CRIS

Permanent URI for this communityhttps://investigadores.udd.cl/handle/123456789/1

Browse

Settings

Access type: UnknownSubject: search.filters.subject.brain

Search Results

Now showing 1 - 10 of 59
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Fish Oil Supplementation Attenuates Offspring’s Neurodevelopmental Changes Induced by a Maternal High-Fat Diet in a Rat Model
    (MDPI AG, 2025-05-21)
    Yasna Muñoz
    ;
    Heidy Kaune
    ;
    Alexies Dagnino-Subiabre
    ;
    Gonzalo Cruz
    ;
    Jorge Toledo
    <jats:p>Background/Objectives: A maternal high-fat diet (HFD) impairs brain structure in offspring. In turn, fish oil (FO) rich in n-3 polyunsaturated fatty acids (PUFAs) has neuroprotective effects. Therefore, we investigated whether maternal HFD exposure affected the neurological reflexes, neuron morphology, and n-3 PUFA levels in the cerebral cortex of the offspring and whether these effects were mitigated by maternal FO consumption. Methods: Female Sprague Dawley rats received a control diet (CD, 10% Kcal fat) or HFD (45% Kcal fat) five weeks before mating and throughout pregnancy and lactation. From mating, a subgroup of HFD was supplemented with 11.4% FO into the diet (HFD-FO). Neurological reflexes were evaluated from postnatal day (PND) 3 until PND20. Brains were removed at PND22 for neuron morphology analysis. Moreover, fatty acid composition and transcripts of genes encoding for factors associated with synapse transmission (SNAP-25), plasticity (BDNF), transport of DHA (MFSD2a), and inflammation (NF-κB and IL-1β) were quantified in prefrontal, motor, and auditory cortices. Results: FO diminished the effects of HFD on the number of thin and mushroom-shaped dendritic spines in the cerebral cortex in both sexes. It also reversed the HFD effects on the motor and auditory reflexes in female and male offspring, respectively. In males, FO up-regulated Bdnf transcript levels in the motor cortex compared with CD and HFD. In females, n-3 PUFAs were higher in HFD and HFD-FO than in CD in the auditory cortex. Conclusions: Our results highlight the protective role of maternal dietary n-3 PUFAs in counteracting the effects induced by HFD on the acquisition of neurological reflexes and neuronal morphology in the cerebral cortex of the offspring of both sexes.</jats:p>
      1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Patterns of brain activity in choice or instructed go and no-go tasks
    (Springer Science and Business Media LLC, 2025-02-21)
    Sanaz Attaripour Isfahani
    ;
    Patrick McGurrin
    ;
    VIAL UNDURRAGA, FELIPE AGUSTIN  
    ;
    Mark Hallett
    The goal of this study was to investigate the decision making process for choosing what movements to make. We used electroencephalography (EEG) to investigate patterns of the contingent negative variation (CNV) associated with free-choice decisions to move or abstain, comparing them to conditions where actions were commanded. Our primary hypothesis was that choice tasks would differ significantly from each other and exhibit EEG patterns akin to their command-driven counterparts after the decisions were made, at least, in the 50 ms block of time prior to movement. A secondary analysis evaluated post hoc comparisons of time, in 50 ms blocks, to understand the temporal development of the CNV for each condition. We also conducted an exploratory analysis of EEG event-related desynchronization (ERD) to identify patterns of brain activity associated with the decision-making process. This approach was taken due to the exploratory nature of our hypotheses concerning the spatial and temporal characteristics of EEG activity during these free-choice versus commanded tasks. We studied 12 right-handed healthy volunteers (7 women, mean age 53 years, range 39–73 years) with no prior history of neurological or major psychiatric illness. A CNV paradigm encompassing commanded and choice tasks was devised, with a 2500 ms interval between S1 and S2, while recording EEG and electromyography (EMG). S1 provided full information about the upcoming task, which was to be executed at the time of S2. We assessed CNV and explored whole scalp EEG activity, including both voltage as well as power in the alpha and beta frequency ranges. Clear and similar CNVs were observed for command and choice go tasks prior to the movements, contrasting with near-zero CNVs for the command and