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 sólido e fluido.

Os dejetos de suínos, após a biodigestão, apresentam-se em forma fluida e diluída, encarecendo o transporte até o local de uso, caso não seja possível utilizá-lo na propriedade geradora. Uma forma de viabilizar o uso dos dejetos líquidos de suínos é enriquecê-los com fontes minerais de N, P e K, viabilizando seu transporte até os usuários finais. Este trabalho objetivou avaliar o efeito de fertilizantes organominerais sólido 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 constituídos por três diferentes fertilizantes, sendo um organomineral na forma sólida (elaborado a partir de cama de aviário), outro na forma fluída (elaborado a partir de dejetos de suínos processados em biodigestor) e outro mineral, todos compostos na formulação 02-10-06. Foram aplicados 4 níveis 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-verão 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 líquidos ou sólidos. O fertilizante mineral proporcionou resposta inferior às formas organominerais em safras com restrição hídrica

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

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

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

Uma ação sinérgica por direitos reprodutivos: uma história sem fim

No Brasil, os direitos reprodutivos estão previstos em legislação nacional e normativas do Ministério da Saúde, devendo ser objeto de políticas públicas, e também uma agenda do movimento de mulheres desde os anos 1970. O planejamento familiar integra essas políticas, tendo como base os princípios da não coerção e escolha informada e responsável, implicando em parâmetros éticos. O Conselho Municipal de Saúde de Porto Alegre, mecanismo instituído por lei para exercer o controle social sobre essas políticas, foi instado em 2006 a assegurar os parâmetros éticos e legais quando um programa de implantes hormonais em adolescentes foi autorizado pela prefeitura sem debate no Conselho. A proposta deste artigo é refletir a partir da Ciência Política e do Feminismo sobre as estratégias utilizadas pelo movimento de mulheres para a reversão desse programa, suas alianças e argumentos, bem como as lições aprendidas. Como resultado se obteve a reversão do programa de implantes e o reposionamento do Conselho como órgão deliberativo da política de saúde.In Brazil, reproductive rights are provided for a national legislation and regulations of the Ministry of Health, should be the object of public policy, and is an agenda of women's movement since 1970 decade. Family planning integrates these policies, based on the principles of non-coercion, informed choice and responsible, resulting in ethical standards. The health council of Porto Alegre, a mechanism established by law to exercise social control over those policies, was asked in 2006 to ensure the ethical and legal parameters when a program of hormone implants in adolescents has been authorized by the city without a debate in the Council. The purpose of this paper is to discuss, from the Political Science and Feminist Theory the strategies used by the feminist movement for the reversal of this program, its alliances and arguments, as well as lessons learned. As a result is has obtained the reversal of the implants program and the deliberative body of the Health Council on health public policy