Can working memory predict target-to-target interval effects in the P300?

It has been suggested that the P300 component of the ERP is an electrophysiological index of memory-updating processes associated with task-relevant stimuli. Component magnitude varies with the time separating target stimuli (target-to-target interval: TTI), with longer TTIs eliciting larger P300 amplitudes. According to the template-update perspective, TTI effects observable in the P300 reflect the updating of stimulus-templates in working memory (WM). The current study explored whether young adults' memory-task ability could predict TTI effects in P300. EEG activity was recorded from 50 university students (aged 18–25 years) while they completed an auditory equiprobable Go/NoGo task with manipulations of TTIs. Participants also completed a CogState® battery and were sorted according to their WM score. ERPs were analysed using a temporal PCA. Two P300 components, P3b and the Slow Wave, were found to linearly increase in amplitude to longer TTIs. This TTI effect differed between groups only for the P3b component: The high WM group showed a steeper increase in P3b amplitude with TTI than the low WM group. These results suggest that TTI effects in P300 are directly related to WM processes.     

Metabolic Patterns (NAD(P)H) in Rat Basophilic Leukemia (RBL-2H3) Cells and Human Hepatocellular Carcinoma (Hep G2) Cells with Autofluorescence Imaging

Although the spatial and temporal distributions of cellular NAD(P)H concentrations have been theoretically predicted as typical patterns of the metabolism in living cells, so far such a pattern was observed only in neutrophils. In this work, the dynamic NAD(P)H distributions in rat basophilic leukemia (RBL-2H3) and human hepatocellular carcinoma (Hep G2) cells were studied by imaging the autofluorescence of cellular NAD(P)H with a sensitive CCD detector in a confocal microscope. The typical pattern of the cytoplasmic NAD(P)H wave traveling along the long axis of the elongated cell with a velocity of 2.2±0.6?μm/s was detected in RBL-2H3 cells. While in the case of Hep G2 cells, only the oscillation of the mitochondrial NAD(P)H was observed because the NAD(P)H mainly localized in mitochondria of Hep G2 cells. These results confirm the metabolic pattern of NAD(P)H in living cells and suggest that the expression of the metabolic pattern probably differs in different cell lines.     

Association between PARK16 and Parkinson's disease in the Han Chinese population: a meta-analysis

PARK16 was reported to alter the risk for Parkinson's disease (PD) in the Japanese population. However, its role in Han Chinese PD patients has not been well established. Herein, we investigated the effect of 4 single-nucleotide polymorphisms (SNPs) within the PARK16 locus, including rs823128, rs947211, rs823156, and rs11240572, on the risk of PD by genotyping 497 Taiwanese patients with PD and 500 age-matched control subjects. The results were then meta-analyzed with available genetic association studies in the same population. The meta-analysis showed that PD patients demonstrated a lower frequency of the rs823128 G allele (11.93%) than control subjects (14.04%; odds ratio [OR] 0.83, 95% confidence interval [CI] 0.72–0.96, p = 0.010). The frequency of the rs947211 A allele (40.35%) in PD patients was lower than in control subjects (43.01%; OR 0.90, 95% CI 0.80–0.99, p = 0.047). The rs823156 G allele was less frequently seen in PD patients (17.32%) than in control subjects (21.35%; OR 0.77, 95% CI 0.69–0.86, p < 0.001). A lower frequency of the rs11240572 A allele was found in PD patients (14.01%) than in control subjects (17.66%; OR 0.76, 95% CI 0.66–0.88, p < 0.001). Our results indicate a robust protective effect of PARK16 in Han Chinese PD patients. Functional approaches are needed to elucidate the effects of these SNPs on the regulation of gene expression.     

Differentiating event‐related potential components sensitive to emotion in middle childhood: Evidence from temporal–spatial PCA

Event‐related potentials (ERPs) may be particularly useful for examining emotional processing across development. Though a number of ERP components are sensitive to emotional content in adults, previous studies have yet to systematically examine the components sensitive to emotion in children. The current study used temporal–spatial principal components analysis (PCA) to identify ERP components in response to complex emotional images in 9‐year‐old children. Three components were modulated by emotional content and were similar to those previously observed in adults, including: the early posterior negativity, the P300, and a sustained relative positivity similar to the late positive potential (LPP). Compared to those previously observed in adults, the components sensitive to emotion in children were maximal over more occipital regions and the LPP component appeared to be less protracted in time, perhaps indicative of less elaborative processing of emotional stimuli. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 539–550, 2013     

Cortical potentials in an auditory oddball task reflect individual differences in working memory capacity

This study determined whether auditory cortical responses associated with mechanisms of attention vary with individual differences in working memory capacity (WMC) and perceptual load. The operation span test defined subjects with low versus high WMC, who then discriminated target/nontarget tones while EEG was recorded. Infrequent white noise distracters were presented at midline or ±90° locations, and perceptual load was manipulated by varying nontarget frequency. Amplitude of the N100 to distracters was negatively correlated with WMC. Relative to targets, only high WMC subjects showed attenuated N100 amplitudes to nontargets. In the higher WMC group, increased perceptual load was associated with decreased P3a amplitudes to distracters and longer‐lasting negative slow wave to nontargets. Results show that auditory cortical processing is associated with multiple facets of attention related to WMC and possibly higher‐level cognition.     

