251 research outputs found
Role of dopamine–adenosine interactions in the brain circuitry regulating effort-related decision making: insights into pathological aspects of motivation
Brain dopamine, particularly in the nucleus accumbens, has been implicated in activational aspects of motivation and effort-related processes. Accumbens dopamine depletions reduce the tendency of rats to work for food, and alter effort-related decision making, but leave aspects of food motivation such as appetite intact. Recent evidence indicates that the purine neuromodulator adenosine, largely through actions on adenosine A2A receptors, also participates in regulating effort-related processes. Adenosine A2A antagonists can reverse the effects of dopamine D2 antagonists on effort-related choice, and intra- accumbens injections of adenosine A2A agonists produce effects that are similar to those induced by accumbens dopamine depletion or antagonism. These studies have implications for the understanding and treatment of energy-related disorders such as anergia and fatigue in psychiatry and neurology
Produtividade de soja e milho em resposta a fertilizantes mineral e organominerais sĂłlido e fluido.
Os dejetos de suĂnos, apĂłs a biodigestĂŁo, apresentam-se em forma fluida e diluĂda, encarecendo o transporte atĂ© o local de uso, caso nĂŁo seja possĂvel utilizá-lo na propriedade geradora. Uma forma de viabilizar o uso dos dejetos lĂquidos de suĂnos Ă© enriquecĂŞ-los com fontes minerais de N, P e K, viabilizando seu transporte atĂ© os usuários finais. Este trabalho objetivou avaliar o efeito de fertilizantes organominerais sĂłlido e fluido na produtividade de soja e milho, nas condições edafoclimáticas de Dourados-MS. O experimento foi conduzido no Campo Experimental da Embrapa Agropecuária Oeste, utilizando delineamento em blocos casualizados, com quatro repetições. Os tratamentos foram constituĂdos por trĂŞs diferentes fertilizantes, sendo um organomineral na forma sĂłlida (elaborado a partir de cama de aviário), outro na forma fluĂda (elaborado a partir de dejetos de suĂnos processados em biodigestor) e outro mineral, todos compostos na formulação 02-10-06. Foram aplicados 4 nĂveis de doses crescentes, que corresponderam a 0, 750, 1000 e 1250 kg ou L ha-1 de cada formulação, sempre no sulco de plantio. Nas safras de primavera-verĂŁo plantou-se soja e nas safras de outono-inverno foi cultivado o milho safrinha. O experimento sofreu com adversidades climáticas, o que causou perdas expressivas em colheitas de safra e safrinha, ocorrendo grandes variações nos rendimentos obtidos nos diferentes anos. As produtividades de milho e soja foram semelhantes quando essas culturas foram fertilizadas com fertilizantes organominerais lĂquidos ou sĂłlidos. O fertilizante mineral proporcionou resposta inferior Ă s formas organominerais em safras com restrição hĂdrica
Effort-related motivational effects of the pro-inflammatory cytokine interleukin 1-beta: studies with the concurrent fixed ratio 5/ chow feeding choice task
Rationale. Effort-related motivational symptoms such as anergia and fatigue are common in patients with depression and other disorders. Research implicates pro-inflammatory cytokines in depression, and administration of cytokines can induce effort-related motivational symptoms in humans. Objectives. The present experiments focused on the effects of the pro-inflammatory cytokine interleukin 1-beta (IL-1β) on effort-related choice behavior. Methods. Rats were tested on a concurrent fixed ratio 5 lever pressing/chow feeding choice procedure, which assesses the tendency of rats to work for a preferred food (high carbohydrate pellets) in the presence of a concurrently available but less preferred substitute (laboratory chow). Results. IL-1β (1.0–4.0 μg/kg IP) shifted choice behavior, significantly decreasing lever pressing and increasing intake of the freely available chow. The second experiment assessed the ability of the adenosine A2A antagonist (E)-phosphoric acid mono-[3-[8-[2-(3-methoxyphenyl)vinyl]-7-methyl-2,6-dioxo-1-prop-2-ynyl-1,2,6,7-tetrahydropurin-3-yl] propyl] ester disodium salt (MSX-3) to reverse the behavioral effects of IL-1β. MSX-3 attenuated the effort-related impairments produced by IL-1β, increasing lever pressing and also decreasing chow intake. In the same dose range that shifted effort-related choice behavior, IL-1β did not alter food intake or preference in parallel free-feeding choice studies, indicating that these low doses were not generally suppressing appetite or altering preference for the high carbohydrate pellets. In addition, IL-1β did not affect core body temperature. Conclusions. These results indicate that IL-1β can reduce the tendency to work for food, even at low doses that do not produce a general sickness, malaise, or loss of appetite. This research has implications for the involvement of cytokines in motivational symptoms such as anergia and fatigue
Effort-Related Motivational Effects of the VMAT-2 Inhibitor Tetrabenazine: Implications for Animal Models of the Motivational Symptoms of Depression
