Striatal hypodopamine phenotypes found in transgenic mice that overexpress glial cell line-derived neurotrophic factor.

•The expression of GDNF transgene increases RET phosphorylation in the brain.•The chronic increase in glial GDNF reduces the dopamine content and tyrosine hydroxylase activity.•Extracellular concentrations of dopamine and its metabolism decrease in the striatum of transgenic mice.•The alteration of locomotor traits of transgenic mice is consistent with dopaminergic changes.