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Bishnoi A, Deshmukh SS. Comparable Theta Phase Coding Dynamics Along the Transverse Axis of CA1. Hippocampus 2024:e23641. [PMID: 39368076 DOI: 10.1002/hipo.23641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/02/2024] [Accepted: 09/19/2024] [Indexed: 10/07/2024]
Abstract
Topographical projection patterns from the entorhinal cortex to area CA1 of the hippocampus have led to a hypothesis that proximal CA1 (pCA1, closer to CA2) is spatially more selective than distal CA1 (dCA1, closer to the subiculum). While earlier studies have shown evidence supporting this hypothesis, we recently showed that this difference does not hold true under all experimental conditions. In a complex environment with distinct local texture cues on a circular track and global visual cues, pCA1 and dCA1 display comparable spatial selectivity. Correlated with the spatial selectivity differences, the earlier studies also showed differences in theta phase coding dynamics between pCA1 and dCA1 neurons. Here we show that there are no differences in theta phase coding dynamics between neurons in these two regions under the experimental conditions where pCA1 and dCA1 neurons are equally spatially selective. These findings challenge the established notion of dCA1 being inherently less spatially selective and theta modulated than pCA1 and suggest further experiments to understand theta-mediated activation of the CA1 sub-networks to represent space.
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Affiliation(s)
- Aditi Bishnoi
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India
| | - Sachin S Deshmukh
- Centre for Neuroscience, Indian Institute of Science, Bangalore, India
- Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, India
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Gomes-Ribeiro J, Martins J, Sereno J, Deslauriers-Gauthier S, Summavielle T, Coelho JE, Remondes M, Castelo-Branco M, Lopes LV. Mapping functional traces of opioid memories in the rat brain. Brain Commun 2024; 6:fcae281. [PMID: 39229487 PMCID: PMC11369824 DOI: 10.1093/braincomms/fcae281] [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: 01/07/2024] [Revised: 07/04/2024] [Accepted: 08/15/2024] [Indexed: 09/05/2024] Open
Abstract
Addiction to psychoactive substances is a maladaptive learned behaviour. Contexts surrounding drug use integrate this aberrant mnemonic process and hold strong relapse-triggering ability. Here, we asked where context and salience might be concurrently represented in the brain during retrieval of drug-context paired associations. For this, we developed a morphine-conditioned place preference protocol that allows contextual stimuli presentation inside a magnetic resonance imaging scanner and investigated differences in activity and connectivity at context recall. We found context-specific responses to stimulus onset in multiple brain regions, namely, limbic, sensory and striatal. Differences in functional interconnectivity were found among amygdala, lateral habenula, and lateral septum. We also investigated alterations to resting-state functional connectivity and found increased centrality of the lateral septum in a proposed limbic network, as well as increased functional connectivity of the lateral habenula and hippocampal 'cornu ammonis' 1 region, after a protocol of associative drug-context. Finally, we found that pre- conditioned place preference resting-state connectivity of the lateral habenula and amygdala was predictive of inter-individual conditioned place preference score differences. Overall, our findings show that drug and saline-paired contexts establish distinct memory traces in overlapping functional brain microcircuits and that intrinsic connectivity of the habenula, septum, and amygdala likely underlies the individual maladaptive contextual learning to opioid exposure. We have identified functional maps of acquisition and retrieval of drug-related memory that may support the relapse-triggering ability of opioid-associated sensory and contextual cues. These findings may clarify the inter-individual sensitivity and vulnerability seen in addiction to opioids found in humans.
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Affiliation(s)
- Joana Gomes-Ribeiro
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - João Martins
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - José Sereno
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- CQC, Chemistry Department, University of Coimbra, 3004-535 Coimbra, Portugal
| | | | - Teresa Summavielle
- Addiction Biology Group, i3S- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
- ESS, Polytechnic of Porto, 4200-072 Porto, Portugal
| | - Joana E Coelho
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Miguel Remondes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, 1649-028 Lisboa, Portugal
- Faculdade de Medicina Veterinária, Universidade Lusófona, 1749-024 Lisboa, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, 3000-370 Coimbra, Portugal
| | - Luísa V Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, 1649-028 Lisboa, Portugal
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Long Y, Xie X, Wang Y, Xu J, Gao Z, Fang X, Xu T, Zhang N, Lv D, Wu T. Atrophy patterns in hippocampal subregions and their relationship with cognitive function in fibromyalgia patients with mild cognitive impairment. Front Neurosci 2024; 18:1380121. [PMID: 38846715 PMCID: PMC11153790 DOI: 10.3389/fnins.2024.1380121] [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: 02/01/2024] [Accepted: 05/14/2024] [Indexed: 06/09/2024] Open
Abstract
Objectives Fibromyalgia (FM) has been associated with decreased hippocampal volume; however, the atrophy patterns of hippocampal subregions have not yet been identified. We therefore aimed to evaluate the volumes of hippocampal subregions in FM patients with mild cognitive impairment (MCI), and to explore the relationship between different subregional alterations and cognitive function. Methods The study included 35 FM patients (21 with MCI and 14 without MCI) and 35 healthy subjects. All subjects performed the Montreal Cognitive Assessment (MoCA) to assess cognitive function. FreeSurfer V.7.3.2 was used to calculate hippocampal subregion volumes. We then compared hippocampal subregion volumes between the groups, and analyzed the relationship between hippocampal subregion volume and cognitive function using a partial correlation analysis method. Results Compared with the healthy subjects, FM patients with MCI had smaller hippocampal volumes in the left and right CA1 head, Molecular layer head, GC-DG head, and CA4 head, and in the left Presubiculum head. Poorer executive function, naming ability, and attention were associated with left CA1 head and left Molecular layer head atrophy. By contrast, hippocampal subregion volumes in the FM patients without MCI were slightly larger than or similar to those in the healthy subjects, and were not significantly correlated with cognitive function. Conclusion Smaller volumes of left CA1 head and left Molecular layer head were associated with poorer executive function, naming ability, and attention in FM patients with MCI. However, these results were not observed in the FM patients without MCI. These findings suggest that the hippocampal subregions of FM patients might present compensatory mechanisms before cognitive decline occurs.
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Affiliation(s)
- Yingming Long
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xinyan Xie
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Yingwei Wang
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Jinping Xu
- Shenzhen Institutes of Advanced Technology, Shenzhen, China
| | - Ziyi Gao
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiaokun Fang
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Tong Xu
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Nan Zhang
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Dongling Lv
- Department of Cardiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Ting Wu
- Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
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Ye Q, Gast G, Wilfley EG, Huynh H, Hays C, Holmes TC, Xu X. Monosynaptic Rabies Tracing Reveals Sex- and Age-Dependent Dorsal Subiculum Connectivity Alterations in an Alzheimer's Disease Mouse Model. J Neurosci 2024; 44:e1796232024. [PMID: 38503494 PMCID: PMC11026364 DOI: 10.1523/jneurosci.1796-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/20/2024] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Abstract
The subiculum (SUB), a hippocampal formation structure, is among the earliest brain regions impacted in Alzheimer's disease (AD). Toward a better understanding of AD circuit-based mechanisms, we mapped synaptic circuit inputs to dorsal SUB using monosynaptic rabies tracing in the 5xFAD mouse model by quantitatively comparing the circuit connectivity of SUB excitatory neurons in age-matched controls and 5xFAD mice at different ages for both sexes. Input-mapped brain regions include the hippocampal subregions (CA1, CA2, CA3), medial septum and diagonal band, retrosplenial cortex, SUB, postsubiculum (postSUB), visual cortex, auditory cortex, somatosensory cortex, entorhinal cortex, thalamus, perirhinal cortex (Prh), ectorhinal cortex, and temporal association cortex. We find sex- and age-dependent changes in connectivity strengths and patterns of SUB presynaptic inputs from hippocampal subregions and other brain regions in 5xFAD mice compared with control mice. Significant sex differences for SUB inputs are found in 5xFAD mice for CA1, CA2, CA3, postSUB, Prh, lateral entorhinal cortex, and medial entorhinal cortex: all of these areas are critical for learning and memory. Notably, we find significant changes at different ages for visual cortical inputs to SUB. While the visual function is not ordinarily considered defective in AD, these specific connectivity changes reflect that altered visual circuitry contributes to learning and memory deficits. Our work provides new insights into SUB-directed neural circuit mechanisms during AD progression and supports the idea that neural circuit disruptions are a prominent feature of AD.
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Affiliation(s)
- Qiao Ye
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
- Department of Biomedical Engineering, University of California, Irvine, California 92697
| | - Gocylen Gast
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
| | - Erik George Wilfley
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
| | - Hanh Huynh
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
| | - Chelsea Hays
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, California 92697
- Center for Neural Circuit Mapping, University of California, Irvine, California 92697
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, California 92697
- Department of Biomedical Engineering, University of California, Irvine, California 92697
- Center for Neural Circuit Mapping, University of California, Irvine, California 92697
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de Melo MB, Daldegan-Bueno D, Favaro VM, Oliveira MGM. The subiculum role on learning and memory tasks using rats and mice: A scoping review. Neurosci Biobehav Rev 2023; 155:105460. [PMID: 37939978 DOI: 10.1016/j.neubiorev.2023.105460] [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: 07/13/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
This scoping review aimed to systematically identify and summarize data related to subiculum involvement in learning and memory behavioral tasks in rats and mice. Following a systematic strategy based on PICO and PRISMA guidelines, we searched five indexed databases (PubMed, Web of Science, EMBASE, Scopus, and PsycInfo) using a standardized search strategy to identify peer-reviewed articles published in English (pre-registration: osf.io/hm5ea). We identified 31 articles investigating the role of the subiculum in spatial, working, and recognition memories (n = 11), memories related to addiction models (n = 9), aversive memories (n = 7), and memories related to appetitive learning (n = 5). We highlight a dissociation in the dorsoventral axis of the subiculum with many studies exploring the ventral subiculum (n = 21) but only a few exploring the dorsal one (n = 10). We also observe the necessity of more data including mice, female animals, genetic tools, and better statistical approaches for replication purposes and research refinement. These findings provide a broad framework of the subiculum involvement in learning and memory, showing essential questions that can be explored by further studies.
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Affiliation(s)
- Márcio Braga de Melo
- Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Dimitri Daldegan-Bueno
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Vanessa Manchim Favaro
- Setor de Investigação de Doenças Neuromusculares, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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Modo M, Sparling K, Novotny J, Perry N, Foley LM, Hitchens TK. Mapping mesoscale connectivity within the human hippocampus. Neuroimage 2023; 282:120406. [PMID: 37827206 PMCID: PMC10623761 DOI: 10.1016/j.neuroimage.2023.120406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/28/2023] [Accepted: 10/10/2023] [Indexed: 10/14/2023] Open
Abstract
The connectivity of the hippocampus is essential to its functions. To gain a whole system view of intrahippocampal connectivity, ex vivo mesoscale (100 μm isotropic resolution) multi-shell diffusion MRI (11.7T) and tractography were performed on entire post-mortem human right hippocampi. Volumetric measurements indicated that the head region was largest followed by the body and tail regions. A unique anatomical organization in the head region reflected a complex organization of the granule cell layer (GCL) of the dentate gyrus. Tractography revealed the volumetric distribution of the perforant path, including both the tri-synaptic and temporoammonic pathways, as well as other well-established canonical connections, such as Schaffer collaterals. Visualization of the perforant path provided a means to verify the borders between the pro-subiculum and CA1, as well as between CA1/CA2. A specific angularity of different layers of fibers in the alveus was evident across the whole sample and allowed a separation of afferent and efferent connections based on their origin (i.e. entorhinal cortex) or destination (i.e. fimbria) using a cluster analysis of streamlines. Non-canonical translamellar connections running along the anterior-posterior axis were also discerned in the hilus. In line with "dentations" of the GCL, mossy fibers were bunching together in the sagittal plane revealing a unique lamellar organization and connections between these. In the head region, mossy fibers projected to the origin of the fimbria, which was distinct from the body and tail region. Mesoscale tractography provides an unprecedented systems view of intrahippocampal connections that underpin cognitive and emotional processing.
