Mutations in the leucine-rich repeat kinase (LRRK2) gene cause lateonset autosomal dominant Parkinson's disease (PD) with pleiomorphic pathology. Previously, we and others found that expression of mutant LRRK2 causes neuronal degeneration in cell culture. Here we used the GAL4/UAS system to generate transgenic Drosophila expressing either wild-type human LRRK2 or LRRK2-G2019S, the most common mutation associated with PD. Expression of either wild-type human LRRK2 or LRRK2-G2019S in the photoreceptor cells caused retinal degeneration. Expression of LRRK2 or LRRK2-G2019S in neurons produced adult-onset selective loss of dopaminergic neurons, locomotor dysfunction, and early mortality. Expression of mutant G2019S-LRRK2 caused a more severe parkinsonism-like phenotype than expression of equivalent levels of wild-type LRRK2. Treatment with L-DOPA improved mutant LRRK2-induced locomotor impairment but did not prevent the loss of tyrosine hydroxylase-positive neurons. To our knowledge, this is the first in vivo''gain-of-function'' model which recapitulates several key features of LRRK2-linked human parkinsonism. These flies may provide a useful model for studying LRRK2-linked pathogenesis and for future therapeutic screens for PD intervention.dopaminergic neuron ͉ Parkinson's disease
In this paper, a systematic framework is developed for the consensus problem, in particular, for formation control of networked dynamic agents. In view of the complexity of the framework with switching coupling topology and nonlinearity, a new decentralized formation strategy based on artificial potential functions (APF) is proposed. Due to the existence of local minima in the APF, the formation controller is designed to introduce some special functions to settle that limitation. A new concept of relative-position-based formation stability is defined, and a Lyapunov approach is used along with an extended LMI algorithm to analyze the condition for formation stability. Finally, an example with simulation is given to demonstrate the effectiveness of the designed formation controller.
The administration of high doses of methamphetamine to mice causes long-lasting depletions of striatal dopamine to a greater extent in males than in females. Likewise, the incidence of Parkinson's disease is higher in males than in females. The present study investigated the roles of estrogen and testosterone in mediating the dopamine depletion induced by methamphetamine. Male and female mice received four cumulative SC doses of methamphetamine (10 mg/kg) at two hour intervals and were sacrificed two weeks later for HPLC analysis of striatal monoamines. Intact male mice were found to have a 76% dopamine depletion, which was significantly greater than the 37% depletion exhibited by the intact female mice. Neither removal of the ovaries nor removal of the testes one month prior to the methamphetamine treatment significantly changed the magnitude of the methamphetamine-induced dopamine depletion. Thus, the reduced sensitivity of female mice to methamphetamine may be independent of physiological gonadal hormones.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.