The Experts below are selected from a list of 11877 Experts worldwide ranked by ideXlab platform
Omar J. Ahmed - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Amplitude and shape of postrhinal theta oscillations differentially encode running speed
2020Co-Authors: Megha Ghosh, Rebecca D Burwell, Sharon C. Furtak, Benjamin E. Shanahan, George A. Mashour, Omar J. AhmedAbstract:Hippocampal theta oscillations have a temporally asymmetric waveform shape, but it is not known if this theta asymmetry extends to all other cortical regions involved in spatial navigation and memory. Here, using both established and improved cycle-by-cycle analysis methods, we show that theta waveforms in the postrhinal cortex are also temporally asymmetric. On average, the falling phase of postrhinal theta cycles lasts longer than the subsequent rising phase. There are, however, rapid changes in both the Instantaneous Amplitude and Instantaneous temporal asymmetry of postrhinal theta cycles. These rapid changes in Amplitude and asymmetry are very poorly correlated, indicative of a mechanistic disconnect between these theta cycle features. We show that the Instantaneous Amplitude and asymmetry of postrhinal theta cycles differentially encode running speed. Although theta Amplitude continues to increase at the fastest running speeds, temporal asymmetry of the theta waveform shape plateaus after medium speeds. Our results suggest that the Amplitude and waveform shape of individual postrhinal theta cycles may be governed by partially independent mechanisms and emphasize the importance of employing a single cycle approach to understanding the genesis and behavioral correlates of cortical theta rhythms.
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Instantaneous Amplitude and shape of postrhinal theta oscillations differentially encode running speed.
Behavioral neuroscience, 2020Co-Authors: Megha Ghosh, Rebecca D Burwell, Sharon C. Furtak, Benjamin E. Shanahan, George A. Mashour, Omar J. AhmedAbstract:Hippocampal theta oscillations have a temporally asymmetric waveform shape, but it is not known if this theta asymmetry extends to all other cortical regions involved in spatial navigation and memory. Here, using both established and improved cycle-by-cycle analysis methods, we show that theta waveforms in the postrhinal cortex are also temporally asymmetric. On average, the falling phase of postrhinal theta cycles lasts longer than the subsequent rising phase. There are, however, rapid changes in both the Instantaneous Amplitude and Instantaneous temporal asymmetry of postrhinal theta cycles. These rapid changes in Amplitude and asymmetry are very poorly correlated, indicative of a mechanistic disconnect between these theta cycle features. We show that the Instantaneous Amplitude and asymmetry of postrhinal theta cycles differentially encode running speed. Although theta Amplitude continues to increase at the fastest running speeds, temporal asymmetry of the theta waveform shape plateaus after medium speeds. Our results suggest that the Amplitude and waveform shape of individual postrhinal theta cycles may be governed by partially independent mechanisms and emphasize the importance of employing a single cycle approach to understanding the genesis and behavioral correlates of cortical theta rhythms. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Jorge G Quintanilla - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Amplitude and frequency modulations detect the footprint of rotational activity and reveal stable driver regions as targets for persistent atrial fibrillation ablation
Circulation Research, 2019Co-Authors: Jorge G Quintanilla, Jose Manuel Alfonsoalmazan, Nicasio Perezcastellano, Sandeep V Pandit, Jose Jalife, Julian Perezvillacastin, David FilgueirasramaAbstract:Rationale: Costly proprietary panoramic multielectrode (64–256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fi...