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Affiliation(s)
- Michel Modo
- Department of Radiology; Department of BioEngineering; McGowan Institute for Regenerative Medicine; Centre for Neuroscience University of Pittsburgh (CNUP); Centre for the Neural Basis of Cognition (CNBC).
| | | | | | | | | | - T Kevin Hitchens
- Small Animal Imaging Center; Departmnet of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15203, USA
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Guo F, Cui Y, Li A, Liu M, Jian Z, Chen K, Yao D, Guo D, Xia Y. Differential patterns of very high-frequency oscillations in two seizure types of the pilocarpine-induced TLE model. Brain Res Bull 2023; 204:110805. [PMID: 37925081 DOI: 10.1016/j.brainresbull.2023.110805] [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: 08/20/2023] [Revised: 10/08/2023] [Accepted: 10/30/2023] [Indexed: 11/06/2023]
Abstract
AIMS Very high-frequency oscillations (VHFOs, >500 Hz) are considered a highly sensitive biomarker of seizures. We hypothesized that VHFOs may exhibit specificity towards hypersynchronous (HYP) seizures and low-voltage fast (LVF) seizures in temporal lobe epilepsy (TLE). METHODS Local field potentials were recorded from the hippocampal network in TLE mice induced by pilocarpine. Subsequently, we analyzed the VHFO features, including their temporal-frequency characteristics and VHFO/theta coupling, during three states: baseline, preictal, and postictal for both HYP- and LVF-seizure groups. RESULTS Significant changes in most of the VHFO features were observed during the preictal state in both seizure groups. In the postictal state, VHFO features in the HYP-seizure group exhibited inverse alterations and appeared to align with those observed during baseline conditions. However, such phenomena were not observed after TLE seizures in the LVF-seizure group. CONCLUSION Our findings highlight distinct patterns of VHFO feature changes across different states of HYP seizures and LVF seizures. These results suggest that VHFOs could serve as indicative biomarkers for seizure alterations specifically associated with HYP-seizure states.
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Affiliation(s)
- Fengru Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yan Cui
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| | - Airui Li
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Mingqi Liu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhaoxin Jian
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Ke Chen
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Dezhong Yao
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Daqing Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yang Xia
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
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Melo MBD, Favaro VM, Oliveira MGM. The contextual fear conditioning consolidation depends on the functional interaction of the dorsal subiculum and basolateral amygdala in rats. Neurobiol Learn Mem 2023; 205:107827. [PMID: 37678544 DOI: 10.1016/j.nlm.2023.107827] [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: 05/01/2023] [Revised: 08/09/2023] [Accepted: 09/04/2023] [Indexed: 09/09/2023]
Abstract
Fear conditioning tasks enable us to explore the neural basis of adaptative and maladaptive behaviors related to aversive memories. Recently, we provided the first evidence of the dorsal subiculum (DSub) involvement in contextual fear conditioning (CFC) consolidation by showing that the post-training bilateral NMDA (N-methyl-D-aspartate) receptor blockade in DSub impaired the performance of animals in the test session. As the memory consolidation process depends on the coordinated engagement of different brain regions, and the DSub share reciprocal projections with the basolateral amygdala (BLA), which is also involved in CFC, it is possible that the functional interaction between these sites can be relevant for the consolidation of this task. In this sense, the present study aimed to explore the effects of the functional disconnection of the DSub and BLA in the CFC consolidation after NMDA post-training blockade. In addition, to verify if the observed effects were due to spatial representation processes mediated by the DSub, we employed a hippocampal-independent procedure: tone fear conditioning (TFC). Results showed that the functional disconnection of these regions by post-training NMDA blockade impaired CFC consolidation, whereas there was no impairment in TFC. Altogether, the present data suggest that the DSub and BLA would functionally interact through NMDA-related synaptic plasticity to support CFC consolidation probably due to DSub-related spatial processing showing that the TFC consolidation was not disrupted. This work contributes to filling a gap of studies exploring the DSub involvement in fear conditioning by providing a broad framework of the subicular-amygdaloid connection functionality.
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Affiliation(s)
- Márcio Braga de Melo
- Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
| | - Vanessa Manchim Favaro
- Setor de Investigação de Doenças Neuromusculares, Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
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Ruelas M, Medina-Ceja L, Fuentes-Aguilar RQ. A scoping review of the relationship between alcohol, memory consolidation and ripple activity: An overview of common methodologies to analyse ripples. Eur J Neurosci 2023; 58:4137-4154. [PMID: 37827165 DOI: 10.1111/ejn.16168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/27/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
Alcohol abuse is not only responsible for 5.3% of the total deaths in the world but also has a substantial impact on neurological and memory disabilities throughout the population. One extensively studied brain area involved in cognitive functions is the hippocampus. Evidence in several rodent models has shown that ethanol produces cognitive impairment in hippocampal-dependent tasks and that the damage is varied according to the stage of development at which the rodent was exposed to ethanol and the dose. To the authors' knowledge, there is a biomarker for cognitive processes in the hippocampus that remains relatively understudied in association with memory impairment by alcohol administration. This biomarker is called sharp wave-ripples (SWRs) which are synchronous neuronal population events that are well known to be involved in memory consolidation. Methodologies for facilitated or automatic identification of ripples and their analysis have been reported for a wider bandwidth than SWRs. This review is focused on communicating the state of the art about the relationship between alcohol, memory consolidation and ripple activity, as well as the use of the common methodologies to identify SWRs automatically.
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Affiliation(s)
- Marina Ruelas
- School of Engineering and Sciences, Tecnológico de Monterrey, Zapopan, Jalisco, Mexico
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Zapopan, Jalisco, Mexico
| | - Rita Q Fuentes-Aguilar
- Institute of Advanced Materials for Sustainable Manufacturing, Tecnológico de Monterrey, Zapopan, Jalisco, Mexico
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10
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Grieco SF, Holmes TC, Xu X. Probing neural circuit mechanisms in Alzheimer's disease using novel technologies. Mol Psychiatry 2023; 28:4407-4420. [PMID: 36959497 PMCID: PMC10827671 DOI: 10.1038/s41380-023-02018-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 02/20/2023] [Accepted: 02/24/2023] [Indexed: 03/25/2023]
Abstract
The study of Alzheimer's Disease (AD) has traditionally focused on neuropathological mechanisms that has guided therapies that attenuate neuropathological features. A new direction is emerging in AD research that focuses on the progressive loss of cognitive function due to disrupted neural circuit mechanisms. Evidence from humans and animal models of AD show that dysregulated circuits initiate a cascade of pathological events that culminate in functional loss of learning, memory, and other aspects of cognition. Recent progress in single-cell, spatial, and circuit omics informs this circuit-focused approach by determining the identities, locations, and circuitry of the specific cells affected by AD. Recently developed neuroscience tools allow for precise access to cell type-specific circuitry so that their functional roles in AD-related cognitive deficits and disease progression can be tested. An integrated systems-level understanding of AD-associated neural circuit mechanisms requires new multimodal and multi-scale interrogations that longitudinally measure and/or manipulate the ensemble properties of specific molecularly-defined neuron populations first susceptible to AD. These newly developed technological and conceptual advances present new opportunities for studying and treating circuits vulnerable in AD and represent the beginning of a new era for circuit-based AD research.
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Affiliation(s)
- Steven F Grieco
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
- Center for Neural Circuit Mapping (CNCM), University of California, Irvine, CA, 92697, USA
| | - Todd C Holmes
- Center for Neural Circuit Mapping (CNCM), University of California, Irvine, CA, 92697, USA
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA.
- Center for Neural Circuit Mapping (CNCM), University of California, Irvine, CA, 92697, USA.
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11
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Lin X, Cyrus N, Avila B, Holmes TC, Xu X. Hippocampal CA3 inhibitory neurons receive extensive noncanonical synaptic inputs from CA1 and subicular complex. J Comp Neurol 2023; 531:1333-1347. [PMID: 37312626 PMCID: PMC10525020 DOI: 10.1002/cne.25510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/06/2023] [Accepted: 04/26/2023] [Indexed: 06/15/2023]
Abstract
Hippocampal CA3 is traditionally conceptualized as a brain region within a unidirectional feedforward trisynaptic pathway that links major hippocampal subregions. Recent genomic and viral tracing studies indicate that the anatomical connectivity of CA3 and the trisynaptic pathway is more complex than initially expected and suggests that there may be cell type-specific input gradients throughout the three-dimensional hippocampal structure. In several recent studies using multiple viral tracing approaches, we describe subdivisions of the subiculum complex and ventral hippocampal CA1 that show significant back projections to CA1 and CA3 excitatory neurons. These novel connections form "noncanonical" circuits that run in the opposite direction relative to the well-characterized feedforward pathway. Diverse subtypes of GABAergic inhibitory neurons participate within the trisynaptic pathway. In the present study, we have applied monosynaptic retrograde viral tracing to examine noncanonical synaptic inputs from CA1 and subicular complex to the inhibitory neuron in hippocampal CA3. We quantitatively mapped synaptic inputs to CA3 inhibitory neurons to understand how they are connected within and beyond the hippocampus formation. Major brain regions that provide typical inputs to CA3 inhibitory neurons include the medial septum, the dentate gyrus, the entorhinal cortex, and CA3. Noncanonical inputs from ventral CA1 and subicular complex to CA3 inhibitory neurons follow a proximodistal topographic gradient with regard to CA3 subregions. We find novel noncanonical circuit connections between inhibitory CA3 neurons and ventral CA1, subiculum complex, and other brain regions. These results provide a new anatomical connectivity basis to further study the function of CA3 inhibitory neurons.
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Affiliation(s)
- Xiaoxiao Lin
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA 92697
| | - Neeyaz Cyrus
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA 92697
| | - Brenda Avila
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA 92697
| | - Todd C. Holmes
- Department Physiology & Biophysics, School of Medicine, University of California, Irvine, CA 92697
| | - Xiangmin Xu
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA 92697
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12
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Wu Y, Chen ZS. Computational models for state-dependent traveling waves in hippocampal formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541436. [PMID: 37292865 PMCID: PMC10245836 DOI: 10.1101/2023.05.19.541436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hippocampal theta (4-10 Hz) oscillations have been identified as traveling waves in both rodents and humans. In freely foraging rodents, the theta traveling wave is a planar wave propagating from the dorsal to ventral hippocampus along the septotemporal axis. Motivated from experimental findings, we develop a spiking neural network of excitatory and inhibitory neurons to generate state-dependent hippocampal traveling waves to improve current mechanistic understanding of propagating waves. Model simulations demonstrate the necessary conditions for generating wave propagation and characterize the traveling wave properties with respect to model parameters, running speed and brain state of the animal. Networks with long-range inhibitory connections are more suitable than networks with long-range excitatory connections. We further generalize the spiking neural network to model traveling waves in the medial entorhinal cortex (MEC) and predict that traveling theta waves in the hippocampus and entorhinal cortex are in sink.
