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Uzun YS, Santos R, Marchetto MC, Padmanabhan K. Network size affects the complexity of activity in human iPSC-derived neuronal populations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.564939. [PMID: 37961249 PMCID: PMC10635014 DOI: 10.1101/2023.10.31.564939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Multi-electrode recording of neural activity in cultures offer opportunities for understanding how the structure of a network gives rise to function. Although it is hypothesized that network size is critical for determining the dynamics of activity, this relationship in human neural cultures remains largely unexplored. By applying new methods for analyzing neural activity to human iPSC derived cultures at either low-densities or high-densities, we uncovered the significant impacts that neuron number has on the individual neurophysiological properties of cells (such as firing rates), the collective behavior of the networks these cultures formed (as measured by entropy), and the relationship between the two. As a result, simply changing the densities of neurons generated dynamics and network behavior that differed not just in degree, but in kind. Beyond revealing the relationship between network structure and function, our findings provide a novel analytical framework to study diseases where network level activity is affected.
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Affiliation(s)
- Yavuz Selim Uzun
- Department of Physics and Astronomy, University of Rochester
- Del Monte Institute for Neuroscience, University of Rochester School of Medicine
| | - Renata Santos
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, Signaling mechanisms in neurological disorders, 102 rue de la Santé, 75014 Paris, France
- Institut Imagine, INSERM U1163, Mechanisms and therapy of genetic brain diseases, Université Paris Cité, 24 Boulevard du Montparnasse, 75015 Paris, France
- Institut des Sciences Biologiques, CNRS, 16 rue Pierre et Marie Curie, 75005 Paris, France
| | | | - Krishnan Padmanabhan
- Del Monte Institute for Neuroscience, University of Rochester School of Medicine
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry
- Center for Visual Science, University of Rochester School of Medicine and Dentistry
- Intellectual Development and Disability Research Center, University of Rochester School of Medicine and Dentistry
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2
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Pronier É, Morici JF, Girardeau G. The role of the hippocampus in the consolidation of emotional memories during sleep. Trends Neurosci 2023; 46:912-925. [PMID: 37714808 DOI: 10.1016/j.tins.2023.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/23/2023] [Accepted: 08/09/2023] [Indexed: 09/17/2023]
Abstract
Episodic memory relies on the hippocampus, a heterogeneous brain region with distinct functions. Spatial representations in the dorsal hippocampus (dHPC) are crucial for contextual memory, while the ventral hippocampus (vHPC) is more involved in emotional processing. Here, we review the literature in rodents highlighting the anatomical and functional properties of the hippocampus along its dorsoventral axis that underlie its role in contextual and emotional memory encoding, consolidation, and retrieval. We propose that the coordination between the dorsal and vHPC through theta oscillations during rapid eye movement (REM) sleep, and through sharp-wave ripples during non-REM (NREM) sleep, might facilitate the transfer of contextual information for integration with valence-related processing in other structures of the network. Further investigation into the physiology of the vHPC and its connections with other brain areas is needed to deepen the current understanding of emotional memory consolidation during sleep.
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Affiliation(s)
- Éléonore Pronier
- Institut du Fer à Moulin, Inserm U1270, Sorbonne Université, Paris, France
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3
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Pasini FW, Busch AN, Mináč J, Padmanabhan K, Muller L. Algebraic approach to spike-time neural codes in the hippocampus. Phys Rev E 2023; 108:054404. [PMID: 38115483 DOI: 10.1103/physreve.108.054404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 08/14/2023] [Indexed: 12/21/2023]
Abstract
Although temporal coding through spike-time patterns has long been of interest in neuroscience, the specific structures that could be useful for spike-time codes remain highly unclear. Here, we introduce an analytical approach, using techniques from discrete mathematics, to study spike-time codes. As an initial example, we focus on the phenomenon of "phase precession" in the rodent hippocampus. During navigation and learning on a physical track, specific cells in a rodent's brain form a highly structured pattern relative to the oscillation of population activity in this region. Studies of phase precession largely focus on its role in precisely ordering spike times for synaptic plasticity, as the role of phase precession in memory formation is well established. Comparatively less attention has been paid to the fact that phase precession represents one of the best candidates for a spike-time neural code. The precise nature of this code remains an open question. Here, we derive an analytical expression for a function mapping points in physical space to complex-valued spikes by representing individual spike times as complex numbers. The properties of this function make explicit a specific relationship between past and future in spike patterns of the hippocampus. Importantly, this mathematical approach generalizes beyond the specific phenomenon studied here, providing a technique to study the neural codes within precise spike-time sequences found during sensory coding and motor behavior. We then introduce a spike-based decoding algorithm, based on this function, that successfully decodes a simulated animal's trajectory using only the animal's initial position and a pattern of spike times. This decoder is robust to noise in spike times and works on a timescale almost an order of magnitude shorter than typically used with decoders that work on average firing rate. These results illustrate the utility of a discrete approach, based on the structure and symmetries in spike patterns across finite sets of cells, to provide insight into the structure and function of neural systems.
