Imaging of cerebellar surface activation in vivo using voltage sensitive dyes.
AuthorsKim JH, Dunn MB, Hua Y, Rydberg J, Yae H, Elias SA, Ebner TJ
JournalNeuroscience
PubMed ID2594193
'The understanding of the information processing performed by complex neuronal networks in the central nervous system will require techniques permitting the simultaneous monitoring of the electrical activity of neuronal ensembles. Voltage sensitive dyes offer the potential for non-invasive optical monitoring of the activity in large populations of neurons. In this ... More
Dynamic origin of spatially discordant alternans in cardiac tissue.
AuthorsHayashi H, Shiferaw Y, Sato D, Nihei M, Lin SF, Chen PS, Garfinkel A, Weiss JN, Qu Z
JournalBiophys J
PubMed ID17071663
'Alternans, a condition in which there is a beat-to-beat alternation in the electromechanical response of a periodically stimulated cardiac cell, has been linked to the genesis of life-threatening ventricular arrhythmias. Optical mapping of membrane voltage (V(m)) and intracellular calcium (Ca(i)) on the surface of animal hearts reveals complex spatial patterns ... More
Fluorescence imaging of local membrane electric fields during the excitation of single neurons in culture.
AuthorsGogan P, Schmiedel-Jakob I, Chitti Y, Tyc-Dumont S
JournalBiophys J
PubMed ID8527643
'The spatial distribution of depolarized patches of membrane during the excitation of single neurons in culture has been recorded with a high spatial resolution (1 micron2/pixel) imaging system based on a liquid-nitrogen-cooled astronomical camera mounted on an inverted microscope. Images were captured from rat nodose neurons stained with the voltage-sensitive ... More
Voltage-sensitive dye recording of action potentials and synaptic potentials from sympathetic microcultures.
AuthorsChien CB, Pine J
JournalBiophys J
PubMed ID1681956
'Given the appropriate multicell electrophysiological techniques, small networks of cultured neurons (microcultures) are well suited to long-term studies of synaptic plasticity. To this end, we have developed an apparatus for optical recording from cultured vertebrate neurons using voltage-sensitive fluorescent dyes (Chien, C.-B., and J. Pine. 1991. J. Neurosci. Methods. 38:93-105). ... More
Charge translocation by the Na,K-pump: I. Kinetics of local field changes studied by time-resolved fluorescence measurements.
AuthorsBühler R, Stürmer W, Apell HJ, Läuger P
JournalJ Membr Biol
PubMed ID1652643
'Membrane fragments containing a high density of Na,K-ATPase can be noncovalently labeled with amphiphilic styryl dyes (e.g., RH 421). Phosphorylation of the Na,K-ATPase by ATP in the presence of Na+ and in the absence of K+ leads to a large increase of the fluorescence of RH 421 (up to 100%). ... More
Quantifying spatial localization of optical mapping using Monte Carlo simulations.
AuthorsDing L, Splinter R, Knisley SB
JournalIEEE Trans Biomed Eng
PubMed ID11585033
'Optical mapping techniques used to study spatial distributions of cardiac activity can be divided into two categories. 1) Broad-field excitation method, in which hearts stained with voltage or calcium sensitive dyes are illuminated with broad-field excitation light and fluorescence is collected by image or photodiode arrays. 2) Laser scanning method, ... More
Fluorescent styryl dyes of the RH series affect a potential drop on the membrane/solution boundary.
AuthorsMalkov DY, Sokolov VS
JournalBiochim Biophys Acta
PubMed ID8593277
'The effects of the adsorption of the fluorescent potential-sensitive dyes RH-421, RH-237 and RH-160 on the bilayer lipid membrane were studied. It was shown that a dipole potential drop, positive in the hydrophobic part of the membrane, arose due to the dye adsorption. The dye adsorption led to a considerable ... More
Origin of the in vivo rat piriform cortex activity recorded with voltage-sensitive dyes: comparison of the optical signals and the field potentials.
AuthorsLitaudon P, Cattarelli M
JournalBrain Res
PubMed ID1467937
'The comparison of optical recordings and evoked field potentials recorded on the rat piriform cortex pointed out that both signals were strongly correlated. As the field potentials, the two waves of the optical signals originated from the mono- (direct olfactory bulb afferents) and polysynaptic (intrinsic association fibers) excitatory postsynaptic potentials. ... More
Microscopic conduction in cultured strands of neonatal rat heart cells measured with voltage-sensitive dyes.
