Effects of Acute and Repeated Administration of Diazepam on Delay Discounting in Lewis and Fischer 344 Rats

Impulsive choice is often examined using a delay-discounting procedure where choice is between two reinforcers of different magnitudes presented at varying delays. Individual discounting rates can be influenced by many factors including strain differences and drug effects. Lewis (LEW) and Fischer 344 (F344) rats have behavioral and neurochemical differences relevant to delay discounting and were used to examine effects of acute and repeated diazepam administration on impulsive choice. Consistent with previous literature, larger-reinforcer choice decreased as a function of increasing delays for all rats, and steeper discounting functions occurred for LEW relative to F344 rats. Acute and repeated diazepam administration resulted in differential effects between rat strains and sometimes between subjects within the same rat strain. Overall, larger-reinforcer choice was unchanged across multiple phases of the experiment for LEW rats, with some exceptions during the acute phase. For F344 rats, larger-reinforcer choice increased following acute administration of smaller doses of diazepam and decreased following acute administration of the largest dose tested. Decreases in larger-reinforcer choice occurred for F344 rats during repeated conditions and persisted throughout a non-drug baseline phase. Results from the present study have raised more questions about, and potential directions for future investigation of, multiple environmental, genetic, and neurochemical variables involved in delay discounting and effects of benzodiazepines on delay discounting

Ionicity-dependent proton-coupled electron transfer of supramolecular self-assembled electroactive heterocycles

Herein, we investigate the electrochemical properties of a class of Supramolecular Self-associated Amphiphilic salts (SSAs). We show that varying ionic strength of an SSA solution can cause a switching of the thermodynamics and kinetics of electron transfer. The effect of self-assembly on proton-coupled electron transfer has implications for the understanding of electron transfer kinetics in aqueous organic redox flow batteries, especially at high concentration where organic–organic intermolecular interactions become dominant even for highly soluble organic species

Trait determinants of impulsive behavior: a comprehensive analysis of 188 rats

Impulsivity is a naturally occurring behavior that, when accentuated, can be found in a variety of neuropsychiatric disorders. The expression of trait impulsivity has been shown to change with a variety of factors, such as age and sex, but the existing literature does not reflect widespread consensus regarding the influence of modulating effects. We designed the present study to investigate, in a cohort of significant size (188 rats), the impact of four specific parameters, namely sex, age, strain and phase of estrous cycle, using the variable delay-to-signal (VDS) task. This cohort included (i) control animals from previous experiments; (ii) animals specifically raised for this study; and (iii) animals previously used for breeding purposes. Aging was associated with a general decrease in action impulsivity and an increase in delay tolerance. Females generally performed more impulsive actions than males but no differences were observed regarding delay intolerance. In terms of estrous cycle, no differences in impulsive behavior were observed and regarding strain, Wistar Han animals were, in general, more impulsive than Sprague-Dawley. In addition to further confirming, in a substantial study cohort, the decrease in impulsivity with age, we have demonstrated that both the strain and sex influences modulate different aspects of impulsive behavior manifestations.FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE) and the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement as well as national funds, through the Foundation for Science and Technology (FCT) [projects POCI-01–0145-FEDER-007038, NORTE-01-0145-FEDER-000013, NORTE-01-0145-FEDER-000023 and PTDC/NEU-SCC/5301/2014]. Researchers were supported by FCT [grant numbers SFRH/BD/52291/2013 to ME and PD/BD/114117/2015 to MRG via Inter-University Doctoral Programme in Ageing and Chronic Disease, PhDOC; PDE/BDE/113601/2015 to PSM via PhD Program in Health Sciences (Applied) and Phd-iHES; SFRH/BD/109111/2015 to AMC; SFRH/BD/51061/2010 to MMC; SFRH/SINTD/60126/2009 to AM; SFRH/BD/98675/2013 to BC; IF/00883/2013 to AJR; IF/00111/2013 to AJS; SFRH/BPD/80118/2011 to HLA]info:eu-repo/semantics/publishedVersio

Transcriptomic Analysis of Toxoplasma Development Reveals Many Novel Functions and Structures Specific to Sporozoites and Oocysts

Sexual reproduction of Toxoplasma gondii occurs exclusively within enterocytes of the definitive felid host. The resulting immature oocysts are excreted into the environment during defecation, where in the days following, they undergo a complex developmental process. Within each oocyst, this culminates in the generation of two sporocysts, each containing 4 sporozoites. A single felid host is capable of shedding millions of oocysts, which can survive for years in the environment, are resistant to most methods of microbial inactivation during water-treatment and are capable of producing infection in warm-blooded hosts at doses as low as 1–10 ingested oocysts. Despite its extremely interesting developmental biology and crucial role in initiating an infection, almost nothing is known about the oocyst stage beyond morphological descriptions. Here, we present a complete transcriptomic analysis of the oocyst from beginning to end of its development. In addition, and to identify genes whose expression is unique to this developmental form, we compared the transcriptomes of developing oocysts with those of in vitro-derived tachyzoites and in vivo-derived bradyzoites. Our results reveal many genes whose expression is specifically up- or down-regulated in different developmental stages, including many genes that are likely critical to oocyst development, wall formation, resistance to environmental destruction and sporozoite infectivity. Of special note is the up-regulation of genes that appear “off” in tachyzoites and bradyzoites but that encode homologues of proteins known to serve key functions in those asexual stages, including a novel pairing of sporozoite-specific paralogues of AMA1 and RON2, two proteins that have recently been shown to form a crucial bridge during tachyzoite invasion of host cells. This work provides the first in-depth insight into the development and functioning of one of the most important but least studied stages in the Toxoplasma life cycle

Varieties of Non-ordinary Experiences in Brazil—a Critical Review of the Contribution of Studies of ‘Religious Experience’ to the Study of Religion

According to the latest national census, 64.6% of Brazilians identified themselves as Roman Catholic. However, the census has little or nothing to do with actual practice or belief. Professing to be a Christian (within any confessional specification) is still part of being Brazilian. But the self-identification does not take into account that religiosity is expressed in very diverse ways nor does it prevent people from believing and practising one of the many Brazilian traditions though identifying themselves as Christian in the census. This perception represents the framework of the following discussion of non-ordinary experiences in Brazil, whether they are perceived as religious, spiritual or ‘just’ extraordinary. This article presents an overview of studies about non-ordinary experiences in Brazil. The aim is to show the importance of these experiences for the understanding of the religious landscape of Brazil