224 research outputs found

    The dopamine D2/D3 receptor agonist quinpirole increases checking-like behaviour in an operant observing response task with uncertain reinforcement: a novel possible model of OCD.

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    Excessive checking is a common, debilitating symptom of obsessive-compulsive disorder (OCD). In an established rodent model of OCD checking behaviour, quinpirole (dopamine D2/3-receptor agonist) increased checking in open-field tests, indicating dopaminergic modulation of checking-like behaviours. We designed a novel operant paradigm for rats (observing response task (ORT)) to further examine cognitive processes underpinning checking behaviour and clarify how and why checking develops. We investigated i) how quinpirole increases checking, ii) dependence of these effects on D2/3 receptor function (following treatment with D2/3 receptor antagonist sulpiride) and iii) effects of reward uncertainty. In the ORT, rats pressed an 'observing' lever for information about the location of an 'active' lever that provided food reinforcement. High- and low-checkers (defined from baseline observing) received quinpirole (0.5mg/kg, 10 treatments) or vehicle. Parametric task manipulations assessed observing/checking under increasing task demands relating to reinforcement uncertainty (variable response requirement and active-lever location switching). Treatment with sulpiride further probed the pharmacological basis of long-term behavioural changes. Quinpirole selectively increased checking, both functional observing lever presses (OLPs) and non-functional extra OLPs (EOLPs). The increase in OLPs and EOLPs was long-lasting, without further quinpirole administration. Quinpirole did not affect the immediate ability to use information from checking. Vehicle and quinpirole-treated rats (VEH and QNP respectively) were selectively sensitive to different forms of uncertainty. Sulpiride reduced non-functional EOLPs in QNP rats but had no effect on functional OLPs. These data have implications for treatment of compulsive checking in OCD, particularly for serotonin-reuptake-inhibitor treatment-refractory cases, where supplementation with dopamine receptor antagonists may be beneficial

    INDOLE AMIDE DERIVATIVES: SYNTHESIS, STUCTURE-ACTIVITY RELATIONSHIPS AND MOLECULAR MODELLING STUDIES OF A NEW SERIES OF HISTAMINE H1-RECEPTOR ANTAGONISTS.

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    A number of indole amide derivatives bearing a basic side chain, in which the indole ring replaces the isoster benzimidazole nucleus typical of some well-known antihistamines, were prepared and tested for their H1-antihistaminic activity. The 1-benzyl-3-indolecarboxamides 32–42 showed antihistaminic (H1) activity (pA2 6–8); the 3-indolylglyoxylylamides 7–16 and the 2-indolecarboxamides 48–56 showed little or no activity. Insertion of the basic side chain of the active 3-indolecarboxamide derivatives into a piperazine ring (compounds 57–59) led to a dramatic loss of activity. All the active compounds proved to be competitive antagonists, since the values of the regression slope were not statistically different from 1. The most active compounds, 32, 33, 38–41, were also tested both in vitro for their anticholinergic activity and in vivo for their ability to antagonize histamine-induced cutaneous vascular permeability in rats. The biological results and the structure–activity relationships of the novel compounds are discussed in the light of molecular modelling studies, taking the molecule of astemizole as a model, and referring to proposed H1-receptor pharmacophore model

    Counteractive effects of antenatal glucocorticoid treatment on D1 receptor modulation of spatial working memory

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    RATIONALE: Antenatal exposure to the glucocorticoid dexamethasone dramatically increases the number of mesencephalic dopaminergic neurons in rat offspring. However, the consequences of this expansion in midbrain dopamine (DA) neurons for behavioural processes in adulthood are poorly understood, including working memory that depends on DA transmission in the prefrontal cortex (PFC). OBJECTIVES: We therefore investigated the influence of antenatal glucocorticoid treatment (AGT) on the modulation of spatial working memory by a D1 receptor agonist and on D1 receptor binding and DA content in the PFC and striatum. METHODS: Pregnant rats received AGT on gestational days 16-19 by adding dexamethasone to their drinking water. Male offspring reared to adulthood were trained on a delayed alternation spatial working memory task and administered the partial D1 agonist SKF38393 (0.3-3 mg/kg) by systemic injection. In separate groups of control and AGT animals, D1 receptor binding and DA content were measured post-mortem in the PFC and striatum. RESULTS: SKF38393 impaired spatial working memory performance in control rats but had no effect in AGT rats. D1 binding was significantly reduced in the anterior cingulate cortex, prelimbic cortex, dorsal striatum and ventral pallidum of AGT rats compared with control animals. However, AGT had no significant effect on brain monoamine levels. CONCLUSIONS: These findings demonstrate that D1 receptors in corticostriatal circuitry down-regulate in response to AGT. This compensatory effect in D1 receptors may result from increased DA-ergic tone in AGT rats and underlie the resilience of these animals to the disruptive effects of D1 receptor activation on spatial working memory

    The mesenchymal stem cell differentiation to osteoblasts is potentiate by the allosteric modulation of A2B adenosine receptors.

