Technological innovations in the field of cell differentiation from iPS cells has made it possible to induce dopamine neurons, inhibitory GABA neurons, and even excitatory glutamate neurons, as well as peripheral neurons such as sensory and motor neurons. Thus, we have been able to analyze the mechanisms of disease in specific cells that are targets for disease. In addition, DNA recombination systems such as the Cre-loxP system can be used to control target gene expression specifically in the rodent brain. By connecting human disease-specific iPS cell research and in vivo neuroscience research, we may be able to elucidate the mechanisms of the onset of intractable neurologic diseases which have not yet been clarified. In the present study, we focused on genetic and sporadic intractable neurologic diseases and applied these techniques to the analysis of disease mechanisms. In this symposium, we will present our recent findings on the pathological mechanisms of familial Parkinson's disease and fibromyalgia. Furthermore, we will discuss the outlines and practice of “reverse translational neuroscience research”, which is useful for applying a patient's information to basic neuroscience research.