scholarly journals Decomposition of neuronal assembly activity via empirical de-Poissonization

2007 ◽  
Vol 1 (0) ◽  
pp. 473-495 ◽  
Author(s):  
Werner Ehm ◽  
Benjamin Staude ◽  
Stefan Rotter
Keyword(s):  
Neuronal Assembly ◽  
Assembly Activity

scholarly journals Test Statistics for the Identification of Assembly Neurons in Parallel Spike Trains

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
David Picado Muiño ◽  
Christian Borgelt
Keyword(s):  
Neural Coding ◽  
Statistical Tests ◽  
Spike Trains ◽  
Test Statistics ◽  
Combinatorial Explosion ◽  
Neuronal Assemblies ◽  
Methodological Problems ◽  
Neuronal Assembly ◽  
Assembly Activity ◽  
Made In

In recent years numerous improvements have been made in multiple-electrode recordings (i.e., parallel spike-train recordings) and spike sorting to the extent that nowadays it is possible to monitor the activity of up to hundreds of neurons simultaneously. Due to these improvements it is now potentially possible to identify assembly activity (roughly understood assignificantsynchronous spiking of a group of neurons) from these recordings, which—if it can be demonstrated reliably—would significantly improve our understanding of neural activity and neural coding. However, several methodological problems remain when trying to do so and, among them, a principal one is the combinatorial explosion that one faces when considering all potential neuronal assemblies, since in principle every subset of the recorded neurons constitutes a candidate set for an assembly. We present several statistical tests to identify assembly neurons (i.e., neurons that participate in a neuronal assembly) from parallel spike trains with the aim of reducing the set of neurons to a relevant subset of them and this way ease the task of identifying neuronal assemblies in further analyses. These tests are an improvement of those introduced in the work by Berger et al. (2010) based on additional features like spike weight or pairwise overlap and on alternative ways to identify spike coincidences (e.g., by avoiding time binning, which tends to lose information).

scholarly journals Differential Suppression of priA2::kan Phenotypes in Escherichia coli K-12 by Mutations in priA, lexA, and dnaC

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Steven J Sandler ◽  
Hardeep S Samra ◽  
Alvin J Clark
Keyword(s):  
Escherichia Coli ◽  
Dna Replication ◽  
Mutant Allele ◽  
Wild Type ◽  
Suppressor Mutations ◽  
Dnab Helicase ◽  
K 12 ◽  
Extragenic Suppressors ◽  
Assembly Activity

Abstract First identified as an essential component of the ϕX174 in vitro DNA replication system, PriA has ATPase, helicase, translocase, and primosome-assembly activities. priA1::kan strains of Escherichia coli are sensitive to UV irradiation, deficient in homologous recombination following transduction, and filamentous. priA2::kan strains have eightfold higher levels of uninduced SOS expression than wild type. We show that (1) priA1::kan strains have eightfold higher levels of uninduced SOS expression, (2) priA2::kan strains are UVS and Rec−, (3) lexA3 suppresses the high basal levels of SOS expression of a priA2::kan strain, and (4) plasmid-encoded priA300 (K230R), a mutant allele retaining only the primosome-assembly activity of priA+, restores both UVR and Rec+ phenotypes to a priA2::kan strain. Finally, we have isolated 17 independent UVR Rec+ revertants of priA2::kan strains that carry extragenic suppressors. All 17 map in the C-terminal half of the dnaC gene. DnaC loads the DnaB helicase onto DNA as a prelude for primosome assembly and DNA replication. We conclude that priA's primosome-assembly activity is essential for DNA repair and recombination and that the dnaC suppressor mutations allow these processes to occur in the absence of priA.

Neuronal Assembly

2019 ◽  
pp. 83-100
Author(s):  
György Buzsáki
Keyword(s):  
Time Window ◽  
Spike Rate ◽  
Point Of View ◽  
Rate Variation ◽  
Cell Assembly ◽  
Excitatory Effect ◽  
Neuronal Communication ◽  
The Individual ◽  
Neuronal Assembly ◽  
Cooperative Assembly

To effectively send a message, a single neuron must cooperate with its peers. Such cooperation can be achieved by synchronizing their spikes together within the time window limited by the ability of the downstream reader neuron to integrate the incoming signals. Therefore, the cell assembly, defined from the point of view of the reader neuron, can be considered as a unit of neuronal communication, a “neuronal letter.” Acting in assemblies has several advantages. A cooperative assembly partnership tolerates spike rate variation in individual cells effectively because the total excitatory effect of the assembly is what matters to the reader mechanism. Interacting assembly members can compute probabilities rather than convey deterministic information and can robustly tolerate noise even if the individual members respond probabilistically.

