scholarly journals Dual Optical Mapping of Action Potentials and Calcium Transients in the Mouse Heart during Optogenetic Stimulation of the ICNS v1 (protocols.io.bcdtis6n)

protocols.io ◽  
2020 ◽  
Author(s):  
Pradeep Rajendran ◽  
Guy Salama ◽  
Ching Zhu ◽  
Peter Hanna
Keyword(s):  
Action Potentials ◽  
Optical Mapping ◽  
Calcium Transients ◽  
Mouse Heart ◽  
Optogenetic Stimulation ◽  
Stimulation Of

scholarly journals A Complete and Low-Cost Cardiac Optical Mapping System in Translational Animal Models

2021 ◽  
Vol 12 ◽  
Author(s):  
Manuel Marina-Breysse ◽  
Alba García-Escolano ◽  
Joaquín Vila-García ◽  
Gabriel Reale-Nosei ◽  
José M. Alfonso-Almazán ◽  
...  
Keyword(s):  
Action Potentials ◽  
Cardiac Electrophysiology ◽  
High Speed ◽  
Optical Mapping ◽  
Low Cost ◽  
Cytosolic Calcium ◽  
Calcium Transients ◽  
Spatiotemporal Resolution ◽  
Mapping System ◽  
Computer Scientists

Clinicians, biologists, physicists, engineers, and computer scientists are coming together to better understand heart disease, which is currently the leading cause of death globally. Optical mapping, a high-speed fluorescence imaging technique that visualizes and measures key cardiac parameters such as action potentials, cytosolic calcium transients, and fibrillation dynamics, is a core research tool that has arisen from such interdisciplinary collaborations. In an effort to broaden its use, especially among clinical scientists and students, we developed a complete and low-cost optical mapping system, including a constant-flow Langendorff perfusion system, which minimizes the economic threshold to widespread use of this powerful tool in cardiac electrophysiology research. The system described here provides high spatiotemporal resolution data about action potentials, intracellular calcium transients and fibrillation wave dynamics in isolated Langendorff-perfused hearts (pigs and rabbits), relevant for translational research. All system components and software elements are fully disclosed with the aim of increasing the use of this affordable and highly versatile tool among clinicians, basic scientists and students wishing to tackle their own research questions with their own customizable systems.

Mapping action potentials and calcium transients simultaneously from the intact heart

2001 ◽  
Vol 280 (5) ◽  
pp. H2053-H2060 ◽  
Author(s):  
Kenneth R. Laurita ◽  
Ashish Singal
Keyword(s):  
Action Potentials ◽  
Cardiac Electrophysiology ◽  
Optical Mapping ◽  
Fluorescence Emission ◽  
Calcium Transients ◽  
Calcium Handling ◽  
Guinea Pig Heart ◽  
Spectral Overlap ◽  
Intact Heart

Intracellular calcium handling plays an important role in cardiac electrophysiology. Using two fluorescent indicators, we developed an optical mapping system that is capable of measuring calcium transients and action potentials at 256 recording sites simultaneously from the intact guinea pig heart. On the basis of in vitro measurements of dye excitation and emission spectra, excitation and emission filters at 515 ± 5 and >695 nm, respectively, were used to measure action potentials with di-4-ANEPPS, and excitation and emission filters at 365 ± 25 and 485 ± 5 nm, respectively, were used to measure calcium transients with indo 1. The percent error due to spectral overlap was small when action potentials were measured (1.7 ± 1.0%, n = 3) and negligible when calcium transients were measured (0%, n = 3). Recordings of calcium transients, action potentials, and isochrone maps of depolarization time and the time of calcium transient onset indicated negligible error due to fluorescence emission overlap. These data demonstrate that the error due to spectral overlap of indo 1 and di-4-ANEPPS is sufficiently small, such that optical mapping techniques can be used to measure calcium transients and action potentials simultaneously in the intact heart.

scholarly journals COSMAS: a lightweight toolbox for cardiac optical mapping analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jakub Tomek ◽  
Zhinuo Jenny Wang ◽  
Rebecca-Ann Beatrice Burton ◽  
Neil Herring ◽  
Gil Bub
Keyword(s):  
Action Potentials ◽  
Optical Mapping ◽  
Calcium Transient ◽  
Automated Analysis ◽  
Calcium Transients ◽  
Data Sets ◽  
User Input ◽  
Core Feature ◽  
Mapping Analysis