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Affiliation(s)
- Federico W Pasini
- Department of Mathematics, Western University London, Ontario, Canada N6A 5B7
- Western Academy for Advanced Research, Western University, London, Ontario, Canada N6A 5B7
- Western Institute for Neuroscience, Western University, London, Ontario, Canada N6A 5B7
| | - Alexandra N Busch
- Department of Mathematics, Western University London, Ontario, Canada N6A 5B7
- Western Academy for Advanced Research, Western University, London, Ontario, Canada N6A 5B7
- Western Institute for Neuroscience, Western University, London, Ontario, Canada N6A 5B7
| | - Ján Mináč
- Department of Mathematics, Western University London, Ontario, Canada N6A 5B7
- Western Academy for Advanced Research, Western University, London, Ontario, Canada N6A 5B7
- Western Institute for Neuroscience, Western University, London, Ontario, Canada N6A 5B7
| | - Krishnan Padmanabhan
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Lyle Muller
- Department of Mathematics, Western University London, Ontario, Canada N6A 5B7
- Western Academy for Advanced Research, Western University, London, Ontario, Canada N6A 5B7
- Western Institute for Neuroscience, Western University, London, Ontario, Canada N6A 5B7
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Ma X, Zheng C, Chen Y, Pereira F, Li Z. Working memory and reward increase the accuracy of animal location encoding in the medial prefrontal cortex. Cereb Cortex 2023; 33:2245-2259. [PMID: 35584788 PMCID: PMC9977377 DOI: 10.1093/cercor/bhac205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/14/2022] Open
Abstract
The ability to perceive spatial environments and locate oneself during navigation is crucial for the survival of animals. Mounting evidence suggests a role of the medial prefrontal cortex (mPFC) in spatially related behaviors. However, the properties of mPFC spatial encoding and how it is influenced by animal behavior are poorly defined. Here, we train the mice to perform 3 tasks differing in working memory and reward-seeking: a delayed non-match to place (DNMTP) task, a passive alternation (PA) task, and a free-running task. Single-unit recording in the mPFC shows that although individual mPFC neurons exhibit spatially selective firing, they do not reliably represent the animal location. The population activity of mPFC neurons predicts the animal location. Notably, the population coding of animal locations by the mPFC is modulated by animal behavior in that the coding accuracy is higher in tasks involved in working memory and reward-seeking. This study reveals an approach whereby the mPFC encodes spatial positions and the behavioral variables affecting it.
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Affiliation(s)
- Xiaoyu Ma
- Section on Synapse Development Plasticity, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States
| | - Charles Zheng
- Machine Learning Team, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States
| | - Yenho Chen
- Machine Learning Team, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States
| | - Francisco Pereira
- Machine Learning Team, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States
| | - Zheng Li
- Section on Synapse Development Plasticity, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, United States
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Rong J, Yang Y, Liang M, Zhong H, Li Y, Zhu Y, Sha S, Chen L, Zhou R. Neonatal inflammation increases hippocampal KCC2 expression through methylation-mediated TGF-β1 downregulation leading to impaired hippocampal cognitive function and synaptic plasticity in adult mice. J Neuroinflammation 2023; 20:15. [PMID: 36691035 PMCID: PMC9872321 DOI: 10.1186/s12974-023-02697-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/12/2023] [Indexed: 01/25/2023] Open
Abstract
The mechanisms by which neonatal inflammation leads to cognitive deficits in adulthood remain poorly understood. Inhibitory GABAergic synaptic transmission plays a vital role in controlling learning, memory and synaptic plasticity. Since early-life inflammation has been reported to adversely affect the GABAergic synaptic transmission, the aim of this study was to investigate whether and how neonatal inflammation affects GABAergic synaptic transmission resulting in cognitive impairment. Neonatal mice received a daily subcutaneous injection of lipopolysaccharide (LPS, 50 μg/kg) or saline on postnatal days 3-5. It was found that blocking GABAergic synaptic transmission reversed the deficit in hippocampus-dependent memory or the induction failure of long-term potentiation in the dorsal CA1 in adult LPS mice. An increase of mIPSCs amplitude was further detected in adult LPS mice indicative of postsynaptic potentiation of GABAergic transmission. Additionally, neonatal LPS resulted in the increased expression and function of K+-Cl--cotransporter 2 (KCC2) and the decreased expression of transforming growth factor-beta 1 (TGF-β1) in the dorsal CA1 during adulthood. The local TGF-β1 overexpression improved KCC2 expression and function, synaptic plasticity and memory of adult LPS mice. Adult LPS mice show hypermethylation of TGFb1 promoter and negatively correlate with reduced TGF-β1 transcripts. 5-Aza-deoxycytidine restored the changes in TGFb1 promoter methylation and TGF-β1 expression. Altogether, the results suggest that hypermethylation-induced reduction of TGF-β1 leads to enhanced GABAergic synaptic inhibition through increased KCC2 expression, which is a underlying mechanism of neonatal inflammation-induced hippocampus-dependent memory impairment in adult mice.