AuthorsFast VG, Kléber AG
JournalCirc Res
PubMed ID8403261
'Microscopic discontinuities in electrical activation were assessed in synthetic strands of neonatal rat myocytes cultured on a growth-directing matrix. An optical method using voltage-sensitive dye (RH-237) and a photodiode technique was used for recordings of membrane potential changes with subcellular resolution. Spatial resolution of the method (diameter of measurement area, ... More
Dipole potential drop due to RH-dye adsorption on the lipid bilayer and its influence on Na+/K+-ATPase activity.
AuthorsMalkov DY, Pavlov KV, Sokolov VS
JournalAnn N Y Acad Sci
PubMed ID9432911
Spatially discordant alternans in cardiomyocyte monolayers.
Authorsde Diego C, Pai RK, Dave AS, Lynch A, Thu M, Chen F, Xie LH, Weiss JN, Valderrábano M,
JournalAm J Physiol Heart Circ Physiol
PubMed ID18223190
Repolarization alternans is a harbinger of sudden cardiac death, particularly when it becomes spatially discordant. Alternans, a beat-to-beat alternation in the action potential duration (APD) and intracellular Ca (Cai), can arise from either tissue heterogeneities or dynamic factors. Distinguishing between these mechanisms in normal cardiac tissue is difficult because of ... More
Functional scaffold-free 3-D cardiac microtissues: a novel model for the investigation of heart cells.
AuthorsDesroches BR, Zhang P, Choi BR, King ME, Maldonado AE, Li W, Rago A, Liu G, Nath N, Hartmann KM, Yang B, Koren G, Morgan JR, Mende U,
JournalAm J Physiol Heart Circ Physiol
PubMed ID22427522
To bridge the gap between two-dimensional cell culture and tissue, various three-dimensional (3-D) cell culture approaches have been developed for the investigation of cardiac myocytes (CMs) and cardiac fibroblasts (CFs). However, several limitations still exist. This study was designed to develop a cardiac 3-D culture model with a scaffold-free technology ... More
Anatomical and functional imaging of neurons using 2-photon laser scanning microscopy.
AuthorsDenk W, Delaney KR, Gelperin A, Kleinfeld D, Strowbridge BW, Tank DW, Yuste R
JournalJ Neurosci Methods
PubMed ID7869748
Light scattering by brain tissue and phototoxicity are major obstacles to the use of high-resolution optical imaging and photo-activation ('uncaging') of bioactive compounds from inactive ('caged') precursors in intact and semi-intact nervous systems. Optical methods based on 2-photon excitation promise to reduce these obstacles (Denk, 1994; Denk et al., 1990, ... More
Voltage-sensitive fluorescence of amphiphilic hemicyanine dyes in neuron membrane.
AuthorsFromherz P, Müller CO
JournalBiochim Biophys Acta
PubMed ID8347665
Fluorescent amphiphilic hemicyanine dyes were adsorbed to the plasma membrane of isolated Retzius neurons of the leech. Voltage steps were applied to the neuron by the patch-clamp technique in whole-cell configuration. The change of fluorescence was observed as induced by the voltage jump. The relative changes of the excitation spectrum ... More
Optical imaging of the heart.
AuthorsEfimov IR, Nikolski VP, Salama G
JournalCirc Res
PubMed ID15242982
Optical techniques have revolutionized the investigation of cardiac cellular physiology and advanced our understanding of basic mechanisms of electrical activity, calcium homeostasis, and metabolism. Although optical methods are widely accepted and have been at the forefront of scientific discoveries, they have been primarily applied at cellular and subcellular levels and ... More
Emission ratiometry for simultaneous calcium and action potential measurements with coloaded dyes in rabbit hearts: reduction of motion and drift.
AuthorsKong W, Walcott GP, Smith WM, Johnson PL, Knisley SB
JournalJ Cardiovasc Electrophysiol
PubMed ID12625615
INTRODUCTION: Optical measurements of the cardiac calcium transient (Ca) and transmembrane action potential (AP) may be performed simultaneously with emission ratiometry to lessen motion artifacts and photobleaching effects. We examined changes in emission spectrum in perfused rabbit hearts coloaded with Rh237 and a green-emitting Ca dye (Fluo-4 or Oregon Green ... More
Functional reentry in cultured monolayers of neonatal rat cardiac cells.
