120 research outputs found

    Effect of Onopordon acanthium L. as add on antihypertensive therapy in patients with primary hypertension taking Losartan: A pilot study

    Get PDF
    Purpose: Onopordon acanthium L. is known for its medicinal properties. Our recent study showed that its seed extract is a novel natura angiotensin-converting-enzyme inhibitor (ACEI). This study was carried out to investigate its possible antihypertensive effects in patients receiving losartan. Methods: This uncontrolled clinical trial was carried out among 20 patients (30-60y) with uncontrolled hypertension despite receiving 50 mg losartan (stage I & II) in two hospitals in Iran. After completing informed consent, patients were treated by 2 capsules each 1g of Onopordon acanthium seed extract (OSE) as add-on therapy, two times per day. Results: 18 patients completed the study (50.94 ±8.37y). Mean systolic blood pressure (SBP) at the baseline was 151.9 ± 13.74mmHg and at the end of the study, it was 134.6 ± 18.25 mmHg and mean diastolic blood pressure (DBP) was 97.41 ± 10.36 at the baseline and was 85.71 ± 7.481 after 8 weeks. OSE significantly reduced SBP and DBP at the end of 8 weeks (P=0.003, 95% CI: -19.7, -15.1; P=0.0006, 95% CI: -10.23, -13.15; respectively). No evidence of hepatic or renal toxicity was detected. Conclusion: Based on the results of this study OSE has antihypertensive property with no significant adverse effects. However, because of the low number of samples, this medication may be not safely administered. The results of this study could be the basis for further studies with larger sample size. IRCT registration number: IRCT2013020712391N. © 2018 The Authors

    Effect of Onopordon acanthium L. as add on antihypertensive therapy in patients with primary hypertension taking Losartan: A pilot study

    Get PDF
    Purpose: Onopordon acanthium L. is known for its medicinal properties. Our recent study showed that its seed extract is a novel natura angiotensin-converting-enzyme inhibitor (ACEI). This study was carried out to investigate its possible antihypertensive effects in patients receiving losartan. Methods: This uncontrolled clinical trial was carried out among 20 patients (30-60y) with uncontrolled hypertension despite receiving 50 mg losartan (stage I & II) in two hospitals in Iran. After completing informed consent, patients were treated by 2 capsules each 1g of Onopordon acanthium seed extract (OSE) as add-on therapy, two times per day. Results: 18 patients completed the study (50.94 ±8.37y). Mean systolic blood pressure (SBP) at the baseline was 151.9 ± 13.74mmHg and at the end of the study, it was 134.6 ± 18.25 mmHg and mean diastolic blood pressure (DBP) was 97.41 ± 10.36 at the baseline and was 85.71 ± 7.481 after 8 weeks. OSE significantly reduced SBP and DBP at the end of 8 weeks (P=0.003, 95% CI: -19.7, -15.1; P=0.0006, 95% CI: -10.23, -13.15; respectively). No evidence of hepatic or renal toxicity was detected. Conclusion: Based on the results of this study OSE has antihypertensive property with no significant adverse effects. However, because of the low number of samples, this medication may be not safely administered. The results of this study could be the basis for further studies with larger sample size. IRCT registration number: IRCT2013020712391N. © 2018 The Authors

    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

    Get PDF
    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

    Chronic Alcohol Exposure Alters Behavioral and Synaptic Plasticity of the Rodent Prefrontal Cortex

    Get PDF
    In the present study, we used a mouse model of chronic intermittent ethanol (CIE) exposure to examine how CIE alters the plasticity of the medial prefrontal cortex (mPFC). In acute slices obtained either immediately or 1-week after the last episode of alcohol exposure, voltage-clamp recording of excitatory post-synaptic currents (EPSCs) in mPFC layer V pyramidal neurons revealed that CIE exposure resulted in an increase in the NMDA/AMPA current ratio. This increase appeared to result from a selective increase in the NMDA component of the EPSC. Consistent with this, Western blot analysis of the postsynaptic density fraction showed that while there was no change in expression of the AMPA GluR1 subunit, NMDA NR1 and NRB subunits were significantly increased in CIE exposed mice when examined immediately after the last episode of alcohol exposure. Unexpectedly, this increase in NR1 and NR2B was no longer observed after 1-week of withdrawal in spite of a persistent increase in synaptic NMDA currents. Analysis of spines on the basal dendrites of layer V neurons revealed that while the total density of spines was not altered, there was a selective increase in the density of mushroom-type spines following CIE exposure. Examination of NMDA-receptor mediated spike-timing-dependent plasticity (STDP) showed that CIE exposure was associated with altered expression of long-term potentiation (LTP). Lastly, behavioral studies using an attentional set-shifting task that depends upon the mPFC for optimal performance revealed deficits in cognitive flexibility in CIE exposed mice when tested up to 1-week after the last episode of alcohol exposure. Taken together, these observations are consistent with those in human alcoholics showing protracted deficits in executive function, and suggest these deficits may be associated with alterations in synaptic plasticity in the mPFC

    Behavioral modeling of human choices reveals dissociable effects of physical effort and temporal delay on reward devaluation

