SLC18A3 and Parkinson disease: While an augmented availability of ACh due to ChI axonal overgrowth in response to DA loss has been proposed6 and a recent work has reported an increase in the binding of vesicular ACh transporter (VAChT) in PD patients16, most morphological studies in the 6-OHDA model have focused on alterations in the ChI dendritic tree15,51.