Three-dimensional model for the simulation of the HPS electrogram.

H Al-Nashash; B Lvov

Home/Archive/PubMed

PubMed · 9622108

Three-dimensional model for the simulation of the HPS electrogram.

H Al-Nashash·B Lvov

View original source ↗Export metadata ↓

Abstract

In this paper, simulation of the His-Purkinje system (HPS) electrogram based on a three-dimensional model is proposed. The simulation is based on transformation of a two-dimensional HPS into a three-dimensional curvilinear system. Furthermore, the proposed HPS takes into consideration not just the left bundle branch but also the right bundle branch. Results obtained from normal and abnormal HPS electrograms show great similarity with those obtained experimentally.

Explore related subjects

Action Potentials Algorithms Bundle of His Computer Simulation Electrocardiography Endocardium Heart Ventricles Humans Models, Neurological Purkinje Fibers Signal Processing, Computer-Assisted Synaptic Transmission Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

H Al-Nashash, B Lvov. 1997. Three-dimensional model for the simulation of the HPS electrogram.. https://pubmed.ncbi.nlm.nih.gov/9622108/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Development of song responses in the zebra finch caudomedial neostriatum: role of genomic and electrophysiological activities.

Zebra finches first form demonstrable memories of specific songs between 25 and 35 days of age--several days after fledging from the nest. What accounts for the late onset of specific song memory formation? Here we investigated physiological development of the caudomedial neostriatum (NCM), part of the avian analogue of auditory cortex and a probable component of the system involved in song perception. Two types of physiological responses were characterized: electrophysiological (single-unit spike rate) and genomic (induction of the immediate early gene zenk, also known as zif-268, egr-1, ngfi-a, krox-24). We found that by day 20, zebra finches already have robust electrophysiological responses in NCM to song stimulation. Spike activity was greater in response to conspecific songs compared to heterospecific songs, white noise, or tones, and approximately 10% of the units showed selective responses to forward versus reversed songs. In contrast, at this age the zenk gene is expressed at a constitutively high level and undergoes no further induction in response to song presentation. At day 30, electrophysiological responses remained similar, but the zenk gene began to shift from a constitutive to an inducible pattern of expression. These results are consistent with a general role for NCM in the representation of song auditory patterns, and with a role for zenk gene expression in governing the efficiency of specific song memory storage at different ages.

Action Potentials↗

PubMed2001

Calcium imaging of epileptiform events with single-cell resolution.

Epileptic discharges propagate through apparently normal circuits, although it is still unclear how this recruitment takes place. To understand the role of different classes of neurons in neocortical epilepsy, we have developed a novel imaging assay that detects which neurons participate in epileptiform discharges. Using calcium imaging of neuronal populations during bicuculline-induced spontaneous epileptiform events in slices from juvenile mouse somatosensory cortex, we find that fast calcium transients correlate with epileptiform field potentials and intracellular depolarizing shifts and can be used as an optical signature that a given neuron has participated in an epileptiform event. Our results demonstrate a novel method to characterize epileptiform events with single-cell resolution. In addition, our data are consistent with an important role for layer 5 in generating neocortical seizures and indicate that subgroups of neurons are particularly prone to epileptiform recruitment.

Action Potentials↗

PubMed2001

Electrophysiological and pharmacological characteristics of two types of spike-wave discharges in WAG/Rij rats.

Rats of the WAG/Rij strain are commonly seen as a genetic model for generalised absence epilepsy in man. Interestingly, generalised absence epilepsy shows, in addition to the fully generalised spike-wave discharges, a second type of spike-wave discharge, which lasts for a shorter time, has a lower frequency, and a lower incidence. The originally described distinction between the two types of spike-wave discharges was mainly based on the shape, polarity and duration of the discharges. In the present study other characteristics such as the spatial and temporal distribution of the spike and wave components of the two discharges and frequency spectra were found to differ between the two types. In addition, a reciprocal regulation of the two types of spike-wave discharges by drugs affecting the dopaminergic system (haloperidol and apomorphine) was observed. The results convincingly demonstrate the difference between the two phenomena and warrant the search for neurobiological mechanisms underlying both types of spike-wave discharges.

Action Potentials↗