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Ewa Kublik

Publications and source records attributed to Ewa Kublik.

5 recordsLinked to original sources
PubMed2026

Subtle cortical thinning in the temporal pole in middle-aged APOE-ε4 and PICALM (rs3851179) AA/AG carriers without dementia.

The symptoms of Alzheimer's disease (AD) are caused by neurodegeneration and atrophy in particular brain regions, especially in the temporal lobe. However, the influence of genetic risk on cortical thickness prior to dementia onset, remains unclear. This study aimed to explore the relationship between AD genetic risk (related to APOE and PICALM genes) and cortical thickness in selected regions of interest (ROIs) in middle-aged individuals without dementia. 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 genetic AD risk: A+ P+ (APOE/PICALM risk variants), A+P- (APOE risk variant, PICALM neutral variants), and the N group (APOE/PICALM neutral alleles). Cortical thickness was analyzed using CAT12 software (surface-based morphometry with the Destrieux atlas) based on T1-weighted MR images in five ROIs referred to as "the cortical signature of AD" in previous studies. The A+P- group had a thinner right temporal pole cortex than non-carriers after controlling for sex, age, and Raven's Progressive Matrices scores. Although this finding did not survive FDR correction across the 10 tested regions, it is consistent with our hypotheses and prior literature. No other differences in cortical thickness were found in the analyzed regions of AD "signature". The observed effect was restricted to single-risk APOE carriers without PICALM risk alleles. Therefore, further research is needed to understand the genetic interplay between these two genes in conferring AD risk.

Humans↗
PubMed2005

Local classifiers for evoked potentials recorded from behaving rats.

Dynamic states of the brain determine the way information is processed in local neural networks. We have applied classical conditioning paradigm in order to study whether habituated and aroused states can be differentiated in single barrel column of rat's somatosensory cortex by means of analysis of field potentials evoked by stimulation of a single vibrissa. A new method using local classifiers is presented which allows for reliable and meaningful classification of single evoked potentials which might be consequently attributed to different functional states of the cortical column.

Algorithms↗
PubMed2004

Contextual impact on sensory processing at the barrel cortex of awake rat.

In order to understand the processing of sensory information in different behavioral situations we recorded evoked potentials (EP) to stimulation of a single vibrissa in the barrel cortex of non-anesthetized rat. We attributed the two principal components of the first negative wave (N1) of the cortical EP to the activation of two pyramidal cell populations (supra- and infragranular) of the central barrel-column. A positive wave of longer latency (P2) reflected the activation of the neighboring columns of the barrel cortex. The EPs recorded continuously throughout the experiment could be sorted into two classes dominated by the activity of either infra- or supragranular pyramidal cells. The introduction of an aversive contextual stimuli increased the amplitude of the second component of the N1 wave, which is built up by activation of infragranular cells, and the amplitude of the P2 wave representing excitation of neighboring columns. We hypothesize that increased activity of infragranular cells activates a cortico-thalamo-cortical loop going through the POm nucleus, which finally excites wider areas of primary somatosensory cortex. This spread of activity enables the comparison of information from neighboring vibrissae at the mystacial pad. The general cortical activation caused by the introduction of the contextual stimuli might be induced by noradrenergic and/or cholinergic systems. Prolonged contextual stimulation causes habituation processes, which return the cortical network to an idle state.

Animals↗
PubMed2003

Sorting functional classes of evoked potentials by wavelets.

Evoked potentials (EPs) recorded within the primary sensory cortex of non-anesthetized rats vary considerably with each peripheral stimulation. We have previously shown that most of this variance reflects the shift of cortical activation between habituated and aroused states. Here we show that a method of matching the potential's course by wavelet functions can reliably differentiate single EPs and may therefore, be used as a probe for indicating the current activation state of the cortex.

Animals↗
PubMed2003

Cortical contribution to sensory volleys recorded at thalamic nuclei of lemniscal and paralemniscal pathways.

In order to elucidate the role of cortical input on sensory information processing in different thalamic somatosensory nuclei we recorded potentials evoked (EPs) by whisker deflections of short duration from ventral posteromedial (VPm) and medial posterior (POm) nuclei while manipulating cortico-thalamic activity by means of local cooling, lidocaine application or electrical stimulation. It appeared that only the earliest sub-component of the first negative wave of the EPs resulted from peripheral input, while the rest of the potential's negativity depended on cortical feedback. The latencies and amplitudes of EPs recorded at both nuclei were not significantly different, which might be attributed to urethane anesthesia.

Animals↗