry diet (2 % w/w) improves the spatial memory performance of young rats (2 months old). Blueberry-fed animals also exhibited a faster rate of learning compared to those on the control diet. These behavioural outputs were accompanied by the activation of extracellular signal-related kinase (ERK1/2), increases in total cAMP-response element-binding protein (CREB) and elevated levels of pro- and mature brain-derived neurotrophic factor (BDNF) in the hippocampus. Changes in hippocampal CREB correlated well with memory performance. Further regional analysis of BDNF gene expression in the hippocampus revealed a specific increase in BDNF mRNA in the dentate gyrus and CA1 areas of hippocampi of blueberry-fed animals. CONCLUSIONS The present study suggests that consumption of flavonoid-rich blueberries has a positive impact on spatial learning performance in young healthy animals, and these improvements are linked to the activation of ERK-CREB-BDNF pathway in the hippocampus.
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Kabadi SV, Stoica BA, Hanscom M, Loane DJ, Kharebava G, Murray II MG, Cabatbat RM, Faden AI. CR8, a selective and potent CDK inhibitor, provides neuroprotection in experimental traumatic brain injury. Neurotherapeutics 2012; 9:405-21. [PMID: 22167461 PMCID: PMC3324621 DOI: 10.1007/s13311-011-0095-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Traumatic brain injury (TBI) induces secondary injury mechanisms, including cell cycle activation (CCA), that leads to neuronal death and neurological dysfunction. We recently reported that delayed administration of roscovitine, a relatively selective cyclin-dependent kinase (CDK) inhibitor, inhibits CCA and attenuates neurodegeneration and functional deficits following controlled cortical impact (CCI) injury in mice. Here we evaluated the neuroprotective potential of CR8, a more potent second-generation roscovitine analog, using the mouse CCI model. Key CCA markers (cyclin A and B1) were significantly up-regulated in the injured cortex following TBI, and phosphorylation of CDK substrates was increased. Central administration of CR8 after TBI, at a dose 20 times less than previously required for roscovitine, attenuated CCA pathways and reduced post-traumatic apoptotic cell death at 24 h post-TBI. Central administration of CR8, at 3 h after TBI, significantly attenuated sensorimotor and cognitive deficits, decreased lesion volume, and improved neuronal survival in the cortex and dentate gyrus. Moreover, unlike roscovitine treatment in the same model, CR8 also attenuated post-traumatic neurodegeneration in the CA3 region of the hippocampus and thalamus at 21 days. Furthermore, delayed systemic administration of CR8, at a dose 10 times less than previously required for roscovitine, significantly improved cognitive performance after CCI. These findings further demonstrate the neuroprotective potential of cell cycle inhibitors following experimental TBI. Given the increased potency and efficacy of CR8 as compared to earlier purine analog types of CDK inhibitors, this drug should be considered as a candidate for future clinical trials of TBI.
