Neuroprotection by Exendin-4 Is GLP-1 Receptor Specific but DA D3 Receptor Dependent, Causing Altered BrdU Incorporation in Subventricular Zone and Substantia Nigra
(a) Representative photomicrographs of 12 μm cryostat sections through the rat SN immunoassayed for TH. Nigral TH cell bodies appear dark brown in colour visualised using DAB staining; (A) and (B) represent right and left untreated SN, respectively; (D) represents 6-OHDA lesion assessed after two weeks compared to untreated side (C); (F) shows the effect of 0.5 μg/kg exendin-4 in a 6-OHDA-treated animal one week after lesion compared to untreated SN (E); (H) and (J) represent the effect of EX-9-39 or NAF coadministration, respectively, in 6-OHDA- and EX-4-treated animals compared to corresponding untreated sides (G) and (I). Scale bars—100 μm. (b) represents quantified data from immunohistochemical analysis of SN for TH. DAB staining was quantified using Lucia G image analysis software based on colour intensity. Results analyzed using one-way ANOVA and a post hoc Bonferroni test to compare differences between groups. *indicates significant differences compared to 6-OHDA + EX-4 group (ANOVA , *, per group, confidence interval set at 95%).