Figure 1.

Chronic stimulation increases phosphorylation of Akt and rpS6 in SNpc neurons in unlesioned rats. A, The timeline for Experiment 1 depicting electrode implantation surgery, stimulation, and death. SNpc of a stimulated, unlesioned rat ipsilateral to the electrode at high magnification, respectively, showing immunofluorescence for TH (B, C), p-rpS6 (F, G), and merged images (J, K). To control for the potential effects of unilateral electrode implantation, data were normalized to percentage expression relative to the identical hemisphere in Inactive rats. SNpc neuron immunoreactivity for Inactive and Active groups was quantified for TH, p-Akt, total Akt, and p-rpS6. No differences were observed in TH immunoreactivity due to stimulation (D, E, p = 0.186), though there was a trend for increased TH immunoreactivity in the contralateral hemisphere (E). STN DBS did result in a statistically significant increase in pAkt (H) and p-rpS6 (I) immunoreactivity in SNpc neurons (p < 0.04). Scale bars: low magnification, 200 μm; high magnification, 50 μm. Graphs represent mean ± SEM.*p < 0.05.