Mental strategies and resting state EEG: Effect on high alpha amplitude modulation by neurofeedback in healthy young adults.

Neurofeedback (NFB) is a brain-computer interface which allows individuals to modulate their brain activity. Despite the self-regulatory nature of NFB, the effectiveness of strategies used during NFB training has been little investigated. In a single session of NFB training (6*3 min training blocks) with healthy young participants, we experimentally tested if providing a list of mental strategies (list group, N = 46), compared with a group receiving no strategies (no list group, N = 39), affected participants' neuromodulation ability of high alpha (10-12 Hz) amplitude. We additionally asked participants to verbally report the mental strategies used to enhance high alpha amplitude. The verbatim was then classified in pre-established categories in order to examine the effect of type of mental strategy on high alpha amplitude. First, we found that giving a list to the participants did not promote the ability to neuromodulate high alpha activity. However, our analysis of the specific strategies reported by learners during training blocks revealed that cognitive effort and recalling memories were associated with higher high alpha amplitude. Furthermore, the resting amplitude of trained high alpha frequency predicted an amplitude increase during training, a factor that may optimize inclusion in NFB protocols. The present results also corroborate the interrelation with other frequency bands during NFB training. Although these findings are based on a single NFB session, our study represents a further step towards developing effective protocols for high alpha neuromodulation by NFB.

Comprehensive Interactome Mapping of Nuclear Receptors Using Proximity Biotinylation.

Nuclear receptors, including hormone receptors, perform their cellular activities by modulating their protein-protein interactions. They engage with specific ligands and translocate to the nucleus, where they bind the DNA and activate extensive transcriptional programs. Therefore, gaining a comprehensive overview of the protein-protein interactions they establish requires methods that function effectively throughout the cell with fast dynamics and high reproducibility. Focusing on estrogen receptor alpha (ESR1), the founding member of the nuclear receptor family, this chapter describes a new lentiviral system that allows the expression of TurboID-hemagglutinin (HA)-2 × Strep tagged proteins in mammalian cells to perform fast proximity biotinylation assays. Key validation steps for these reagents and their use in interactome mapping experiments in two distinct breast cancer cell lines are described. Our protocol enabled the quantification of ESR1 interactome generated by cellular contexts that were hormone-sensitive or not.

EEG power spectral measures of cognitive workload: A meta-analysis.

Cognitive workload (CWL) is a fundamental concept in the assessment and monitoring of human performance during cognitive tasks. Numerous studies have attempted to objectively and continuously measure the CWL using neuroimaging techniques. Although the electroencephalogram (EEG) is a widely used technique, the impact of CWL on the spectral power of brain frequencies has shown inconsistent results. The present review aimed to synthesize the results of the literature and quantitatively assess which brain frequency is the most sensitive to CWL. A systematic literature search following PRISMA recommendations highlighted three main frequency bands used to measure CWL: theta (4-8 Hz), alpha (8-12 Hz), and beta (12-30 Hz). Three meta-analyses were conducted to quantitatively examine the effect of CWL on these frequencies. A total of 45 effect sizes from 24 studies involving 723 participants were computed. CWL was associated with significant effects on theta (g = 0.68, CI [0.41, 0.95]), alpha (g = -0.25, CI [-0.45, 0.04]), and beta (g = 0.50, CI [0.21, 0.79]) power. Our results suggests that theta, especially the frontal theta, is the best index of CWL. Alpha and beta power were also significantly impacted by CWL; however, their association seemed less straightforward. These results are critically analyzed considering the literature on cerebral oscillations. We conclude by emphasizing the need to investigate the interaction between CWL and other factors that may influence spectral power (e.g., emotional load), and to combine this measure with other methods of analysis of the central and peripheral nervous system (e.g., functional connectivity, heart rate).

R-BPMV-Mediated Resistance to Bean pod mottle virus in Phaseolus vulgaris L. Is Heat-Stable but Elevated Temperatures Boost Viral Infection in Susceptible Genotypes.