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13
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Ajaz R, Mousavi SR, Mirsattari SM, Leung LS. Paroxysmal slow-wave discharges in a model of absence seizure are coupled to gamma oscillations in the thalamocortical and limbic systems. Epilepsy Res 2023; 191:107103. [PMID: 36841021 DOI: 10.1016/j.eplepsyres.2023.107103] [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: 11/08/2022] [Revised: 01/21/2023] [Accepted: 02/09/2023] [Indexed: 02/16/2023]
Abstract
OBJECTIVE Using the gamma-butyrolactone (GBL) model of absence seizures in Long-Evans rats, this study investigated if gamma (30-160 Hz) activity were cross-frequency modulated by the 2-6 Hz slow-wave discharges induced by GBL in the limbic system. We hypothesized that inactivation of the nucleus reuniens (RE), which projects to frontal cortex (FC) and hippocampus, would affect the cross-frequency coupling of gamma (γ) in different brain regions. METHODS Local field potentials were recorded by electrodes implanted in the FC, ventrolateral thalamus (TH), basolateral amygdala (BLA), nucleus accumbens (NAC), and dorsal hippocampus (CA1) of behaving rats. At each electrode, the coupling between the γ amplitude envelope to the phase of the 2-6 Hz slow-waves (SW) was measured by modulation index (MI) or cross-frequency coherence (CFC) of γ amplitude with SW. In separate experiments, the RE was infused with saline or GABAA receptor agonist, muscimol, before the injection of GBL. RESULTS Following GBL injection, an increase in MI and CFC of SW to γ1 (30-58 Hz), γ2 (62-100 Hz) and γ3 (100-160 Hz) bands was observed at the FC, hippocampus and BLA, with significant increase in SW-γ1 and SW-γ3 coupling at TH, and increase in peak SW-γ1 CFC at NAC. Strong SW-γ modulation was also found during baseline immobility high-voltage spindles. Muscimol inactivation of RE, as compared to saline infusion, significantly decreased SW-γ1 CFC in the FC, and peak frequency of the SW-γ1 CFC in the thalamus, but did not significantly alter SW-γ CFCs in the hippocampus, BLA or NAC. SIGNIFICANCE The paroxysmal 2-6 Hz SW discharges, a hallmark of absence seizure, significantly modulate γ activity in the hippocampus, BLA and NAC, suggesting a modulation of limbic functions. RE inactivation disrupted the SW modulation of FC and TH, partly supporting our hypothesis that RE participates in the modulation of SW discharges.
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Affiliation(s)
- Rukham Ajaz
- Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada
| | - Seyed Reza Mousavi
- Clinical Neurological Sciences, University of Western Ontario, London, ON, Canada
| | - Seyed M Mirsattari
- Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada; Clinical Neurological Sciences, University of Western Ontario, London, ON, Canada
| | - L Stan Leung
- Graduate Program in Neuroscience, University of Western Ontario, London, ON, Canada; Departments of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
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14
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Relations of hippocampal subfields atrophy patterns with memory and biochemical changes in end stage renal disease. Sci Rep 2023; 13:2982. [PMID: 36804419 PMCID: PMC9941083 DOI: 10.1038/s41598-023-29083-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/30/2023] [Indexed: 02/22/2023] Open
Abstract
End-stage renal disease (ESRD) results in hippocampal volume reduction, but the hippocampal subfields atrophy patterns cannot be identified. We explored the volumes and asymmetry of the hippocampal subfields and their relationships with memory function and biochemical changes. Hippocampal global and subfields volumes were derived from 33 ESRD patients and 46 healthy controls (HCs) from structural MRI. We compared the volume and asymmetric index of each subfield, with receiver operating characteristic curve analysis to evaluate the differentiation between ESRD and HCs. The relations of hippocampal subfield volumes with memory performance and biochemical data were investigated in ESRD group. ESRD patients had smaller hippocampal subfield volumes, mainly in the left CA1 body, left fimbria, right molecular layer head, right molecular layer body and right HATA. The right molecular layer body exhibited the highest accuracy for differentiating ESRD from HCs, with a sensitivity of 80.43% and specificity of 72.73%. Worse learning process (r = 0.414, p = 0.032), immediate recall (r = 0.396, p = 0.041) and delayed recall (r = 0.482, p = 0.011) was associated with left fimbria atrophy. The left fimbria volume was positively correlated with Hb (r = 0.388, p = 0.05); the left CA1 body volume was negatively correlated with Urea (r = - 0.469, p = 0.016). ESRD patients showed global and hippocampal subfields atrophy. Left fimbria atrophy was related to memory function. Anemia and Urea level may be associated with the atrophy of left fimbria and CA1 body, respectively.
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15
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Fan LZ, Kim DK, Jennings JH, Tian H, Wang PY, Ramakrishnan C, Randles S, Sun Y, Thadhani E, Kim YS, Quirin S, Giocomo L, Cohen AE, Deisseroth K. All-optical physiology resolves a synaptic basis for behavioral timescale plasticity. Cell 2023; 186:543-559.e19. [PMID: 36669484 PMCID: PMC10327443 DOI: 10.1016/j.cell.2022.12.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 10/19/2022] [Accepted: 12/19/2022] [Indexed: 01/20/2023]
Abstract
Learning has been associated with modifications of synaptic and circuit properties, but the precise changes storing information in mammals have remained largely unclear. We combined genetically targeted voltage imaging with targeted optogenetic activation and silencing of pre- and post-synaptic neurons to study the mechanisms underlying hippocampal behavioral timescale plasticity. In mice navigating a virtual-reality environment, targeted optogenetic activation of individual CA1 cells at specific places induced stable representations of these places in the targeted cells. Optical elicitation, recording, and modulation of synaptic transmission in behaving mice revealed that activity in presynaptic CA2/3 cells was required for the induction of plasticity in CA1 and, furthermore, that during induction of these place fields in single CA1 cells, synaptic input from CA2/3 onto these same cells was potentiated. These results reveal synaptic implementation of hippocampal behavioral timescale plasticity and define a methodology to resolve synaptic plasticity during learning and memory in behaving mammals.
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Affiliation(s)
- Linlin Z Fan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Doo Kyung Kim
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Joshua H Jennings
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - He Tian
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Peter Y Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | - Sawyer Randles
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Yanjun Sun
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Elina Thadhani
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Yoon Seok Kim
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Sean Quirin
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Lisa Giocomo
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Adam E Cohen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA; Department of Physics, Harvard University, Cambridge, MA, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, USA; Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA; Howard Hughes Medical Institute, Stanford, CA, USA.
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16
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Wickham J, Ledri M, Andersson M, Kokaia M. Cell-specific switch for epileptiform activity: critical role of interneurons in the mouse subicular network. Cereb Cortex 2023; 33:6171-6183. [PMID: 36611229 PMCID: PMC10183737 DOI: 10.1093/cercor/bhac493] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 01/09/2023] Open
Abstract
During epileptic seizures, neuronal network activity is hyper synchronized whereby GABAergic parvalbumin-interneurons may have a key role. Previous studies have mostly utilized 4-aminopyridine to induce epileptiform discharges in brain slices from healthy animals. However, it is not clear if the seizure-triggering ability of parvalbumin-interneurons also holds true without the use of external convulsive agents. Here, we investigate whether synchronized activation of parvalbumin-interneurons or principal cells can elicit epileptiform discharges in subiculum slices of epileptic mice. We found that selective synchronized activation of parvalbumin-interneurons or principal cells with optogenetics do not result in light-induced epileptiform discharges (LIEDs) neither in epileptic nor in normal brain slices. Adding 4-aminopyridine to slices, activation of parvalbumin-interneurons still failed to trigger LIEDs. In contrast, such activation of principal neurons readily generated LIEDs with features resembling afterdischarges. When GABAA receptor blocker was added to the perfusion medium, the LIEDs were abolished. These results demonstrate that in subiculum, selective synchronized activation of principal excitatory neurons can trigger epileptiform discharges by recruiting a large pool of downstream interneurons. This study also suggests region-specific role of principal neurons and interneurons in ictogenesis, opening towards differential targeting of specific brain areas for future treatment strategies tailored for individual patients with epilepsy.
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Affiliation(s)
- J Wickham
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Ledri
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Andersson
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Kokaia
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
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17
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Ye Q, Gast G, Su X, Saito T, Saido TC, Holmes TC, Xu X. Hippocampal neural circuit connectivity alterations in an Alzheimer's disease mouse model revealed by monosynaptic rabies virus tracing. Neurobiol Dis 2022; 172:105820. [PMID: 35843448 PMCID: PMC9482455 DOI: 10.1016/j.nbd.2022.105820] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/07/2022] [Accepted: 07/11/2022] [Indexed: 11/27/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with growing major health impacts, particularly in countries with aging populations. The examination of neural circuit mechanisms in AD mouse models is a recent focus for identifying new AD treatment strategies. We hypothesize that age-progressive changes of both long-range and local hippocampal neural circuit connectivity occur in AD. Recent advancements in viral-genetic technologies provide new opportunities for semi-quantitative mapping of cell-type-specific neural circuit connections in AD mouse models. We applied a recently developed monosynaptic rabies tracing method to hippocampal neural circuit mapping studies in AD model mice to determine how local and global circuit connectivity to hippocampal CA1 excitatory neurons may be altered in the single APP knock-in (APP-KI) AD mouse model. To determine age-related AD progression, we measured circuit connectivity in age-matched littermate control and AD model mice at two different ages (3-4 vs. 10-11 months old). We quantitatively mapped the connectivity strengths of neural circuit inputs to hippocampal CA1 excitatory neurons from brain regions including hippocampal subregions, medial septum, subiculum and entorhinal cortex, comparing different age groups and genotypes. We focused on hippocampal CA1 because of its clear relationship with learning and memory and that the hippocampal formation shows clear neuropathological changes in human AD. Our results reveal alterations in circuit connectivity of hippocampal CA1 in AD model mice. Overall, we find weaker extrinsic CA1 input connectivity strengths in AD model mice compared with control mice, including sex differences of reduced subiculum to CA1 inputs in aged female AD mice compared with aged male AD mice. Unexpectedly, we find a connectivity pattern shift with an increased proportion of inputs from the CA3 region to CA1 excitatory neurons when comparing young and old AD model mice, as well as old wild-type mice and old AD model mice. These unexpected shifts in CA3-CA1 input proportions in this AD mouse model suggest the possibility that compensatory circuit increases may occur in response to connectivity losses in other parts of the hippocampal circuits. We expect that this work provides new insights into the neural circuit mechanisms of AD pathogenesis.
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Affiliation(s)
- Qiao Ye
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA; Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA.
| | - Gocylen Gast
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA.
| | - Xilin Su
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA.
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi 467-8601, Japan; Lab for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama 351-0106, Japan.
| | - Takaomi C Saido
- Lab for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama 351-0106, Japan.
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA 92697, USA; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, USA.
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA; Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, USA.
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18
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Mizuseki K, Kitanishi T. Oscillation-coordinated, noise-resistant information distribution via the subiculum. Curr Opin Neurobiol 2022; 75:102556. [DOI: 10.1016/j.conb.2022.102556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 11/03/2022]
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19
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Zhang X, Lin PY, Liakath-Ali K, Südhof TC. Teneurins assemble into presynaptic nanoclusters that promote synapse formation via postsynaptic non-teneurin ligands. Nat Commun 2022; 13:2297. [PMID: 35484136 PMCID: PMC9050732 DOI: 10.1038/s41467-022-29751-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/24/2022] [Indexed: 02/04/2023] Open
Abstract
Extensive studies concluded that homophilic interactions between pre- and postsynaptic teneurins, evolutionarily conserved cell-adhesion molecules, encode the specificity of synaptic connections. However, no direct evidence is available to demonstrate that teneurins are actually required on both pre- and postsynaptic neurons for establishing synaptic connections, nor is it known whether teneurins are localized to synapses. Using super-resolution microscopy, we demonstrate that Teneurin-3 assembles into presynaptic nanoclusters of approximately 80 nm in most excitatory synapses of the hippocampus. Presynaptic deletions of Teneurin-3 and Teneurin-4 in the medial entorhinal cortex revealed that they are required for assembly of entorhinal cortex-CA1, entorhinal cortex-subiculum, and entorhinal cortex-dentate gyrus synapses. Postsynaptic deletions of teneurins in the CA1 region, however, had no effect on synaptic connections from any presynaptic input. Our data suggest that different from the current prevailing view, teneurins promote the establishment of synaptic connections exclusively as presynaptic cell-adhesion molecules, most likely via their nanomolar-affinity binding to postsynaptic latrophilins.
