Background: Parkinson’s disease (PD) is a degenerative disorder of the central nervous system mainly affecting the motor system. Presently, there is no effective and safe drug to treat patients with PD. Ginkgo biloba extract (GBE), obtained from leaves of the Ginkgo biloba tree, is a complex mixture of ingredients primarily containing two active components: flavonoids and terpenoids. In this study, we investigated the effects of GBE on A53T α-synuclein transgenic mice, a PD model that has better simulated the progression of PD patients than other models such as the 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine–induced PD model. Methods: Fifty α-synuclein A53T transgenic mice were fed and treated with GBE, and locomotor activity was detected by pole test, forced swim test, and wire-hang test. The expression of tyrosine hydroxylase and dopamine transporters was detected using immunohistochemistry. Superoxide dismutase activity, glutathione peroxidase activity, and malondialdehyde expression were detected using an assay kit. Results: Our results show that GBE treatment improved locomotor activity and that superoxide dismutase and glutathione peroxidase inhibited the expression of methane dicarboxylic aldehyde and recovered the expression of tyrosine hydroxylase and dopamine transporters. Conclusions: The GBE treatment improved locomotor activity and inhibited the development of PD in the A53T α-synuclein transgenic mice, which may be partly responsible for decreased oxidative damage and maintain the normal dopamine homeostasis.

A DBA/2J (D2) transgenic mouse line with cyan fluorescent protein (CFP) reporter expression in ganglion cells was developed for the analysis of ganglion cells during progressive glaucoma. The Thy1-CFP D2 (CFP-D2) line was created by congenically breeding the D2 line, which develops pigmentary glaucoma, and the Thy1-CFP line, which expresses CFP in ganglion cells. Microsatellite marker analysis of CFP-D2 progeny verified the genetic inclusion of the D2 isa and ipd loci. Specific mutations within these loci lead to dysfunctional melanosomal proteins and glaucomatous phenotype in D2 mice. Polymerase chain reaction analysis confirmed the inclusion of the Thy1-CFP transgene. CFP-fluorescent ganglion cells, 6–20 μm in diameter, were distributed in all retinal regions, CFP processes were throughout the inner plexiform layer, and CFP-fluorescent axons were in the fiber layer and optic nerve head. Immunohistochemistry with antibodies to ganglion cell markers NF-L, NeuN, Brn3a, and SMI32 was used to confirm CFP expression in ganglion cells. Immunohistochemistry with antibodies to amacrine cell markers HPC-1 and ChAT was used to confirm weak CFP expression in cholinergic amacrine cells. CFP-D2 mice developed a glaucomatous phenotype, including iris disease, ganglion cell loss, attrition of the fiber layer, and elevated intraocular pressure. A CFP-D2 transgenic line with CFP-expressing ganglion cells was developed, which has (1) a predominantly D2 genetic background, (2) CFP-expressing ganglion cells, and (3) age-related progressive glaucoma. This line will be of value for experimental studies investigating ganglion cells and their axons in vivo and in vitro during the progressive development of glaucoma.

The goal of this study was to determine whether the jellyfish green fluorescent protein (GFP) could be used in transgenic mice to label and purify cone photoreceptors from the living retina. We created a transgene containing the 5′ regulatory sequence of the human red pigment gene (pR6.5 lacZ clone; kindly provided by J. Nathans & Y. Wang), fused to the GFP coding sequence. This transgene was used to generate seven lines of PCR-positive founders. Three of the lines had bright green fluorescent cone photoreceptors. The GFP fills the entire cell. Two mouse lines had only a few (∼10–100) fluorescent cells per retina, and one line (R6.85933) had many thousands. In the latter, double labeling of the cones with RITC-conjugated peanut agglutinin reveals that in the ventral retina a small proportion of the cones express GFP, while in the dorsal retina the majority do. Cells dissociated from the retinae of line R6.85933 continue to fluoresce and can be readily detected and enriched with flow cytometry. The signal provides a log unit of separation between the fluorescent cone soma and the remaining retinal cells. Roughly 3% of the cells are this fluorescent, and it is possible to purify up to 30,000 cells from one mouse. RT-PCR analysis of the mRNA from these isolated cells detects both the middle and short wavelength opsins with little if any contamination from rhodopsin.