Reduced Nucleus Accumbens SK Channel Activity Enhances Alcohol Seeking during Abstinence

SummaryThe cellular mechanisms underlying pathological alcohol seeking remain poorly understood. Here, we show an enhancement of nucleus accumbens (NAcb) core action potential firing ex vivo after protracted abstinence from alcohol but not sucrose self-administration. Increased firing is associated with reduced small-conductance calcium-activated potassium channel (SK) currents and decreased SK3 but not SK2 subunit protein expression. Furthermore, SK activation ex vivo produces greater firing suppression in NAcb core neurons from alcohol- versus sucrose-abstinent rats. Accordingly, SK activation in the NAcb core significantly reduces alcohol but not sucrose seeking after abstinence. In contrast, NAcb shell and lateral dorsal striatal firing ex vivo are not altered after abstinence from alcohol, and SK activation in these regions has little effect on alcohol seeking. Thus, decreased NAcb core SK currents and increased excitability represents a critical mechanism that facilitates motivation to seek alcohol after abstinence

Seminal characteristics, sperm fatty acids, and blood biochemical attributes in breeder roosters orally administered with sage (Salvia officinalis) extract

peer reviewedSeminal characteristics and blood biochemical attributes were studied in breeder roosters orally administered with sage extract (SG), an herbal extract well known to have potent antioxidant activities. Sixty roosters (34 weeks old) were randomly allotted to five treatment groups to receive no SG, or orally administered with 110, 210, 320, or 420 mg SG/kg liveweight for 8 weeks. Semen samples were evaluated weekly. Blood samples were taken fortnightly and a total of 21 biochemical indices were measured to unmask the effects of SG (especially the adverse ones) on the clinical profile. Excluding the sperm concentration and seminal content of thiobarbituric acid reactive substances (sperm membrane lipid peroxidation index), other seminal traits exhibited one of the linear, quadratic, or cubic responses to the various levels of SG. The most improvements in total live sperm number and sperm membrane integrity (as determined by the hypoosmotic swelling test) were observed in birds receiving 210 and 320 mg SG/kg liveweight, respectively. Serum testosterone level was generally higher (cubically, P ≤ 0.015), but serum copper was lower (linearly, P ≤ 0.014) in SG-administered birds. Birds receiving 320 and 420 mg SG showed a decreased content of C18:2(n-6) in sperm plasma membrane. Other biochemical attributes or sperm fatty acids were not affected. It seems that most improvement in the seminal characteristics could be achieved 5-6 weeks following the administration of 210 and 320 mg SG/kg liveweight without any apparent adverse effect on the blood biochemical indices. The improvements, however, could not be attributed to the antioxidative effect of SG. Although it is hypothesised that an increased serum testosterone might have been involved, the underlying mechanism(s) remain(s) to be clarified. © CSIRO 2013

Effects of Long-term Induced Hyperthyroidism on Egg Quality Traits in Cobb 500 Broiler Breeder Hens

Published data on 4-week-long administration of exogenous thyroxine in broiler breeder hens to decline the cold-induced ascites in their progeny suggest that the long-term maternal hyperthyroidism would affect egg quality characteristics traits in Cobb 500 broiler breeder hens. Seventy 47-w-old broiler breeder Cobb 500 hens (5 replicates and 7 hens each) were assigned in separate cages and allotted to two treatments, control and hyperthyroid. Thyroxine was orally administered to the hyperthyroid group (0.3 mg hen/day) for a period of 100 days consecutively. Simultaneously, distilled water was orally administered to the control group. The blood sampling was done every two weeks to analyze T3, T4, and estrogen assays, using commercially kits and the egg quality attributes were evaluated for weeks 0, 3, 6, 9, and 12. Thyroxine treatment resulted in an increase in plasma concentration of T4; however, the T3 level and estrogen were not affected. The results of this study showed that the long-term administration of thyroxine had adverse effect on the most of egg quality traits in broiler breeder hens; although the results may be distinct for treatments that using other birds, doses and duration of treatments, among the different egg quality traits of broiler breeder hens evaluated in this research. Therefore, further studies should be done to make a final conclusion to use of long-term maternal hyperthyroidism treatment to reduce the ascites incidence

An assay of tetramizole cyclamate by oral route, in comparison to tetramizole hydrochloride by both oral and parenteral routes, for the treatment of helminthiasis in domestic swines

O artigo apresenta resumo em inglês.The AA tested comparatively the anthelmintic efficiency of both cyclamate and hydrochloride of tetramizole, in pigs. The cyclamate salt was tested orally and the hydrochloride one was studied by both the oral and intramuscular routes. In all cases the dosis was 12.5 mg/kg. Both drugs were highly efficient against mature Ascaris, Metastrongylus and Macracanthorhynchus and were also significantly active on immature forms of Ascaris, Metastrongylus and Oesophagostomum. Mature Strongyloides and Oesophagostomum were expelled by the hydrochloride compound; they were not statistically interfered with by the cyclamate salt. The AA present also a survey on pig helminths at the Campo Florido region, State of Minas Gerais, Brasil

Photoswitching Using Visible Light: A New Class of Organic Photochromic Molecules

A versatile new class of organic photochromic molecules that offers an unprecedented combination of physical properties including tunable photoswitching using visible light, excellent fatigue resistance, and large polarity changes is described. These unique features offer significant opportunities in diverse fields ranging from biosensors to targeted delivery systems while also allowing non-experts ready synthetic access to these materials

The effects of strength-based versus deficit-based self-regulated learning strategies on students' effort intentions

In two randomized experiments, one conducted online (n = 174) and one in the classroom (n = 267), we tested the effects of two types of self-regulated learning (SRL) strategies on students’ intentions to put effort into professional development activities: strength-based SRL strategies (i.e., identifying perceived relative strengths and, subsequently, selecting professional development activities to further improve those strengths) versus deficit-based SRL strategies (i.e., identifying perceived relative short- comings and, subsequently, selecting professional develop- ment activities to improve those shortcomings). Across both studies, analysis of variance revealed that, relative to students who used deficit-based SRL strategies, students who used strength-based SRL strategies were higher in perceived competence, intrinsic motivation, and effort in- tentions. Moreover, the results of multi-mediator analysis and structural equation modeling supported the hypothesis that the effect of strength-based versus deficit-based SRL strategies on students’ effort intentions was sequentially mediated by perceived competence and intrinsic motiva- tion. Implications for the application of self-regulated learning strategies in the context of professional self-de- velopment are discussed

Early developmental and allometric patterns in the electric yellow cichlid Labidochromis caeruleus

The electric yellow cichlid Labidochromis caeruleus is a mouth-brooding haplochromine cichlid from Lake Malawi and one of the most popular cichlids in the ornamental fish industry. To investigate the early development of L. caeruleus from hatching until the juvenile stage, we studied its morphological development and allometric growth patterns. In newly-hatched larvae, most organs and body parts were not yet differentiated and continued to develop until 15 days post hatching (dph). The yolk sac was depleted at 13 dph. There was allometric growth, primarily in the anterior and posterior regions of the body, and inflection points when trajectories of allometric growth changed. Head and tail growth was prioritized, suggesting that body parts linked to feeding and swimming behaviour mature earlier than the rest of the body. Additionally, growth patterns revealed that development of organs related to vital functions such as branchial respiration, sensation, exogenous feeding and swimming was prioritized. Comparisons with other African and Neotropical cichlids revealed differences in ontogenetic processes and allometric growth along the anterior-posterior axis as well as variation in developmental timing. These results indicate how early morphological development and ontogenic processes might respond to the distinctive parental care observed in mouth-brooding cichlids.publishe