Figure 2.
Overexpression of mutant LRRK2 causes no loss of nigral dopaminergic neurons and striatal dopamine contents in aged rats. A-F, Representative photos of low (A-C) or high (D-F) magnification show the SNpc of transgenic rats at 18 months of age. Transgenic rats carried a CAG-tTA single transgene (1: tTA), or CAG-tTA and TRE-LRRK2G2019S double transgenes (2 and 3: LRRK2). Constitutive expression of mutant LRRK2 (2: constitutive LRRK2) was achieved by withholding Dox throughout rat's lives, and temporal expression of the transgene (3: temporal LRRK2) was achieved by withdrawing Dox from rats at the age of 5 months. G, H, Stereological cell counting revealed no loss of TH-positive neurons in the SNpc and locus coeruleus (LC). Data are means ± SEM (n = 7). I-K, HPLC revealed the contents of striatal dopamine (DA) and DA metabolites (DOPAC and HVA) in transgenic rats. Data are means ± SEM (n = 10). Experimental group number in panels G-K corresponds to that in panels A-F.