Neurodegenerative disorders are a major public health issue affecting the worldwide aging population. Especially, Parkinson's disease (PD) caused by loss and dysfunction of dopaminergic neurons is not curable by pharmacological treatment. To this date, progressing PD can be retarded mainly by deep brain stimulation (DBS) or antiparkinson medication like levodopa (L-DOPA). In efforts to treat Morbus Parkinson, cell replacement strategies are considered very promising. However, controlling the cell behavior after transplantation, in particular the directed fibre outgrowth for functional integration in the neuronal network will be a fundamental challenge.