Stable modulation of neuronal oscillations produced through brain-machine equilibrium

Brain stimulation is predominantly delivered independent of ongoing activity, whereas closed-loop systems can modify activity through interaction. They have the unrealised potential to continuously bind external stimulation to specific dynamics of a neural circuit. Such manipulations are particularly suited to rhythmic activities, where neuronal activity is organised in oscillatory cycles. Here, we developed a fast algorithm that responds on a cycle-by-cycle basis to stimulate basal ganglia nuclei at predetermined phases of successive cortical beta cycles in parkinsonian rats. Using this approach, we demonstrate a stable brain-machine interaction. An equilibrium emerged between the modified brain signal and feedback-dependent stimulation pattern, which led to sustained amplification or suppression of the oscillation. Sustained beta amplification slowed movement speed by altering the mode of locomotion. Integrating an external stimulus with network activity in this way could be used to correct maladaptive activities and to define the role of oscillations in fundamental brain functions.

Significance of the Diagnosis of Executive Functions in Patients with Relapsing-Remitting Multiple Sclerosis

Multiple sclerosis (MS) is a progressive chronic disease of the Central Nervous System (CNS). Cognitive decline occurs rather rarely in relapsing–remitting multiple sclerosis (RRMS) compared to other types. The present study aimed to assess executive functions (EF) in relation to clinical and demographic variables in patients with RRMS. The study involved 22 individuals with RRMS (aged 23 to 49 years) and 22 matching controls. All the individuals with RRMS were in the remission phase. The assessments were carried out using MoCA, BDI-II, Halstead Category Test, Porteus Maze Test, verbal fluency tasks and Stroop Colour-Word Interference Test. The findings show that the two groups differed significantly in all the tests. All patients with RRMS in the remission phase presented at least one cognitive deficit, observed in general cognitive functioning, abstract reasoning or other executive functions, i.e., fluency, interference suppression, planning, or ability to modify activity in response to feedback. The deficits in most cases (except for those measured with the MoCA, Category Tests and phonemic fluency), are not related to intensity of depression and duration of the disease. Findings suggest that the diagnostic process in the case of patients with RRMS may include psychological assessment focusing on potentially existing cognitive, mainly executive, deficits and their severity.

Piperine as a Potential Anti-cancer Agent: A Review on Preclinical Studies

Recently many studies showed anticancer activities of piperine, a pungent alkaloid found in black pepper and some other Piper species. We attempted to summarize acquired data that support anticancer potential of this natural agent. Piperine has been reported to possess effective chemopreventive activity. It has been studied to affect via several mechanisms of action, in brief enhancing antioxidant system, increasing level and activity of detoxifying enzymes and suppressing stem cell self-renewal. Moreover, piperine has been found to inhibit proliferation and survival of various cancerous cell lines via modulating cell cycle progression and exhibiting anti-apoptotic activity, respectively. This compound has been shown to modify activity of various enzymes and transcription factors to inhibit invasion, metastasis and angiogenesis. Interestingly, piperine has exhibited antimutagenic activity and also inhibited activity and expression of multidrug resistance transporters such as P-gp and MRP-1. Besides, about all reviewed studies have reported selective cytotoxic activity of piperine on cancerous cells in compared with normal cells. Altogether, the studies completely underline promising candidacy of piperine for further development. The collected preclinical data we provided in this article can be useful in the design of future researches especially clinical trials with piperine.

Increased intracellular and extracellular oxidant production in phagocytes of rheumatic patients treated with biological therapy – whole blood quantification

Infectious complications, resulting from reduced activity of immune cells, are the most severe and common adverse effects of biological therapy. This study analyzed the effect of biological therapy on blood phagocytes, focusing on the formation of reactive oxygen species (ROS), an important factor in the defence against invading pathogens. Intra- and extracellular ROS production were recorded separately, on the basis of luminol and isoluminol chemiluminescence in patients treated with antibodies against tumor necrosis factor-α or against interleukin-6 receptor. In comparison to healthy donors or to rheumatic patients treated with classical immunosuppressive drugs, biological therapy increased ROS formation in both compartments. This indicates that the anti-microbial activity of blood phagocytes was not reduced by TNFα- or IL-6-neutralizing therapy, at least in terms of ROS.The method presented does not require blood fractionation, which could modify activity of phagocytes and cause loss of some sub-populations of these cells. The technique is simple, requires microliter volumes of blood and is thus well applicable to clinical studies.