In the context of climate change, elevated temperature is a major concern due to the impact on plant-pathogen interactions. Although atmospheric temperature is predicted to increase in the next century, heat waves during summer seasons have already become a current problem. Elevated temperatures strongly influence plant-virus interactions, the most drastic effect being a breakdown of plant viral resistance conferred by some major resistance genes. In this work, we focused on the R-BPMV gene, a major resistance gene against Bean pod mottle virus in Phaseolus vulgaris. We inoculated different BPMV constructs in order to study the behavior of the R-BPMV-mediated resistance at normal (20 °C) and elevated temperatures (constant 25, 30, and 35 °C). Our results show that R-BPMV mediates a temperature-dependent phenotype of resistance from hypersensitive reaction at 20 °C to chlorotic lesions at 35 °C in the resistant genotype BAT93. BPMV is detected in inoculated leaves but not in systemic ones, suggesting that the resistance remains heat-stable up to 35 °C. R-BPMV segregates as an incompletely dominant gene in an F2 population. We also investigated the impact of elevated temperature on BPMV infection in susceptible genotypes, and our results reveal that elevated temperatures boost BPMV infection both locally and systemically in susceptible genotypes.

Event-related potentials of episodic encoding after traumatic brain injury in older adults.

Episodic memory and attention impairments are frequently observed following a traumatic brain injury (TBI). Older adults are more affected than young adults after a TBI, partly because of the age-related neural and memory changes. Neural mechanisms underlying episodic memory deficits in older adults with chronic TBI remain to be investigated. The current study aimed to investigate the impact of TBI in older adults on the neural mechanisms of episodic encoding. Event-related potentials were recorded while 13 participants with mild-to-severe TBI and 14 matched controls were performing an episodic memory task in which the level of organizational strategy was manipulated through three encoding conditions. Participants were explicitly instructed to memorize words without any semantic relationship (Unrelated condition), words semantically related without any given strategies (Spontaneous condition) and words semantically related with provided category labels and organizational strategy (Guided condition). Behavioral performances indicated that older individuals with a TBI were impaired compared to matched controls whatever the condition. The electrophysiological findings showed a reduction of the P200 and LPC components amplitude in the TBI group relative to control group. Moreover, control participants without any neurological history showed a right frontal sustained activity only in the Spontaneous condition, whereas a right frontal asymmetry was observed in participants with chronic TBI whatever the encoding conditions. This was mainly the result of negative left frontal activity. These findings evidence neural dysfunctions underlying attentional and associative processes involved in memory strategies after a TBI sustained at an older age that are consistent with executive functions impairments.

A common bean truncated CRINKLY4 kinase controls gene-for-gene resistance to the fungus Colletotrichum lindemuthianum.

Identifying the molecular basis of resistance to pathogens is critical to promote a chemical-free cropping system. In plants, nucleotide-binding leucine-rich repeat constitute the largest family of disease resistance (R) genes, but this resistance can be rapidly overcome by the pathogen, prompting research into alternative sources of resistance. Anthracnose, caused by the fungus Colletotrichum lindemuthianum, is one of the most important diseases of common bean. This study aimed to identify the molecular basis of Co-x, an anthracnose R gene conferring total resistance to the extremely virulent C. lindemuthianum strain 100. To that end, we sequenced the Co-x 58 kb target region in the resistant JaloEEP558 (Co-x) common bean and identified KTR2/3, an additional gene encoding a truncated and chimeric CRINKLY4 kinase, located within a CRINKLY4 kinase cluster. The presence of KTR2/3 is strictly correlated with resistance to strain 100 in a diversity panel of common beans. Furthermore, KTR2/3 expression is up-regulated 24 hours post-inoculation and its transient expression in a susceptible genotype increases resistance to strain 100. Our results provide evidence that Co-x encodes a truncated and chimeric CRINKLY4 kinase probably resulting from an unequal recombination event that occurred recently in the Andean domesticated gene pool. This atypical R gene may act as a decoy involved in indirect recognition of a fungal effector.

Working memory training in normal and pathological ageing: neurocognitive gains and their impact on daily-living activities.

