GDNF and multiple system atrophy: To detect whether oligodendroglial overexpression of α-syn under the control of the PLP promoter in PLP-α-syn mice had an effect on the production of neurotrophic factors, as suggested by findings in a different transgenic mouse model of MSA, the MBP-α-syn mouse [65], we measured the levels of protein expression of BDNF and GDNF.