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Affiliation(s)
- Xuchen Zhang
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA. .,Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
| | - Pei-Yi Lin
- grid.168010.e0000000419368956Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA USA
| | - Kif Liakath-Ali
- grid.168010.e0000000419368956Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA USA
| | - Thomas C. Südhof
- grid.168010.e0000000419368956Howard Hughes Medical Institute, Stanford University, Stanford, CA USA ,grid.168010.e0000000419368956Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA USA
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20
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Kim S, Nam Y, Kim HS, Jung H, Jeon SG, Hong SB, Moon M. Alteration of Neural Pathways and Its Implications in Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10040845. [PMID: 35453595 PMCID: PMC9025507 DOI: 10.3390/biomedicines10040845] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease accompanied by cognitive and behavioral symptoms. These AD-related manifestations result from the alteration of neural circuitry by aggregated forms of amyloid-β (Aβ) and hyperphosphorylated tau, which are neurotoxic. From a neuroscience perspective, identifying neural circuits that integrate various inputs and outputs to determine behaviors can provide insight into the principles of behavior. Therefore, it is crucial to understand the alterations in the neural circuits associated with AD-related behavioral and psychological symptoms. Interestingly, it is well known that the alteration of neural circuitry is prominent in the brains of patients with AD. Here, we selected specific regions in the AD brain that are associated with AD-related behavioral and psychological symptoms, and reviewed studies of healthy and altered efferent pathways to the target regions. Moreover, we propose that specific neural circuits that are altered in the AD brain can be potential targets for AD treatment. Furthermore, we provide therapeutic implications for targeting neuronal circuits through various therapeutic approaches and the appropriate timing of treatment for AD.
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Affiliation(s)
- Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
| | - Yunkwon Nam
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Hyeon soo Kim
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Haram Jung
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Seong Gak Jeon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Sang Bum Hong
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea; (S.K.); (Y.N.); (H.s.K.); (H.J.); (S.G.J.); (S.B.H.)
- Research Institute for Dementia Science, Konyang University, 158, Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
- Correspondence:
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21
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Rolls ET, Deco G, Huang CC, Feng J. The Effective Connectivity of the Human Hippocampal Memory System. Cereb Cortex 2022; 32:3706-3725. [PMID: 35034120 DOI: 10.1093/cercor/bhab442] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 02/04/2023] Open
Abstract
Effective connectivity measurements in the human hippocampal memory system based on the resting-state blood oxygenation-level dependent signal were made in 172 participants in the Human Connectome Project to reveal the directionality and strength of the connectivity. A ventral "what" hippocampal stream involves the temporal lobe cortex, perirhinal and parahippocampal TF cortex, and entorhinal cortex. A dorsal "where" hippocampal stream connects parietal cortex with posterior and retrosplenial cingulate cortex, and with parahippocampal TH cortex, which, in turn, project to the presubiculum, which connects to the hippocampus. A third stream involves the orbitofrontal and ventromedial-prefrontal cortex with effective connectivity with the hippocampal, entorhinal, and perirhinal cortex. There is generally stronger forward connectivity to the hippocampus than backward. Thus separate "what," "where," and "reward" streams can converge in the hippocampus, from which back projections return to the sources. However, unlike the simple dual stream hippocampal model, there is a third stream related to reward value; there is some cross-connectivity between these systems before the hippocampus is reached; and the hippocampus has some effective connectivity with earlier stages of processing than the entorhinal cortex and presubiculum. These findings complement diffusion tractography and provide a foundation for new concepts on the operation of the human hippocampal memory system.
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Affiliation(s)
- Edmund T Rolls
- Oxford Centre for Computational Neuroscience, Oxford, UK
- Department of Computer Science, University of Warwick, Coventry CV4 7AL, UK
- Institute of Science and Technology for Brain Inspired Intelligence, Fudan University, Shanghai 200433, China
| | - Gustavo Deco
- Department of Information and Communication Technologies, Center for Brain and Cognition, Computational Neuroscience Group, Universitat Pompeu Fabra, Barcelona 08018, Spain
- Brain and Cognition, Pompeu Fabra University, Barcelona 08018, Spain
- Institució Catalana de la Recerca i Estudis Avançats (ICREA), Universitat Pompeu Fabra, Barcelona 08010, Spain
| | - Chu-Chung Huang
- Shanghai Key Laboratory of Brain Functional Genomics (Ministry of Education), School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China
| | - Jianfeng Feng
- Department of Computer Science, University of Warwick, Coventry CV4 7AL, UK
- Institute of Science and Technology for Brain Inspired Intelligence, Fudan University, Shanghai 200433, China
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22
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Lin X, Chen L, Baglietto-Vargas D, Kamalipour P, Ye Q, LaFerla FM, Nitz DA, Holmes TC, Xu X. Spatial coding defects of hippocampal neural ensemble calcium activities in the triple-transgenic Alzheimer's disease mouse model. Neurobiol Dis 2022; 162:105562. [PMID: 34838667 PMCID: PMC9482454 DOI: 10.1016/j.nbd.2021.105562] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/24/2021] [Accepted: 11/22/2021] [Indexed: 12/21/2022] Open
Abstract
Alzheimer's disease (AD) causes progressive age-related defects in memory and cognitive function and has emerged as a major health and socio-economic concern in the US and worldwide. To develop effective therapeutic treatments for AD, we need to better understand the neural mechanisms by which AD causes memory loss and cognitive deficits. Here we examine large-scale hippocampal neural population calcium activities imaged at single cell resolution in a triple-transgenic Alzheimer's disease mouse model (3xTg-AD) that presents both amyloid plaque and neurofibrillary pathological features along with age-related behavioral defects. To measure encoding of environmental location in hippocampal neural ensembles in the 3xTg-AD mice in vivo, we performed GCaMP6-based calcium imaging using head-mounted, miniature fluorescent microscopes ("miniscopes") on freely moving animals. We compared hippocampal CA1 excitatory neural ensemble activities during open-field exploration and track-based route-running behaviors in age-matched AD and control mice at young (3-6.5 months old) and old (18-21 months old) ages. During open-field exploration, 3xTg-AD CA1 excitatory cells display significantly higher calcium activity rates compared with Non-Tg controls for both the young and old age groups, suggesting that in vivo enhanced neuronal calcium ensemble activity is a disease feature. CA1 neuronal populations of 3xTg-AD mice show lower spatial information scores compared with control mice. The spatial firing of CA1 neurons of old 3xTg-AD mice also displays higher sparsity and spatial coherence, indicating less place specificity for spatial representation. We find locomotor speed significantly modulates the amplitude of hippocampal neural calcium ensemble activities to a greater extent in 3xTg-AD mice during open field exploration. Our data offer new and comprehensive information about age-dependent neural circuit activity changes in this important AD mouse model and provide strong evidence that spatial coding defects in the neuronal population activities are associated with AD pathology and AD-related memory behavioral deficits.
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Affiliation(s)
- Xiaoxiao Lin
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America
| | - Lujia Chen
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States of America
| | - David Baglietto-Vargas
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Centro de Investigacion Biomedica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Facultad de Ciencias, Universidad de Malaga, Malaga 29071, Spain; Institute for Memory Impairments and Neurological Disorder, University of California, Irvine, CA 92697, United States of America
| | - Parsa Kamalipour
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America
| | - Qiao Ye
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States of America
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorder, University of California, Irvine, CA 92697, United States of America
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, CA 92093, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA 92697, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America; Institute for Memory Impairments and Neurological Disorder, University of California, Irvine, CA 92697, United States of America; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America.
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Chaudhary S, Zhornitsky S, Chao HH, van Dyck CH, Li CSR. Emotion Processing Dysfunction in Alzheimer's Disease: An Overview of Behavioral Findings, Systems Neural Correlates, and Underlying Neural Biology. Am J Alzheimers Dis Other Demen 2022; 37:15333175221082834. [PMID: 35357236 PMCID: PMC9212074 DOI: 10.1177/15333175221082834] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We described behavioral studies to highlight emotional processing deficits in Alzheimer's disease (AD). The findings suggest prominent deficit in recognizing negative emotions, pronounced effect of positive emotion on enhancing memory, and a critical role of cognitive deficits in manifesting emotional processing dysfunction in AD. We reviewed imaging studies to highlight morphometric and functional markers of hippocampal circuit dysfunction in emotional processing deficits. Despite amygdala reactivity to emotional stimuli, hippocampal dysfunction conduces to deficits in emotional memory. Finally, the reviewed studies implicating major neurotransmitter systems in anxiety and depression in AD supported altered cholinergic and noradrenergic signaling in AD emotional disorders. Overall, the studies showed altered emotions early in the course of illness and suggest the need of multimodal imaging for further investigations. Particularly, longitudinal studies with multiple behavioral paradigms translatable between preclinical and clinical models would provide data to elucidate the time course and underlying neurobiology of emotion processing dysfunction in AD.
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Affiliation(s)
- Shefali Chaudhary
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Simon Zhornitsky
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Herta H. Chao
- Department of Medicine, Yale University School of Medicine, New Haven, CT, USA,VA Connecticut Healthcare System, West Haven, CT, USA
| | - Christopher H. van Dyck
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA
| | - Chiang-Shan R. Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA,Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA,Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA,Wu Tsai Institute, Yale University, New Haven, CT, USA
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24
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Lin X, Amalraj M, Blanton C, Avila B, Holmes TC, Nitz DA, Xu X. Noncanonical projections to the hippocampal CA3 regulate spatial learning and memory by modulating the feedforward hippocampal trisynaptic pathway. PLoS Biol 2021; 19:e3001127. [PMID: 34928938 PMCID: PMC8741299 DOI: 10.1371/journal.pbio.3001127] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 01/07/2022] [Accepted: 11/24/2021] [Indexed: 12/27/2022] Open
Abstract
The hippocampal formation (HF) is well documented as having a feedforward, unidirectional circuit organization termed the trisynaptic pathway. This circuit organization exists along the septotemporal axis of the HF, but the circuit connectivity across septal to temporal regions is less well described. The emergence of viral genetic mapping techniques enhances our ability to determine the detailed complexity of HF circuitry. In earlier work, we mapped a subiculum (SUB) back projection to CA1 prompted by the discovery of theta wave back propagation from the SUB to CA1 and CA3. We reason that this circuitry may represent multiple extended noncanonical pathways involving the subicular complex and hippocampal subregions CA1 and CA3. In the present study, multiple retrograde viral tracing approaches produced robust mapping results, which supports this prediction. We find significant noncanonical synaptic inputs to dorsal hippocampal CA3 from ventral CA1 (vCA1), perirhinal cortex (Prh), and the subicular complex. Thus, CA1 inputs to CA3 run opposite the trisynaptic pathway and in a temporal to septal direction. Our retrograde viral tracing results are confirmed by anterograde-directed viral mapping of projections from input mapped regions to hippocampal dorsal CA3 (dCA3). We find that genetic inactivation of the projection of vCA1 to dCA3 impairs object-related spatial learning and memory but does not modulate anxiety-related behaviors. Our data provide a circuit foundation to explore novel functional roles contributed by these noncanonical hippocampal circuit connections to hippocampal circuit dynamics and learning and memory behaviors.