Working memory is one of the cognitive functions that is the most sensitive to the effects of normal and pathological ageing. In older individuals with mild cognitive impairments, working memory deficits are frequent and can precede episodic memory impairments, in addition to having a strong prognostic value of evolution toward an Alzheimer-type dementia. Due to its involvement in numerous cognitive and cognitive-motor tasks, working memory is called upon in a wide range of daily activities. An impaired working memory therefore increases the risk of loss of autonomy. In this review, we present different working memory training programmes. We show how these training programmes are associated with specific effects, and near and far transfer effects on other cognitive functions in older adults without cognitive impairment or with mild cognitive impairment, as well as in patients with dementia. We show that the benefits are confirmed by neuronal modifications, suggesting an improvement in the neuronal efficiency of the processes that are trained or related to them. Finally, we consider the central question of the impact of the cognitive gains made by working memory training on activities of daily living.

[Working memory training in normal and pathological aging: neurocognitive gains and generalization]. / Entraînements de la mémoire de travail dans le vieillissement normal et pathologique : gains neurocognitifs et généralisation.

Working memory is one of the cognitive functions that is the most sensitive to normal and pathological age-related effects. In older individuals with a mild cognitive impairment, deficits in working memory are frequent and can precede those of episodic memory, in addition to having a strong prognostic value of evolution toward a dementia of Alzheimer type. Because of its implication in numerous cognitive and cognitive-motor tasks, working memory is called upon in a wide range of daily life activities. Impairment in working memory therefore increases the risk of a loss of autonomy. In the current review, we present different working memory training programs. We show how these training programs are associated with specific effects and to near and far transfers towards other cognitive functions in older adults without cognitive impairment or with mild cognitive impairment, as well as in patients with dementia. We show that the benefits are confirmed by neuronal modifications, suggesting an improvement in the neuronal efficiency of the targeted or related trained processes. Finally, we consider the central question of the generalization of the cognitive gains of working memory training toward ecological situations.

Community-dwelling older adults with mild cognitive impairments show subtle visual attention costs when descending stairs.

BACKGROUND: Older adults are at greater risk of falls while descending stairs. Cognitive deficits can further influence one's ability and mild cognitive impairments (MCI) specifically affect visual attention and dual tasking behavior. The present study aimed at comparing the attentional costs at different points during the approach to and descent of a staircase between older adults with and without MCI. METHODS: Eleven older adults with MCI and twenty-three healthy older individuals without cognitive impairments were recruited. Neuropsychological tests were carried out. In addition, participants approached and descended a 5-step staircase while a simultaneous visual Stroop dual-task was randomly introduced during the approach, transition or steady state descent phases across trials. Three-dimensional kinematics and accuracy on the Stroop task were analyzed and dual task costs were calculated. RESULTS: The MCI group showed deficits for visuo-spatial attention, memory and multi-tasking abilities, as well as balance and decreased confidence for falls efficacy, but not for daily activity scores. Despite such changes, this group of community-dwelling individuals with MCI presented a functional capacity to descend stairs even during divided visual attention. However, there were subtle, but significant, group differences for movement fluidity and performance on the simultaneous cognitive task, particularly during the approach and transition to descent phases. The MCI group also tended to descend slower while using the handrails more than healthy older adults. CONCLUSION: The present cohort of community-dwelling older adults with MCI were functional, but appeared to prioritize locomotor demands over the simultaneous cognitive task in a possible "posture first" strategy to descend stairs. The present findings should be considered for developing more ecologically based clinical assessments of mobility deficits following cognitive impairments, with the approach and transition phases during stair descent as key points of focus.

Mobile phone use impairs stair gait: A pilot study on young adults.

Human movement control requires attention to accurately tune motor commands in response to environmental changes. Dual task paradigms are used to test the role of attention on motor performance. Usually the tasks used have little resemblance with every day experience. Here we ask: Does a common cognitive task, such as a mobile phone conversation, compromise motor performance on stairs? Eight young participants negotiated an instrumented seven-step staircase. Stair negotiation while talking on a mobile phone was compared to normal stair negotiation. Stepping parameters, jerk cost (measure of smoothness of locomotion) and step clearance were measured. When talking on a mobile phone, participants' overall body velocity (mean(sd): Ascent 0.534(0.026) vs 0.511(0.024) m/s, Descent 0.642(0.026) vs 0.511(0.024) m/s, No phone/Phone respectively) and cadence decreased significantly (Ascent 75.8(5.8) vs 65.6(4.4) steps/min, Descent 117.4(4.2) vs 108.6(6.0) steps/min, No Phone/Phone respectively). Pelvis and feet jerk cost also changed significantly, mostly decreasing with phone use. Foot clearance did not show significant changes between No Phone and Phone conditions. These pilot results show that, even for young, healthy and cognitively intact individuals, talking on a mobile phone whilst negotiating a staircase induces measurable changes in motor performance. Participants moved slowly but more smoothly, reducing the motor control cost, possibly at the expense of movement accuracy. The reduction in motor performance is likely to be due to the difficulty in integrating the two sub-tasks. These results suggest that even young, healthy individuals show stair gait impairment when simultaneously negotiating stairs and performing another cognitive task, such as talking on the phone.

