Detection and measurement of the intracellular calcium variation in follicular cells.

Ana M Herrera-Navarro,Iván R Terol-Villalobos,Hayde Peregrina-Barreto,Hugo Jiménez-Hernández,José-Joel Gonzalez-Barboza

doi:10.1155/2014/484656

Abstract

This work presents a new method for measuring the variation of intracellular calcium in follicular cells. The proposal consists in two stages: (i) the detection of the cell's nuclei and (ii) the analysis of the fluorescence variations. The first stage is performed via watershed modified transformation, where the process of labeling is controlled. The detection process uses the contours of the cells as descriptors, where they are enhanced with a morphological filter that homogenizes the luminance variation of the image. In the second stage, the fluorescence variations are modeled as an exponential decreasing function, where the fluorescence variations are highly correlated with the changes of intracellular free Ca2+. Additionally, it is introduced a new morphological called medium reconstruction process, which helps to enhance the data for the modeling process. This filter exploits the undermodeling and overmodeling properties of reconstruction operators, such that it preserves the structure of the original signal. Finally, an experimental process shows evidence of the capabilities of the proposal.

Highlights

Calcium (Ca2+) is an ubiquitous intracellular ion signaling responsible for controlling many cellular processes [1, 2]
We introduce a method to analyze automatically the intracellular calcium variation
The sequence was obtained from cells of Xenopus laevis frog

Summary

Introduction

Calcium (Ca2+) is an ubiquitous intracellular ion signaling responsible for controlling many cellular processes [1, 2]. There are factors that affect the performance of an automatic detection of markers such as noise, cells occlusions, and abrupt changes in the images Those factors can lead these algorithms to overand undersegmentation, that is, create regions containing partial or multiple cells. We introduce a method to analyze automatically the intracellular calcium variation This approach consists in two stages: (1) the image enhancement and cell segmentation and (2) the calcium variation modeling. The process of cells segmentation is performed using the marked-controlled watershed transform and filters by reconstruction, which is used to detect markers efficiently, after the homotopy of the gradient image was computed. Results and conclusions can be found in the last section

Concepts of Morphological Filtering

Automatic Detection of Cells

Modeling the Intracellular Calcium Dynamic

Results and Discuss

Conclusions

Conflict of Interests