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PloS One 2013Hypnotic suggestions may change the perceived color of objects. Given that chromatic stimulus information is processed rapidly and automatically by the visual system,...
Hypnotic suggestions may change the perceived color of objects. Given that chromatic stimulus information is processed rapidly and automatically by the visual system, how can hypnotic suggestions affect perceived colors in a seemingly immediate fashion? We studied the mechanisms of such color alterations by measuring electroencephalography in two highly suggestible participants as they perceived briefly presented visual shapes under posthypnotic color alternation suggestions such as "all the squares are blue". One participant consistently reported seeing the suggested colors. Her reports correlated with enhanced evoked upper beta-band activity (22 Hz) 70-120 ms after stimulus in response to the shapes mentioned in the suggestion. This effect was not observed in a control condition where the participants merely tried to simulate the effects of the suggestion on behavior. The second participant neither reported color alterations nor showed the evoked beta activity, although her subjective experience and event-related potentials were changed by the suggestions. The results indicate a preconscious mechanism that first compares early visual input with a memory representation of the suggestion and consequently triggers the color alteration process in response to the objects specified by the suggestion. Conscious color experience is not purely the result of bottom-up processing but it can be modulated, at least in some individuals, by top-down factors such as hypnotic suggestions.
Topics: Adult; Amnesia; Beta Rhythm; Color Perception; Consciousness; Electroencephalography; Evoked Potentials, Visual; Female; Hallucinations; Humans; Hypnosis; Middle Aged; Pattern Recognition, Visual; Photic Stimulation; Suggestion
PubMed: 23940663
DOI: 10.1371/journal.pone.0070900 -
Brain and Behavior Jun 2016Children are more vulnerable to the effects of environmental elements. A variety of air pollutants are among the identified factors causing neural damage at toxic...
INTRODUCTION
Children are more vulnerable to the effects of environmental elements. A variety of air pollutants are among the identified factors causing neural damage at toxic concentrations. It is not obvious, however, to what extent the tolerated high levels of air pollutants are able to alter brain development. We have specifically investigated the neurotoxic effects of airborne copper exposure in school environments.
METHODS
Speed and consistency of motor response were assessed in 2836 children aged from 8 to 12 years. Anatomical MRI, diffusion tensor imaging, and functional MRI were used to directly test the brain repercussions in a subgroup of 263 children.
RESULTS
Higher copper exposure was associated with poorer motor performance and altered structure of the basal ganglia. Specifically, the architecture of the caudate nucleus region was less complete in terms of both tissue composition and neural track water diffusion. Functional MRI consistently showed a reciprocal connectivity reduction between the caudate nucleus and the frontal cortex.
CONCLUSIONS
The results establish an association between environmental copper exposure in children and alterations of basal ganglia structure and function.
Topics: Air Pollutants; Basal Ganglia; Caudate Nucleus; Child; Child Development; Copper; Diffusion Tensor Imaging; Environmental Exposure; Female; Follow-Up Studies; Frontal Lobe; Humans; Magnetic Resonance Imaging; Male; Psychomotor Performance; Schools; Spain
PubMed: 27134768
DOI: 10.1002/brb3.467 -
Ecological Applications : a Publication... Dec 2021Ecologists commonly assess ecological patterns at the population level, focusing on the average response of all individuals within a population, but to predict how...
Ecologists commonly assess ecological patterns at the population level, focusing on the average response of all individuals within a population, but to predict how populations will respond to land-use change we must understand how changes to habitat differentially affect individuals within a population. For example, forest management is a widespread type of land-use that impacts wildlife through the loss of key habitat features, but individuals within a population may vary in their responses to this loss due to differences in habitat selection among individuals. Specifically, intraspecific variation in habitat selection has been linked to animal personalities (i.e., consistent behavioral differences among conspecifics), but previous research has not examined whether the relationship between personality and habitat selection is influenced by land-use change. To address this knowledge gap, we tested the hypothesis that land-use change alters the association between personality and microhabitat selection in small mammals. Specifically, we investigated two main questions: (1) To what extent are personality type and microhabitat selection correlated among conspecifics? (2) Does land-use change alter individual patterns of microhabitat selection? To answer these questions, we conducted a large-scale field experiment over 4 years, contrasting unmanaged forest (control) with managed forest (two silvicultural treatments) in Maine, USA. We examined the relationships between habitat selection and personality traits in deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi). We found that personality traits were correlated with microhabitat selection at multiple spatial scales. Furthermore, land-use change altered these patterns of selection; resulting in either the loss of personality-associated selection or in novel patterns of selection in managed forests. These findings suggest that promoting structural complexity at multiple spatial scales, such as by interspersing stands of mature forest with managed stands, may maintain a variety of intraspecific habitat selection patterns and the associated ecological outcomes.
Topics: Animals; Animals, Wild; Ecosystem; Forests; Mammals; Mice; Personality
PubMed: 34455633
DOI: 10.1002/eap.2443 -
Neuropsychologia 2008Regions that show task-induced deactivations may be part of a default-mode network related to processes that are more engaged during passive than active task conditions....
