Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

3 Acta Neurobiologiae Experimentalis

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Neuronal and ionic mechanisms of focal seizure - insight from in silico study

100%

Suffczynski P.

2019

tom 79

nr Suppl.1

It is generally considered that epilepsy and seizures are related to alteration in neuronal excitation/ inhibition balance. On the other hand, using an in vi‑ tro isolated guinea pig brain model of focal seizures, it has been shown that seizures start with strong firing of inhibitory interneurons, silence of principal cells, and a massive increase of extracellular potassium concentration. In order to investigate the link between ionic dynamics and experimentally observed seizure pattern, we developed a computational model of hippocampal network embedded in the extracellular space with realistic Na+ , K+ , Cl- , and Ca2+ dynamics, glial cells, and a diffusion mechanism. The model exhibits seizure‑like activity that is qualitatively similar to experimentally observed seizures in the isolated guinea pig brain. We show that, in the model, strong discharge of inhibitory interneurons leads to long lasting accumulation of extracellular potassium, which triggers and sustains abnormal discharges of the neuronal network, including ictal bursting. Using computational modeling, we also suggest novel antiepileptic therapies targeting potassium regulation systems.

Power modulation of SSVEP

51%

Labecki M. , Nowicka M. , Suffczynski P.

Acta Neurobiologiae Experimentalis

2017

tom 77

nr Suppl.1

Steady State Visual Evoked Potentials are the steady‑state responses elicited by flicker stimulation. Frequency of oscillation of these responses corresponds to the stimulus frequency and its harmonics. Since the very first reports on SSVEP in 1966, they have been commonly assumed to be stationary (i.e. steady-state) signals which power and other properties are stable over time. In our study we submitted human subjects to long term (i.e. 60 seconds) visual periodic stimulation. In most cases, the instantaneous power of SSVEP significantly evolved over time. Furthermore the temporal behavior of the response was strongly dependent on the stimulus frequency. The possible explanation and potential impact of these results is discussed.

Event-related desynchronization and synchronization in evoked K-complexes

45%

Zygierewicz J. , Malinowska U. , Suffczynski P. , Piotrowski T. , Durka P. J.

Acta Neurobiologiae Experimentalis

2009

tom 69

nr 2

254-261

K-complexes - phenomena occurring in sleep EEG - pose severe challenges in terms of detection as well as finding their physiological origin. In this study, K-complexes (KCs) were evoked by auditory stimuli delivered during sleep. The use of evoked KCs enables testing the sleeping nervous system under good experimental control. This paradigm allowed us to adopt into the KC studies a method of signal analysis that provides time-frequency maps of statistically significant changes in signal energy density. Our results indicate that KCs and sleep spindles may be organized by a slow oscillation. Accordingly, KCs might be evoked only if the stimulus occurs in a certain phase of the slow oscillation. We also observed middle-latency evoked responses following auditory stimulation in the last sleep cycle. This effect was revealed only by the time-frequency maps and was not visible in standard averages.