TAT and Parkinson disease: Given our results indicating that Tat-βsyn can reduce motor deficits without lowering α-synuclein levels (Figs. 6 and 7), we propose that Tat-βsyn, by inhibiting α-synuclein oligomerization21 (without affecting the amount of α-synuclein), may also be effective in reducing PD-associated motor deficits, as long as a sufficient number of dopaminergic neurons remain functional.