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Affiliation(s)
- Xiaoxiao Lin
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, California, United States of America
| | - Michelle Amalraj
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, California, United States of America
| | - Crisylle Blanton
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, California, United States of America
| | - Brenda Avila
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, California, United States of America
| | - Todd C. Holmes
- Department Physiology & Biophysics, School of Medicine, University of California, Irvine, California, United States of America
- The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, California, United States of America
| | - Douglas A. Nitz
- The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, California, United States of America
- Department of Cognitive Science, University of California San Diego, La Jolla, California, United States of America
| | - Xiangmin Xu
- Department Anatomy & Neurobiology, School of Medicine, University of California, Irvine, California, United States of America
- The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, California, United States of America
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Distal CA1 Maintains a More Coherent Spatial Representation than Proximal CA1 When Local and Global Cues Conflict. J Neurosci 2021; 41:9767-9781. [PMID: 34670850 DOI: 10.1523/jneurosci.2938-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 09/10/2021] [Accepted: 10/13/2021] [Indexed: 11/21/2022] Open
Abstract
Entorhinal cortical projections show segregation along the transverse axis of CA1, with the medial entorhinal cortex (MEC) sending denser projections to proximal CA1 (pCA1) and the lateral entorhinal cortex (LEC) sending denser projections to distal CA1 (dCA1). Previous studies have reported functional segregation along the transverse axis of CA1 correlated with the functional differences in MEC and LEC. pCA1 shows higher spatial selectivity than dCA1 in these studies. We employ a double rotation protocol, which creates an explicit conflict between the local and the global cues, to understand the differential contributions of these reference frames to the spatial code in pCA1 and dCA1 in male Long-Evans rats. We show that pCA1 and dCA1 respond differently to this local-global cue conflict. pCA1 representation splits as predicted from the strong conflicting inputs it receives from MEC and dCA3. In contrast, dCA1 rotates more in concert with the global cues. In addition, pCA1 and dCA1 display comparable levels of spatial selectivity in this study. This finding differs from the previous studies, perhaps because of richer sensory information available in our behavior arena. Together, these observations indicate that the functional segregation along proximodistal axis of CA1 is not of the amount of spatial selectivity but that of the nature of the different inputs used to create and anchor spatial representations.SIGNIFICANCE STATEMENT Subregions of the hippocampus are thought to play different roles in spatial navigation and episodic memory. It was previously thought that the distal part of area CA1 of the hippocampus carries lesser information about space than proximal CA1 (pCA1). We report that distal CA1 (dCA1) spatial representation moves more in concert with the global cues than pCA1 when the local and the global cues conflict. We also show that spatial selectivity is comparable along the proximodistal axis in this experimental protocol. Thus, different parts of the brain receiving differential outputs from pCA1 and dCA1 receive spatial information in different spatial reference frames encoded using different sets of inputs, rather than different amounts of spatial information as thought earlier.
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26
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Impact of Frailty on Hippocampal Volume in Patients with Chronic Obstructive Pulmonary Disease. Biomedicines 2021; 9:biomedicines9091103. [PMID: 34572291 PMCID: PMC8468719 DOI: 10.3390/biomedicines9091103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/22/2021] [Accepted: 08/25/2021] [Indexed: 12/11/2022] Open
Abstract
Brain frailty may be related to the pathophysiology of poor clinical outcomes in chronic obstructive pulmonary disease (COPD). This study examines the relationship between hippocampal subfield volumes and frailty and depressive symptoms, and their combined association with quality of life (QOL) in patients with COPD. The study involved 40 patients with COPD. Frailty, depressive symptoms and QOL were assessed using Kihon Checklist (KCL), Hospital Anxiety and Depression Scale (HADS), and World Health Organization Quality of Life Assessment (WHO/QOL-26). Anatomical MRI data were acquired, and volumes of the hippocampal subfields were obtained using FreeSurfer (version 6.0). Statistically, HADS score had significant association with WHO/QOL-26 and KCL scores. KCL scores were significantly associated with volumes of left and right whole hippocampi, presubiculum and subiculum, but HADS score had no significant association with whole hippocampi or hippocampal subfield volumes. Meanwhile, WHO/QOL-26 score was significantly associated with volume of the left CA1. There was a significant association between frailty, depression, and QOL. Hippocampal pathology was related to frailty and, to some extent, with QOL in patients with COPD. Our results suggest the impact of frailty on hippocampal volume and their combined associations with poor QOL in COPD.
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27
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Santos-Pata D, Amil AF, Raikov IG, Rennó-Costa C, Mura A, Soltesz I, Verschure PFMJ. Epistemic Autonomy: Self-supervised Learning in the Mammalian Hippocampus. Trends Cogn Sci 2021; 25:582-595. [PMID: 33906817 PMCID: PMC10631471 DOI: 10.1016/j.tics.2021.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/05/2023]
Abstract
Biological cognition is based on the ability to autonomously acquire knowledge, or epistemic autonomy. Such self-supervision is largely absent in artificial neural networks (ANN) because they depend on externally set learning criteria. Yet training ANN using error backpropagation has created the current revolution in artificial intelligence, raising the question of whether the epistemic autonomy displayed in biological cognition can be achieved with error backpropagation-based learning. We present evidence suggesting that the entorhinal-hippocampal complex combines epistemic autonomy with error backpropagation. Specifically, we propose that the hippocampus minimizes the error between its input and output signals through a modulatory counter-current inhibitory network. We further discuss the computational emulation of this principle and analyze it in the context of autonomous cognitive systems.
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Affiliation(s)
- Diogo Santos-Pata
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Adrián F Amil
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | - César Rennó-Costa
- Digital Metropolis Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Anna Mura
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
| | - Ivan Soltesz
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Paul F M J Verschure
- Laboratory of Synthetic, Perceptive, Emotive and Cognitive Systems (SPECS), Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
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28
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Ness N, Schultz SR. A computational grid-to-place-cell transformation model indicates a synaptic driver of place cell impairment in early-stage Alzheimer's Disease. PLoS Comput Biol 2021; 17:e1009115. [PMID: 34133417 PMCID: PMC8238223 DOI: 10.1371/journal.pcbi.1009115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 06/28/2021] [Accepted: 05/26/2021] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's Disease (AD) is characterized by progressive neurodegeneration and cognitive impairment. Synaptic dysfunction is an established early symptom, which correlates strongly with cognitive decline, and is hypothesised to mediate the diverse neuronal network abnormalities observed in AD. However, how synaptic dysfunction contributes to network pathology and cognitive impairment in AD remains elusive. Here, we present a grid-cell-to-place-cell transformation model of long-term CA1 place cell dynamics to interrogate the effect of synaptic loss on network function and environmental representation. Synapse loss modelled after experimental observations in the APP/PS1 mouse model was found to induce firing rate alterations and place cell abnormalities that have previously been observed in AD mouse models, including enlarged place fields and lower across-session stability of place fields. Our results support the hypothesis that synaptic dysfunction underlies cognitive deficits, and demonstrate how impaired environmental representation may arise in the early stages of AD. We further propose that dysfunction of excitatory and inhibitory inputs to CA1 pyramidal cells may cause distinct impairments in place cell function, namely reduced stability and place map resolution.
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Affiliation(s)
- Natalie Ness
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Simon R. Schultz
- Centre for Neurotechnology and Department of Bioengineering, Imperial College London, London, United Kingdom
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29
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Convergent and divergent functional connectivityalterations of hippocampal subregions between short-term and chronic insomnia disorder. Brain Imaging Behav 2021; 15:986-995. [PMID: 32720181 DOI: 10.1007/s11682-020-00306-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Insomnia disorder (ID) is reclassified into short-term and chronic subtypes based on recent etiological advances, however, neural mechanisms underlying the subtypes are rarely examined. In this study, we investigated gray matter volume and resting-state functional connectivity (RSFC) alterations of hippocampal subregions in short-term and chronic ID using multimodal MRI. We found convergent and divergent alterations between both ID groups in specific hippocampal subregions [right cornu ammonis 1 (CA1), subicular complex (Subc), and caudal hippocampus, (cHipp)] with prefrontal cortex [bilateral medial prefrontal cortex (MPFC), and right middle frontal gyrus] and limbic/paralimbic regions (bilateral middle cingulate cortex and left parahippocampal gyrus). Intriguingly, the RSFC of the right CA1/cHipp, particularly the intersection between these two subregions, with bilateral MPFC exhibited gradual increases from healthy controls to short-term ID and from short-term ID to chronic ID. Moreover, a negative correlation between the right CA1-left parahippocampal gyrus RSFC and Epworth Sleepiness Scale scores, and a positive correlation between the right CA1-bilateral MPFC RSFC and Insomnia Severity Index scores were found in the chronic ID group (P < 0.05). Our findings suggest convergent and divergent RSFC alterations of specific hippocampal subregions with the prefrontal cortex and limbic/paralimbic regions between short-term and chronic ID. These findings suggest that the hippocampus is a key node in establishing diagnostic and categorical biomarkers in ID and developing more effective treatment strategies.
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30
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Bach EC, Ewin SE, Baldassaro AD, Carlson HN, Weiner JL. Chronic intermittent ethanol promotes ventral subiculum hyperexcitability via increases in extrinsic basolateral amygdala input and local network activity. Sci Rep 2021; 11:8749. [PMID: 33888757 PMCID: PMC8062451 DOI: 10.1038/s41598-021-87899-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/23/2021] [Indexed: 11/09/2022] Open
Abstract
The hippocampus, particularly its ventral domain, can promote negative affective states (i.e. stress and anxiety) that play an integral role in the development and persistence of alcohol use disorder (AUD). The ventral hippocampus (vHC) receives strong excitatory input from the basolateral amygdala (BLA) and the BLA-vHC projection bidirectionally modulates anxiety-like behaviors. However, no studies have examined the effects of chronic alcohol on the BLA-vHC circuit. In the present study, we used ex vivo electrophysiology in conjunction with optogenetic approaches to examine the effects of chronic intermittent ethanol exposure (CIE), a well-established rodent model of AUD, on the BLA-vHC projection and putative intrinsic vHC synaptic plasticity. We discovered prominent BLA innervation in the subicular region of the vHC (vSub). CIE led to an overall increase in the excitatory/inhibitory balance, an increase in AMPA/NMDA ratios but no change in paired-pulse ratios, consistent with a postsynaptic increase in excitability in the BLA-vSub circuit. CIE treatment also led to an increase in intrinsic network excitability in the vSub. Overall, our findings suggest a hyperexcitable state in BLA-vSub specific inputs as well as intrinsic inputs to vSub pyramidal neurons which may contribute to the negative affective behaviors associated with CIE.