AuthorsIravanian S, Nabutovsky Y, Kong CR, Saha S, Bursac N, Tung L
JournalAm J Physiol Heart Circ Physiol
PubMed ID12623789
Previous studies of reentrant arrhythmias in the heart have been performed in computer models and tissue experiments. We hypothesized that confluent monolayers of cardiac cells can provide a simple, controlled, and reproducible experimental model of reentry. Neonatal rat ventricular cells were cultured on 22-mm-diameter coverslips and stained with the voltage-sensitive ... More
Development of an optrode for intramural multisite optical recordings of Vm in the heart.
AuthorsByars JL, Smith WM, Ideker RE, Fast VG
JournalJ Cardiovasc Electrophysiol
PubMed ID14678134
INTRODUCTION: Optical mapping of transmembrane potential (Vm) is an important tool in the investigation of impulse propagation in the heart. It provides valuable information about spatiotemporal changes of Vm that cannot be obtained by other techniques, but it presently is limited to measurements from the heart surfaces. Therefore, the goal ... More
Simultaneous maps of optical action potentials and calcium transients in guinea-pig hearts: mechanisms underlying concordant alternans.
AuthorsChoi BR, Salama G
JournalJ Physiol
PubMed ID11080260
1. The mechanisms underlying electro-mechanical alternans caused by faster heart rates were investigated in perfused guinea-pig hearts stained with RH237 and Rhod-2 AM to simultaneously map optical action potentials (APs) and intracellular free Ca2+ (Ca2+i). 2. Fluorescence images of the heart were focused on two 16 x 16 photodiode arrays ... More
Intracellular Ca dynamics in ventricular fibrillation.
AuthorsOmichi C, Lamp ST, Lin SF, Yang J, Baher A, Zhou S, Attin M, Lee MH, Karagueuzian HS, Kogan B, Qu Z, Garfinkel A, Chen PS, Weiss JN
JournalAm J Physiol Heart Circ Physiol
PubMed ID14704235
In the heart, membrane voltage (Vm) and intracellular Ca (Cai) are bidirectionally coupled, so that ionic membrane currents regulate Cai cycling and Cai affects ionic currents regulating action potential duration (APD). Although Cai reliably and consistently tracks Vm at normal heart rates, it is possible that at very rapid rates, ... More
Anisotropic activation spread in heart cell monolayers assessed by high-resolution optical mapping. Role of tissue discontinuities.
AuthorsFast VG, Darrow BJ, Saffitz JE, Kléber AG
JournalCirc Res
PubMed ID8925559
The role of tissue discontinuities in anisotropic impulse propagation was assessed in two-dimensional anisotropic monolayers of neonatal rat myocytes cultured on a growth-directing substrate of collagen. Activation spread and distribution of maximal upstroke rate of rise (Vmax) of the action potential were measured with an optical system using a voltage-sensitive ... More
Formation of specific afferent connections in organotypic slice cultures from rat visual cortex cocultured with lateral geniculate nucleus.
AuthorsBolz J, Novak N, Staiger V
JournalJ Neurosci
PubMed ID1494945
The development of the cerebral cortex involves the specification of intrinsic circuitry and extrinsic connections, the pattern of inputs and outputs. To investigate the development of a major afferent input to the cortex, we studied the formation of thalamocortical connections in an organotypic culture system. Slices from the lateral thalamus ... More
Effects of electrical shocks on Cai2+ and Vm in myocyte cultures.
AuthorsFast VG, Cheek ER, Pollard AE, Ideker RE
JournalCirc Res
PubMed ID15155528
Changes in intracellular calcium concentration (DeltaCa(i)2+) induced by electrical shocks may play an important role in defibrillation, but high-resolution DeltaCa(i)2+ measurements in a multicellular cardiac tissue and their relationship to corresponding Vm changes (DeltaVm) are lacking. Here, we measured shock-induced DeltaCa(i)2+ and DeltaV(m) in geometrically defined myocyte cultures. Cell strands ... More
Simultaneous optical mapping of transmembrane potential and intracellular calcium in myocyte cultures.
AuthorsFast VG, Ideker RE
JournalJ Cardiovasc Electrophysiol
PubMed ID10826934
INTRODUCTION: Fast spatially resolved measurements of transmembrane potential (Vm) and intracellular calcium (Ca(i)2+) are important for studying mechanisms of arrhythmias and defibrillation. The goals of this work were (1) to develop an optical technique for simultaneous multisite optical recordings of Vm and Ca(i)2+, and (2) to determine the relationship between ... More
High-resolution structure-function mapping of intact hearts reveals altered sympathetic control of infarct border zones.