choice no-go tasks. Separation of CNVs for command go and no-go tasks occurred around 1600 ms post-S1, and choice CNVs separated about 2150 ms post-S1. Exploratory analysis revealed that beta power provided information about decision and preparation processes much earlier. The left dorsolateral prefrontal cortex (DLPFC) exhibited the initial sign of decision approximately 500 ms post-S1 for all tasks, with subsequent preparation for movement or restraint involving distinct activity in various brain regions. The localization of effects in the left DLPFC was determined by visual analysis of the informative electrode sites. The CNVs separate about 2 s after S1, and it appears that this process represents preparation for movement (or no movement). Exploration of the beta activity suggests an earlier decision process which leads eventually to subsequent task preparation and activation. Choice decisions lag slightly behind command decisions, with the CNV apparently reflecting motor implementation rather than the decision-making process. In a simple motor task with an exploratory analysis, both commanded and choice-based decisions are rapidly initiated in the left DLPFC. While the CNV distinguishes between go and no-go conditions, it primarily appears to signify preparation for implementation of the task following the earlier decision. Further controlled studies will be needed to confirm these results.
    Scopus© Citations 3  1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    White matter volume and microstructural integrity are associated with fatigue in relapsing multiple sclerosis
    (Springer Science and Business Media LLC, 2025-05-12)
    FIGUEROA VARGAS, ALEJANDRA MABEL  
    ;
    Sebastián Navarrete-Caro
    ;
    Claudia Cárcamo
    ;
    Ethel Ciampi
    ;
    Macarena Vásquez-Torres
      10
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    The BrainLat project, a multimodal neuroimaging dataset of neurodegeneration from underrepresented backgrounds
    (2023)
    Pavel Prado
    ;
    Vicente Medel
    ;
    Raul Gonzalez-Gomez
    ;
    Agustín Sainz-Ballesteros
    ;
    Victor Vidal
    The Latin American Brain Health Institute (BrainLat) has released a unique multimodal neuroimaging dataset of 780 participants from Latin American. The dataset includes 530 patients with neurodegenerative diseases such as Alzheimer’s disease (AD), behavioral variant frontotemporal dementia (bvFTD), multiple sclerosis (MS), Parkinson’s disease (PD), and 250 healthy controls (HCs). This dataset (62.7 ± 9.5 years, age range 21–89 years) was collected through a multicentric effort across five Latin American countries to address the need for affordable, scalable, and available biomarkers in regions with larger inequities. The BrainLat is the first regional collection of clinical and cognitive assessments, anatomical magnetic resonance imaging (MRI), resting-state functional MRI (fMRI), diffusion-weighted MRI (DWI), and high density resting-state electroencephalography (EEG) in dementia patients. In addition, it includes demographic information about harmonized recruitment and assessment protocols. The dataset is publicly available to encourage further research and development of tools and health applications for neurodegeneration based on multimodal neuroimaging, promoting the assessment of regional variability and inclusion of underrepresented participants in research.
      30Scopus© Citations 22
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
      5
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Trasplante de órganos, una mirada desde el judaísmo en el siglo XXI
    (2012)
    Nicole Grossman K
    ;
    Javiera Herrera V
    ;
    Lorna Luco C
      24Scopus© Citations 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Peptides and peptide-derived molecules targeting the intracellular domains of Cx43: Gap junctions versus hemichannels
    (2013)
    Jegan Iyyathurai
    ;
    Catheleyne D'hondt
    ;
    Nan Wang
    ;
    Marijke De Bock
    ;
    Bernard Himpens
      5Scopus© Citations 86
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Scopus© Citations 83  1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Network anatomy in logopenic variant of primary progressive aphasia
    (2023)
    Maria Luisa Mandelli
    ;
    Diego L. Lorca‐Puls
    ;
    Sladjana Lukic
    ;
    Maxime Montembeault
    ;
