IGF1 and multiple system atrophy: While PD models with neuronal αSyn overexpression showed a similar decrease of brain derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) expression like the MSA mouse, it was demonstrated that the MBP-αSyn mouse had a specific decline of glial cell-line derived neurotrophic factor (GDNF) levels, suggesting a pivotal role of disrupted trophic support by oligodendrocytes in MSA [27].