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Affiliation(s)
- Shruti V. Kabadi
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Bogdan A. Stoica
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Marie Hanscom
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - David J. Loane
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Giorgi Kharebava
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Michael G. Murray II
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Rainier M. Cabatbat
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Alan I. Faden
- Department of Anesthesiology, Center for Shock, Trauma, and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD 21201 USA
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Morris AM, Churchwell JC, Kesner RP, Gilbert PE. Selective lesions of the dentate gyrus produce disruptions in place learning for adjacent spatial locations. Neurobiol Learn Mem 2012; 97:326-31. [PMID: 22390856 DOI: 10.1016/j.nlm.2012.02.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 01/19/2012] [Accepted: 02/06/2012] [Indexed: 01/10/2023]
Abstract
The hippocampus (HPP) plays a known role in learning novel spatial information. More specifically, the dentate gyrus (DG) hippocampal subregion is thought to support pattern separation, a mechanism for encoding and separating spatially similar events into distinct representations. Several studies have shown that lesions of the dorsal DG (dDG) in rodents result in inefficient spatial pattern separation for working memory; however, it is unclear whether selective dDG lesions disrupt spatial pattern separation for reference memory. Therefore, the current study investigated the role of the dDG in pattern separation using a spatial reference memory paradigm to determine whether the dDG is necessary for acquiring spatial discriminations for adjacent locations. Male Long-Evans rats were randomly assigned to receive bilateral intracranial infusions of colchicine or saline (control) into the dDG. Following recovery from surgery, each rat was pseudo-randomly assigned to an adjacent arm or separate arm condition and subsequently tested on a place-learning task using an eight-arm radial maze. Rats were trained to discriminate between a rewarded arm and a nonrewarded arm that were either adjacent to one another or separated by a distance of two arm positions. Each rat received 10 trials per day and was tested until the animal reached a criterion of nine correct choices out of 10 consecutive trials across 2 consecutive days of testing. Both groups acquired spatial discriminations for the separate condition at similar rates. However, in the adjacent condition, dDG lesioned animals required significantly more trials to reach the learning criterion than controls. The results suggest that dDG lesions decrease efficiency in pattern separation resulting in impairments in the adjacent condition involving greater overlap among the distal cues. Conversely, in the separate condition, there was less overlap among distal cues during encoding and less need for pattern separation. These findings provide further support for a critical role for the dDG in spatial pattern separation by demonstrating the importance of a processing mechanism that is capable of reducing interference among overlapping spatial inputs across a variety of memory demands.
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Affiliation(s)
- Andrea M Morris
- Department of Psychology, University of Utah, Salt Lake City, UT 84112, USA
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38
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Gutiérrez-Guzmán BE, Hernández-Pérez JJ, López-Vázquez MÁ, Fregozo CS, Guevara MÁ, Olvera-Cortés ME. Serotonin depletion of supramammillary/posterior hypothalamus nuclei produces place learning deficiencies and alters the concomitant hippocampal theta activity in rats. Eur J Pharmacol 2012; 682:99-109. [PMID: 22387092 DOI: 10.1016/j.ejphar.2012.02.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 02/10/2012] [Accepted: 02/15/2012] [Indexed: 11/25/2022]
Abstract
Hippocampal theta activity is important for the acquisition of spatial information and is strongly influenced and regulated by extra-hippocampal inputs from the synchronising ascending system (SAS), which includes the supramammillary nucleus (SUMn) and the posterior hypothalamic nucleus (PHn). Together these nuclei play an important role in controlling the frequency encoding of theta activity and are innervated by serotonin synapses, which also regulate theta activity and learning abilities. The participation of the SUMn in place learning and modulation of hippocampal theta activity were recently shown; thus, we questioned whether serotonin acting on SUMn/PHn could modulate place learning ability and concurrent hippocampal theta activity. The serotonergic terminals of the SUMn/PHn in rats were lesioned through 5,7-dihydroxytryptamine (5,7-DHT) infusion, and hippocampal theta activity during the Morris water maze test was recorded. Rats in the vehicle group learned the task efficiently and showed learning-related theta changes in the CA1 and dentate gyrus regions throughout the training. The 5-HT-depleted rats were deficient in the Morris water maze task and showed theta activity in the CA1 and dentate gyrus that were unrelated to the processing of learning. We conclude that serotonin can regulate the hippocampal theta activity acting on the SUMn/PHn relay of the SAS and that the influence of 5-HT in these nuclei is required for the learning-related changes in hippocampal theta activity that underlie the successful resolution of the Morris water maze task.
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Affiliation(s)
- Blanca Erika Gutiérrez-Guzmán
- Laboratorio de Neurofisiología Experimental, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Camino de la Arboleda # 300, Ex-hacienda de San José de la Huerta, C.P. 58341, Morelia, Mich., México.
