Figure 1. Increased PCNA labeling in the SVZ after deep brain stimulation compared with normal or PD-only brains.

a. Demonstrates diagrammatically the localization and placement of a deep brain stimulation electrode very close to the subthalamic nucleus just below the globus pallidus. The deep brain stimulation electrode lead sits within close proximity of the lateral and third ventricles. Diagram labeling is as follows: 1 = lateral ventricle, 2 = third ventricle, 3 = subthalamic nucleus, 4 = globus pallidus and 5 = deep brain stimulation electrode. b. Graph shows the mean numbers of PCNA-positive cells in the SVZ adjacent to the caudate nucleus of normal, PD and DBS brains. The graph shows a significantly greater number of PCNA-positive cells in brains that received DBS treatment compared with normal brains, but there was no significant difference in the numbers of PCNA-positive cells between normal and PD brains. c–e. Overall, the DBS cases show significantly greater mean numbers of PCNA-positive cells compared with normal and PD brains. The figures below the graph illustrate PCNA-positive immunolabelling in the SVZ adjacent to the caudate nucleus of normal, PD and PD-DBS brains. PD-DBS brains had an expanded SVZ compared with normal and untreated PD brains. Scale bar = 100 µm f–i. Demonstrates double labeling of PCNA (red) together with δ-GFAP (green) and Hoechst (blue) labeling in the SVZ of a PD-DBS brain. Scale bar = 10 µm.