A see-through Zebrafish? Looks like it! Researchers in Germany have some newly generated tools, including transgenic MitoFish, that can be used to study the in vivo “life cycle” of mitochondria. Neurodegenerative diseases such as Alzheimer’s, Parkinson’s, ALS (amyotrophic lateral sclerosis), and MS (multiple sclerosis) may have something in common: a disturbance in the transport of mitochondria. Mitochondria are known as the powerhouse of a cell, subcellular organelles¾a double-walled subunit within a cell that has a specific function. In this case, the specific function is producing energy for the cells. No surprise, mitochondria typically can be found in large numbers in cells that have high energy needs. In neurons, for example, that are extremely power-hungry cells. Researchers hope that the MitoFish will open a whole new window on brain diseases.