Two-dimensional wave patterns of spreading depolarization: retracting, re-entrant, and stationary waves
نویسندگان
چکیده
We present spatio-temporal characteristics of spreading depolarizations (SD) in two experimental systems: retracting SD wave segments observed with intrinsic optical signals in chicken retina, and spontaneously occurring re-entrant SD waves that repeatedly spread across gyrencephalic feline cortex observed by laser speckle flowmetry. A mathematical framework of reaction-diffusion systems with augmented transmission capabilities is developed to explain the emergence and transitions between these patterns. Our prediction is that the observed patterns are reaction-diffusion patterns controlled and modulated by weak nonlocal coupling. The described spatio-temporal characteristics of SD are of important clinical relevance under conditions of migraine and stroke. In stroke, the emergence of re-entrant SD waves is believed to worsen outcome. In migraine, retracting SD wave segments cause neurological symptoms and transitions to stationary SD wave patterns may cause persistent symptoms without evidence from noninvasive imaging of infarction.
منابع مشابه
Steep. Short-Crested Waves and Related Phenomena
Steep, short-crested waves, as well as a large variety of three-dimensional propagating wave patterns have been created in laboratory, utilizing a plunging half-cone. Monochromatic waves, over a range of frequencies and amplitudes through breaking and including soliton wave groups near resonance, have been observed and studied in a small wave flume. This monochromatic wavemaker creates complex ...
متن کاملLinear and nonlinear characteristics of ECG signals produced by simulations of ventricular tachyarrhythmias
The aim of this study was to compare pseudo-ECGs produced by different configurations of re-entry in a computational model. We initiated single, double and multiple re-entrant waves in a cuboid with Fitz-Hugh Nagumo excitability. We estimated one component of the pseudo-ECG, and applied linear time-frequency and nonlinear dimensional analysis. The pseudo-ECG produced by a single re-entrant wave...
متن کاملUsing electrocardiographic activation time and diastolic intervals to separate focal from macro-re-entrant atrial tachycardias.
OBJECTIVES This study was designed to separate focal from atypical macro-re-entrant atrial tachycardia (AT) on the electrocardiogram (ECG). BACKGROUND Focal AT often cannot be distinguished from macro-re-entrant AT until the time of electrophysiology study (EPS). We hypothesized that quantitative ECG metrics should separate focal AT, using its short activation relative to tachycardia cycle le...
متن کاملSelf-terminating wave patterns and self-organized pacemakers in a phenomenological model of spreading depression.
A simple reaction-diffusion model of spreading depression (SD) is presented. Its local dynamics are governed by two activator and two inhibitor variables that provide an extremely simplified description of the mutual interaction between the neurons and extracellular space. This interaction is realized by the substances in the extracellular space that are increasing excitability of the neurons t...
متن کاملStatement Erin Munro November 30 , 2007
A gap junction is a perforation connecting the cytoplasms of two neurons so that ions flow freely from one to the other. Thus when one neuron fires, it may induce its electrically coupled neighbors to fire. There is increasing evidence that gap junctions among pyramidal cell axons play a role in oscillations. The gamma oscillations (30-80 Hz) seen in hippocampal experiments in [8, 9] and models...
متن کامل