Human papillomavirus E7 oncoprotein targets RNF168 to hijack the host DNA damage response.

High-risk human papillomaviruses (HR-HPVs) promote cervical cancer as well as a subset of anogenital and head and neck cancers. Due to their limited coding capacity, HPVs hijack the host cell's DNA replication and repair machineries to replicate their own genomes. How this host-pathogen interaction contributes to genomic instability is unknown. Here, we report that HPV-infected cancer cells express high levels of RNF168, an E3 ubiquitin ligase that is critical for proper DNA repair following DNA double-strand breaks, and accumulate high numbers of 53BP1 nuclear bodies, a marker of genomic instability induced by replication stress. We describe a mechanism by which HPV E7 subverts the function of RNF168 at DNA double-strand breaks, providing a rationale for increased homology-directed recombination in E6/E7-expressing cervical cancer cells. By targeting a new regulatory domain of RNF168, E7 binds directly to the E3 ligase without affecting its enzymatic activity. As RNF168 knockdown impairs viral genome amplification in differentiated keratinocytes, we propose that E7 hijacks the E3 ligase to promote the viral replicative cycle. This study reveals a mechanism by which tumor viruses reshape the cellular response to DNA damage by manipulating RNF168-dependent ubiquitin signaling. Importantly, our findings reveal a pathway by which HPV may promote the genomic instability that drives oncogenesis.

The benefits of physical activities on cognitive and mental health in healthy and pathological aging.

Aging is associated with a decreased efficiency of different cognitive functions as well as in the perceptive, physical and physiological changes. The age-related cognitive decline concerns mainly attention, executive control and episodic memory. Some factors such as being physically active protect against the age-related decline. This review will discuss how physical activity can positively affect the cognitive efficiency and mental health of older healthy individuals, and possibly reduces the risk of progression into dementia, and depression. Underlying neurophysiological mechanisms play an important role for improving attention and episodic memory, which are the most sensitive to the effects of aging. We also present recommendations for the management of physical activity for the prevention of cognitive deficits, and the reduction of depressive symptoms in older persons. Given the benefits of physical activity for the prevention of neurodegenerative disease and the improvement of the well-being, it appears to be an important low cost therapeutic approach that should be integrated into clinical practice.

Normative data for the Rey Auditory Verbal Learning Test in the older French-Quebec population.

OBJECTIVE: The aim of this study was to establish normative data for the Rey Auditory Verbal Learning Test, a test assessing verbal episodic memory, in the older French-Quebec population. METHOD: A total of 432 French-speaking participants aged between 55 and 93 years old, from the Province of Quebec (Canada), were included in the study. Using multiple regression analyses, normative data were developed for five variable of interest, namely scores on trial 1, sum of trials 1 to 5, interference list B, immediate recall of list A, and delayed recall of list A. RESULTS: Results showed that age, education, and sex were associated with performance on all variables. Equations to calculate the expected score for a participant based on sex, age, and education level as well as the Z score were developed. CONCLUSION: This study provides clinicians with normative data that take into account the participants' sociodemographic characteristics, thus giving a more accurate interpretation of the results.

Genetic resistance against viruses in Phaseolus vulgaris L.: State of the art and future prospects.