AbstractOptical mapping is widely used in experimental cardiology, as it allows visualization of cardiac membrane potential and calcium transients. However, optical mapping measurements from a single heart or cell culture can produce several gigabytes of data, warranting automated computer analysis. Here we present COSMAS, a software toolkit for automated analysis of optical mapping recordings in cardiac preparations. COSMAS generates activation and conduction velocity maps, as well as visualizations of action potential and calcium transient duration, S1-S2 protocol analysis, and alternans mapping. The software is built around our recent ‘comb’ algorithm for segmentation of action potentials and calcium transients, offering excellent performance and high resistance to noise. A core feature of our software is that it is based on scripting as opposed to relying on a graphical user interface for user input. The central role of scripts in the analysis pipeline enables batch processing and promotes reproducibility and transparency in the interpretation of large cardiac data sets. Finally, the code is designed to be easily extended, allowing researchers to add functionality if needed. COSMAS is provided in two languages, Matlab and Python, and is distributed with a user guide and sample scripts, so that accessibility to researchers is maximized.

Epidermal Laser Stimulation of Action Potentials in the Frog Sciatic Nerve

2008 ◽  
Author(s):  
Nichole M. Jindra ◽  
Robert J. Thomas ◽  
Douglas N. Goddard ◽  
Michelle L. Imholte
Keyword(s):  
Sciatic Nerve ◽  
Action Potentials ◽  
Laser Stimulation ◽  
Frog Sciatic Nerve ◽  
Stimulation Of

scholarly journals Incerto-thalamic modulation of fear via GABA and dopamine

2021 ◽  
Author(s):  
Archana Venkataraman ◽  
Sarah C. Hunter ◽  
Maria Dhinojwala ◽  
Diana Ghebrezadik ◽  
JiDong Guo ◽  
...  
Keyword(s):  
Brain Regions ◽  
Zona Incerta ◽  
Dependent Manner ◽  
Post Traumatic Stress ◽  
Functional Roles ◽  
Functional Connections ◽  
Optogenetic Stimulation ◽  
Fear Generalization ◽  
Stimulation Of

AbstractFear generalization and deficits in extinction learning are debilitating dimensions of Post-Traumatic Stress Disorder (PTSD). Most understanding of the neurobiology underlying these dimensions comes from studies of cortical and limbic brain regions. While thalamic and subthalamic regions have been implicated in modulating fear, the potential for incerto-thalamic pathways to suppress fear generalization and rescue deficits in extinction recall remains unexplored. We first used patch-clamp electrophysiology to examine functional connections between the subthalamic zona incerta and thalamic reuniens (RE). Optogenetic stimulation of GABAergic ZI → RE cell terminals in vitro induced inhibitory post-synaptic currents (IPSCs) in the RE. We then combined high-intensity discriminative auditory fear conditioning with cell-type-specific and projection-specific optogenetics in mice to assess functional roles of GABAergic ZI → RE cell projections in modulating fear generalization and extinction recall. In addition, we used a similar approach to test the possibility of fear generalization and extinction recall being modulated by a smaller subset of GABAergic ZI → RE cells, the A13 dopaminergic cell population. Optogenetic stimulation of GABAergic ZI → RE cell terminals attenuated fear generalization and enhanced extinction recall. In contrast, optogenetic stimulation of dopaminergic ZI → RE cell terminals had no effect on fear generalization but enhanced extinction recall in a dopamine receptor D1-dependent manner. Our findings shed new light on the neuroanatomy and neurochemistry of ZI-located cells that contribute to adaptive fear by increasing the precision and extinction of learned associations. In so doing, these data reveal novel neuroanatomical substrates that could be therapeutically targeted for treatment of PTSD.

Tetrodotoxin-resistant release of ATP from superfused rabbit detrusor muscle during electrical field stimulation in the presence of luciferin–luciferase

1984 ◽  
Vol 62 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Archana Chaudhry ◽  
John W. Downie ◽  
Thomas D. White
Keyword(s):  
Action Potentials ◽  
Electrical Field Stimulation ◽  
Detrusor Muscle ◽  
Electrical Field ◽  
Stimulation Parameters ◽  
Rabbit Bladder ◽  
Firefly Luciferin ◽  
Rabbit Urinary Bladder ◽  
Stimulation Of

The present study was carried out to assess the possible role of ATP in the noncholinergic, nonadrenergic transmission in the rabbit urinary bladder. When rabbit detrusor muscle strips were superfused with medium containing firefly luciferin–luciferase and stimulated transmurally at low stimulation parameters, tetrodotoxin-sensitive contractions were obtained but no release of ATP could be detected. However, at somewhat higher stimulation parameters, release of ATP was observed. This release of ATP was not diminished by tetrodotoxin indicating that ATP was not likely released as a result of propagated action potentials in nerves. Because contractions persisted in the presence of tetrodotoxin, it is possible that the ATP might have been released as a result of direct electrical stimulation of the muscle. These results do not support the idea that ATP is released as a neurotransmitter in the rabbit bladder.

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