scholarly journals A model of free monkey scribbling based on the propagation of cell assembly activity

2009 ◽  
Vol 10 (S1) ◽  
Author(s):  
Alexander Hanuschkin ◽  
J Michael Herrmann ◽  
Abigail Morrison ◽  
Markus Diesmann
Keyword(s):  
Cell Assembly ◽  
Assembly Activity

scholarly journals CAL1 is the Drosophila CENP-A assembly factor

2014 ◽  
Vol 204 (3) ◽  
pp. 313-329 ◽  
Author(s):  
Chin-Chi Chen ◽  
Mekonnen Lemma Dechassa ◽  
Emily Bettini ◽  
Mary B. Ledoux ◽  
Christian Belisario ◽  
...  
Keyword(s):  
Histone H3 ◽  
Specific Protein ◽  
Terminal Domain ◽  
Left Handed ◽  
C Terminus ◽  
Assembly Factors ◽  
Histone H3 Variant ◽  
Assembly Factor ◽  
Drosophila Cells ◽  
Assembly Activity

Centromeres are specified epigenetically by the incorporation of the histone H3 variant CENP-A. In humans, amphibians, and fungi, CENP-A is deposited at centromeres by the HJURP/Scm3 family of assembly factors, but homologues of these chaperones are absent from a number of major eukaryotic lineages such as insects, fish, nematodes, and plants. In Drosophila, centromeric deposition of CENP-A requires the fly-specific protein CAL1. Here, we show that targeting CAL1 to noncentromeric DNA in Drosophila cells is sufficient to heritably recruit CENP-A, kinetochore proteins, and microtubule attachments. CAL1 selectively interacts with CENP-A and is sufficient to assemble CENP-A nucleosomes that display properties consistent with left-handed octamers. The CENP-A assembly activity of CAL1 resides within an N-terminal domain, whereas the C terminus mediates centromere recognition through an interaction with CENP-C. Collectively, this work identifies the “missing” CENP-A chaperone in flies, revealing fundamental conservation between insect and vertebrate centromere-specification mechanisms.

A Methodology for Integrating Welding in DFA

2004 ◽  
Author(s):  
Robert Rule ◽  
Larry Stauffer
Keyword(s):  
Design For Assembly ◽  
Complex Products ◽  
Large Complex ◽  
Potential Benefits ◽  
Engineering Cost ◽  
Assembly Activity

A design for assembly worksheet is introduced that enables flexible accounting of assembly activities, especially welding. Welding activity is broken down into a variety of pre- and post-welding activities and the time penalty is estimated. This weld estimate is included into the traditional worksheet. This approach is especially useful for large complex products that are produced in small volumes where a significant portion of the assembly activity is through welding. These types of products often pose challenges for employing DFMA techniques cost effectively because of the increased engineering cost, divided among relatively few products, outweighs the potential benefits.

Lighting up the Mind: Evolving a Model of Consciousness and its Application to Improvisation in Music Therapy

1998 ◽  
Vol 12 (1) ◽  
pp. 4-19 ◽  
Author(s):  
Julia Usher ◽  
Susan Greenfield
Keyword(s):  
Music Therapy ◽  
Learning Difficulties ◽  
Primary Language ◽  
Communicative Responses ◽  
Residential Unit ◽  
Neurological Processes ◽  
The Mind ◽  
Neuronal Assembly ◽  
The Brain

This paper explores Professor Susan Greenfield's theory of Neuronal Assembly Formation (Neuronal Gestalts) within a clinical music therapy context. Neuronal events in the brain are seen not only as shaping the physiological and communicative responses of the client, but also contributing to the character of the musical material itself, as it evolves in improvisation. This paper describes work with adults with profound learning difficulties living in a long-term residential unit. For these non-verbal clients, music becomes a primary language for translating and exchanging feelings and meanings. Greenfield's Concentric Theory offers new ways of analysing and characterising the somatic and neurological processes of stimulation and arousal underlying this process in each individual. Some current theories of consciousness are compared, and the evidence for possible links between the formation of neuronal assemblies and the development of musical gestalts is investigated through a series of case studies.

scholarly journals Neuronal Assembly Detection and Cell Membership Specification by Principal Component Analysis

PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e20996 ◽  
Author(s):  
Vítor Lopes-dos-Santos ◽  
Sergio Conde-Ocazionez ◽  
Miguel A. L. Nicolelis ◽  
Sidarta T. Ribeiro ◽  
Adriano B. L. Tort
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Neuronal Assembly
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