Latency correction in sparse neuronal spike trains

Background: In neurophysiological data, latency refers to a global shift of spikes from one spike train to the next, either caused by response onset fluctuations or by finite propagation speed. Such systematic shifts in spike timing lead to a spurious decrease in synchrony which needs to be corrected. New Method: We propose a new algorithm of multivariate latency correction suitable for sparse data for which the relevant information is not primarily in the rate but in the timing of each individual spike. The algorithm is designed to correct systematic delays while maintaining all other kinds of noisy disturbances. It consists of two steps, spike matching and distance minimization between the matched spikes using simulated annealing. Results: We show its effectiveness on simulated and real data: cortical propagation patterns recorded via calcium imaging from mice before and after stroke. Using simulations of these data we also establish criteria that can be evaluated beforehand in order to anticipate whether our algorithm is likely to yield a considerable improvement for a given dataset. Comparison with Existing Method(s): Existing methods of latency correction rely on adjusting peaks in rate profiles, an approach that is not feasible for spike trains with low firing in which the timing of individual spikes contains essential information. Conclusions: For any given dataset the criterion for applicability of the algorithm can be evaluated quickly and in case of a positive outcome the latency correction can be applied easily since the source codes of the algorithm are publicly available.Comment: 15 pages, 9 figure

1962

Turf on the Launching Pad (page 1) Turf management Club News (3) Education, Experience and Attitude (4) A Blade of Grass (5) Picture - Professor Lawrence S. Dickinson (6) Picture - Thomas Mascaro - Banquet Speaker (7) Planting Trees on the Golf Course (8) Two-Way Radios (8) Greens Mowing Procedure (9) Watering and Topdressing as Related to Poa annua Infestations (10) Picture - Stockbridge Majors in Turf Management (12) Picture - Graduates of Winter School for Turf Managers - 1962 (13) Review of Season\u27s Pests by Joseph Troll (A-1) Today\u27s Trends in Golf Course Development by Col. Harry C. Eckoff (A-3) Breeding and Selection of Fine Turf Grasses by Dr. B. R. Anderson Penncross Bentgrass by J. Dutch(A-13) Poa annua by Alexander Radko (A-16) Velvet Bent by Jesse DeFrance (A-19) Vegetative Creeping Bentgrasses by Fred Grau (A-21) Modification of SOils for Green Construction & Top Dressing by Prof. H. B. Musser (A-27) Soil COmpaction by Donald Waddington (A-32) Irrigation Practices and the Need of Basic Research by Prof. Edward PIra (A-36) Water Sources by Z. Mills (A-39) Athletic Field Maintenance by Thomas Mascaro (A-41) Planning the Landscape Around the House by Prof. Harold Mosher (A-43

1968

Maintenance of Golf Carts by Thomas Pepe (page 1) Why a Golf Course Superintendent Should Play Golf by Stephen Skowronski (2) Tree Pruning by Martin Walsh (3) Golf Course Labor: A Dilemma by Robert Barber (5) Turf Problems by Alexander M. Radko (A-1) 1967 Turfgrass Problems by Lee Record (A-3) Southern Turfgrass Production and Problems by Ralph W. White Jr. (A-5) Canadian Turf Grass Production and Problems by David Moote (A-8) Turf Research Abroad by C.R. Skogley (A-13) Turf Research at Home by Victor B. Younger (A-14) Turfgrass Research - An Industrial Approach by J. A. Simmons (A-16) Cutting Labor Costs in Turfgrass Managemnt by Tom Mascaro (A-24) The Reluctant human by John W. Denison (A-28) The Problem Drinker - Management Responsibility by G.E. Osburn (A-31) Contemporary Design Standards by Geoffrey S. Cornish (A-34) Construction - Superintendents\u27 Viewpoint by Robert E. Grant (A-36) Construction b Contract and the Role of the Superintendent by David Canavan (A-39) Seed Production by Robert J. Peterson (A-41) Cemetery Turf Maintenance on a High and Low Budget by Stanley Sosenski (A-45) Ten Steps to a Good Lawn by John Zak (A-49) Review of Herbicides for Turf Weed Control by Alvin A. Baber (A-53

Development and Application of Microsatellites in Carcinus maenas: Genetic Differentiation between Northern and Central Portuguese Populations

Carcinus maenas, the common shore crab of European coastal waters, has recently gained notoriety due to its globally invasive nature associated with drastic ecological and economic effects. The native ubiquity and worldwide importance of C. maenas has resulted in it becoming one of the best-studied estuarine crustacean species globally. Accordingly, there is significant interest in investigating the population genetic structure of this broadly distributed crab along European and invaded coastlines. Here, we developed polymerase chain reaction (PCR) primers for one dinucleotide and two trinucleotide microsatellite loci, resulting from an enrichment process based on Portuguese populations. Combining these three new markers with six existing markers, we examined levels of genetic diversity and population structure of C. maenas in two coastal regions from Northern and Central Portugal. Genotypes showed that locus polymorphism ranged from 10 to 42 alleles (N = 135) and observed heterozygosity per locus ranged from 0.745 to 0.987 with expected heterozygosity ranging from 0.711 to 0.960; values typical of marine decapods. The markers revealed weak, but significant structuring among populations (global FST = 0.004) across a 450 km (over-water distance) spatial scale. Combinations of these and existing markers will be useful for studying population genetic parameters at a range of spatial scales of C. maenas throughout its expanding species range

