Manipulation Of Mitochondrial Dynamics Based On Femtosecond Laser

Mitochondrion is a widely-existed organelle in eukaryotic cells. It can not only provide necessary energy for cellular metabolism but also serve as a key role in maintaining ion homeostasis and mediating cell apoptosis. Meanwhile, mitochondrion itself has various metabolic stasis including fission, fusion and transportation. All these process are crucial in deciding cell fate. Mutations in mito-DNAs could initiate mitochondrial abnormalities and eventually lead to mitochondria related neurodegenerative diseases such as Parkinson's Disease and Alzheimer's Disease. However, due to the defects in spacial and temporal resolution of the traditional research techniques, it is quite hard to observe the pathological process in vitro and in vivo, which results in obscurity of molecular process for such diseases. In this thesis, we will introduce a novel technique in precise manipulation of mitochondrial dynamics by femtosecond laser. By coupling a femtosecond laser beam into a confocal microscope, we are thereby able to provide subtle stimulation to a single cell or a cellular organelle. Better spacial and temporal resolution are attained by this method comparing to the traditional ones and various novel reactions are observed after the irradiation to femtosecond laser. However, these ‘stimulated reactions' can happen spontaneously as physiological or pathological reactions of cells. By stimulate the cell organelle, this novel method can therefore simulate different changes in cell with great controllability. To sum up, on the basis of traditional methods, our method has improved the spacial and temporal resolution of cell stimulation and proved a possible way to observe the molecular process in vitro. We will also introduce a molecular model of acute mitochondrial morphological change after laser irradiation, which may have a potential in exploring mitochondrial dynamics such as mitochondrial fission & fusion and superoxide flashes.