Regions that show task-induced deactivations may be part of a default-mode network related to processes that are more engaged during passive than active task conditions. Alteration of task-induced deactivations with age and dementia is indicated by atypical engagement of default-mode network regions. Genetic studies show a relation between the apolipoprotein E4 (APOE4) allele and the common form of Alzheimer's disease (AD), and altered functional brain activation has been observed in non-demented APOE4 carriers compared to non-carriers. Here we investigate the hypothesis of altered default-mode network brain responses in individuals with genetic risk for AD. Functional MRI was used to assess task-induced deactivation in 60 subjects of which 30 carried at least one copy of the APOE4 allele, and 30 non-carriers. Subjects were scanned while performing a semantic categorization task shown to promote episodic memory encoding. The results show patterns of deactivation consistent with the default-mode network. We also found reduced deactivation in non-demented APOE4 carriers compared to non-carriers, suggesting alterations in the default-mode network in the absence of dementia. These results implicate possibilities for investigating altered properties of task-induced deactivations in individuals with genetic risk for AD, and may prove useful for pre-clinical identification of individuals susceptible to memory problems and AD.
Topics: Aged; Alzheimer Disease; Apolipoprotein E4; Brain; Brain Mapping; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Memory; Middle Aged; Neuropsychological Tests; Oxygen; Semantics
PubMed: 18346764
DOI: 10.1016/j.neuropsychologia.2008.01.026 -
MBio Mar 2019Many flagellated bacteria "swarm" over a solid surface as a dense consortium. In different bacteria, swarming is facilitated by several alterations such as those...
Many flagellated bacteria "swarm" over a solid surface as a dense consortium. In different bacteria, swarming is facilitated by several alterations such as those corresponding to increased flagellum numbers, special stator proteins, or secreted surfactants. We report here a change in the chemosensory physiology of swarming which alters its normal "run tumble" bias. bacteria taken from a swarm exhibit more highly extended runs (low tumble bias) and higher speeds than bacteria swimming individually in a liquid medium. The stability of the signaling protein CheZ is higher in swarmers, consistent with the observed elevation of CheZ levels and with the low tumble bias. We show that the tumble bias displayed by wild-type swarmers is the optimal bias for maximizing swarm expansion. In assays performed in liquid, swarm cells have reduced chemotactic performance. This behavior is specific to swarming, is not specific to growth on surfaces, and persists for a generation. Therefore, the chemotaxis signaling pathway is reprogrammed for swarming. The fundamental motile behavior of is a random walk, where straight "runs" are punctuated by "tumbles." This behavior, conferred by the chemotaxis signaling system, is used to track chemical gradients in liquid. Our study results show that when migrating collectively on surfaces, modifies its chemosensory physiology to decrease its tumble bias (and hence to increase run durations) by post-transcriptional changes that alter the levels of a key signaling protein. We speculate that the low tumble bias may contribute to the observed Lévy walk (LW) trajectories within the swarm, where run durations have a power law distribution. In animals, LW patterns are hypothesized to maximize searches in unpredictable environments. Swarming bacteria face several challenges while moving collectively over a surface-maintaining cohesion, overcoming constraints imposed by a physical substrate, searching for nutrients as a group, and surviving lethal levels of antimicrobials. The altered chemosensory behavior that we describe in this report may help with these challenges.
Topics: Chemotaxis; Culture Media; Escherichia coli; Methyl-Accepting Chemotaxis Proteins
PubMed: 30890609
DOI: 10.1128/mBio.00316-19 -
Food Chemistry Mar 2022Previously we reported the cytoprotective effects of polyphenols rich in hydroxyl groups against ZnO nanoparticles (NPs). This study used RNA-sequencing to evaluate the...
Previously we reported the cytoprotective effects of polyphenols rich in hydroxyl groups against ZnO nanoparticles (NPs). This study used RNA-sequencing to evaluate the toxicity of ZnO NPs and epigallocatechin gallate (EGCG) to 3D Caco-2 spheroids. EGCG altered the colloidal stability of ZnO NPs, shown as the changes of atomic force microscopic height, solubility in cell culture medium, and hydrodynamic sizes. EGCG almost completely reversed ZnO NP-induced cytotoxicity, and consistently, alleviated ZnO NP-induced gene ontology (GO) terms and genes related with apoptosis. EGCG also modestly decreased intracellular Zn ions and changed GO terms and genes related with endocytosis/exocytosis in ZnO NP-exposed spheroids. Meanwhile, EGCG changed ZnO NP-induced alteration of GO terms and genes related with the functions of mitochondria, endoplasmic reticulum and lysosomes. We concluded that EGCG alleviated the cytotoxicity of ZnO NPs to 3D Caco-2 spheroids by altering NPs' colloidal properties and the pathways related with internalization and organelle dysfunction.
