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Kloc ML, Chen Y, Daglian JM, Holmes GL, Baram TZ, Barry JM. Spatial learning impairments and discoordination of entorhinal-hippocampal circuit coding following prolonged febrile seizures. Hippocampus 2023; 33:970-992. [PMID: 37096324 PMCID: PMC10529121 DOI: 10.1002/hipo.23541] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 04/26/2023]
Abstract
How the development and function of neural circuits governing learning and memory are affected by insults in early life remains poorly understood. The goal of this study was to identify putative changes in cortico-hippocampal signaling mechanisms that could lead to learning and memory deficits in a clinically relevant developmental pathophysiological rodent model, Febrile status epilepticus (FSE). FSE in both pediatric cases and the experimental animal model, is associated with enduring physiological alterations of the hippocampal circuit and cognitive impairment. Here, we deconstruct hippocampal circuit throughput by inducing slow theta oscillations in rats under urethane anesthesia and isolating the dendritic compartments of CA1 and dentate gyrus subfields, their reception of medial and lateral entorhinal cortex inputs, and the efficacy of signal propagation to each somatic cell layer. We identify FSE-induced theta-gamma decoupling at cortical synaptic input pathways and altered signal phase coherence along the CA1 and dentate gyrus somatodendritic axes. Moreover, increased DG synaptic activity levels are predictive of poor cognitive outcomes. We propose that these alterations in cortico-hippocampal coordination interfere with the ability of hippocampal dendrites to receive, decode and propagate neocortical inputs. If this frequency-specific syntax is necessary for cortico-hippocampal coordination and spatial learning and memory, its loss could be a mechanism for FSE cognitive comorbidities.
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Affiliation(s)
- Michelle L. Kloc
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Yuncai Chen
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
| | - Jennifer M. Daglian
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
| | - Gregory L. Holmes
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Tallie Z. Baram
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
- Departments of Neurology, University California-Irvine, Irvine, California, USA
| | - Jeremy M. Barry
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
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Fehrmann AM, Steinbeisser K, Wolff AR, Coenen M. Health promotion networks in two districts in Bavaria, Germany: an exploratory case study mapping networks with respect to thematic agenda and location. Front Public Health 2023; 11:1111642. [PMID: 37441646 PMCID: PMC10335572 DOI: 10.3389/fpubh.2023.1111642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/07/2023] [Indexed: 07/15/2023] Open
Abstract
Introduction Building networks is an essential part of health promotion. However, network analysis remains relatively unexplored in this field. This study introduces a new technique that maps thematic agendas and geographical locations of health promotion actors. Methods This case study used elements of quantitative and qualitative methods to analyse network data. We used empirical data from two networks in Bavaria, a federal state of Germany. Results We identified a total of 55 actors in the first network and 64 actors in the second. We categorized the thematic agenda of actors according to their main field of work: "healthy childhood development," "healthy middle age phase," "healthy ageing," "health equity in all phases of life." One network showed a significant surplus of actors that focus on "healthy ageing." We combined and analysed data from both networks collectively. Two districts with no health promotion actors within their geographical borders were identified. To put geographical gaps into context, data about deprivation and age was included. Discussion Results identified geographical areas with high need for support from health promotion actors. Through comparison of our results with existing literature, we derived potential network strategies for further successful networking. This study adds a new perspective to characterize health promotion networks by mapping them thematically and geographically. The concept can be used to give health promotion organisations relevant insight into network structures. This can improve decision-making processes concerning partnership strategy and finally lead to a positive health impact. Hence, our findings encourage further development of this technique and other networking methods in the field of health equity and health promotion.
