Brain Deletion of Insulin Receptor Substrate 2 Disrupts Hippocampal Synaptic Plasticity and Metaplasticity

Diabetes mellitus is associated with cognitive deficits and an increased risk of dementia, particularly in the elderly. These deficits and the corresponding neurophysiological structural and functional alterations are linked to both metabolic and vascular changes, related to chronic hyperglycaemia, but probably also defects in insulin action in the brain. To elucidate the specific role of brain insulin signalling in neuronal functions that are relevant for cognitive processes we have investigated the behaviour of neurons and synaptic plasticity in the hippocampus of mice lacking the insulin receptor substrate protein 2 (IRS-2)

Modern American populism: Analyzing the economics behind the Silent Majority, the Tea Party and Trumpism

This article researches populism, more specifically, Modern American Populism (MAP), constructed of white, rural, and economically oppressed reactionarianism, which was borne out of the political upheaval of the 1960’s Civil Rights movement. The research looks to explain the causes of populism and what leads voters to support populist movements and politicians. The research focuses on economic anxiety as the main cause but also examines an alternative theory of racial resentment. In an effort to answer the question, what causes populist movements and motivations, I apply a research approach that utilizes qualitative and quantitative methods. There is an examination of literature that defines populism, its causes and a detailed discussion of the case studies, including the 1972 election of Richard Nixon; the Tea Party election of 2010; and the 2016 election of Donald Trump. In addition, statistical data analysis was run using American National Election Studies (ANES) surveys associated with each specific case study. These case studies were chosen because they most represent forms of populist movements in modern American history. While ample qualitative evidence suggested support for the hypothesis that economic anxiety is a necessary condition for populist voting patterns that elected Nixon, the Tea Party and Trump, the statistical data only supported the hypothesis in two cases, 2010 and 2016, with 1972 coming back inconclusive. The data also suggested that both economic anxiety and racial resentment played a role in 2010 and 2016, while having no significant effect in 1972 in either case. This suggests that further research needs to be conducted into additional populist case studies, as well as an examination into the role economic anxiety and economic crises play on racial resentment and racially motivated voting behavior

Refilling of cortical calcium stores in Paramecium cells : in situ analysis in correlation with store-operated calcium influx

This is the first thorough study of refilling of a cortical calcium store in a secretory cell after stimulation in which we combined widely different methodologies. Stimulation of dense-core vesicle ( trichocysts ) exocytosis in Paramecium involves a Ca2+-influx superimposed to Ca2+-release from cortical stores ( alveolar sacs (ASs)). In quenched-flow experiments, membrane fusion frequency rose with increasing [Ca2+]o in the medium, from 20 25% at [Ca2+]o ≤0.25 μM to 100% at [Ca2+]o between 2 and 10 μM, i.e. close to the range of estimated local intracellular [Ca2+] during membrane fusion. Next, we analyzed Ca2+-specific fluorochrome signals during stimulation under different conditions. Treatment with actin-reactive drugs had no effect on Ca2+-signaling. In double trigger experiments, with BAPTA in the second secretagogue application (BAPTA only for stimulation and analysis), the cortical Ca2+-signal (due solely to Ca2+ released from cortical stores) recovered with t1/2 65 min. When ASs were analyzed in situ by X-ray microanalysis after different trigger times (+Ca2+o), t1/2 for store refilling was similar, 60 min. These values are similar to previously measured 45Ca2+-uptake by isolated ASs. In sum we find, (i) exogenous Ca2+ increases exocytosis/membrane fusion performance with EC50=0.7 μM, (ii) Ca2+-signaling in this system is not sensitive to actin-reactive drugs, and (iii) refilling of these cortical calcium stores goes on over hours and thus is much slower than expected