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Affiliation(s)
- Jing Rong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yang Yang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Min Liang
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Haiquan Zhong
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yingchun Li
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Yichao Zhu
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Sha Sha
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Lei Chen
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
| | - Rong Zhou
- grid.89957.3a0000 0000 9255 8984Department of Physiology, Nanjing Medical University, Longmian Avenue 101, Jiangning District, Nanjing, 211166 Jiangsu China
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Chockanathan U, Padmanabhan K. From synapses to circuits and back: Bridging levels of understanding in animal models of Alzheimer's disease. Eur J Neurosci 2022; 56:5564-5586. [PMID: 35244297 PMCID: PMC10926359 DOI: 10.1111/ejn.15636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/04/2022] [Accepted: 02/23/2022] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by behavioural changes that include memory loss and cognitive decline and is associated with the appearance of amyloid-β plaques and neurofibrillary tangles throughout the brain. Although aspects of the disease percolate across multiple levels of neuronal organization, from the cellular to the behavioural, it is increasingly clear that circuits are a critical junction between the cellular pathology and the behavioural phenotypes that bookend these levels of analyses. In this review, we discuss critical aspects of neural circuit research, beginning with synapses and progressing to network activity and how they influence our understanding of disease processed in AD.
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Affiliation(s)
- Udaysankar Chockanathan
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Neuroscience Graduate Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Medical Scientist Training Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Krishnan Padmanabhan
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Neuroscience Graduate Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Medical Scientist Training Program, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Ernest J. Del Monte Institute for Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Center for Visual Science, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
- Intellectual and Developmental Disabilities Research Center, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
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Twarkowksi H, Steininger V, Kim MJ, Sahay A. A dentate gyrus- CA3 inhibitory circuit promotes evolution of hippocampal-cortical ensembles during memory consolidation. eLife 2022; 11:70586. [PMID: 35191834 PMCID: PMC8903830 DOI: 10.7554/elife.70586] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Memories encoded in the dentate gyrus (DG) - CA3 circuit of the hippocampus are routed from CA1 to anterior cingulate cortex (ACC) for consolidation. Although CA1 parvalbumin inhibitory neurons (PV INs) orchestrate hippocampal-cortical communication, we know less about CA3 PV INs or DG - CA3 principal neuron - IN circuit mechanisms that contribute to evolution of hippocampal-cortical ensembles during memory consolidation. Using viral genetics to selectively mimic and boost an endogenous learning-dependent circuit mechanism, DG cell recruitment of CA3 PV INs and feed-forward inhibition (FFI) in CA3, in combination with longitudinal in vivo calcium imaging, we demonstrate that FFI facilitates formation and maintenance of context-associated neuronal ensembles in CA1. Increasing FFI in DG - CA3 promoted context specificity of neuronal ensembles in ACC over time and enhanced long-term contextual fear memory. In vivo LFP recordings in mice with increased FFI in DG - CA3 identified enhanced CA1 sharp-wave ripple - ACC spindle coupling as a potential network mechanism facilitating memory consolidation. Our findings illuminate how FFI in DG - CA3 dictates evolution of ensemble properties in CA1 and ACC during memory consolidation and suggest a teacher-like function for hippocampal CA1 in stabilization and re-organization of cortical representations.
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Affiliation(s)
- Hannah Twarkowksi
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States
| | - Victor Steininger
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States
| | - Min Jae Kim
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, United States
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Tomar A, McHugh TJ. The impact of stress on the hippocampal spatial code. Trends Neurosci 2021; 45:120-132. [PMID: 34916083 DOI: 10.1016/j.tins.2021.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/10/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022]
Abstract
Hippocampal function is severely compromised by prolonged, uncontrollable stress. However, how stress alters neural representations of our surroundings and events that occur within them remains less clear. We review hippocampal place cell studies that examine how spatial coding is affected by acute and chronic stress, as well as by stress accompanying fear conditioning. Emerging data suggest that chronic stress disrupts the acuity and specificity of CA1 spatial coding, both in familiar and novel contexts, and alters hippocampal oscillations. By contrast, acute stress may have a facilitatory impact on spatial representations. These findings encourage a fresh look at the documented stress-induced changes in hippocampal anatomy and in vitro excitability, and offer a new perspective on the links between stress and memory.
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Affiliation(s)
- Anupratap Tomar
- Center for Synaptic Plasticity, School of Physiology, Pharmacology, and Neuroscience, University of Bristol, University Walk, Bristol BS8 1TD, UK.
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, Japan.
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