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Affiliation(s)
- Annika Marie Fehrmann
- Institute for Medical Information Processing, Biometry, and Epidemiology – IBE, Chair for Public Health and Health Services Research, Faculty of Medicine, LMU Munich, Munich, Germany
- Pettenkofer School of Public Health, Munich, Germany
- Coordinating Office for Health Equity, Bavarian Association for Health Promotion and Disease Prevention, Munich, Germany
| | - Kathrin Steinbeisser
- Coordinating Office for Health Equity, Bavarian Association for Health Promotion and Disease Prevention, Munich, Germany
- Faculty for Applied Healthcare Sciences, Deggendorf Institute of Technology, Deggendorf, Germany
| | - Andrea R. Wolff
- Coordinating Office for Health Equity, Bavarian Association for Health Promotion and Disease Prevention, Munich, Germany
| | - Michaela Coenen
- Institute for Medical Information Processing, Biometry, and Epidemiology – IBE, Chair for Public Health and Health Services Research, Faculty of Medicine, LMU Munich, Munich, Germany
- Pettenkofer School of Public Health, Munich, Germany
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3
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Vo A, Nguyen N, Fujita K, Schindlbeck KA, Rommal A, Bressman SB, Niethammer M, Eidelberg D. Disordered network structure and function in dystonia: pathological connectivity vs. adaptive responses. Cereb Cortex 2023; 33:6943-6958. [PMID: 36749014 PMCID: PMC10233302 DOI: 10.1093/cercor/bhad012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/21/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023] Open
Abstract
Primary dystonia is thought to emerge through abnormal functional relationships between basal ganglia and cerebellar motor circuits. These interactions may differ across disease subtypes and provide a novel biomarker for diagnosis and treatment. Using a network mapping algorithm based on resting-state functional MRI (rs-fMRI), a method that is readily implemented on conventional MRI scanners, we identified similar disease topographies in hereditary dystonia associated with the DYT1 or DYT6 mutations and in sporadic patients lacking these mutations. Both networks were characterized by contributions from the basal ganglia, cerebellum, thalamus, sensorimotor areas, as well as cortical association regions. Expression levels for the two networks were elevated in hereditary and sporadic dystonia, and in non-manifesting carriers of dystonia mutations. Nonetheless, the distribution of abnormal functional connections differed across groups, as did metrics of network organization and efficiency in key modules. Despite these differences, network expression correlated with dystonia motor ratings, significantly improving the accuracy of predictions based on thalamocortical tract integrity obtained with diffusion tensor MRI (DTI). Thus, in addition to providing unique information regarding the anatomy of abnormal brain circuits, rs-fMRI functional networks may provide a widely accessible method to help in the objective evaluation of new treatments for this disorder.
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Affiliation(s)
- An Vo
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
| | - Nha Nguyen
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Koji Fujita
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
| | - Katharina A Schindlbeck
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Andrea Rommal
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
| | - Susan B Bressman
- Department of Neurology, Mount Sinai Beth Israel, New York, NY 10003, USA
| | - Martin Niethammer
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
| | - David Eidelberg
- Center for Neurosciences, The Feinstein Institutes for Medical Research, Manhasset, NY 11030, USA
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Wagoner CW, Dreger J, Keats MR, Santa Mina D, McNeely ML, Cuthbert C, Capozzi LC, Francis GJ, Trinh L, Sibley D, Langley J, Chiekwe J, Ester M, Foucaut AM, Culos-Reed SN. First-Year Implementation of the EXercise for Cancer to Enhance Living Well (EXCEL) Study: Building Networks to Support Rural and Remote Community Access to Exercise Oncology Resources. Int J Environ Res Public Health 2023; 20:ijerph20031930. [PMID: 36767296 PMCID: PMC9915392 DOI: 10.3390/ijerph20031930] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 05/27/2023]
Abstract
Barriers to exercise-oncology programs remain for those living with and beyond cancer in rural and remote communities, including geographic isolation and access to programs. The EXercise for Cancer to Enhance Living Well (EXCEL) study was designed to support exercise-oncology implementation in rural and remote communities across Canada. The purpose of this analysis was to evaluate the first-year reach, adoption, and implementation of the EXCEL study. Reach outcomes included participant characteristics, study enrolment, and referral type (self vs. healthcare-provider [HCP] referral). Adoption outcomes included the number of clinical contacts, trained qualified exercise professionals (QEPs), and QEPs delivering EXCEL exercise classes. Implementation outcomes included retention, adherence, assessment completion rates, and adverse-event reporting. A total of 290 individuals living with cancer enrolled in EXCEL in year one, with an 81.4% retention to the study intervention. Most participants self-referred to EXCEL (75.8%). EXCEL's HCP network consisted of 163 clinical contacts, and the QEP network included 45 trained QEPs, 22 of whom delivered EXCEL classes. Adherence to the exercise intervention was 78.2%, and only one adverse event (mild) was reported. Fitness assessment and patient-reported outcome completion rates were above 85% pre- and post-intervention. EXCEL has developed HCP and QEP networks supporting exercise referral and online delivery, and the intervention is meeting feasibility markers. These implementation findings will inform the continued gathering of feedback across stakeholders to ensure that best evidence informs best practices.
