Biology subjects

Kublik, E.

Publications and source records attributed to Kublik, E..

8 recordsLinked to original sources

bioRxiv2025

Common but different: An ERP study of single- and multi-source interference processing in MSIT

Flexible behavior often requires processing of complex, interfering information. Research has investigated conflict-related brain processes mostly using single tasks which hindered direct comparison of different interference types. Thus, the question if they are resolved by a common mechanism or by a set of different, task-specific mechanisms remains open. In this study, we used event-related potentials (ERPs) to examine the spatio-temporal dynamics of cognitive control across Simon, flanker, multi-source and no-conflict conditions. Our findings reveal that all trial types engaged the same sequence of processing stages, as indicated by common ERP waveforms and consistent number and order of microstates across conditions. However, the intensity and duration of these common stages scaled with difficulty of the conflict task (as measured by RTs and accuracy) from Simon to flanker to multi-source interference. Flanker conflict uniquely influenced early ERP components strongly engaging the dorsal attentional system and visual areas, likely due to demands posed by the presence of flanker distractors. Later ERP components (with sources including ventral attention and somatomotor network areas) were affected by both conflicts. Accordingly, when flanker and Simon conflicts were presented together, early processes lineary summed up, but there was an interaction at the later stage of processing paralleling nonlinear drop of accuracy in a multi-conflict condition. Our study provides novel insights into the neural dynamics underlying cognitive control engaged across different conflict types and their interaction. The use of source analysis allowed us to ground ERP-based findings in the wider context of studies, including those using neuroimaging techniques. Highlights- The same processing stages, in same order are evoked in control and conflict trials - Their intensity/duration scale with conflict behavioral difficulty - Flanker conflict demands enhanced early attentional (DAN) and visual processing - Flanker and Simon interact at the late-stage processing involving VAN and SM networks - Flanker and Simon interaction is sublinear

neuroscience↗

bioRxiv2025

Cortical thinning in temporal pole, a core region in Alzheimer's disease, in non-demented, middle-aged APOE-e4 and PICALM-AA/AG carriers

The symptoms of Alzheimers disease (AD) are caused by neurodegeneration and atrophy in particular brain regions, especially in the temporal cortex. However, the influence of genetic risk on cortical thickness in non-demented individuals prior to disease onset remains unclear. This study aimed to explore the relationship between two AD risk genes (APOE/PICALM) and cortical thickness in selected regions of interest (ROIs) in non-demented, middle-aged individuals. Sixty-nine (N = 69) participants (34 females, 35 males; age: 55.45{+/-}3.19) underwent magnetic resonance imaging (MRI). They were divided into three groups based on their AD risk. Cortical thickness was analyzed using CAT12 software (surface-based morphometry with the Destrieux atlas) based on T1-weighted MR images in five ROIs referred as "the cortical signature of AD" in previous studies. APOE-{varepsilon}4 with PICALM-AA/AG carriers (A+P-) are characterized by a thinner cortex in the right temporal pole compared to non-carriers, controlling for sex. No other differences in cortical thickness were found in the selected ROIs. The direction of the findings aligns with existing literature reporting cortical thinning in amyloid-positive individuals, as well as in patients with mild cognitive impairment and Alzheimers disease when compared to control groups.

neuroscience↗

bioRxiv2024

Alzheimer's disease-like features in resting state EEG/fMRI of cognitively intact and healthy middle-aged APOE/PICALM risk carriers

IntroductionGenetic susceptibility is a primary factor contributing to etiology of late-onset Alzheimers disease (LOAD). The exact mechanisms and timeline through which APOE/PICALM influence brain functions and contribute to LOAD remain unidentified. This includes their effects on individuals prior to the development of the disease. MethodsAPOE/PICALM alleles were assessed to determine the genetic risk of LOAD in 79 healthy, middle-aged participants who underwent EEG and fMRI recordings. The resting-state signal was analyzed to estimate relative spectral power, complexity (Higuchis algorithm), and connectivity (coherence in EEG and ICA-based connectivity in fMRI). ResultsThe main findings indicated that individuals at risk for LOAD exhibited reduced signal complexity and the so-called "slowing of EEG" which are well-known EEG markers of AD. Additionally, these individuals showed altered functional connectivity in fMRI (within attention related areas). DiscussionRisk alleles of APOE/PICALM may affect brain integrity and function prior to the onset of the disease

neuroscience↗

bioRxiv2023

Local contribution to the somatosensory evoked potentials in rat's thalamus

Local Field Potential (LFP), despite its name, often reflects remote activity. Depending on the orientation and synchrony of their sources, both oscillations and more complex waves may passively spread in brain tissue over long distances and be falsely interpreted as local activity at such distant recording site. Current Source Density method was proposed to recover locally active currents from multi-site LFP recordings. Here we use a model-based kernel CSD (kCSD) to study the contribution of local and distant currents to LFP recorded with dense multichannel probes from rat thalamic nuclei and barrel cortex, activated by whisker stimulation. We show that the evoked potential wave seen in the thalamic nuclei around 7-15 ms post-stimulus has a substantial negative component reaching from cortex. This component can be analytically removed and truly local thalamic LFP, with purely thalamic contributions, can be recovered reliably using kCSD. In particular, concurrent recordings from the cortex are not essential for reliable thalamic CSD estimation. Proposed framework can be used to analyse LFP from other brain areas and has consequences for general LFP interpretation and analysis. 1 BRIEF SUMMARYWhile recording LFP simultaneously in multiple structures, we often see significant correlations between the observed waves. A natural question is if they are propagated passively from one structure to another or if they are simultaneously generated by different, separated sets of sources. We argue this can be answered reliably using CSD analysis. We focus on the case of thalamic and cortical recordings in the somatosensory system in response to whisker stimulation where we observe significant correlations between early thalamic and cortical responses to whisker deflection.