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Capilla-Gonzalez V, Hernandez-Rabaza V. Cocaine and MDMA Induce Cellular and Molecular Changes in Adult Neurogenic Systems: Functional Implications. Pharmaceuticals (Basel) 2011. [PMCID: PMC4055961 DOI: 10.3390/ph4060915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The capacity of the brain to generate new adult neurons is a recent discovery that challenges the old theory of an immutable adult brain. A new and fascinating field of research now focuses on this regenerative process. The two brain systems that constantly produce new adult neurons, known as the adult neurogenic systems, are the dentate gyrus (DG) of the hippocampus and the lateral ventricules/olfactory bulb system. Both systems are involved in memory and learning processes. Different drugs of abuse, such as cocaine and MDMA, have been shown to produce cellular and molecular changes that affect adult neurogenesis. This review summarizes the effects that these drugs have on the adult neurogenic systems. The functional relevance of adult neurogenesis is obscured by the functions of the systems that integrate adult neurons. Therefore, we explore the effects that cocaine and MDMA produce not only on adult neurogenesis, but also on the DG and olfactory bulbs. Finally, we discuss the possible role of new adult neurons in cocaine- and MDMA-induced impairments. We conclude that, although harmful drug effects are produced at multiple physiological and anatomical levels, the specific consequences of reduced hippocampus neurogenesis are unclear and require further exploration.
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Affiliation(s)
- Vivian Capilla-Gonzalez
- Laboratory of Comparative Neurobiology, Instituto Cavanilles de Biodiversidad y Biologia Evolutiva, Universidad de Valencia, Catedratico Jose Beltran 2, 46980, Paterna, Valencia, Spain
- Brain Tumor Stem Cell Laboratory, Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA
| | - Vicente Hernandez-Rabaza
- Laboratory of Neurobiology, Centro de Investigacion Principe Felipe, Avda Autopista del Saler 16, 46012, Valencia, Spain
- Author to whom correspondence should be addressed; E-Mail: ; Tel: +34-96-328-9680; Fax: +34-96-328-9701
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NMDA receptors are not required for pattern completion during associative memory recall. PLoS One 2011; 6:e19326. [PMID: 21559402 PMCID: PMC3084823 DOI: 10.1371/journal.pone.0019326] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 03/26/2011] [Indexed: 01/09/2023] Open
Abstract
Pattern completion, the ability to retrieve complete memories initiated by subsets of external cues, has been a major focus of many computation models. A previously study reports that such pattern completion requires NMDA receptors in the hippocampus. However, such a claim was derived from a non-inducible gene knockout experiment in which the NMDA receptors were absent throughout all stages of memory processes as well as animal's adult life. This raises the critical question regarding whether the previously described results were truly resulting from the requirement of the NMDA receptors in retrieval. Here, we have examined the role of the NMDA receptors in pattern completion via inducible knockout of NMDA receptors limited to the memory retrieval stage. By using two independent mouse lines, we found that inducible knockout mice, lacking NMDA receptor in either forebrain or hippocampus CA1 region at the time of memory retrieval, exhibited normal recall of associative spatial reference memory regardless of whether retrievals took place under full-cue or partial-cue conditions. Moreover, systemic antagonism of NMDA receptor during retention tests also had no effect on full-cue or partial-cue recall of spatial water maze memories. Thus, both genetic and pharmacological experiments collectively demonstrate that pattern completion during spatial associative memory recall does not require the NMDA receptor in the hippocampus or forebrain.