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Affiliation(s)
- Chad W. Wagoner
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Julianna Dreger
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Melanie R. Keats
- School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Medicine, Division of Medical Oncology, Nova Scotia Health, Halifax, NS B3H 2Y9, Canada
| | - Daniel Santa Mina
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2W6, Canada
| | - Margaret L. McNeely
- Department of Physical Therapy, University of Alberta, Edmonton, AB T6G 2G4, Canada
- Supportive Care Services, Cancer Care Alberta, Edmonton, AB T5J 3E4, Canada
| | - Colleen Cuthbert
- Faculty of Nursing, University of Calgary, Calgary, AB T2N 4V8, Canada
| | - Lauren C. Capozzi
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - George J. Francis
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Linda Trinh
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2W6, Canada
| | - Daniel Sibley
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON M5S 2W6, Canada
| | - Jodi Langley
- School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Joy Chiekwe
- School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Manuel Ester
- Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Aude-Marie Foucaut
- Health Educations and Promotion Laboratory, UR 3412, University Sorbonne Paris North, F-93000 Bobigny, France
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Anderson JL, Reamey RA, Levitan EB, M Asif I, S Aswani M, Fletcher FE, G Hall A, Kennedy KC, Long D, Redden D, Tunagur A, Wasko M, Willig J, Wyatt M, Mugavero MJ. The University of Alabama at Birmingham COVID-19 Collaborative Outcomes Research Enterprise: Developing an institutional learning health system in response to the global pandemic. Learn Health Syst 2021; 6:e10292. [PMID: 34901441 PMCID: PMC8646452 DOI: 10.1002/lrh2.10292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/31/2021] [Accepted: 09/12/2021] [Indexed: 11/28/2022] Open
Abstract
Introduction As a local response to the COVID‐19 global pandemic, the University of Alabama at Birmingham (UAB) established the UAB COVID‐19 Collaborative Outcomes Research Enterprise (CORE), an institutional learning health system (LHS) to achieve an integrated health services outcomes and research response. Methods We developed a network of expertise and capabilities to rapidly develop and deploy an institutional‐level interdisciplinary LHS. Based upon a scoping review of the literature and the Knowledge to Action Framework, we adopted a LHS framework identifying contributors and components necessary to developing a system within and between the university academic and medical centers. We used social network analysis to examine the emergence of informal work patterns and diversified network capabilities based on the LHS framework. Results This experience report details three principal characteristics of the UAB COVID‐19 CORE LHS development: (a) identifying network contributors and components; (b) building the institutional network; and (c) diversifying network capabilities. Contributors and committees were identified from seven components of LHS: (a) collaborative and executive leadership committee, (b) research coordinating committee, (c) oversight and ethics committee, (d) thematic scientific working groups, (e) programmatic working groups, (f) informatics capabilities, and (g) patient advisory groups. Evolving from the topical interests of the initial CORE participants, scientific working groups emerged to support the learning system network. Programmatic working groups were charged with developing a comprehensive and mutually accessible COVID‐19 database. Discussion Our LHS framework allowed for effective integration of multiple academic and medical centers into a cohesive institutional‐level learning system. Network analysis indicated diversity of institutional disciplines, professional rank, and topical focus pertaining to COVID‐19, with each center leveraging existing institutional responsibilities to minimize gaps in network capabilities. Conclusion Incorporating an adapted LHS framework designed for academic medical centers served as a foundational resource supporting further institutional‐level efforts to develop agile and responsive learning networks.
