Font Size: 

The interior of cells contains a large number of filamentous structures of varying thicknesses, lengths, and mechanical properties, such as microtubules, intermediate filaments, and mitochondria. In addition, they are constantly subjected to passive and active mechanical impulses of various origins, resulting in a variety of behaviors (translations, oscillations, bending, stretching). Although there are many experimental studies based on direct imaging, where the actual shape of the filament can be tracked over time, it is very difficult to determine from these images the presence of the forces or stimuli causing these deformations.
In this study, simulations are conducted on semi-flexible filaments immersed in a viscous medium, exposed to stationary thermal noise and external localized forces varying in intensity, duration, and direction. We review various techniques for reconstructing the force patterns solely from filament configurations (an inverse problem). These methods include curvature analysis and the examination of material point displacements, employing robust statistical approaches.
These tools were applied to experimental images of fluorescent mitochondria and microtubules of Xenopus Laevis melophores, to determine intensity, location and frequency of active forces in the context of a living cell.