DREAM Controls the On/Off Switch of Specific Activity-Dependent Transcription Pathways

Changes in nuclear Ca2+homeostasis activate specific gene expression programs and are central to the acquisition and storage of information in the brain. DREAM (downstreamregulatoryelementantagonistmodulator), also known as calsenilin/KChIP-3 (K+channelinteractingprotein 3), is a Ca2+-binding protein that binds DNA and represses transcription in a Ca2+-dependent manner. To study the function of DREAM in the brain, we used transgenic mice expressing a Ca2+-insensitive/CREB-independent dominant active mutant DREAM (daDREAM). Using genome-wide analysis, we show that DREAM regulates the expression of specific activity-dependent transcription factors in the hippocampus, including Npas4, Nr4a1, Mef2c, JunB, and c-Fos. Furthermore, DREAM regulates its own expression, establishing an autoinhibitory feedback loop to terminate activity-dependent transcription. Ablation of DREAM does not modify activity-dependent transcription because of gene compensation by the other KChIP family members. The expression of daDREAM in the forebrain resulted in a complex phenotype characterized by loss of recurrent inhibition and enhanced long-term potentiation (LTP) in the dentate gyrus and impaired learning and memory. Our results indicate that DREAM is a major master switch transcription factor that regulates the on/off status of specific activity-dependent gene expression programs that control synaptic plasticity, learning, and memory.

Survivin S81A Enhanced TRAIL's Activity in Inducing Apoptosis

BACKGROUND: Survivin is rarely expressed in normal healthy adult tissues, however, it is upregulated in the majority of cancers. Survivin, which belongs to IAPs family, has been widely reported to protect cells from apoptosis by inhibiting caspases pathway. Survivin’s mitotic activity is modulated by many kinases, and its phosphor status can also influence its ability to inhibit apoptosis. There are several important survivin’s phosphorylation sites, such as S20 and T34. We have continued our investigation on other potential survivin’s phosphorylation sites that could be important site for regulating survivin’s cyto-protection.METHODS: By assuming that S81 could be a potential target to modify activity of survivin, wild-type survivin (Survivin), antisense survivin (Survivin-AS), mutated-survivin Thr34Ala (Survivin-T34A) and mutated-survivin Ser81Ala (Survivin-S81A) were constructed and inserted into pMSCV-IRES-GFP vector with cytomegalovirus (CMV) promoter. Each retroviral product was produced in BOSC23 cells. LY294002 pretreatment and TRAIL treatment along with infection of retroviral products were performed in murine fibrosarcoma L929 cells. For analysis, flow cytometric apoptosis assay and western blot were performed.RESULTS: In our present study, survivin for providing cytoprotection was regulated by PI3K. The results showed that LY294002, an inhibitor of PI3K, effectively suppressed survivin-modulated cytoprotection in a TRAIL-induced apoptotic model. In addition, mutated survivin S81A showed marked suppression on survivin’s cytoprotection. Along with that, TRAIL’s apoptotic activity was enhanced for inducing apoptosis.CONCLUSION: We suggested that survivin could inhibit apoptosis through PI3K and S81A could be another potential target in order to inhibit Survivin-modulated cytoprotection as well as to sensitize efficacy of TRAIL or other related apoptotic inducers.KEYWORDS: apoptosis, survivin, TRAIL, S81A, L929, LY294002

fMRI Brain-Computer Interface: A Tool for Neuroscientific Research and Treatment

Brain-computer interfaces based on functional magnetic resonance imaging (fMRI-BCI) allow volitional control of anatomically specific regions of the brain. Technological advancement in higher field MRI scanners, fast data acquisition sequences, preprocessing algorithms, and robust statistical analysis are anticipated to make fMRI-BCI more widely available and applicable. This noninvasive technique could potentially complement the traditional neuroscientific experimental methods by varying the activity of the neural substrates of a region of interest as an independent variable to study its effects on behavior. If the neurobiological basis of a disorder (e.g., chronic pain, motor diseases, psychopathy, social phobia, depression) is known in terms of abnormal activity in certain regions of the brain, fMRI-BCI can be targeted to modify activity in those regions with high specificity for treatment. In this paper, we review recent results of the application of fMRI-BCI to neuroscientific research and psychophysiological treatment.