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Affiliation(s)
- Jami L Anderson
- Department of Health Services Administration, School of Health Professions University of Alabama at Birmingham Birmingham Alabama USA
| | - Rebecca A Reamey
- Division of Infectious Diseases, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Emily B Levitan
- Department of Epidemiology, School of Public Health University of Alabama at Birmingham Birmingham Alabama USA
| | - Irfan M Asif
- Department of Family and Community Medicine, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Monica S Aswani
- Department of Health Services Administration, School of Health Professions University of Alabama at Birmingham Birmingham Alabama USA
| | - Faith E Fletcher
- Center for Medical Ethics and Health Policy College of Medicine, Baylor University Houston Texas USA
| | - Allyson G Hall
- Department of Health Services Administration, School of Health Professions University of Alabama at Birmingham Birmingham Alabama USA
| | - Kierstin C Kennedy
- Department of Hospital Medicine, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Dustin Long
- Department of Biostatistics, School of Public Health University of Alabama at Birmingham Birmingham Alabama USA
| | - David Redden
- Department of Biostatistics, School of Public Health University of Alabama at Birmingham Birmingham Alabama USA
| | - Alia Tunagur
- Division of Infectious Diseases, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Molly Wasko
- Department of Management, Information Systems, and Quantitative Methods, Collat School of Business University of Alabama at Birmingham Birmingham Alabama USA
| | - James Willig
- Division of Infectious Diseases, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Matthew Wyatt
- Informatics Institute, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
| | - Michael J Mugavero
- Division of Infectious Diseases, School of Medicine University of Alabama at Birmingham Birmingham Alabama USA
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6
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Abstract
For a biological neural network to be functional, its neurons need to be connected with synapses of appropriate strength, and each neuron needs to appropriately respond to its synaptic inputs. This second aspect of network tuning is maintained by intrinsic plasticity; yet it is often considered secondary to changes in connectivity and mostly limited to adjustments of overall excitability of each neuron. Here we argue that even nonoscillatory neurons can be tuned to inputs of different temporal dynamics and that they can routinely adjust this tuning to match the statistics of their synaptic activation. Using the dynamic clamp technique, we show that, in the tectum of Xenopus tadpole, neurons become selective for faster inputs when animals are exposed to fast visual stimuli but remain responsive to longer inputs in animals exposed to slower, looming, or multisensory stimulation. We also report a homeostatic cotuning between synaptic and intrinsic temporal properties of individual tectal cells. These results expand our understanding of intrinsic plasticity in the brain and suggest that there may exist an additional dimension of network tuning that has been so far overlooked.NEW & NOTEWORTHY We use dynamic clamp to show that individual neurons in the tectum of Xenopus tadpoles are selectively tuned to either shorter (more synchronous) or longer (less synchronous) synaptic inputs. We also demonstrate that this intrinsic temporal tuning is strongly shaped by sensory experiences. This new phenomenon, which is likely to be mediated by changes in sodium channel inactivation, is bound to have important consequences for signal processing and the development of local recurrent connections.
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Affiliation(s)
- Silas E Busch
- Biology Program, Bard College, Annandale-on-Hudson, New York
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7
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Edwards RL, Wollner SB, Weddle J, Zembrodt JW, Birdwhistell MD. Diagnosing and Resolving Conflict Created by Strategic Plans: Where Outreach Strategies and Execution Meet at an Academic Health Center. Hosp Top 2017; 95:72-78. [PMID: 28406365 DOI: 10.1080/00185868.2017.1301172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The imperative for strategic change at academic health centers has never been stronger. Underpinning the success of strategic change is an effective process to implement a strategy. Healthcare organizations, however, often fail to execute on strategy because they do not activate the requisite capabilities and management processes. The University of Kentucky HealthCare recently defined its 2020 strategic plan to adapt to emerging market conditions. The authors outline the strategic importance of strengthening partnership networks and the initial challenges faced in executing their strategy. The findings are a case study in how one academic health center has approached strategy implementation.
