This study sought to determine if administration of rotenone directly into the rat striatum could also mimic the motor dysfunction and neuropathological features of the human condition while overcoming
the toxicity associated with systemic administration. Male Sprague Dawley rats were infused with control or rotenone solutions into the striatum. The effect of the pesticide on body weight and spontaneous motor function (Corridor, Stepping and Whisker Tests) was assessed ante mortem, and its effect on nigrostriatal integrity (quantitative tyrosine hydroxylase immunohistochemistry), a-synuclein expression (quantitative a-synuclein immunohistochemistry), and striatel neurotransmitter content (HLPC
for dopamine, GABA and noradrenaline) was assessed post mortem. LY3039478 price Intra-striatal infusion of rotenone had no detrimental effect on the rats’ body weight but caused significant impairments in contralateral motor function. Neuropathologically, rotenone caused significant nigrostriatal Selleck BV-6 degeneration and selective loss of dopamine from the striatum but there was no evidence of any change in a-synuclein expression in the rotenone-infused rats. This study shows intra-striatal rotenone to be capable of modelling some of the main behavioural and neuropathological features of human Parkinsonism,
while being less toxic than its systemic counterpart. Thus, this model may prove to be useful in future Parkinson’s disease drug discovery programmes. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Marine macroalgae (seaweed) show diverse life cycles. Species with a heteromorphic life cycle have a large multicellular buy Tozasertib algal body in one generation but have a very small body in the second generation of the same year. In contrast, the diploid and haploid life forms of isomorphic species have similar morphology, and these species often have more than two generations in a year. Here, we first study the optimal life cycle schedule of marine macroalgae when daily mortality changes seasonally, and then we discuss the conditions for coexistence and relative dominance of different life cycles. According to the optimal life cycle schedule, heteromorphic species tend to have a generation with a large algal body when mortality is low, and a microscopic-sized generation when mortality is high. In contrast, isomorphic species tend to mature when body size reaches a threshold value that is the same for different generations. We then examine the coexistence of the two life cycles when growth rate decreases with biomass. The model predicts that (1) at high latitudes (i.e.