Fig 4. Higher volume of AAV1/2 hA53T alpha synuclein produces sustained transgene expression in the substantia nigra (SN) and putamen and produces a loss in SN dopamine neurons.

In the second experiment AAV1/2 hA53T alpha synuclein was delivered either at the same titer (1.7 x 10¹² gp/ml) and at higher volume (28 μl) or at the same volume (20 μl) and at a higher titer (5.1 x 10¹² gp/ml) compared to Experiment 1. In both conditions, a loss in tyrosine hydroxylase immunoreactive neurons within the substantia nigra was observed (C vs. D and see Table 1). Despite the loss in these neurons, those that remained continued to express the transgene (A). Furthermore, overexpression of alpha synuclein remained elevated in the terminals of the putamen (B). The control used in Experiment 2 was scrambled hA53T alpha synuclein. Scale bar in panel B, 25 μm.