Motivated behaviors are often characterized by a high degree of behavioral activation, and work output and organisms frequently make effort-related decisions based upon cost/benefit analyses. Moreover, people with major depression and other disorders often show effort-related motivational symptoms such as anergia, psychomotor retardation, and fatigue. It has been suggested that tasks measuring effort-related choice behavior could be used as animal models of the motivational symptoms of depression, and the present studies characterized the effort-related effects of the vesicular monoamine transport (VMAT) inhibitor tetrabenazine. Tetrabenazine produces depressive symptoms in humans and, because of its selective inhibition of VMAT-2, it preferentially depletes dopamine (DA). Rats were assessed using a concurrent fixed-ratio 5/chow feeding choice task that is known to be sensitive to dopaminergic manipulations. Tetrabenazine shifted response choice in rats, producing a dose-related decrease in lever pressing and a concomitant increase in chow intake. However, it did not alter food intake or preference in parallel free-feeding choice studies. The effects of tetrabenazine on effort-related choice were reversed by the adenosine A2A antagonist MSX-3 and the antidepressant bupropion. A behaviorally active dose of tetrabenazine decreased extracellular DA in nucleus accumbens and increased expression of DARPP-32 in accumbens medium spiny neurons in a pattern indicative of reduced transmission at both D1 and D2 DA receptors. These experiments demonstrate that tetrabenazine, which is used in animal models to produce depression-like effects, can alter effort-related choice behavior. These studies have implications for the development of animal models of the motivational symptoms of depression and related disorders
Assessment of WASH scenarios in urban and rural schools of a small city in the Brazilian Amazon
Bupropion Increases Selection of High Effort Activity in Rats Tested on a Progressive Ratio/Chow Feeding Choice Procedure: Implications for Treatment of Effort-Related Motivational Symptoms
Background:
Depression and related disorders are characterized by deficits in behavioral activation, exertion of effort, and other psychomotor/motivational dysfunctions. Depressed patients show alterations in effort-related decision making and a bias towards selection of low effort activities. It has been suggested that animal tests of effort-related decision making could be useful as models of motivational dysfunctions seen in psychopathology.
Methods:
Because clinical studies have suggested that inhibition of catecholamine uptake may be a useful strategy for treatment of effort-related motivational symptoms, the present research assessed the ability of bupropion to increase work output in rats responding on a test of effort-related decision-making (ie, a progressive ratio/chow feeding choice task). With this task, rats can choose between working for a preferred food (high-carbohydrate pellets) by lever pressing on a progressive ratio schedule vs obtaining a less preferred laboratory chow that is freely available in the chamber.
Results:
Bupropion (10.0–40.0 mg/kg intraperitoneal) significantly increased all measures of progressive ratio lever pressing, but decreased chow intake. These effects were greatest in animals with low baseline levels of work output on the progressive ratio schedule. Because accumbens dopamine is implicated in effort-related processes, the effects of bupropion on markers of accumbens dopamine transmission were examined. Bupropion elevated extracellular dopamine levels in accumbens core as measured by microdialysis and increased phosphorylated dopamine and cyclic-AMP related phosphoprotein 32 kDaltons (pDARPP-32) immunoreactivity in a manner consistent with D1 and D2 receptor stimulation.
Conclusion:
The ability of bupropion to increase exertion of effort in instrumental behavior may have implications for the pathophysiology and treatment of effort-related motivational symptoms in humans
Short term associations of ambient nitrogen dioxide with daily total, cardiovascular, and respiratory mortality: Multilocation analysis in 398 cities
Profiling of spatial metabolite distributions in wheat leaves under normal and nitrate limiting conditions
The control and interaction between nitrogen and carbon assimilatory pathways is essential in both photosynthetic and non-photosynthetic tissue in order to support metabolic processes without compromising growth. Physiological differences between the basal and mature region of wheat (Triticum aestivum) primary leaves confirmed that there was a change from heterotrophic to autotrophic metabolism. Fourier Transform Infrared (FT-IR) spectroscopy confirmed the suitability and phenotypic reproducibility of the leaf growth conditions. Principal Component–Discriminant Function Analysis (PC–DFA) revealed distinct clustering between base, and tip sections of the developing wheat leaf, and from plants grown in the presence or absence of nitrate. Gas Chromatography-Time of Flight/Mass Spectrometry (GC-TOF/MS) combined with multivariate and univariate analyses, and Bayesian network (BN) analysis, distinguished different tissues and confirmed the physiological switch from high rates of respiration to photosynthesis along the leaf. The operation of nitrogen metabolism impacted on the levels and distribution of amino acids, organic acids and carbohydrates within the wheat leaf. In plants grown in the presence of nitrate there was reduced levels of a number of sugar metabolites in the leaf base and an increase in maltose levels, possibly reflecting an increase in starch turnover. The value of using this combined metabolomics analysis for further functional investigations in the future are discussed
Contribuição ao estudo da distribuição geográfica de triatomĂneos no estado do PiauĂ
Influences of the signal border extension in the discrete wavelet transform in EEG spike detection
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