Filgueiras-rama David - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Amplitude and Frequency Modulations Detect the Footprint of Rotational Activity and Reveal Stable Driver Regions as Targets for Persistent Atrial Fibrillation Ablation
American Heart Association, 2019Co-Authors: Quintanilla, Jorge G., Alfonso-almazan, Jose M., Pérez-castellano Nicasio, Pandit Sandeep, Jalife Jose, Pérez-villacastín Julián, Filgueiras-rama DavidAbstract:RATIONALE: Costly proprietary panoramic multielectrode (64-256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fibrillation (PersAF) ablation. However, such approaches target alleged drivers (rotational/focal) regardless of their activation frequency dynamics. OBJECTIVES: To test the hypothesis that stable regions of higher than surrounding Instantaneous frequency modulation (iFM) drive PersAF and determine whether rotational activity is specific for such regions. METHODS AND RESULTS: First, novel single-signal algorithms based on Instantaneous Amplitude modulation (iAM) and iFM to detect rotational-footprints without panoramic multielectrode acquisition systems were tested in 125 optical movies from 5 ex vivo Langendorff-perfused PersAF sheep hearts (sensitivity/specificity, 92.6/97.5%; accuracy, 2.5-mm) and in computer simulations. Then, 16 pigs underwent high-rate atrial pacing to develop PersAF. After a median (interquartile range [IQR]) of 4.4 (IQR, 2.5-9.9) months of high-rate atrial pacing followed by 4.1 (IQR, 2.7-5.4) months of self-sustained PersAF, pigs underwent in vivo high-density electroanatomical atrial mapping (4920 [IQR, 4435-5855] 8-second unipolar signals per map). The first 4 out of 16 pigs were used to adapt ex vivo optical proccessing of iFM/iAM to in vivo electrical signals. In the remaining 12 out of 16 pigs, regions of higher than surrounding average iFM were considered leading-drivers. Two leading-driver + rotational-footprint maps were generated 2.6 (IQR, 2.4-2.9) hours apart to test leading-driver spatiotemporal stability and guide ablation. Leading-driver regions (2.5 [IQR, 2.0-4.0] regions/map) exactly colocalized (95.7%) in the 2 maps, and their ablation terminated PersAF in 92.3% of procedures (radiofrequency until termination, 16.9 [IQR, 9.2-35.8] minutes; until nonsustainability, 20.4 [IQR, 12.8-44.0] minutes). Rotational-footprints were found at every leading-driver region, albeit most (76.8% [IQR, 70.5%-83.6%]) were located outside. Finally, the translational ability of this approach was tested in 3 PersAF redo patients. CONCLUSIONS: Both rotational-footprints and spatiotemporally stable leading-driver regions can be located using iFM/iAM algorithms without panoramic multielectrode acquisition systems. In pigs, ablation of leading-driver regions usually terminates PersAF and prevents its sustainability. Rotational activations are sensitive but not specific to such regions. Single-signal iFM/iAM algorithms could be integrated into conventional electroanatomical mapping systems to improve driver detection accuracy and reduce the cost of patient-tailored/mechanistic approaches.This study was supported by the European Regional Development Fund and the Spanish Ministry of Science, Innovation and Universities (SAF2016-80324-R). The CNIC is supported by the Spanish Ministry of Science, Innovation and Universities and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S
David Filgueirasrama - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Amplitude and frequency modulations detect the footprint of rotational activity and reveal stable driver regions as targets for persistent atrial fibrillation ablation
Circulation Research, 2019Co-Authors: Jorge G Quintanilla, Jose Manuel Alfonsoalmazan, Nicasio Perezcastellano, Sandeep V Pandit, Jose Jalife, Julian Perezvillacastin, David FilgueirasramaAbstract:Rationale: Costly proprietary panoramic multielectrode (64–256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fi...
Jose Jalife - One of the best experts on this subject based on the ideXlab platform.
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Instantaneous Amplitude and frequency modulations detect the footprint of rotational activity and reveal stable driver regions as targets for persistent atrial fibrillation ablation
Circulation Research, 2019Co-Authors: Jorge G Quintanilla, Jose Manuel Alfonsoalmazan, Nicasio Perezcastellano, Sandeep V Pandit, Jose Jalife, Julian Perezvillacastin, David FilgueirasramaAbstract:Rationale: Costly proprietary panoramic multielectrode (64–256) acquisition systems are being increasingly used together with conventional electroanatomical mapping systems for persistent atrial fi...
