A quantitative approach to the dynamics of neurite sprouting induced by a neurotrophic factor

Zamburlin, Pollyanna; Lovisolo, Davide; Ariano, Paolo; Panero, Riccardo; Ferraro, Mario

doi:10.1016/j.jneumeth.2009.09.013

Cited by 2 publications

(2 citation statements)

References 19 publications

(22 reference statements)

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“…Dissociated CG neurons in short term (– hours) culture actively protrude (and in some cases retract) one or more neurites [23]. During this process, a subpopulation (about out of cells) showed spontaneous oscillations in , in the absence of any exogenous signal.…”

Section: Methodsmentioning

confidence: 99%

Spatial Wavelet Analysis of Calcium Oscillations in Developing Neurons

2013

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Calcium signals play a major role in the control of all key stages of neuronal development, and in particular in the growth and orientation of neuritic processes. These signals are characterized by high spatial compartmentalization, a property which has a strong relevance in the different roles of specific neuronal regions in information coding. In this context it is therefore important to understand the structural and functional basis of this spatial compartmentalization, and in particular whether the behavior at each compartment is merely a consequence of its specific geometry or the result of the spatial segregation of specific calcium influx/efflux mechanisms. Here we have developed a novel approach to separate geometrical from functional differences, regardless on the assumptions on the actual mechanisms involved in the generation of calcium signals. First, spatial indices are derived with a wavelet-theoretic approach which define a measure of the oscillations of cytosolic calcium concentration in specific regions of interests (ROIs) along a cell, in our case developing chick ciliary ganglion neurons. The resulting spatial profile demonstrates clearly that different ROIs along the neuron are characterized by specific patterns of calcium oscillations. Next we have investigated whether this inhomogeneity is due just to geometrical factors, namely the surface to volume ratio in the different subcompartments (e.g. soma vs. growth cone) or it depends on their specific biophysical properties. To this aim correlation functions are computed between the activity indices and the surface/volume ratio along the cell: the data thus obtained are validated by a statistical analysis on a dataset of different cells. This analysis shows that whereas in the soma calcium dynamics is highly correlated to the surface/volume ratio, correlations drop in the growth cone-neurite region, suggesting that in this latter case the key factor is the expression of specific mechanisms controlling calcium influx/efflux.

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Section: Methodsmentioning

confidence: 99%

Spatial Wavelet Analysis of Calcium Oscillations in Developing Neurons

2013

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“…Such a strategy requires a measure of (configurational) disorder that can be employed to rank different configuration-disordered images, or configurational disorders in general. However, the long-used standard measure of disorder is Shannon entropy itself [61,62], but, as mentioned in the introduction, its value is not related to configurational disorders.…”

Section: A Thermodynamics-based Strategy For Generating Testing Imagesmentioning

confidence: 99%

Thermodynamics-Based Evaluation of Various Improved Shannon Entropies for Configurational Information of Gray-Level Images

Gao

Zhang

2018

Entropy

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Abstract:The quality of an image affects its utility and image quality assessment has been a hot research topic for many years. One widely used measure for image quality assessment is Shannon entropy, which has a well-established information-theoretic basis. The value of this entropy can be interpreted as the amount of information. However, Shannon entropy is badly adapted to information measurement in images, because it captures only the compositional information of an image and ignores the configurational aspect. To fix this problem, improved Shannon entropies have been actively proposed in the last few decades, but a thorough evaluation of their performance is still lacking. This study presents such an evaluation, involving twenty-three improved Shannon entropies based on various tools such as gray-level co-occurrence matrices and local binary patterns. For the evaluation, we proposed: (a) a strategy to generate testing (gray-level) images by simulating the mixing of ideal gases in thermodynamics; (b) three criteria consisting of validity, reliability, and ability to capture configurational disorder; and (c) three measures to assess the fulfillment of each criterion. The evaluation results show only the improved entropies based on local binary patterns are invalid for use in quantifying the configurational information of images, and the best variant of Shannon entropy in terms of reliability and ability is the one based on the average distance between same/different-value pixels. These conclusions are theoretically important in setting a direction for the future research on improving entropy and are practically useful in selecting an effective entropy for various image processing applications.

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A quantitative approach to the dynamics of neurite sprouting induced by a neurotrophic factor

Cited by 2 publications

References 19 publications

Spatial Wavelet Analysis of Calcium Oscillations in Developing Neurons

Spatial Wavelet Analysis of Calcium Oscillations in Developing Neurons

Thermodynamics-Based Evaluation of Various Improved Shannon Entropies for Configurational Information of Gray-Level Images

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