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Affiliation(s)
- Robert L Edwards
- a External Affairs, UK HealthCare/University of Kentucky , Lexington , Kentucky , USA
| | | | | | - James W Zembrodt
- d Strategic Planning, UK HealthCare , Lexington , Kentucky , USA
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8
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Lippi G, Fernandes CC, Ewell LA, John D, Romoli B, Curia G, Taylor SR, Frady EP, Jensen AB, Liu JC, Chaabane MM, Belal C, Nathanson JL, Zoli M, Leutgeb JK, Biagini G, Yeo GW, Berg DK. MicroRNA-101 Regulates Multiple Developmental Programs to Constrain Excitation in Adult Neural Networks. Neuron 2016; 92:1337-1351. [PMID: 27939580 DOI: 10.1016/j.neuron.2016.11.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 10/07/2016] [Accepted: 11/03/2016] [Indexed: 11/15/2022]
Abstract
A critical feature of neural networks is that they balance excitation and inhibition to prevent pathological dysfunction. How this is achieved is largely unknown, although deficits in the balance contribute to many neurological disorders. We show here that a microRNA (miR-101) is a key orchestrator of this essential feature, shaping the developing network to constrain excitation in the adult. Transient early blockade of miR-101 induces long-lasting hyper-excitability and persistent memory deficits. Using target site blockers in vivo, we identify multiple developmental programs regulated in parallel by miR-101 to achieve balanced networks. Repression of one target, NKCC1, initiates the switch in γ-aminobutyric acid (GABA) signaling, limits early spontaneous activity, and constrains dendritic growth. Kif1a and Ank2 are targeted to prevent excessive synapse formation. Simultaneous de-repression of these three targets completely phenocopies major dysfunctions produced by miR-101 blockade. Our results provide new mechanistic insight into brain development and suggest novel candidates for therapeutic intervention.
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Affiliation(s)
- Giordano Lippi
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Catarina C Fernandes
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Laura A Ewell
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Danielle John
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Benedetto Romoli
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Giulia Curia
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Seth R Taylor
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - E Paxon Frady
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Anne B Jensen
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jerry C Liu
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Melanie M Chaabane
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cherine Belal
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason L Nathanson
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michele Zoli
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Jill K Leutgeb
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA 92093, USA
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic, and Neural Sciences, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Gene W Yeo
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Darwin K Berg
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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9
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Abstract
Early brain connectivity development consists of multiple stages: birth of neurons, their migration and the subsequent growth of axons and dendrites. Each stage occurs within a certain period of time depending on types of neurons and cortical layers. Forming synapses between neurons either by growing axons starting at similar times for all neurons (much-overlapped time windows) or at different time points (less-overlapped) may affect the topological and spatial properties of neuronal networks. Here, we explore the extreme cases of axon formation during early development, either starting at the same time for all neurons (parallel, i.e., maximally overlapped time windows) or occurring for each neuron separately one neuron after another (serial, i.e., no overlaps in time windows). For both cases, the number of potential and established synapses remained comparable. Topological and spatial properties, however, differed: Neurons that started axon growth early on in serial growth achieved higher out-degrees, higher local efficiency and longer axon lengths while neurons demonstrated more homogeneous connectivity patterns for parallel growth. Second, connection probability decreased more rapidly with distance between neurons for parallel growth than for serial growth. Third, bidirectional connections were more numerous for parallel growth. Finally, we tested our predictions with C. elegans data. Together, this indicates that time windows for axon growth influence the topological and spatial properties of neuronal networks opening up the possibility to a posteriori estimate developmental mechanisms based on network properties of a developed network.