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Affiliation(s)
- Eva C Bach
- Department of Physiology and Pharmacology, Wake Forest Baptist School of Medicine, PTCRC 212, 115 South Chestnut Avenue, Winston-Salem, NC, 27284, USA.
| | - Sarah E Ewin
- Department of Physiology and Pharmacology, Wake Forest Baptist School of Medicine, PTCRC 212, 115 South Chestnut Avenue, Winston-Salem, NC, 27284, USA
| | - Alexandra D Baldassaro
- Department of Physiology and Pharmacology, Wake Forest Baptist School of Medicine, PTCRC 212, 115 South Chestnut Avenue, Winston-Salem, NC, 27284, USA
| | - Hannah N Carlson
- Department of Physiology and Pharmacology, Wake Forest Baptist School of Medicine, PTCRC 212, 115 South Chestnut Avenue, Winston-Salem, NC, 27284, USA
| | - Jeffrey L Weiner
- Department of Physiology and Pharmacology, Wake Forest Baptist School of Medicine, PTCRC 212, 115 South Chestnut Avenue, Winston-Salem, NC, 27284, USA
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31
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Imbrosci B, Nitzan N, McKenzie S, Donoso JR, Swaminathan A, Böhm C, Maier N, Schmitz D. Subiculum as a generator of sharp wave-ripples in the rodent hippocampus. Cell Rep 2021; 35:109021. [PMID: 33882307 PMCID: PMC9239734 DOI: 10.1016/j.celrep.2021.109021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 02/22/2021] [Accepted: 03/31/2021] [Indexed: 12/04/2022] Open
Abstract
Sharp wave-ripples (SWRs) represent synchronous discharges of hippocampal neurons and are believed to play a major role in memory consolidation. A large body of evidence suggests that SWRs are exclusively generated in the CA3-CA2 network. In contrast, here, we provide several lines of evidence showing that the subiculum can function as a secondary SWRs generator. SWRs with subicular origin propagate forward into the entorhinal cortex as well as backward into the hippocampus proper. Our findings suggest that the output structures of the hippocampus are not only passively facilitating the transfer of SWRs to the cortex, but they also can actively contribute to the genesis of SWRs. We hypothesize that SWRs with a subicular origin may be important for the consolidation of information conveyed to the hippocampus via the temporoammonic pathway. Imbrosci et al. show that the subiculum can work as a secondary generator of sharp wave-ripples (SWRs). SWRs with their origin in subiculum can propagate to the entorhinal cortex and backward to CA1 and CA3.
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Affiliation(s)
- Barbara Imbrosci
- German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Noam Nitzan
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Sam McKenzie
- Neuroscience Institute, New York University, New York, NY 10016, USA
| | - José R Donoso
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience (BCCN) Berlin, 10115 Berlin, Germany
| | - Aarti Swaminathan
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Claudia Böhm
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Nikolaus Maier
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany
| | - Dietmar Schmitz
- German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117 Berlin, Germany; NeuroCure Cluster of Excellence, Charitéplatz 1, 10117 Berlin, Germany; Bernstein Center for Computational Neuroscience (BCCN) Berlin, 10115 Berlin, Germany; Einstein Center for Neurosciences (ECN) Berlin, 10117 Berlin, Germany; Max-Delbrück-Centrum (MDC) for Molecular Medicine, 13125 Berlin, Germany.
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32
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Dillingham CM, Milczarek MM, Perry JC, Vann SD. Time to put the mammillothalamic pathway into context. Neurosci Biobehav Rev 2021; 121:60-74. [PMID: 33309908 PMCID: PMC8137464 DOI: 10.1016/j.neubiorev.2020.11.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/10/2020] [Accepted: 11/13/2020] [Indexed: 12/11/2022]
Abstract
The medial diencephalon, in particular the mammillary bodies and anterior thalamic nuclei, has long been linked to memory and amnesia. The mammillary bodies provide a dense input into the anterior thalamic nuclei, via the mammillothalamic tract. In both animal models, and in patients, lesions of the mammillary bodies, mammillothalamic tract and anterior thalamic nuclei all produce severe impairments in temporal and contextual memory, yet it is uncertain why these regions are critical. Mounting evidence from electrophysiological and neural imaging studies suggests that mammillothalamic projections exercise considerable distal influence over thalamo-cortical and hippocampo-cortical interactions. Here, we outline how damage to the mammillary body-anterior thalamic axis, in both patients and animal models, disrupts behavioural performance on tasks that relate to contextual ("where") and temporal ("when") processing. Focusing on the medial mammillary nuclei as a possible 'theta-generator' (through their interconnections with the ventral tegmental nucleus of Gudden) we discuss how the mammillary body-anterior thalamic pathway may contribute to the mechanisms via which the hippocampus and neocortex encode representations of experience.
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Affiliation(s)
- Christopher M Dillingham
- School of Psychology, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Michal M Milczarek
- School of Psychology, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - James C Perry
- School of Psychology, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Seralynne D Vann
- School of Psychology, Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, CF10 3AT, UK.
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33
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Wan M, Ye Y, Lin H, Xu Y, Liang S, Xia R, He J, Qiu P, Huang C, Tao J, Chen L, Zheng G. Deviations in Hippocampal Subregion in Older Adults With Cognitive Frailty. Front Aging Neurosci 2021; 12:615852. [PMID: 33519422 PMCID: PMC7838368 DOI: 10.3389/fnagi.2020.615852] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/15/2020] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Cognitive frailty is a particular state of cognitive vulnerability toward dementia with neuropathological hallmarks. The hippocampus is a complex, heterogeneous structure closely relates to the cognitive impairment in elderly which is composed of 12 subregions. Atrophy of these subregions has been implicated in a variety of neurodegenerative diseases. The aim of this study was to explore the changes in hippocampal subregions in older adults with cognitive frailty and the relationship between subregions and cognitive impairment as well as physical frailty. METHODS Twenty-six older adults with cognitive frailty and 26 matched healthy controls were included in this study. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA) scale (Fuzhou version) and Wechsler Memory Scale-Revised Chinese version (WMS-RC), while physical frailty was tested with the Chinese version of the Edmonton Frailty Scale (EFS) and grip strength. The volume of the hippocampal subregions was measured with structural brain magnetic resonance imaging. Partial correlation analysis was carried out between the volumes of hippocampal subregions and MoCA scores, Wechsler's Memory Quotient and physical frailty indexes. RESULTS A significant volume decrease was found in six hippocampal subregions, including the bilateral presubiculum, the left parasubiculum, molecular layer of the hippocampus proper (molecular layer of the HP), and hippocampal amygdala transition area (HATA), and the right cornu ammonis subfield 1 (CA1) area, in older adults with cognitive frailty, while the proportion of brain parenchyma and total number of white matter fibers were lower than those in the healthy controls. Positive correlations were found between Wechsler's Memory Quotient and the size of the left molecular layer of the HP and HATA and the right presubiculum. The sizes of the left presubiculum, molecular of the layer HP, and HATA and right CA1 and presubiculum were found to be positively correlated with MoCA score. The sizes of the left parasubiculum, molecular layer of the HP and HATA were found to be negatively correlated with the physical frailty index. CONCLUSION Significant volume decrease occurs in hippocampal subregions of older adults with cognitive frailty, and these changes are correlated with cognitive impairment and physical frailty. Therefore, the atrophy of hippocampal subregions could participate in the pathological progression of cognitive frailty.
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Affiliation(s)
- Mingyue Wan
- College of Nursing and Health Management, Shanghai University of Medicine and Health Sciences, Shanghai, China
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Yu Ye
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Huiying Lin
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Ying Xu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Shengxiang Liang
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Rui Xia
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Jianquan He
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Pingting Qiu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Chengwu Huang
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Jing Tao
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Lidian Chen
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Guohua Zheng
- College of Nursing and Health Management, Shanghai University of Medicine and Health Sciences, Shanghai, China
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Mampay M, Velasco-Estevez M, Rolle SO, Chaney AM, Boutin H, Dev KK, Moeendarbary E, Sheridan GK. Spatiotemporal immunolocalisation of REST in the brain of healthy ageing and Alzheimer's disease rats. FEBS Open Bio 2020; 11:146-163. [PMID: 33185010 PMCID: PMC7780110 DOI: 10.1002/2211-5463.13036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/25/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022] Open
Abstract
In the brain, REST (Repressor Element‐1 Silencing Transcription factor) is a key regulator of neuron cell‐specific gene expression. Nuclear translocation of neuronal REST has been shown to be neuroprotective in a healthy ageing context. In contrast, inability to upregulate nuclear REST is thought to leave ageing neurons vulnerable to neurodegenerative stimuli, such as Alzheimer’s disease (AD) pathology. Hippocampal and cortical neurons are known to be particularly susceptible to AD‐associated neurodegeneration. However, REST expression has not been extensively characterised in the healthy ageing brain. Here, we examined the spatiotemporal immunolocalisation of REST in the brains of healthy ageing wild‐type Fischer‐344 and transgenic Alzheimer’s disease rats (TgF344‐AD). Nuclear expression of REST increased from 6 months to 18 months of age in the hippocampus, frontal cortex and subiculum of wild‐type rats, but not in TgF344‐AD rats. No changes in REST were measured in more posterior cortical regions or in the thalamus. Interestingly, levels of the presynaptic marker synaptophysin, a known gene target of REST, were lower in CA1 hippocampal neurons of 18‐month TgF344‐AD rats compared to 18‐month wild‐types, suggesting that elevated nuclear REST may protect against synapse loss in the CA1 of 18‐month wild‐type rats. High REST expression in ageing wild‐type rats did not, however, protect against axonal loss nor against astroglial reactivity in the hippocampus. Taken together, our data confirm that changes in nuclear REST expression are context‐, age‐ and brain region‐specific. Moreover, key brain structures involved in learning and memory display elevated REST expression in healthy ageing wild‐type rats but not TgF344‐AD rats.
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Affiliation(s)
- Myrthe Mampay
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - María Velasco-Estevez
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Ireland
| | - Sara O Rolle
- The Sainsbury Welcome Centre for Neural Circuits and Behaviour, University College London, UK
| | - Aisling M Chaney
- Faculty of Biology, Medicine and Health, School of Health Sciences, Division of Informatics, Imaging and Data Sciences, University of Manchester, UK
| | - Hervé Boutin
- Wolfson Molecular Imaging Centre, University of Manchester, UK.,Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, UK
| | - Kumlesh K Dev
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Ireland
| | | | - Graham K Sheridan
- School of Life Sciences, Queens Medical Centre, University of Nottingham, UK
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Differential expression of microRNAs in the hippocampi of male and female rodents after chronic alcohol administration. Biol Sex Differ 2020; 11:65. [PMID: 33228793 PMCID: PMC7684718 DOI: 10.1186/s13293-020-00342-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/09/2020] [Indexed: 12/14/2022] Open
Abstract
Background Women are more vulnerable than men to the neurotoxicity and severe brain damage caused by chronic heavy alcohol use. In addition, brain damage due to chronic heavy alcohol use may be associated with sex-dependent epigenetic modifications. This study aimed to identify microRNAs (miRNAs) and their target genes that are differentially expressed in the hippocampi of male and female animal models in response to alcohol. Methods After chronic alcohol administration (3~3.5 g/kg/day) in male (control, n = 10; alcohol, n = 12) or female (control, n = 10; alcohol, n = 12) Sprague-Dawley rats for 6 weeks, we measured body weights and doublecortin (DCX; a neurogenesis marker) concentrations and analyzed up- or downregulated miRNAs using GeneChip miRNA 4.0 arrays. The differentially expressed miRNAs and their putative target genes were validated by RT-qPCR. Results Alcohol attenuated body weight gain only in the male group. On the other hand, alcohol led to increased serum AST in female rats and decreased serum total cholesterol concentrations in male rats. The expression of DCX was significantly reduced in the hippocampi of male alcohol-treated rats. Nine miRNAs were significantly up- or downregulated in male alcohol-treated rats, including upregulation of miR-125a-3p, let-7a-5p, and miR-3541, and downregulation of their target genes (Prdm5, Suv39h1, Ptprz1, Mapk9, Ing4, Wt1, Nkx3-1, Dab2ip, Rnf152, Ripk1, Lin28a, Apbb3, Nras, and Acvr1c). On the other hand, 7 miRNAs were significantly up- or downregulated in alcohol-treated female rats, including downregulation of miR-881-3p and miR-504 and upregulation of their target genes (Naa50, Clock, Cbfb, Arih1, Ube2g1, and Gng7). Conclusions These results suggest that chronic heavy alcohol use produces sex-dependent effects on neurogenesis and miRNA expression in the hippocampus and that sex differences should be considered when developing miRNA biomarkers to diagnose or treat alcoholics. Supplementary Information The online version contains supplementary material available at 10.1186/s13293-020-00342-3.
