Optical mapping is a fluorescence-based physiological method to image spreading of action potential in excitable tissues, such as the heart and central nervous system. Because of the requirements for high speed imaging in low light conditions, highly sensitive high-speed cameras together with an optical system with maximum photon efficiency are required. While the optimization of these two components is relatively straightforward, the choice of the perfect light source is less simple; depending on the other (usually fixed) components, various parameters may acquire different weight in decision-making process. Here we describe the rationale for building an optical mapping setup and consider the relative advantages and disadvantages of three different commonly available light sources: mercury vapor lamp (HBO), xenon lamp (XBO), and light emitting diode (LED). Using the same optical system (fluorescence macroscope) and high-speed camera (Ultima L), we have tested each of the sources for its ability to provide bright and even illumination of the field of view and measured its temporal fluctuations in intensity. Then we used each in the actual optical mapping experiment using isolated, perfused adult mouse heart or chick embryonic heart to determine the actual signal to noise ratio at various acquisition rates. While the LED sources have undergone significant improvements in the recent past, the other alternatives may still surpass them in some parameters, so they may not be the automatic number one choice for every application.
- MeSH
- akční potenciály MeSH
- fluorescenční barviva chemie MeSH
- kuřecí embryo MeSH
- myši MeSH
- srdce fyziologie MeSH
- světlo MeSH
- vápník analýza metabolismus MeSH
- zobrazování pomocí barviva citlivého na potenciál metody normy MeSH
- zvířata MeSH
- Check Tag
- kuřecí embryo MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The development of exaggerated avoidance behavior is largely responsible for the decreased quality of life in patients suffering from anxiety disorders. Studies using animal models have contributed to the understanding of the neural mechanisms underlying the acquisition of avoidance responses. However, much less is known about its extinction. Here we provide evidence in mice that learning about the safety of an environment (i.e., safety learning) rather than repeated execution of the avoided response in absence of negative consequences (i.e., response extinction) allowed the animals to overcome their avoidance behavior in a step-down avoidance task. This process was context-dependent and could be blocked by pharmacological (3 mg/kg, s.c.; SR141716) or genetic (lack of cannabinoid CB1 receptors in neurons expressing dopamine D1 receptors) inactivation of CB1 receptors. In turn, the endocannabinoid reuptake inhibitor AM404 (3 mg/kg, i.p.) facilitated safety learning in a CB1-dependent manner and attenuated the relapse of avoidance behavior 28 days after conditioning. Safety learning crucially depended on endocannabinoid signaling at level of the hippocampus, since intrahippocampal SR141716 treatment impaired, whereas AM404 facilitated safety learning. Other than AM404, treatment with diazepam (1 mg/kg, i.p.) impaired safety learning. Drug effects on behavior were directly mirrored by drug effects on evoked activity propagation through the hippocampal trisynaptic circuit in brain slices: As revealed by voltage-sensitive dye imaging, diazepam impaired whereas AM404 facilitated activity propagation to CA1 in a CB1-dependent manner. In line with this, systemic AM404 enhanced safety learning-induced expression of Egr1 at level of CA1. Together, our data render it likely that AM404 promotes safety learning by enhancing information flow through the trisynaptic circuit to CA1.
- MeSH
- antagonisté kanabinoidních receptorů farmakologie MeSH
- extinkce (psychologie) účinky léků fyziologie MeSH
- hipokampus diagnostické zobrazování účinky léků metabolismus MeSH
- inhibice (psychologie) MeSH
- kyseliny arachidonové farmakologie MeSH
- myši inbrední C57BL MeSH
- myši transgenní MeSH
- myši MeSH
- piperidiny farmakologie MeSH
- protein 1 časné růstové odpovědi metabolismus MeSH
- pyrazoly farmakologie MeSH
- receptor kanabinoidní CB1 nedostatek genetika MeSH
- učení vyhýbat se účinky léků fyziologie MeSH
- zobrazování pomocí barviva citlivého na potenciál MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- blokáda Tawarova raménka * MeSH
- myši MeSH
- zobrazování pomocí barviva citlivého na potenciál MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
Differentiation and conduction properties of the cardiomyocytes are critically dependent on physical conditioning both in vitro and in vivo. Historically, various techniques were introduced to study dynamic events such as electrical currents and changes in ionic concentrations in live cells, multicellular preparations, or entire hearts. Here we review this technological progress demonstrating how each improvement in spatial or temporal resolution provided answers to old and provoked new questions. We further demonstrate how high-speed optical mapping of voltage and calcium can uncover pacemaking potential within the outflow tract myocardium, providing a developmental explanation of ectopic beats originating from this region in the clinical settings.