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Kesner RP, Hunsaker MR. The temporal attributes of episodic memory. Behav Brain Res 2010; 215:299-309. [DOI: 10.1016/j.bbr.2009.12.029] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 12/15/2009] [Accepted: 12/20/2009] [Indexed: 11/26/2022]
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Kesner RP, Goodrich-Hunsaker NJ. Developing an animal model of human amnesia: The role of the hippocampus. Neuropsychologia 2010; 48:2290-302. [DOI: 10.1016/j.neuropsychologia.2009.10.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 08/27/2009] [Accepted: 10/26/2009] [Indexed: 11/16/2022]
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Jilg A, Lesny S, Peruzki N, Schwegler H, Selbach O, Dehghani F, Stehle JH. Temporal dynamics of mouse hippocampal clock gene expression support memory processing. Hippocampus 2010; 20:377-88. [PMID: 19437502 DOI: 10.1002/hipo.20637] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hippocampal plasticity and mnemonic processing exhibit a striking time-of-day dependence and likely implicate a temporally structured replay of memory traces. Molecular mechanisms fulfilling the requirements of sensing time and capturing time-related information are coded in dynamics of so-called clock genes and their protein products, first discovered and described in the hypothalamic suprachiasmatic nucleus. Using real-time PCR and immunohistochemical analyses, we show that in wildtype mice core clock components (mPer1/PER1, mPer2/PER2, mCry1/CRY1, mCry2/CRY2, mClock/CLOCK, mBmal1/BMAL1) are expressed in neurons of all subregions of the hippocampus in a time-locked fashion over a 24-h (diurnal) day/night cycle. Temporal profiling of these transcriptional regulators reveals distinct and parallel peaks, at times when memory traces are usually formed and/or consolidated. The coordinated rhythmic expression of hippocampal clock gene expression is greatly disordered in mice deficient for the clock gene mPer1, a key player implicated in both, maintenance and adaptative plasticity of circadian clocks. Moreover, Per1-knockout animals are severely handicapped in a hippocampus-dependent long-term spatial learning paradigm. We propose that the dynamics of hippocampal clock gene expression imprint a temporal structure on memory processing and shape at the same time the efficacy of behavioral learning.
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Affiliation(s)
- Antje Jilg
- Institute of Cellular and Molecular Anatomy, Dr. Senckenbergische Anatomie, Goethe-University, Frankfurt, Germany
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Sil'kis IG. Paradoxical sleep as a tool for understanding the hippocampal mechanisms of contextual memory. NEUROSCIENCE AND BEHAVIORAL PHYSIOLOGY 2009; 40:5-19. [PMID: 20012489 DOI: 10.1007/s11055-009-9230-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Accepted: 02/27/2008] [Indexed: 11/30/2022]
Abstract
Existing data on the involvement of the hippocampus in contextual memory and the fact that contextual memory is impaired in dreams occurring during paradoxical sleep allowed us to suggest that one of the causes of this impairment consists of changes in the efficiency of synaptic transmission in the hippocampus due to increases (as compared with waking) in the concentrations of acetylcholine, dopamine, and cortisol, as well as the absence of serotonin and noradrenaline. Our previous analysis showed that in paradoxical sleep, long-term depression can be induced all components of the polysynaptic pathway through the hippocampal formation, while potentiation can occur at the inputs from the entorhinal cortex to hippocampal fields CA1 and CA3 and in the associative connections in field CA3. It is hypothesized that the correct functioning of episodic memory requires efficient transmission of signals in each component of the polysynaptic pathway through the hippocampus, allowing a neuronal representation of the context to be created within it. In the state of waking, reproduction of the context of an episode simultaneously activates the neuronal representation of the context remembered in the hippocampus and neuronal representations of the details of the episode remembered in those areas of the cortex in which they were processed. It follows from the proposed mechanism that any neurotransmitter or neuropeptide able to promote longterm potentiation in all components of the polysynaptic pathway through the hippocampus can improve episodic memory. As the consequences of the mechanism are consistent with experimental data, it can be used to seek agents improving episodic memory.
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Affiliation(s)
- I G Sil'kis
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
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The impact of flavonoids on spatial memory in rodents: from behaviour to underlying hippocampal mechanisms. GENES AND NUTRITION 2009; 4:251-70. [PMID: 19727888 DOI: 10.1007/s12263-009-0137-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Accepted: 07/28/2009] [Indexed: 12/15/2022]
Abstract
Emerging evidence suggests that a group of dietary-derived phytochemicals known as flavonoids are able to induce improvements in memory, learning and cognition. Flavonoids have been shown to modulate critical neuronal signalling pathways involved in processes of memory, and therefore are likely to affect synaptic plasticity and long-term potentiation mechanisms, widely considered to provide a basis for memory. Animal dietary supplementation studies have further shown that flavonoid-rich foods are able to reverse age-related spatial memory and spatial learning impairments. A more accurate understanding of how a particular spatial memory task works and of which aspects of memory and learning can be assessed in each case, are necessary for a correct interpretation of data relating to diet-cognition experiments. Further understanding of how specific behavioural tasks relate to the functioning of hippocampal circuitry during learning processes might be also elucidative of the specific observed memory improvements. The overall goal of this review is to give an overview of how the hippocampal circuitry operates as a memory system during behavioural tasks, which we believe will provide a new insight into the underlying mechanisms of the action of flavonoids on cognition.