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    The A2B adenosine receptor (A2BAR) has been recently emerged as the major adenosine receptor involved in the mesenchymal stem cell differentiation to osteoblast and bone formation, highlighting this receptor as a new target in bone diseases. In the present study, we characterized a new 3-keto-indole-derivative (KI-7) as the first positive allosteric modulator (PAM) of the human A2B AR in mesenchymal stem cells (MSCs), and we investigated the potential activity of this compound as osteogenic agent. KI-7 was able to increase the effects of A2B AR of both endogenous and orthosteric agonists on the expression of osteogenic markers and on osteoblast mineralization. In the early phase of differentiation program, KI-7 significantly potentiated physiological and A2B agonist-mediated down-regulation of IL-6 release. Conversely, during the late stage of differentiation, when most of the cells have an osteoblast phenotype, KI-7 caused a sustained raise in IL-6 levels and an improvement in osteoblast viability. These data suggest that positive allosteric modulation of A2B AR not only favors MSC commitment to osteoblasts, but also ensures a greater survival of mature osteoblasts. Our study paves the way for a therapeutic use of selective positive allosteric modulators of A2B AR in the control of osteoblast differentiation, bone formation and fracture repair

    Temperament and Impulsivity Predictors of Smoking Cessation Outcomes

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    Aims: Temperament and impulsivity are powerful predictors of addiction treatment outcomes. However, a comprehensive assessment of these features has not been examined in relation to smoking cessation outcomes.Methods: Naturalistic prospective study. Treatment-seeking smokers (n = 140) were recruited as they engaged in an occupational health clinic providing smoking cessation treatment between 2009 and 2013. Participants were assessed at baseline with measures of temperament (Temperament and Character Inventory), trait impulsivity (Barratt Impulsivity Scale), and cognitive impulsivity (Go/No Go, Delay Discounting and Iowa Gambling Task). The outcome measure was treatment status, coded as “dropout” versus “relapse” versus “abstinence” at 3, 6, and 12 months endpoints. Participants were telephonically contacted and reminded of follow-up face to face assessments at each endpoint. The participants that failed to answer the phone calls or self-reported discontinuation of treatment and failed to attend the upcoming follow-up session were coded as dropouts. The participants that self-reported continuing treatment, and successfully attended the upcoming follow-up session were coded as either “relapse” or “abstinence”, based on the results of smoking behavior self-reports cross-validated with co-oximetry hemoglobin levels. Multinomial regression models were conducted to test whether temperament and impulsivity measures predicted dropout and relapse relative to abstinence outcomes.Results: Higher scores on temperament dimensions of novelty seeking and reward dependence predicted poorer retention across endpoints, whereas only higher scores on persistence predicted greater relapse. Higher scores on the trait dimension of non-planning impulsivity but not performance on cognitive impulsivity predicted poorer retention. Higher non-planning impulsivity and poorer performance in the Iowa Gambling Task predicted greater relapse at 3 and 6 months and 6 months respectively.Conclusion: Temperament measures, and specifically novelty seeking and reward dependence, predict smoking cessation treatment retention, whereas persistence, non-planning impulsivity and poor decision-making predict smoking relapse.This research was funded by the Occupational Medicine Area (Prevention Service); Department of Personality, Assessment and Psychological Treatment, University of Granada (Spain); and Ministerio de Economía y Competitividad grant (MINICO, ref. # PSI2013-45055-P) for the first and second authors

    Efeito do uso da gessagem e adubação de cobertura na composição bromatológica e qualidade da silagem de capiaçu.

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    A agricultura familiar na região Noroeste de Minas Gerais desempenha um papel crucial na produção de leite bovino, com 80,41% dos estabelecimentos na região representando agricultores familiares e produzindo 59,68% do leite total (IBGE, 2017). A região enfrenta desafios significativos, incluindo pequenas dimensões das propriedades, baixa mecanização e dificuldades na produção de volumosos durante a seca. O bioma Cerrado, com suas altas temperaturas e veranicos, agrava esses desafios (NASCIMENTO et al., 2015).VIII SINMCA

    Uso da gessagem e adubação de cobertura para melhoria da produtividade do capiaçu.

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    O rebanho bovino brasileiro cresceu pelo quarto ano consecutivo, com um crescimento de 4,3%, o que representa um número total de 234,4 Milhões de cabeças (IBGE, 2023). Entretanto, os efeitos da sazonalidade na produção e qualidade da forragem, tanto reduzem o desempenho animal durante o período seco do ano (Braga et al., 2018). Cerca de 95% da carne bovina brasileira é produzida em regime de pastagens, cuja área total é de cerca de 167 milhões de hectares. A pecuária bovina do futuro demandará soluções de baixo custo para o uso cada vez mais racional dos insumos, em especial a água (Casagranda et al., 2021). Este estudo tem como objetivo avaliar o efeito do gesso agrícola e adubação de cobertura com o uso de nitrogênio, na produtividade do BRS Capiaçu.VIII SINMCA
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