Topics: Caco-2 Cells; Catechin; Humans; Metal Nanoparticles; Solubility; Zinc Oxide
PubMed: 34808776
DOI: 10.1016/j.foodchem.2021.131383 -
Psychiatria Danubina Sep 2013The role of BDNF in depression and Major Depressive Disorder (MDD) has been extensively investigated in the literature. A summary of relevant papers, including a number... (Review)
Review
The role of BDNF in depression and Major Depressive Disorder (MDD) has been extensively investigated in the literature. A summary of relevant papers, including a number of independent literature reviews, is presented, and the possibility that alteration in BDNF causes depression by altering memory is analysed and criticised in the context of consistency with cognitive models of depression.
Topics: Brain-Derived Neurotrophic Factor; Depressive Disorder, Major; Emotions; Humans; Memory
PubMed: 23995212
DOI: No ID Found -
Translational Psychiatry Aug 2021A dysfunction of the glutamatergic transmission, especially of the NMDA receptor (NMDAR), constitutes one of the main biological substrate of psychotic disorders, such...
A dysfunction of the glutamatergic transmission, especially of the NMDA receptor (NMDAR), constitutes one of the main biological substrate of psychotic disorders, such as schizophrenia. The NMDAR signaling hypofunction, through genetic and/or environmental insults, would cause a neurodevelopmental myriad of molecular, cellular, and network alterations that persist throughout life. Yet, the mechanisms underpinning NMDAR dysfunctions remain elusive. Here, we compared the membrane trafficking of NMDAR in three gold-standard models of schizophrenia, i.e., patient's cerebrospinal fluids, genetic manipulations of susceptibility genes, and prenatal developmental alterations. Using a combination of single nanoparticle tracking, electrophysiological, biochemical, and behavioral approaches in rodents, we identified that the NMDAR trafficking in hippocampal neurons was consistently altered in all these different models. Artificial manipulations of the NMDAR surface dynamics with competing ligands or antibody-induced receptor cross-link in the developing rat brain were sufficient to regulate the adult acoustic startle reflex and compensate for an early pathological challenge. Collectively, we show that the NMDAR trafficking is markedly altered in all clinically relevant models of psychosis, opening new avenues of therapeutical strategies.
Topics: Animals; Hippocampus; Psychotic Disorders; Rats; Receptors, N-Methyl-D-Aspartate; Schizophrenia; Signal Transduction
PubMed: 34462417
DOI: 10.1038/s41398-021-01549-7 -
Social Networks May 2022Egocentric sampling of networks selects a subset of nodes ("egos") and collects information from them on themselves and their immediate network neighbours ("alters"),...
Egocentric sampling of networks selects a subset of nodes ("egos") and collects information from them on themselves and their immediate network neighbours ("alters"), leaving the rest of the nodes in the network unobserved. This design is popular because it is relatively inexpensive to implement and can be integrated into standard sample surveys. Recent methodological developments now make it possible to statistically analyse this type of network data with Exponential-family Random Graph Models (ERGMs). This provides a framework for principled statistical inference, and the fitted models can in turn be used to simulate complete networks of arbitrary size that are consistent with the observed sample data, allowing one to infer the distribution of whole-network properties generated by the observed egocentric network statistics. In this paper, we discuss how design choices for egocentric network studies impact statistical estimation and inference for ERGMs. The design choices include both measurement strategies (for ego and alter attributes, and for ego-alter and alter-alter ties) and sampling strategies (for egos and alters). We discuss the importance of harmonising measurement specifications across egos and alters, and conduct simulation studies to demonstrate the impact of sampling design on statistical inference, specifically stratified sampling and degree censoring.
PubMed: 35400801
DOI: 10.1016/j.socnet.2020.10.001 -
Urology Practice Nov 2023We evaluated germline and somatic testing practices and compared results from tissue and liquid biopsy specimens in a large community urology setting.
INTRODUCTION
We evaluated germline and somatic testing practices and compared results from tissue and liquid biopsy specimens in a large community urology setting.
METHODS
A retrospective analysis was performed on advanced prostate cancer patients from a single community practice between June 2016 and September 2021. Clinical data and sequencing results from tissue and liquid biopsy specimens were available for 389 patients. Genomic data were available for 81 tissues and 74 liquid biopsy specimens. Comparison of genomic findings included 81 tissues and 27 liquid biopsy specimens. The number of actionable biomarkers and patients screened and enrolled in clinical trials was assessed from germline and somatic testing. Frequency of pathogenically altered genes, alteration types, and biomarkers were assessed from tissue and liquid specimens. Alteration frequency was compared between specimen types for the top 25 altered genes.
RESULTS
Clinically relevant alterations were found from germline and somatic testing in both tissue and liquid biopsy specimens. The frequency of microsatellite instability-high, tumor mutational burden-high, or alterations in homologous recombination repair genes was consistent with published findings. Concordance between tissue and liquid findings varied with low circulating tumor DNA.
CONCLUSIONS
Germline and somatic testing is critical for treatment decisions and should be standard of care for community practices. Liquid biopsy is a viable alternative when circulating tumor DNA is high.
PubMed: 37647173
DOI: 10.1097/UPJ.0000000000000454