Viruses are obligate parasites that replicate intracellularly in many living organisms, including plants. Consequently, no chemicals are available that target only the virus without impacting host cells or vector organisms. The use of natural resistant varieties appears as the most reliable control strategy and remains the best and cheapest option in managing virus diseases, especially in the current ecological context of preserving biodiversity and environment in which the use of phytosanitary products becomes limited. Common bean is a grain legume cultivated mainly in Africa and Central-South America. Virus diseases of common bean have been extensively studied both by breeders to identify natural resistance genes in existing germplasms and by pathologists to understand the molecular bases of plant-virus interactions. Here we present a critical review in which we synthesize previous and recent information concerning 1) main viruses causing diseases in common bean, 2) genetic resistance to viruses in common bean, 3) the different resistance phenotypes observed and more particularly the effect of temperature, 4) the molecular bases of resistance genes to viruses in common bean, and 5) future prospects using transgenic-engineered resistant lines.

Virus-Induced Gene Silencing (VIGS) and Foreign Gene Expression in Pisum sativum L. Using the "One-Step" Bean pod mottle virus (BPMV) Viral Vector.

Plant viral vectors have been developed to facilitate gene function studies especially in plant species not amenable to traditional mutational or transgenic modifications. In the Fabaceae plant family, the most widely used viral vector is derived from Bean pod mottle virus (BPMV). Originally developed for overexpression of foreign proteins and VIGS studies in soybean, we adapted the BPMV-derived vector for use in other legume species such as Phaseolus vulgaris and Pisum sativum. Here, we describe a protocol for efficient protein expression and virus-induced gene silencing (VIGS) in Pisum sativum leaves and roots using the "one-step" Bean pod mottle virus (BPMV) viral vector.

Metabolomics analysis of postphotosynthetic effects of gaseous O2 on primary metabolism in illuminated leaves.

The response of underground plant tissues to O2 limitation is currently an important topic in crop plants since adverse environmental conditions (e.g. waterlogging) may cause root hypoxia and thus compromise plant growth. However, little is known on the effect of low O2 conditions in leaves, probably because O2 limitation is improbable in these tissues under natural conditions, unless under complete submersion. Nevertheless, an O2-depleted atmosphere is commonly used in gas exchange experiments to suppress photorespiration and estimate gross photosynthesis. However, the nonphotosynthetic effects of gaseous O2 depletion, particularly on respiratory metabolism, are not well documented. Here, we used metabolomics obtained under contrasting O2 and CO2 conditions to examine the specific effect of a changing O2 mole fraction from ambient (21%) to 0%, 2% or 100%. In addition to the typical decrease in photorespiratory intermediates (glycolate, glycine and serine) and a build-up in photosynthates (sucrose), low O2 (0% or 2%) was found to trigger an accumulation of alanine and change succinate metabolism. In 100% O2, the synthesis of threonine and methionine from aspartate appeared to be stimulated. These responses were observed in two species, sunflower (Helianthus annuus L.) and Arabidopsis thaliana (L.) Heynh. Our results show that O2 causes a change in the oxygenation : carboxylation ratio and also alters postphotosynthetic metabolism: (i) a hypoxic response at low O2 mole fractions and (ii) a stimulation of S metabolism at high O2 mole fractions. The latter effect is an important piece of information to better understand how photorespiration may control S assimilation.

Executive dysfunction following a mild traumatic brain injury revealed in early adolescence with locomotor-cognitive dual-tasks.

OBJECTIVE: To compare gait parameters between children in early adolescence (EA) with and without a mild traumatic brain injury (mTBI) during dual-task walking (DTW). METHODS: Children in EA with mTBI (n = 14; six girls) were compared to those without (n = 13; five girls) while walking in different combinations of obstacle avoidance and cognitive dual-tasks. Gait speed and fluidity and their related dual-task costs (DTC) were analysed along with foot clearance and proximity to the obstacle. RESULTS: No group effects were found for gait speed, proximity or clearance, but were found for fluidity DTC, specifically during the dual Stroop task and when crossing the deeper obstacle. There were also group differences for fluidity during the planning of obstacle avoidance for the narrow obstacle combined with the verbal fluency task and the deep obstacle with no cognitive task. Finally, gait fluidity showed group differences across unobstructed dual-task situations. CONCLUSIONS: Gait fluidity may be a more sensitive variable than gait speed for revealing executive dysfunction following mTBI in EA. Assessing DTW in level walking also seems to show a potential to reveal executive dysfunctions in this age group. These results provide direction for future research on clinical assessment using DTW post-mTBI in adolescents.

The Victoria Stroop Test: Normative Data in Quebec-French Adults and Elderly.