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Affiliation(s)
- Sol Lim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Republic of Korea
- Interdisciplinary Computing and Complex BioSystems Group (ICOS), School of Computing Science, Newcastle University, Claremont Tower, Newcastle upon Tyne, NE1 7RU UK
| | - Marcus Kaiser
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Republic of Korea
- Interdisciplinary Computing and Complex BioSystems Group (ICOS), School of Computing Science, Newcastle University, Claremont Tower, Newcastle upon Tyne, NE1 7RU UK
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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10
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Tibau E, Valencia M, Soriano J. Identification of neuronal network properties from the spectral analysis of calcium imaging signals in neuronal cultures. Front Neural Circuits 2013; 7:199. [PMID: 24385953 PMCID: PMC3866384 DOI: 10.3389/fncir.2013.00199] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 12/01/2013] [Indexed: 11/13/2022] Open
Abstract
Neuronal networks in vitro are prominent systems to study the development of connections in living neuronal networks and the interplay between connectivity, activity and function. These cultured networks show a rich spontaneous activity that evolves concurrently with the connectivity of the underlying network. In this work we monitor the development of neuronal cultures, and record their activity using calcium fluorescence imaging. We use spectral analysis to characterize global dynamical and structural traits of the neuronal cultures. We first observe that the power spectrum can be used as a signature of the state of the network, for instance when inhibition is active or silent, as well as a measure of the network's connectivity strength. Second, the power spectrum identifies prominent developmental changes in the network such as GABAA switch. And third, the analysis of the spatial distribution of the spectral density, in experiments with a controlled disintegration of the network through CNQX, an AMPA-glutamate receptor antagonist in excitatory neurons, reveals the existence of communities of strongly connected, highly active neurons that display synchronous oscillations. Our work illustrates the interest of spectral analysis for the study of in vitro networks, and its potential use as a network-state indicator, for instance to compare healthy and diseased neuronal networks.
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Affiliation(s)
- Elisenda Tibau
- Neurophysics Laboratory, Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona Barcelona, Spain
| | - Miguel Valencia
- Neurophysiology Laboratory, Division of Neurosciences, CIMA, Universidad de Navarra Pamplona, Spain
| | - Jordi Soriano
- Neurophysics Laboratory, Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona Barcelona, Spain
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11
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Waddington A, Appleby PA, De Kamps M, Cohen N. Triphasic spike-timing-dependent plasticity organizes networks to produce robust sequences of neural activity. Front Comput Neurosci 2012; 6:88. [PMID: 23162457 PMCID: PMC3495293 DOI: 10.3389/fncom.2012.00088] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 10/05/2012] [Indexed: 11/13/2022] Open
Abstract
Synfire chains have long been proposed to generate precisely timed sequences of neural activity. Such activity has been linked to numerous neural functions including sensory encoding, cognitive and motor responses. In particular, it has been argued that synfire chains underlie the precise spatiotemporal firing patterns that control song production in a variety of songbirds. Previous studies have suggested that the development of synfire chains requires either initial sparse connectivity or strong topological constraints, in addition to any synaptic learning rules. Here, we show that this necessity can be removed by using a previously reported but hitherto unconsidered spike-timing-dependent plasticity (STDP) rule and activity-dependent excitability. Under this rule the network develops stable synfire chains that possess a non-trivial, scalable multi-layer structure, in which relative layer sizes appear to follow a universal function. Using computational modeling and a coarse grained random walk model, we demonstrate the role of the STDP rule in growing, molding and stabilizing the chain, and link model parameters to the resulting structure.
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12
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Abstract
INTRODUCTION Over the past two decades, the service delivery landscape across health and social care in England has been reshaped in order to separate the commissioning of services from their delivery. POLICY/PRACTICE The market ethic that underpinned this move has depicted the previously roles as unresponsive to the needs of service users and dominated by provider interests. As well as seeming to offer commissioners the chance to change the nature of provision and type of provider, this policy model also created a further new opportunity-for joint commissioning across organisational boundaries. The logic here is that if two or more commissioners can jointly shape their programmes then they will be better able to secure integrated provision across a range of separate agencies and professions. CONCLUSION This article reviews the experience of joint commissioning across health and social care over the past decade in England. It contrasts the proliferation of policies against the paucity of achievements, seeks explanations for this situation, and offers pointers for future development.
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Affiliation(s)
- Bob Hudson
- School of Applied Social Sciences, Elvet Riverside II, New Elvet, Durham DH1 3JT, UK
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