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Lee H, GoodSmith D, Knierim JJ. Parallel processing streams in the hippocampus. Curr Opin Neurobiol 2020; 64:127-134. [PMID: 32502734 PMCID: PMC8136469 DOI: 10.1016/j.conb.2020.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/12/2020] [Indexed: 01/06/2023]
Abstract
The hippocampus performs two complementary processes, pattern separation and pattern completion, to minimize interference and maximize the storage capacity of memories. Classic computational models have suggested that the dentate gyrus (DG) supports pattern separation and the putative attractor circuitry in CA3 supports pattern completion. However, recent evidence of functional heterogeneity along the CA3 transverse axis of the hippocampus suggests that the DG and proximal CA3 work as a functional unit for pattern separation, while distal CA3 forms an autoassociative network for pattern completion. We propose that the outputs of these functional circuits, combined with direct projections from entorhinal cortex to CA1, form interconnected, parallel processing circuits to support accurate memory storage and retrieval.
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Affiliation(s)
- Heekyung Lee
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Douglas GoodSmith
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - James J Knierim
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
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Abstract
Several types of neurons involved in spatial navigation and memory encode the distance and direction (that is, the vector) between an agent and items in its environment. Such vectorial information provides a powerful basis for spatial cognition by representing the geometric relationships between the self and the external world. Here, we review the explicit encoding of vectorial information by neurons in and around the hippocampal formation, far from the sensory periphery. The parahippocampal, retrosplenial and parietal cortices, as well as the hippocampal formation and striatum, provide a plethora of examples of vector coding at the single neuron level. We provide a functional taxonomy of cells with vectorial receptive fields as reported in experiments and proposed in theoretical work. The responses of these neurons may provide the fundamental neural basis for the (bottom-up) representation of environmental layout and (top-down) memory-guided generation of visuospatial imagery and navigational planning.
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The dorsal subiculum is required for contextual fear conditioning consolidation in rats. Behav Brain Res 2020; 390:112661. [PMID: 32407819 DOI: 10.1016/j.bbr.2020.112661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/14/2020] [Accepted: 04/17/2020] [Indexed: 02/07/2023]
Abstract
The hippocampal formation has a well-known role in contextual fear conditioning. The dorsal subiculum connects the hippocampus to the entorhinal cortex through pathways that seemingly rely on NMDA-dependent synaptic plasticity. The role of the dorsal subiculum in contextual fear conditioning retrieval, but not acquisition, has been previously reported. However, most of the critical biological phenomena involved in memory formation occur in the consolidation phase. The present study aimed to assess the effects of intra-dorsal subiculum muscimol or AP5 infusion on contextual fear conditioning consolidation. Our data show that dorsal subiculum integrity, as well as NMDA transmission in this region, seem to be necessary for contextual fear conditioning consolidation.
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Li M, Huang L, Yang D, Luo C, Qin R, Zhang B, Zhao H, Xu Y. Atrophy patterns of hippocampal subfields in T2DM patients with cognitive impairment. Endocrine 2020; 68:536-548. [PMID: 32172485 PMCID: PMC7308251 DOI: 10.1007/s12020-020-02249-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE To identify the volume changes of hippocampus subfields in T2DM patients with cognitive impairment and to determine how these atrophy patterns associate with impairments in different cognitive domain. METHODS A total of 117 individuals were recruited, including T2DM patients with cognitive impairment (T2DM-CI) (n = 34), T2DM patients without cognitive impairment (T2DM-non-CI) (n = 36) and normal controls (NC) (n = 47). All subjects went through a 3.0 T magnetic resonance (MR) scan and a neuropsychological assessment. Hippocampal subfield volumes were processed using the FreeSurfer 6.0.0 and compared among the three groups. Partial correlation analyses were used to estimate the relationship between cognitive function and hippocampal subfield volume, with age, sex, education, and eTIV (estimated total intracranial volume) as covariants. RESULTS The total hippocampal volume had a reduction trend among the three groups, and the significantly statistical difference only was found between T2DM-CI group and NC group. Regarding the hippocampal subfields, the volumes of left subiculum, left presubiculum, left fimbria, right CA1 and right molecular layer HP decreased significantly in the T2DM-CI group (P < 0.05/12). Partial correlation analyses showed that the volumes of the left subiculum, left fimbria, and left presubiculum were significantly related to executive function. The right hippocampal CA1 volume was significantly correlated with memory in the T2DM-CI group (P < 0.05). But in T2DM-non-CI group, the correlation between the left fimbria volume and the memory, the left subiculum volume and MoCA were different with the T2DM-CI group and NC group (P < 0.05). CONCLUSIONS The smaller the volume of left presubiculum, the worse the executive function, and the atrophy of the right CA1 was related to memory impairment in T2DM-CI group. However the result was the opposite in T2DM-non-CI group. There might be a compensation mechanism of hippocampus of T2DM patients before cognitive impairment.
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Affiliation(s)
- MengChun Li
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China
| | - LiLi Huang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China
| | - Dan Yang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China
| | - CaiMei Luo
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China
| | - RuoMeng Qin
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China
| | - Bing Zhang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China
- Department of Radiology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Hui Zhao
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China.
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China.
| | - Yun Xu
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
- Jiangsu Key Laboratory for Molecular Medicine, Nanjing University Medical School, Nanjing, China.
- Nanjing Medicine Center For Neurological and Psychiatric Diseases, Nanjing, China.
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Choi MR, Han JS, Chai YG, Jin YB, Lee SR, Kim DJ. Gene expression profiling in the hippocampus of adolescent rats after chronic alcohol administration. Basic Clin Pharmacol Toxicol 2019; 126:389-398. [PMID: 31628824 DOI: 10.1111/bcpt.13342] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/15/2019] [Indexed: 11/29/2022]
Abstract
In South Korea, the average age of onset of alcohol drinking is 13.3 years and half of adolescents drink alcohol more than once a month; 8.45% of the Korean adolescent population become future high-risk alcohol drinkers. Chronic alcohol abuse causes physical and psychiatric health problems such as alcohol addiction, liver disease, stroke and cognitive impairments. This study aimed to investigate the effect of alcohol on gene expression and their function in the hippocampus of adolescent rats. After chronic alcohol administration in male (control, n = 6; alcohol, n = 6) Sprague-Dawley rats for 6 weeks, we analysed up- or down-regulated genes using RNA-sequencing technology. We found 83 genes more than 1.5-fold up- or down-regulated in the alcohol-treated group. Among them, genes (Dnai1, Cfap206 and Dnah1) associated with cilium movement were up-regulated in the alcohol-treated group. Mlf1, related to cell cycle arrest, was also up-regulated in the alcohol-treated group. On the other hand, genes (Smad3 and Plk5) involved in negative regulation of cell proliferation were down-regulated in the hippocampus by chronic alcohol administration. In addition, expression levels of genes associated with oxidative stress (Krt8 and Car3) and migration (Vim) were changed by chronic alcohol administration. These results pave a path for a better understanding of the neuromolecular mechanisms mediated by chronic alcohol exposure in the hippocampus of adolescents and negative pathology due to chronic alcohol abuse.
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Affiliation(s)
- Mi Ran Choi
- Department of Psychiatry, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Jasmin Sanghyun Han
- Department of Psychiatry, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Young Gyu Chai
- Department of Molecular and Life Sciences, Hanyang University, Ansan, Korea
| | - Yeung-Bae Jin
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Sang-Rae Lee
- National Primate Research Center (NPRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Cheongju, Korea
| | - Dai-Jin Kim
- Department of Psychiatry, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea
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Sun Y, Jin S, Lin X, Chen L, Qiao X, Jiang L, Zhou P, Johnston KG, Golshani P, Nie Q, Holmes TC, Nitz DA, Xu X. CA1-projecting subiculum neurons facilitate object-place learning. Nat Neurosci 2019; 22:1857-1870. [PMID: 31548723 PMCID: PMC6819262 DOI: 10.1038/s41593-019-0496-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 08/09/2019] [Indexed: 11/09/2022]
Abstract
Recent anatomical evidence suggests a functionally significant back-projection pathway from the subiculum to the CA1. Here we show that the afferent circuitry of CA1-projecting subicular neurons is biased by inputs from CA1 inhibitory neurons and the visual cortex, but lacks input from the entorhinal cortex. Efferents of the CA1-projecting subiculum neurons also target the perirhinal cortex, an area strongly implicated in object-place learning. We identify a critical role for CA1-projecting subicular neurons in object-location learning and memory, and show that this projection modulates place-specific activity of CA1 neurons and their responses to displaced objects. Together, these experiments reveal a novel pathway by which cortical inputs, particularly those from the visual cortex, reach the hippocampal output region CA1. Our findings also implicate this circuitry in the formation of complex spatial representations and learning of object-place associations.
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Affiliation(s)
- Yanjun Sun
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Suoqin Jin
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Xiaoxiao Lin
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Lujia Chen
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Xin Qiao
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Li Jiang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Pengcheng Zhou
- Department of Statistics and Center for Theoretical Neuroscience, Columbia University, New York, NY, USA
| | - Kevin G Johnston
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- West Los Angeles VA Medical Center, Los Angeles, CA, USA
| | - Qing Nie
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA.
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA.
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, USA.
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA.
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Matsumoto N, Kitanishi T, Mizuseki K. The subiculum: Unique hippocampal hub and more. Neurosci Res 2019; 143:1-12. [DOI: 10.1016/j.neures.2018.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/10/2018] [Accepted: 08/03/2018] [Indexed: 01/09/2023]
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Dalton MA, McCormick C, De Luca F, Clark IA, Maguire EA. Functional connectivity along the anterior-posterior axis of hippocampal subfields in the ageing human brain. Hippocampus 2019; 29:1049-1062. [PMID: 31058404 PMCID: PMC6849752 DOI: 10.1002/hipo.23097] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/02/2019] [Accepted: 04/22/2019] [Indexed: 12/19/2022]
Abstract
While age‐related volumetric changes in human hippocampal subfields have been reported, little is known about patterns of subfield functional connectivity (FC) in the context of healthy ageing. Here we investigated age‐related changes in patterns of FC down the anterior–posterior axis of each subfield. Using high resolution structural MRI we delineated the dentate gyrus (DG), CA fields (including separating DG from CA3), the subiculum, pre/parasubiculum, and the uncus in healthy young and older adults. We then used high resolution resting state functional MRI to measure FC in each group and to directly compare them. We first examined the FC of each subfield in its entirety, in terms of FC with other subfields and with neighboring cortical regions, namely, entorhinal, perirhinal, posterior parahippocampal, and retrosplenial cortices. Next, we analyzed subfield to subfield FC within different portions along the hippocampal anterior–posterior axis, and FC of each subfield portion with the neighboring cortical regions of interest. In general, the FC of the older adults was similar to that observed in the younger adults. We found that, as in the young group, the older group displayed intrinsic FC between the subfields that aligned with the tri‐synaptic circuit but also extended beyond it, and that FC between the subfields and neighboring cortical areas differed markedly along the anterior–posterior axis of each subfield. We observed only one significant difference between the young and older groups. Compared to the young group, the older participants had significantly reduced FC between the anterior CA1‐subiculum transition region and the transentorhinal cortex, two brain regions known to be disproportionately affected during the early stages of age‐related tau accumulation. Overall, these results contribute to ongoing efforts to characterize human hippocampal subfield connectivity, with implications for understanding hippocampal function and its modulation in the ageing brain.