Confirmation of functional zones within the human subthalamic nucleus: Patterns of connectivity and sub-parcellation using diffusion weighted imaging

The subthalamic nucleus (STN) is a small, glutamatergic nucleus situated in the diencephalon. A critical component of normal motor function, it has become a key target for deep brain stimulation in the treatment of Parkinson's disease. Animal studies have demonstrated the existence of three functional sub-zones but these have never been shown conclusively in humans. In this work, a data driven method with diffusion weighted imaging demonstrated that three distinct clusters exist within the human STN based on brain connectivity profiles. The STN was successfully sub-parcellated into these regions, demonstrating good correspondence with that described in the animal literature. The local connectivity of each sub-region supported the hypothesis of bilateral limbic, associative and motor regions occupying the anterior, mid and posterior portions of the nucleus respectively. This study is the first to achieve in-vivo, non-invasive anatomical parcellation of the human STN into three anatomical zones within normal diagnostic scan times, which has important future implications for deep brain stimulation surgery

PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability

The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T&gt;G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C&gt;A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.</p

PTPA variants and impaired PP2A activity in early-onset Parkinsonism with intellectual disability

APPENDIX 1 : French and Mediterranean clinicians’ network for Parkinson’s disease genetics (the PDG group) collaborators French PDG collaborators Yves Agid, Mathieu Anheim, Michel Borg, Alexis Brice, Emmanuel Broussolle, Jean-Christophe Corvol, Philippe Damier, Luc Defebvre, Alexandra Dürr, Franck Durif, Jean Luc Houeto, Paul Krack, Stephan Klebe, Suzanne Lesage, Ebba Lohmann, Maria Martinez, Graziella Mangone, Louise-Laure Mariani, Pierre Pollak, Olivier Rascol, François Tison, Christine Tranchant, Marc Vérin, François Viallet, and Marie Vidailhet. Collaborators from Mediterranean countries Ebba Lohmann, Murat Emre, Hasmet Hanagasi, Basar Bilgic, Bedia Marangozoğlu, Mustapha Benmahdjoub, Mohammed Arezki, Sofiane A. Bouchetara, Traki Benhassine, Meriem Tazir, Mouna Ben Djebara, Riadh Gouider, Sawssan Ben Romdhan, Chokri Mhiri, Ahmed Bouhouche.APPENDIX 2 : Collaborators of the International Parkinsonism Genetics Network. Vincenzo Bonifati, Wim Mandemakers, Anneke J. A. Kievit, Agnita J. W. Boon, Joaquim J. Ferreira, Leonor Correia Guedes, Murat Emre, Hasmet A. Hanagasi, Basar Bilgic, Zeynep Tufekcioglu, Bülent Elibol, Okan Doğu, Murat Gultekin, Hsin F. Chien, Egberto Barbosa, Laura Bannach Jardim, Carlos R. M. Rieder, Hsiu-Chen Chang, Chin-Song Lu, Yah-Huei Wu-Chou, Tu-Hsueh Yeh, Leonardo Lopiano, Cristina Tassorelli, Claudio Pacchetti, Cristoforo Comi, Francesco Raudino, Laura Bertolasi, Michele Tinazzi, Alberto Bonizzato, Carlo Ferracci, Roberto Marconi, Marco Guidi, Marco Onofrj, Astrid Thomas, Nicola Vanacore, Giuseppe Meco, Edito Fabrizio, Giovanni Fabbrini, Alfredo Berardelli, Fabrizio Stocchi, Laura Vacca, Paolo Barone, Marina Picillo, Giuseppe De Michele, Chiara Criscuolo, Michele De Mari, Claudia Dell’Aquila, Giovanni Iliceto, Vincenzo Toni, Giorgio Trianni, Valeria Saddi, Gianni Cossu, Maurizio Melis.The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alphasynuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T>G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C>A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.The Stichting ParkinsonFonds (The Netherlands); the Fondation pour la Recherche Médicale; PTC Therapeutics, the Fondation de France, France-Parkinson Association, la Fédération pour la Recherche sur le Cerveau (FRC) and the French program ‘Investissements d’avenir’ (ANR-10-IAIHU-06) to AB; and grants from the South African Medical Research Council (Self-Initiated Research Grant) and the National Research Foundation of South Africa.https://academic.oup.com/brainNeurologySDG-03:Good heatlh and well-bein

The coming decade of digital brain research: a vision for neuroscience at the intersection of technology and computing

In recent years, brain research has indisputably entered a new epoch, driven by substantial methodological advances and digitally enabled data integration and modelling at multiple scales— from molecules to the whole brain. Major advances are emerging at the intersection of neuroscience with technology and computing. This new science of the brain combines high-quality research, data integration across multiple scales, a new culture of multidisciplinary large-scale collaboration and translation into applications. As pioneered in Europe’s Human Brain Project (HBP), a systematic approach will be essential for meeting the coming decade’s pressing medical and technological challenges. The aims of this paper are to: develop a concept for the coming decade of digital brain research, discuss this new concept with the research community at large, to identify points of convergence, and derive therefrom scientific common goals; provide a scientific framework for the current and future development of EBRAINS, a research infrastructure resulting from the HBP’s work; inform and engage stakeholders, funding organisations and research institutions regarding future digital brain research; identify and address the transformational potential of comprehensive brain models for artificial intelligence, including machine learning and deep learning; outline a collaborative approach that integrates reflection, dialogues and societal engagement on ethical and societal opportunities and challenges as part of future neuroscience research