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Gilbert PE, Brushfield AM. The role of the CA3 hippocampal subregion in spatial memory: a process oriented behavioral assessment. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:774-81. [PMID: 19375477 PMCID: PMC2743458 DOI: 10.1016/j.pnpbp.2009.03.037] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2009] [Accepted: 03/30/2009] [Indexed: 10/20/2022]
Abstract
Computational models, behavioral data, and electrophysiological data suggest that the CA3 subregion of the hippocampus may support multiple mnemonic processes critical to the formation and subsequent retrieval of spatial memories. Multiple researchers have proposed that the CA3 subregion contains an autoassociative network in which synaptic connections between CA3 neurons that represent different components of a memory are strengthened via recurrent collateral connections. As a result, it has been suggested that the CA3 autoassociative network may support multiple processes including the formation of spatial arbitrary associations, temporary maintenance of spatial working memory, and spatial pattern completion. In addition, the CA3 subregion has been suggested to be involved in spatial pattern separation. The separation of patterns is hypothesized to be accomplished based on the low probability that any two CA3 neurons will receive mossy-fiber input synapses from a similar subset of dentate gyrus cells. The separation of patterns also may be enhanced by competitive inhibition within CA3 and dentate gyrus. This review will focus on the mnemonic processes supported by CA3 neurons and how these processes may facilitate the encoding and retrieval of spatial information. Although there is growing evidence indicating that the hippocampus plays a role in the processing of nonspatial information as well, the scope of the present review will focus on the role of the CA3 subregion in spatial memory.
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Affiliation(s)
- Paul E. Gilbert
- Department of Psychology, San Diego State University, San Diego CA,San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego CA
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Hunsaker MR, Kesner RP. Evaluating the differential roles of the dorsal dentate gyrus, dorsal CA3, and dorsal CA1 during a temporal ordering for spatial locations task. Hippocampus 2009; 18:955-64. [PMID: 18493930 DOI: 10.1002/hipo.20455] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
It has been demonstrated that the dorsal CA1 subregion of the hippocampus mediates temporal processing of information, that dorsal CA3 participates in the spatiotemporal processing of memory, and the dorsal dentate gyrus (DG) mediates spatial pattern separation. A temporal ordering of spatial locations task was developed to test the role of the dorsal DG, CA3, and CA1 for the temporal processing of spatial information with either high or low levels of spatial interference. The results indicate that animals with DG lesions showed difficulty performing the task at high levels of spatial interference, but were able to perform the task well when there was low spatial interference. Animals with lesions to CA3 did not show a preference for either spatial location presented during the study phase during the preference test, suggesting impaired spatiotemporal processing. Animals with lesions to CA1 showed a preference for a later presented spatial location over the earlier, the opposite preference to that shown by control animals.
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Affiliation(s)
- Michael R Hunsaker
- Department of Psychology, University of Utah, Salt Lake City, Utah 84112, USA
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Hunsaker MR, Tran GT, Kesner RP. A double dissociation of subcortical hippocampal efferents for encoding and consolidation/retrieval of spatial information. Hippocampus 2008; 18:699-709. [PMID: 18493950 DOI: 10.1002/hipo.20429] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CA3 lesions impair encoding, whereas CA1 lesions impair retrieval during learning of a Hebb-Williams maze. CA3 efferents in the fimbria were transected, taking care to spare cholinergic and GABAergic afferents. CA1 efferents in the dorsal fornix were similarly transected. Fimbria transections, but not dorsal fornix transections, resulted in deficits for the encoding of spatial information during learning of a Hebb-Williams maze. Dorsal fornix, but not fimbria, transections resulted in deficits for retrieval of spatial memory during learning of a Hebb-Williams maze. These results reveal a double dissociation for the roles of CA3 and CA1 subcortical efferents in encoding and retrieval processes that mirror the double dissociation seen after excitotoxic lesions of CA1 and CA3. These data provide support for the theory that the cholinergic projections from the septal nuclei modulate the dynamics for encoding and consolidation/retrieval in the hippocampus.
