Embryonic stem (ES) cells are a powerful source for generating potentially unlimited numbers of specialized cells. An important progress has been made to differentiate pluripotent stem cells toward different cell populations, in particular toward neuronal populations owing to their potential use in neurodegenerative diseases. However, ES cell based approaches face a number of challenges that hindered their application in biology and regenerative medicine. This book, therefore, present studies addressing these challenges by establishing a large panel of neural markers and region specific transcription factors linked to embryonic brain development in vivo. These markers were used to monitor and compare the in vitro and in vivo ES cell differentiation toward telencephalic and mesencephalic phenotypes. These studies allow a further optimization of the human and mouse ES cell culture protocols in order to obtain specific neuronal population as a source for neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. The book should be useful for neuroscientists, students, or anyone else interested in stem cells and regenerative medicine.