    Get PDF
    There has been considerable interest from the fields of biology, economics, psychology, and ecology about how decision costs decrease the value of rewarding outcomes. For example, formal descriptions of how reward value changes with increasing temporal delays allow for quantifying individual decision preferences, as in animal species populating different habitats, or normal and clinical human populations. Strikingly, it remains largely unclear how humans evaluate rewards when these are tied to energetic costs, despite the surge of interest in the neural basis of effort-guided decision-making and the prevalence of disorders showing a diminished willingness to exert effort (e.g., depression). One common assumption is that effort discounts reward in a similar way to delay. Here we challenge this assumption by formally comparing competing hypotheses about effort and delay discounting. We used a design specifically optimized to compare discounting behavior for both effort and delay over a wide range of decision costs (Experiment 1). We then additionally characterized the profile of effort discounting free of model assumptions (Experiment 2). Contrary to previous reports, in both experiments effort costs devalued reward in a manner opposite to delay, with small devaluations for lower efforts, and progressively larger devaluations for higher effort-levels (concave shape). Bayesian model comparison confirmed that delay-choices were best predicted by a hyperbolic model, with the largest reward devaluations occurring at shorter delays. In contrast, an altogether different relationship was observed for effort-choices, which were best described by a model of inverse sigmoidal shape that is initially concave. Our results provide a novel characterization of human effort discounting behavior and its first dissociation from delay discounting. This enables accurate modelling of cost-benefit decisions, a prerequisite for the investigation of the neural underpinnings of effort-guided choice and for understanding the deficits in clinical disorders characterized by behavioral inactivity

    The NEWMEDS rodent touchscreen test battery for cognition relevant to schizophrenia.

    Get PDF
    RATIONALE: The NEWMEDS initiative (Novel Methods leading to New Medications in Depression and Schizophrenia, http://www.newmeds-europe.com ) is a large industrial-academic collaborative project aimed at developing new methods for drug discovery for schizophrenia. As part of this project, Work package 2 (WP02) has developed and validated a comprehensive battery of novel touchscreen tasks for rats and mice for assessing cognitive domains relevant to schizophrenia. OBJECTIVES: This article provides a review of the touchscreen battery of tasks for rats and mice for assessing cognitive domains relevant to schizophrenia and highlights validation data presented in several primary articles in this issue and elsewhere. METHODS: The battery consists of the five-choice serial reaction time task and a novel rodent continuous performance task for measuring attention, a three-stimulus visual reversal and the serial visual reversal task for measuring cognitive flexibility, novel non-matching to sample-based tasks for measuring spatial working memory and paired-associates learning for measuring long-term memory. RESULTS: The rodent (i.e. both rats and mice) touchscreen operant chamber and battery has high translational value across species due to its emphasis on construct as well as face validity. In addition, it offers cognitive profiling of models of diseases with cognitive symptoms (not limited to schizophrenia) through a battery approach, whereby multiple cognitive constructs can be measured using the same apparatus, enabling comparisons of performance across tasks. CONCLUSION: This battery of tests constitutes an extensive tool package for both model characterisation and pre-clinical drug discovery.This work was supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 115008 of which resources are composed of EFPIA in-kind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013). The authors thank Charlotte Oomen for valuable comments on the manuscript.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4007-

    Dissociable involvement of the nucleus accumbens subregions in effort-based decision making

    No full text
    Animals routinely engage in cost-benefit analysis, choosing between different courses of actions with potentially greater response costs that may lead to greater rewards. Previous research has shown that the preference to exert more physical effort to obtain a larger magnitude of reward is mediated by a complex neural circuit including the anterior cingulate, basolateral amygdala, and mesoaccumbens dopamine system. Past studies investigating the neural basis of effort-based decision making have utilized a T-maze task whereby rats have had to choose between climbing a barrier in one arm to obtain a high reward (HR), or retrieve a low reward (LR) from an arm with no barrier. Destruction of dopamine terminals in the nucleus accumbens (NAc) has been shown to reduce the preference to work harder to obtain a larger reward. Yet, the role of the different subregions of the NAc on this form of decision making is not very clear. The present study investigated the contributions of the NAc core and shell in effort-based decision making using an automated procedure conducted in an operant chamber. The task consisted of 4 discrete blocks of 10 trials. A response on one lever delivered an LR immediately (2 reward pellets), whereas responding on the other lever delivered an HR (4 pellets) after a fixed ratio of presses, which increased with each block (2, 5, 10, or 20). Inactivation of the NAc core, but not shell, via infusion of GABAA/B agonists muscimol/baclofen (75 ng each) reduced the preference for animals to exert greater effort to obtain the HR. In order to control for the greater delay from initiation of response to delivery of reward in the HR compared to LR condition, we conducted a subsequent experiment that equalized the delay. Inactivation of the core, but not shell reduced the preference for the HR. Therefore the NAc core, but not the shell, is part of a neural circuit that mediates effort-based decision making. Additionally the contributions by the NAc core to this form of decision making are distinct from those involving delay-based decisions.Medicine, Faculty ofGraduat
    corecore