Expression of lentiviral A53T in the monkey brain. A, Stereotaxic injection of lentiviral A53T into the substantia nigra of rhesus monkeys. B, Immunostaining of the control injection (PBS) and lentiviral A53T-injected regions in the left and right substantia nigra, respectively, of the same monkey at 8 years of age. The brain sections were stained with anti-α-syn. Scale bars: Top, 50 μm (top); bottom, 5 μm. C, A53T forms puncta (arrows) in long process of neurons, which resemble Lewy neurites in PD patient brains. Scale bar, 5 μm.