    GAJARDO VIDAL, ANDREA ELIZABETH  
    <jats:title>Abstract</jats:title><jats:p>The logopenic variant of primary progressive aphasia (lvPPA) is a neurodegenerative syndrome characterized linguistically by gradual loss of repetition and naming skills resulting from left posterior temporal and inferior parietal atrophy. Here, we sought to identify which specific cortical loci are initially targeted by the disease (epicenters) and investigate whether atrophy spreads through predetermined networks. First, we used cross‐sectional structural MRI data from individuals with lvPPA to define putative disease epicenters using a surface‐based approach paired with an anatomically fine‐grained parcellation of the cortical surface (i.e., HCP‐MMP1.0 atlas). Second, we combined cross‐sectional functional MRI data from healthy controls and longitudinal structural MRI data from individuals with lvPPA to derive the epicenter‐seeded resting‐state networks most relevant to lvPPA symptomatology and ascertain whether functional connectivity in these networks predicts longitudinal atrophy spread in lvPPA. Our results show that two partially distinct brain networks anchored to the left anterior angular and posterior superior temporal gyri epicenters were preferentially associated with sentence repetition and naming skills in lvPPA. Critically, the strength of connectivity within these two networks in the neurologically‐intact brain significantly predicted longitudinal atrophy progression in lvPPA. Taken together, our findings indicate that atrophy progression in lvPPA, starting from inferior parietal and temporoparietal junction regions, predominantly follows at least two partially nonoverlapping pathways, which may influence the heterogeneity in clinical presentation and prognosis.</jats:p>
    Scopus© Citations 10  2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Multivariate word properties in fluency tasks reveal markers of Alzheimer's dementia
    (2023)
    Franco J. Ferrante
    ;
    Joaquín Migeot
    ;
    Agustina Birba
    ;
    Lucía Amoruso
    ;
    Gonzalo Pérez
    <jats:title>Abstract</jats:title><jats:sec><jats:title>INTRODUCTION</jats:title><jats:p>Verbal fluency tasks are common in Alzheimer's disease (AD) assessments. Yet, standard valid response counts fail to reveal disease‐specific semantic memory patterns. Here, we leveraged automated word‐property analysis to capture neurocognitive markers of AD vis‐à‐vis behavioral variant frontotemporal dementia (bvFTD).</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Patients and healthy controls completed two fluency tasks. We counted valid responses and computed each word's frequency, granularity, neighborhood, length, familiarity, and imageability. These features were used for group‐level discrimination, patient‐level identification, and correlations with executive and neural (magnetic resonanance imaging [MRI], functional MRI [fMRI], electroencephalography [EEG]) patterns.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Valid responses revealed deficits in both disorders. Conversely, frequency, granularity, and neighborhood yielded robust group‐ and subject‐level discrimination only in AD, also predicting executive outcomes. Disease‐specific cortical thickness patterns were predicted by frequency in both disorders. Default‐mode and salience network hypoconnectivity, and EEG beta hypoconnectivity, were predicted by frequency and granularity only in AD.</jats:p></jats:sec><jats:sec><jats:title>DISCUSSION</jats:title><jats:p>Word‐property analysis of fluency can boost AD characterization and diagnosis.</jats:p></jats:sec><jats:sec><jats:title>Highlights</jats:title><jats:p><jats:list list-type="bullet"> <jats:list-item><jats:p>We report novel word‐property analyses of verbal fluency in AD and bvFTD.</jats:p></jats:list-item> <jats:list-item><jats:p>Standard valid response counts captured deficits and brain patterns in both groups.</jats:p></jats:list-item> <jats:list-item><jats:p>Specific word properties (e.g., frequency, granularity) were altered only in AD.</jats:p></jats:list-item> <jats:list-item><jats:p>Such properties predicted cognitive and neural (MRI, fMRI, EEG) patterns in AD.</jats:p></jats:list-item> <jats:list-item><jats:p>Word‐property analysis of fluency can boost AD characterization and diagnosis.</jats:p></jats:list-item> </jats:list></jats:p></jats:sec>
      3Scopus© Citations 10