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Affiliation(s)
- Marshall A Dalton
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Cornelia McCormick
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Flavia De Luca
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Ian A Clark
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
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Development of Local Circuit Connections to Hilar Mossy Cells in the Mouse Dentate Gyrus. eNeuro 2019; 6:eN-NWR-0370-18. [PMID: 30937358 PMCID: PMC6439204 DOI: 10.1523/eneuro.0370-18.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 02/15/2019] [Accepted: 02/22/2019] [Indexed: 12/14/2022] Open
Abstract
Hilar mossy cells in the dentate gyrus (DG) shape the firing and function of the hippocampal circuit. However, the neural circuitry providing afferent input to mossy cells is incompletely understood, and little is known about the development of these inputs. Thus, we used whole-cell recording and laser scanning photostimulation (LSPS) to characterize the developmental trajectory of local excitatory and inhibitory synaptic inputs to mossy cells in the mouse hippocampus. Hilar mossy cells were targeted by visualizing non-red fluorescent cells in the dentate hilus of GAD2-Cre; Ai9 mice that expressed tdTomato in GAD+ neurons, and were confirmed by post hoc morphological characterization. Our results show that at postnatal day (P)6–P7, mossy cells received more excitatory input from neurons in the proximal CA3 versus those in the DG. In contrast, at P13–P14 and P21–P28, the largest source of excitatory input originated in DG cells, while the strength of CA3 and hilar inputs declined. A developmental trend was also evident for inhibitory inputs. Overall inhibitory input at P6–P7 was weak, while inhibitory inputs from the DG cell layer and the hilus predominated at P13–P14 and P21–P28. The strength of local DG excitation and inhibition to mossy cells peaked at P13–P14 and decreased slightly in older P21–P28 mice. Together, these data provide new detailed information on the development of local synaptic connectivity of mossy cells, and suggests mechanisms through which developmental changes in local circuit inputs to hilar mossy cells shape their physiology and vulnerability to injury during postnatal periods.
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Bao H, Song J. Treating Brain Disorders by Targeting Adult Neural Stem Cells. Trends Mol Med 2018; 24:991-1006. [PMID: 30447904 PMCID: PMC6351137 DOI: 10.1016/j.molmed.2018.10.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/15/2022]
Abstract
Adult neurogenesis, a developmental process of generating functionally integrated neurons from neural stem cells, occurs throughout life in the hippocampus of the mammalian brain and highlights the plastic nature of the mature central nervous system. Substantial evidence suggests that new neurons participate in cognitive and affective brain functions and aberrant adult neurogenesis contributes to various brain disorders. Focusing on adult hippocampal neurogenesis, we review recent findings that advance our understanding of the key properties and potential functions of adult neural stem cells. We further discuss the key evidence demonstrating the causal role of aberrant hippocampal neurogenesis and various brain disorders. Finally, we propose strategies aimed at simultaneously correcting stem cells and their niche for treating brain disorders.
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Affiliation(s)
- Hechen Bao
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Juan Song
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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Cembrowski MS, Wang L, Lemire AL, Copeland M, DiLisio SF, Clements J, Spruston N. The subiculum is a patchwork of discrete subregions. eLife 2018; 7:e37701. [PMID: 30375971 PMCID: PMC6226292 DOI: 10.7554/elife.37701] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/27/2018] [Indexed: 11/13/2022] Open
Abstract
In the hippocampus, the classical pyramidal cell type of the subiculum acts as a primary output, conveying hippocampal signals to a diverse suite of downstream regions. Accumulating evidence suggests that the subiculum pyramidal cell population may actually be comprised of discrete subclasses. Here, we investigated the extent and organizational principles governing pyramidal cell heterogeneity throughout the mouse subiculum. Using single-cell RNA-seq, we find that the subiculum pyramidal cell population can be deconstructed into eight separable subclasses. These subclasses were mapped onto abutting spatial domains, ultimately producing a complex laminar and columnar organization with heterogeneity across classical dorsal-ventral, proximal-distal, and superficial-deep axes. We further show that these transcriptomically defined subclasses correspond to differential protein products and can be associated with specific projection targets. This work deconstructs the complex landscape of subiculum pyramidal cells into spatially segregated subclasses that may be observed, controlled, and interpreted in future experiments.
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Affiliation(s)
- Mark S Cembrowski
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Lihua Wang
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Andrew L Lemire
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Monique Copeland
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | | | - Jody Clements
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
| | - Nelson Spruston
- Janelia Research CampusHoward Hughes Medical InstituteAshburnUnited States
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Choi MR, Chun JW, Kwak SM, Bang SH, Jin YB, Lee Y, Kim HN, Chang KT, Chai YG, Lee SR, Kim DJ. Effects of acute and chronic methamphetamine administration on cynomolgus monkey hippocampus structure and cellular transcriptome. Toxicol Appl Pharmacol 2018; 355:68-79. [DOI: 10.1016/j.taap.2018.05.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 12/13/2022]
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Altered tryptophan catabolite concentrations in major depressive disorder and associated changes in hippocampal subfield volumes. Psychoneuroendocrinology 2018; 95:8-17. [PMID: 29787958 DOI: 10.1016/j.psyneuen.2018.05.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Tryptophan depletion is a well-replicated biological finding in Major Depressive Disorder (MDD). The kynurenine pathway (KP) and its rate-limiting tryptophan degrading enzyme, indolamine 2,3 dioxygenase (IDO), have been implicated in the pathogenesis of depression. IDO expression is driven by inflammatory cytokines, providing a putative link between inflammation and neuropathology. This study examined circulating concentrations of C-reactive protein (CRP), plasma tryptophan, kynurenine (KYN), kynurenic acid (KYNA) and quinolinic acid (QUIN) and whole blood mRNA expression of IDO in patients with major depressive disorder (MDD) compared with healthy controls (HC). METHODS A diagnosis of major depression was made according to DSM-IV. Depression severity was assessed using the Hamilton depression (HAM-D) rating scale. 74 MDD patients, 39 with a first presentation of MDD (fpMDD) and 35 with chronic or recurrent episodes (rMDD), and 37 HC were recruited to the study. Whole blood and plasma samples were collected. Expression of markers in whole blood were measured by PCR, circulating CRP by ELISA and KP metabolites by LC-MS/MS. Hippocampal cornu ammonis (CA) and subiculum volumes were determined by MRI and calculated using FreeSurfer. RESULTS Tryptophan concentrations were significantly reduced in MDD compared to HC. There was a positive correlation between QUIN and both CRP concentrations and whole blood IDO1 in MDD. KYNA concentrations were reduced in MDD patients presenting with a first episode (fpMDD) compared to those presenting with recurrent depression (rMDD) and HC. By contrast QUIN concentrations were elevated in rMDD compared to fpMDD and HC. KYNA/QUIN was reduced in MDD and rMDD but not fpMDD compared to HC. Hippocampal subfield volumes were smaller in MDD patients than HC for CA1 (left only), CA2/3 (left and right) and CA4 (right only). CRP and CA1 volumes were negatively correlated bilaterally in MDD patients. KYNA and subiculum volume were positively correlated bilaterally. DISCUSSION This study found evidence of KP metabolism imbalance in MDD patients in addition to tryptophan reduction and mild immune activation. Relationships between CRP and KYNA with some hippocampal subfield volumes in MDD patients suggest that this inflammatory signature may be associated with reduced hippocampal subfield volumes in depression.
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Optogenetic induction of the schizophrenia-related endophenotype of ventral hippocampal hyperactivity causes rodent correlates of positive and cognitive symptoms. Sci Rep 2018; 8:12871. [PMID: 30150758 PMCID: PMC6110795 DOI: 10.1038/s41598-018-31163-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/07/2018] [Indexed: 01/01/2023] Open
Abstract
Pathological over-activity of the CA1 subfield of the human anterior hippocampus has been identified as a potential predictive marker for transition from a prodromal state to overt schizophrenia. Psychosis, in turn, is associated with elevated activity in the anterior subiculum, the hippocampal output stage directly activated by CA1. Over-activity in these subfields may represent a useful endophenotype to guide translationally predictive preclinical models. To recreate this endophenotype and study its causal relation to deficits in the positive and cognitive symptom domains, we optogenetically activated excitatory neurons of the ventral hippocampus (vHPC; analogous to the human anterior hippocampus), targeting the ventral subiculum. Consistent with previous studies, we found that vHPC over-activity evokes hyperlocomotion, a rodent correlate of positive symptoms. vHPC activation also impaired performance on the spatial novelty preference (SNP) test of short-term memory, regardless of whether stimulation was applied during the encoding or retrieval stage of the task. Increasing dopamine transmission with amphetamine produced hyperlocomotion, but was not associated with SNP impairments. This suggests that short-term memory impairments resulting from hippocampal over-activity likely arise independently of a hyperdopaminergic state, a finding that is consistent with the pharmaco-resistance of cognitive symptoms in patients.
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Schultz MK, Gentzel R, Usenovic M, Gretzula C, Ware C, Parmentier-Batteur S, Schachter JB, Zariwala HA. Pharmacogenetic neuronal stimulation increases human tau pathology and trans-synaptic spread of tau to distal brain regions in mice. Neurobiol Dis 2018; 118:161-176. [PMID: 30049665 DOI: 10.1016/j.nbd.2018.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 06/15/2018] [Accepted: 07/04/2018] [Indexed: 12/26/2022] Open
Abstract
In Alzheimer's Disease (AD), tau pathology has a spatiotemporally distinct pattern of progressive spread along anatomically connected neural pathways. Extracellular tau in the brain interstitial space increases in response to neuronal activity suggesting that neural activity may also drive pathogenic tau spread. Here we tested the hypothesis that neuronal activity drives human Tau (hTau) release and trans-synaptic spread to neuroanatomically connected regions. We used AAV to overexpress wild type full-length hTau and an excitatory DREADD (Designer Receptors Exclusively Activated by a Designer Drug) in mouse primary hippocampal cultures and determined that excitatory stimulation with the DREADD ligand clozapine N-oxide (CNO) promoted extracellular hTau release. We translated this approach to an in vivo model and used AAV to express hTau and the excitatory DREADD in the ventral hippocampus of wild type mice, P301L hTau-expressing mice, or tau knockout mice. Six to eight weeks following AAV injection, we determined that CNO treatment in DREADD-expressing mice resulted in increased hTau pathology and hTau spread to distal brain regions compared to unstimulated controls (CNO in non-DREADD mice, or vehicle in DREADD mice). The results highlight a potentially disease relevant exacerbation of tau pathology in response to elevated neuronal activity. This model underscores the propensity of non-mutant hTau to undergo neuronal spreading, as seen in AD. The model can translate to other preclinical species and can be used to evaluate modes of tau transmission and test the efficacy of therapeutic approaches that target tau or hyperexcitability.
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Affiliation(s)
- M K Schultz
- Pharmacology, Merck & Co., Inc., West Point, PA, USA
| | - R Gentzel
- Neuroscience, Merck & Co., Inc., West Point, PA, USA
| | - M Usenovic
- Neuroscience, Merck & Co., Inc., West Point, PA, USA
| | - C Gretzula
- Neuroscience, Merck & Co., Inc., West Point, PA, USA
| | - C Ware
- Neuroscience, Merck & Co., Inc., Boston, MA, USA
| | | | - J B Schachter
- Neuroscience, Merck & Co., Inc., West Point, PA, USA
| | - H A Zariwala
- Pharmacology, Merck & Co., Inc., West Point, PA, USA.
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