Reversing multidrug resistance by intracellular delivery of Pluronic P85 unimers

Pluronics have been demonstrated as excellent multidrug resistance (MDR) reversal agent in the form of unimers rather than micelles. However, the effective intracellular delivery of Pluronic^® unimers to MDR cancer cells still remains a big challenge. To address this issue, a mixed micellar system based mainly on the pH-sensitive copolymer of poly (l-histidine)-poly (d,l-lactide)-polyethyleneglycol-poly (d,l-lactide)-poly (l-histidine) (PHis-PLA-PEG-PLA-PHis) and Pluronic^® F127, some of which was conjugated with folate, was constructed to intracellularly deliver the unimers of Pluronic^® P85 to MDR cells. The folate-mediated endosomal pH-sensitive mixed micelles (pH_endoSM-P85/f) were prepared by a thin-film hydration method, by which Pluronic^® P85 unimers and doxorubicin (DOX) were incoporated into the mixed micelles. The incorporation of Pluronic^® P85 unimers was investigated by the surface tension test. The results indicated that the Pluronic^® P85 unimers probably first inserted into the binary mixed micelles and then formed a triple-component mixed micelles with Pluronic^® F127 and PHis-PLA-PEG-PLA-PHis as the loading content increased. Further analyzed with flow cytometry, confocal laser scanning microscopy (CLSM) and MTT assay, the micelles with inserted Pluronic^® P85 unimers demonstrated much more cellular uptake and higher cytotoxicity against MDR cells than the triple-component mixed micelles and plain Pluronic^® micelles. The enhanced MDR reversal effect was attributed to the successful intracellular delivery of Pluronic^® P85 unimers to the MDR cells, which was confirmed by the subcellular colocalization of Pluronic^® P85 unimers with mitochondria, the decreased ATP energy and mitochondrial membrane potential (MP) in the MCF-7/ADR cells. The pH_endoSM-P85/f/DOX also demonstrated more dramatic antitumor efficiency and remarkable reduction of ATP energy in the MDR cells in tumors than the control formulations. The intracellular delivery of Pluronic^® P85 unimers to the MDR cells based on the targeted and endosomal pH triggerd release mixed micelles has been demonstrated as a promising approach to reverse MDR.     

Decontamination Strategies for Creutzfeldt-Jakob Disease Agent

Abstract

A polymethylmethacrylate technique that permits processing of enucleated eye globes with intact bone and tissue is described. The process includes decalcification in 5% formic acid, 22 hr dehydration in ascending alcohols, and 4hr clearing with xylenes to facilitate sectioning.

The combination of established techniques, decalcification agent, and plastic embedment decreases artifact and damage to ocular tissue and avoids lengthy celloidin procedures. (The J Histotechnol 15:311, 1992)     

Possible involvement of oxido-nitrosative stress induced neuro-inflammatory cascade and monoaminergic pathway: Underpinning the correlation between nociceptive and depressive behaviour in a rodent model

Background

Pain and depression are frequent co-morbid disorders. The prevalence rate of depression is several times higher in patients with chronic pain than in the general population but the mechanism underlying this association is unknown. A combination of interactions between neurotransmitters, neuropeptides, oxidative and nitrosative stress and cytokines are thought to take part in pathogenesis of pain as well as depression. Thus, the aim of the present study was two-fold, first to investigate the interplay between nociception and associated depression and second to investigate the protective potential of berberine against the reserpine-induced nociceptive and depressive behaviour and further to explore the role of oxidative–nitrosative stress mediated inflammatory cascade and apoptotic signalling pathway in this dyad.

Methods and results

Nociception and associated depression were induced by administration of reserpine (1 mg/kg subcutaneous daily) for three consecutive days. This behavioural deficit was integrated with decrease in the biogenic amine (dopamine, norepinephrine and serotonin) levels along with increased substance P concentration, oxidative–nitrosative stress, inflammatory cytokines, NF-κβ and caspase-3 levels in different brain regions (cortex and hippocampus) of the reserpinised rats.

Limitation

More studies are still warranted in similar rodent models of pain and depression, so, that the present findings can be further substantiated to establish the clinical effectiveness of berberine in a subset of patients suffering from pain as well as depression.

Conclusion

The findings from the current study suggested that reserpine-induced neurochemical alterations and dysregulation of oxidative–nitrosative stress induced inflammatory cascade underlies the co-morbidity of nociceptive behaviour and associated depression in rats.