183,502 research outputs found

    Underlying Mechanisms of Epilepsy

    Get PDF
    This book is a very provocative and interesting addition to the literature on Epilepsy. It offers a lot of appealing and stimulating work to offer food of thought to the readers from different disciplines. Around 5% of the total world population have seizures but only 0.9% is diagnosed with epilepsy, so it is very important to understand the differences between seizures and epilepsy, and also to identify the factors responsible for its etiology so as to have more effective therapeutic regime. In this book we have twenty chapters ranging from causes and underlying mechanisms to the treatment and side effects of epilepsy. This book contains a variety of chapters which will stimulate the readers to think about the complex interplay of epigenetics and epilepsy

    Estrous behavior in dairy cows: identification of underlying mechanisms and gene functions

    Get PDF
    Selection in dairy cattle for a higher milk yield has coincided with declined fertility. One of the factors is reduced expression of estrous behavior. Changes in systems that regulate the estrous behavior could be manifested by altered gene expression. This literature review describes the current knowledge on mechanisms and genes involved in the regulation of estrous behavior. The endocrinological regulation of the estrous cycle in dairy cows is well described. Estradiol (E2) is assumed to be the key regulator that synchronizes endocrine and behavioral events. Other pivotal hormones are, for example, progesterone, gonadotropin releasing hormone and insulin-like growth factor-1. Interactions between the latter and E2 may play a role in the unfavorable effects of milk yield-related metabolic stress on fertility in high milk-producing dairy cows. However, a clear understanding of how endocrine mechanisms are tied to estrous behavior in cows is only starting to emerge. Recent studies on gene expression and signaling pathways in rodents and other animals contribute to our understanding of genes and mechanisms involved in estrous behavior. Studies in rodents, for example, show that estrogen-induced gene expression in specific brain areas such as the hypothalamus play an important role. Through these estrogen-induced gene expressions, E2 alters the functioning of neuronal networks that underlie estrous behavior, by affecting dendritic connections between cells, receptor populations and neurotransmitter releases. To improve the understanding of complex biological networks, like estrus regulation, and to deal with the increasing amount of genomic information that becomes available, mathematical models can be helpful. Systems biology combines physiological and genomic data with mathematical modeling. Possible applications of systems biology approaches in the field of female fertility and estrous behavior are discusse

    Mindfulness reduces reactivity to food cues: underlying mechanisms and applications in daily life

    Get PDF
    Purpose of Review: Mindfulness-based interventions are becoming increasingly popular as a means to facilitate healthy eating. We suggest that the decentering component of mindfulness, which is the metacognitive insight that all experiences are impermanent, plays an especially important role in such interventions. To facilitate the application of decentering, we address its psychological mechanism to reduce reactivity to food cues, proposing that it makes thoughts and simulations in response to food cues less compelling. We discuss supporting evidence, applications, and challenges for future research. Recent Findings: Experimental and correlational studies consistently find that the adoption of a decentering perspective reduces subjective cravings, physiological reactivity such as salivation, and unhealthy eating. Summary: We suggest that the decentering perspective can be adopted in any situation to reduce reactivity to food cues. Considering people’s high exposure to food temptations in daily life, this makes it a powerful tool to empower people to eat healthily

    Rapid-Acting Antidepressants and Underlying Mechanisms

    Get PDF
    Loss of glial cells with resulting atrophy of the medial prefrontal cortex (mPFC) as well as the hippocampal area is demonstrated in depressed patients by brain imaging and postmortem studies. The mPFC is the master control of mood and emotional response. The hippocampus is part of the limbic system, the main function of which is to regulate emotions. The mPFC depends on the hippocampus for rapid learning and memory consolidation. Unlike monoamine reuptake inhibitor antidepressants, which take 6 to 8 weeks to exert their full effects, and with 30 - 40% unresponsive rate, ketamine acts rapidly, within a couple of hours, and has higher responsive rates. It suggests that in theory, due to its rapid effect, Ketamine could well serve as a bridging remedy to lower the rate of suicidal risk before Selective serotonin re-uptake inhibitors (SSRIs) reach their full effect for long-term depression management. Yet, ketamine has long been linked with abusive potential and possible neurotoxicity if used in large doses over a prolonged period. Even though there are no collected data to prove the associated adverse effects, awareness of this negative aspect of ketamine is sufficiently widespread to propel the psychiatric community to look for other rapidly acting antidepressant alternatives. Recent studies have shown that scopolamine, the Yueju pill, and magnesium are rapid-onset antidepressants that have mechanisms comparable to that of ketamine. These rapid-acting antidepressant agents promise to be effective and safer choices for depression management in the future, providing that further studies and investigations to produce a better and fuller understanding of their effects and limitations

    Estrus cyclicity of spinogenesis: underlying mechanisms

    Get PDF
    Hippocampal spine density varies with the estrus cycle. The cyclic change in estradiol levels in serum was hypothesized to underlie this phenomenon, since treatment of ovariectomized animals with estradiol induced an increase in spine density in hippocampal dendrites of rats, as compared to ovariectomized controls. In contrast, application of estradiol to hippocampal slice cultures did not promote spinogenesis. In addressing this discrepancy, we found that hippocampal neurons themselves are capable of synthesizing estradiol de novo. Estradiol synthesis can be suppressed by aromatase inhibitors and by knock-down of Steroid Acute Regulatory Protein (StAR) and enhanced by substrates of steroidogenesis. Expression of estrogen receptors (ERs) and synaptic proteins, synaptogenesis, and long-term potentiation (LTP) correlated positively with aromatase activity in hippocampal cultures without any difference between genders. All effects due to inhibition of aromatase activity were rescued by application of estradiol to the cultures. Most importantly, gonadotropin-releasing hormone (GnRH) increased estradiol synthesis dose-dependently via an aromatase-mediated mechanism and consistently increased spine synapse density and spinophilin expression. As a consequence, our data suggest that cyclic fluctuations in spine synapse density result from pulsative release of GnRH from the hypothalamus and its effect on hippocampal estradiol synthesis, rather than from varying levels of serum estradiol. This hypothesis is further supported by higher GnRH receptor (GnRH-R) density in the hippocampus than in the cortex and hypothalamus and the specificity of estrus cyclicity of spinogenesis in the hippocampus, as compared to the cortex

    Modeling the underlying mechanisms for organic memory devices: Tunneling, electron emission and oxygen adsorbing

    Full text link
    We present a combined experimental and theoretical study to get insight into both memory and negative differential resistance (NDR) effect in organic memory devices. The theoretical model we propose is simply a one-dimensional metallic island array embedding within two electrodes. We use scattering operator method to evaluate the tunneling current among the electrode and islands to establish the basic bistable I-V curves for several devices. The theoretical results match the experiments very well, and both memory and NDR effect could be understood comprehensively. The experimental correspondence, say, the experiment of changing the pressure of oxygen, is addressed as well.Comment: 5 pages, 3 figure
    corecore