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Affiliation(s)
- Michael R Hunsaker
- Department of Psychology, University of Utah, Salt Lake City, Utah 84112, USA
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Ji J, Maren S. Differential roles for hippocampal areas CA1 and CA3 in the contextual encoding and retrieval of extinguished fear. Learn Mem 2008; 15:244-51. [PMID: 18391185 DOI: 10.1101/lm.794808] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recent studies demonstrate that context-specific memory retrieval after extinction requires the hippocampus. However, the contribution of hippocampal subfields to the context-dependent expression of extinction is not known. In the present experiments, we examined the roles of areas CA1 and CA3 of the dorsal hippocampus in the context specificity of extinction. After pairing an auditory conditional stimulus (CS) with an aversive footshock (unconditional stimulus or US), rats received extinction sessions in which the CS was presented without the US. In Experiment 1, pretraining neurotoxic lesions in either CA1 or CA3 eliminated the context dependence of extinguished fear. In Experiment 2, lesions of CA1 or CA3 were made after extinction training. In this case, only CA1 lesions impaired the context dependence of extinction. Collectively, these results reveal that both hippocampal areas CA1 and CA3 contribute to the acquisition of context-dependent extinction, but that only area CA1 is required for contextual memory retrieval.
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Affiliation(s)
- Jinzhao Ji
- Department of Psychology, University of Michigan, Ann Arbor, Michigan 48109-1043, USA
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Vago DR, Bevan A, Kesner RP. The role of the direct perforant path input to the CA1 subregion of the dorsal hippocampus in memory retention and retrieval. Hippocampus 2008; 17:977-87. [PMID: 17604347 PMCID: PMC3057091 DOI: 10.1002/hipo.20329] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Subregional analyses of the hippocampus have suggested a selective role for the CA1 subregion in intermediate/long-term spatial memory and consolidation, but not short-term acquisition or encoding processes. It remains unclear how the direct cortical projection to CA1 via the perforant path (pp) contributes to these CA1-dependent processes. It has been suggested that dopamine selectively modulates the pp projection to CA1 while having little to no effect on the Schaffer collateral (SC) projection to CA1. This series of behavioral and electrophysiological experiments takes advantage of this pharmacological dissociation to demonstrate that the direct pp inputs to CA1 are critical in CA1-dependent intermediate-term retention and retrieval function. Here we demonstrate that local infusion of the nonselective dopamine agonist, apomorphine (10, 15 microg), into the CA1 subregion of awake animals produces impairments in between-day retention and retrieval, sparing within-day encoding of a modified Hebb-Williams maze and contextual conditioning of fear. In contrast, apomorphine produces no deficits when infused into the CA3 subregion. To complement the behavioral analyses, electrophysiological data was collected. In anesthetized animals, local infusion of the same doses of apomorphine significantly modifies evoked responses in the distal dendrites of CA1 following angular bundle stimulation, but produces no significant effects in the more proximal dendritic layer following stimulation of the SC. These results support a modulatory role for dopamine in the EC-CA1, but not CA3-CA1 circuitry, and suggest the possibility of a more fundamental role for EC-CA1 synaptic transmission in terms of intermediate-term, but not short-term spatial memory.
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Affiliation(s)
| | | | - Raymond P. Kesner
- Correspondence to: Raymond P. Kesner, Department of Psychology, University of Utah, 380 South, 1530 E, Rm. 502, Salt Lake City, UT 84112, USA.,
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