neuroscience↗

bioRxiv2023

Common and distinct BOLD correlates of Simon and flanker conflicts which can(not) be reduced to time-on-task effects

The ability to identify and resolve conflicts between standard, well trained behaviors, and behaviors required by the current context is an essential feature of cognitive control. To date, no consensus has been reached on the brain mechanisms involved in exerting such control: while some studies identified diverse patterns of activity across different conflicts, other studies reported common resources across conflict tasks or even across simple tasks devoid of conflict component. The latter reports attributed the entire activity observed in the presence of conflict to longer time spent on the task (i.e. to the so-called time-on-task effects). Here we used an extended Multi-Source Interference Task (MSIT) which combines Simon and flanker types of interference to determine shared and conflict-specific mechanisms of conflict resolution in fMRI, and their separability from the time-on-task effects. Large portions of the activity in the dorsal attention network and decreases of activity in the default mode network were shared across the tasks and scaled in parallel with increasing reaction times. Importantly, activity in the sensory and sensorimotor cortices, as well as in the posterior medial frontal cortex (pMFC)-a key region implicated in conflict processing-could not be exhaustively explained by the time-on-task effects.

neuroscience↗

bioRxiv2020

What we can and what we cannot see with extracellular multielectrodes

Extracellular recording is an accessible technique used in animals and humans to study the brain physiology and pathology. As the number of recording channels and their density grows it is natural to ask how much improvement the additional channels bring in and how we can optimally use the new capabilities for monitoring the brain. Here we show that for any given distribution of electrodes we can establish exactly what information about current sources in the brain can be recovered and what information is strictly unobservable. We demonstrate this in the general setting of previously proposed kernel Current Source Density method and illustrate it with simplified examples as well as using evoked potentials from the barrel cortex obtained with a Neuropixels probe and with compatible model data. Author SummaryEvery set of measurements is a window into reality rendering its incomplete or distorted picture. It is often difficult to relate the obtained representation of the world to underlying ground truth. Here we show, for brain electrophysiology, for arbitrary experimental setup (distribution of electrodes), and arbitrary analytical setup (function space of current source densities), that one can identify distributions of current sources which can be recovered precisely, and those which are invisible in the system. This shows what is and what is not observable in the studied system for a given setup, allows to improve the analysis results by modifying analytical setup, and facilitates interpretation of the measured sets of LFP, ECoG and EEG recordings.

neuroscience↗

bioRxiv2020

Network and synaptic mechanisms underlying high frequency oscillations in the rat and cat olfactory bulb under ketamine-xylazine anesthesia.

High frequency oscillations (HFO) are receiving increased attention for their role in health and disease. Ketamine-dependent HFO have been identified in cortical and subcortical regions in rodents, however, the mechanisms underlying their generation and whether they occur in higher mammals is unclear. Here, we show under ketamine-xylazine anesthesia, classical gamma oscillations diminish and a prominent > 80 Hz oscillation emerges in the olfactory bulb of rats and cats. In cats negligible HFO was observed in the thamalus and visual cortex indicating the OB was a suitable site for further investigation. Simultaneous local field potential and thermocouple recordings demonstrated HFO was dependent on nasal airflow. Silicon probe mapping studies spanning almost the entire dorsal ventral aspect of the OB revealed this rhythm was strongest in ventral areas of the bulb and associated with microcurrent sources about the mitral layer. Pharmacological microinfusion studies revealed HFO was dependent on excitatory-inhibitory synaptic activity, but not gap junctions. Finally, we showed HFO was preserved despite surgical removal of the piriform cortex. We conclude that ketamine-dependent HFO in the OB are driven by nasal airflow and local dendrodendritic interactions. The relevance of our findings to ketamines model of psychosis in awake state are also discussed.

neuroscience↗

bioRxiv2020

More than a feeling: central amygdala mediates social transfer of information about proximity of danger

To survive, an animal must adequately respond to challenges presented by the environment. Social animals can learn about danger from fear of conspecifics which allows them to avoid predation and other threats without costly, first-hand experience. However, it remains unclear as to whether animals can transmit specific information that helps an individual avoid harm or whether the transmitted social signals simply increase vigilance in a non-specific manner. Here we demonstrate that animals can select appropriate defensive strategies in a novel environment depending on cues from the conspecific and, using opsins targeted to behaviorally activated neurons, identify distinct neuronal circuits in the central amygdala (CeA) that are crucial for choosing a context-appropriate reaction. The identified circuits differ in molecular markers and patterns of connectivity. Thus, we show that social signals carry explicit information about proximity of danger, necessary for choosing a context-appropriate reaction, and that the choosing process is mediated by the CeA circuits.

neuroscience↗