OBJECTIVE: Despite the widespread use of the Victoria Stroop Test (VST; Regard, 1981) in clinical and research settings, information regarding the impact of sociodemographic variables on test performance in Quebec-French adults and elderly people is still nonexistent. Thus, this study aimed to establish normative data for error scores and completion time on all test trials (Dot, Word, and Interference) taking into account the impact of age, education, and sex on test performance. METHOD: The sample consisted of 646 community-dwelling and healthy Quebec-French individuals aged between 47 and 87 years. RESULTS: Regression analyses indicated that age was associated with completion time and error scores on all trials. The association was also positive for low and high interference conditions. Education was associated with completion time on Word and Interference trials, and with both interference scores. Finally, sex was associated with completion time on all trials, with women being consistently faster than men. Equations to calculate Z scores and percentiles are presented. CONCLUSIONS: Norms for the VST will ease interpretation of executive functioning in Quebec-French adults and elderly and favor accurate discrimination between normal and pathological cognitive states.

Cardiorespiratory fitness and cognitive functioning following short-term interventions in chronic stroke survivors with cognitive impairment: a pilot study.

This study, a quasi-experimental, one-group pretest-post-test design, evaluated the effects on cognitive functioning and cardiorespiratory fitness of 8-week interventions (aerobic exercise alone and aerobic exercise and cognitive training combined) in patients with chronic stroke and cognitive impairment living in the community (participants: n=14, 61.93±9.90 years old, 51.50±38.22 months after stroke, n=7 per intervention group). Cognitive functions and cardiorespiratory fitness were evaluated before and after intervention, and at a 3-month follow-up visit (episodic memory: revised-Hopkins Verbal Learning Test; working memory: Brown-Peterson paradigm; attention omission and commission errors: Continuous Performance Test; cardiorespiratory fitness: peak oxygen uptake during a symptom-limited, graded exercise test performed on a semirecumbent ergometer). Friedman's two-way analysis of variance by ranks evaluated differences in score distributions related to time (for the two groups combined). Post-hoc testing was adjusted for multiple comparisons. Compared with before the intervention, there was a significant reduction in attention errors immediately following the intervention (omission errors: 14.6±21.5 vs. 8±13.9, P=0.01; commission errors: 16.4±6.3 vs. 10.9±7.2, P=0.04), and in part at follow-up (omission errors on follow-up: 3.4±4.3, P=0.03; commission errors on follow-up: 13.2±7.6, P=0.42). These results suggest that attention may improve in chronic stroke survivors with cognitive impairment following short-term training that includes an aerobic component, without a change in cardiorespiratory fitness. Randomized-controlled studies are required to confirm these findings.

Bean pod mottle virus: a new powerful tool for functional genomics studies in Pisum sativum.

Pea (Pisum sativum L.) is an important legume worldwide. The importance of pea in arable rotations and nutritional value for both human and animal consumption have fostered sustained production and different studies to improve agronomic traits of interest. Moreover, complete sequencing of the pea genome is currently underway and will lead to the identification of a large number of genes potentially associated with important agronomic traits. Because stable genetic transformation is laborious for pea, virus-induced gene silencing (VIGS) appears as a powerful alternative technology for determining the function of unknown genes. In this work, we present a rapid and efficient viral inoculation method using DNA infectious plasmids of Bean pod mottle virus (BPMV)-derived VIGS vector. Six pea genotypes with important genes controlling biotic and/or abiotic stresses were found susceptible to BPMV carrying a GFP reporter gene and showed fluorescence in both shoots and roots. In a second step, we investigated 37 additional pea genotypes and found that 30 were susceptible to BPMV and only 7 were resistant. The capacity of BPMV to induce silencing of endogenes was investigated in the most susceptible genotype using two visual reporter genes: PsPDS and PsKORRIGAN1 (PsKOR1) encoding PHYTOENE DESATURASE and a 1,4-ß-D-glucanase, respectively. The features of the 'one-step' BPMV-derived VIGS vector include (i) the ease of rub-inoculation, without any need for biolistic or agro-inoculation procedures, (ii) simple cost-effective procedure and (iii) noninterference of viral symptoms with silencing. These features make BPMV the most adapted VIGS vector in pea to make low- to high-throughput VIGS studies.