F-actin cytoskeleton functional architecture and dynamics in secretion in neuroendocrine model

The PhD thesis submitted by the PhD student Yolanda Gimenez Molina is focused on F-actin cytoskeleton study in terms of structure and dynamics. The objective is expanding the knowledge about the F-actin distribution and dynamics role in neurosecretion process. Firstly, this thesis tries to improve the F-actin microfilaments cytoarchitecture description including last scientific findings about F-actin cytoplasmic organization in native chromaffin cells from bovine adrenal medulla, comparing the F-actin architecture from isolated chromaffin cells and showing the influence on vesicles and mitochondria distribution inside cell by F-actin configuration. Secondly, the thesis describes F-actin local dynamics by stimulation, not only in terms of fibbers displacements but also for cytoskeletal network´s cavities remodeling under active zones. Moreover, this work explains and reports new transport systems for vesicles and mitochondria linked to F-actin fibbers, especially to F-actin dynamics and fibbers polymerization potential. In order to reach all these objectives, chromaffin cells have been selected as a neuroendocrine cellular model accepted for secretion studies and a multidisciplinary set of techniques have been used, combining: biochemistry and molecular biology tools, biophysical analysis with a high temporal resolution of secretion and bioimaging by dynamic confocal microscopy.