- MeSH
- akční potenciály fyziologie MeSH
- kardiomyocyty fyziologie MeSH
- lidé MeSH
- mapování potenciálů tělesného povrchu metody MeSH
- nervové vedení fyziologie MeSH
- převodní systém srdeční embryologie fyziologie MeSH
- vápníková signalizace fyziologie MeSH
- zobrazování pomocí barviva citlivého na potenciál metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Motion artefact (MA) in voltage-sensitive fluorescent signals causes significant debasement of action potential. During ischemia and reperfusion in isolated rabbit heart, this artefact develops in a manner which may be described by the time of its onset, level, and shape. The MA during ischemia: (a) may become substantial with approximately two minutes delay after establishing global ischemia; (b) may be almost twice as high as the physiological action potential and decreases both with time and repetition of ischemia; (c) the MA shape is unpredictable and depends on individual rabbit.
- MeSH
- akční potenciály MeSH
- artefakty * MeSH
- časové faktory MeSH
- fluorescenční barviva diagnostické užití MeSH
- králíci MeSH
- perfuze MeSH
- prediktivní hodnota testů MeSH
- pyridinové sloučeniny diagnostické užití MeSH
- reperfuzní poškození myokardu diagnóza patofyziologie MeSH
- zobrazování pomocí barviva citlivého na potenciál metody MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- techniky in vitro MeSH
- MeSH
- anatomie MeSH
- biologie buňky MeSH
- financování organizované MeSH
- zobrazování pomocí barviva citlivého na potenciál metody přístrojové vybavení trendy využití MeSH
- Publikační typ
- biografie MeSH
- novinové články MeSH
- Geografické názvy
- Spojené státy americké MeSH
- O autorovi
- Sedmera, David, 1971- Autorita
We present a 34-year-old woman with idiopathic ventricular tachycardia that resisted 2 previous attempts for catheter ablation and was successfully ablated in the myocardial extension within the noncoronary aortic cusp.
- MeSH
- akční potenciály MeSH
- aortální chlopeň patofyziologie chirurgie MeSH
- časové faktory MeSH
- dospělí MeSH
- elektrofyziologické techniky kardiologické MeSH
- elektrokardiografie MeSH
- kardiostimulace umělá MeSH
- katetrizační ablace MeSH
- komorová tachykardie diagnóza patofyziologie chirurgie MeSH
- lidé MeSH
- myokard MeSH
- reoperace MeSH
- srdeční komory patofyziologie chirurgie MeSH
- výsledek terapie MeSH
- zobrazování pomocí barviva citlivého na potenciál MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
AIMS: The aim of this study was to characterize ventricular activation patterns in normal and connexin40-deficient mice in order to dissect the role of connexin40 in developing the conduction system. METHODS AND RESULTS: We performed optical mapping of epicardial activation between ED9.5-18.5 and analysed ventricular activation patterns and times of left ventricular activation. Mouse embryos deficient for connexin40 were compared with normal and heterozygous littermates. Morphology of the primary interventricular ring (PIR) was delineated with the help of T3-LacZ transgene. Four major types of ventricular activation patterns characterized by primary breakthrough in different parts of the heart were detected during development: PIR, left ventricular apex, right ventricular apex, and dual right and left ventricular apices. Activation through PIR was frequently present at the early stages until ED12.5. From ED14.5, the majority of hearts showed dual left and right apical breakthrough, suggesting functionality of both bundle branches. Connexin40-deficient embryos showed initially a delay in left bundle branch function, but the right bundle branch block, previously described in the adults, was not detected in ED14.5 embryos and appeared only gradually with 80% penetrance at ED18.5. CONCLUSION: The switch of function from the early PIR conduction pathway to the mature apex to base activation is dependent upon upregulation of connexin40 expression in the ventricular trabeculae. The early function of right bundle branch does not depend on connexin40. Quantitative analysis of normal mouse embryonic ventricular conduction patterns will be useful for interpretation of effects of mutations affecting the function of the cardiac conduction system.
- MeSH
- akční potenciály MeSH
- blokáda Tawarova raménka genetika metabolismus MeSH
- gestační stáří MeSH
- Hisův svazek embryologie metabolismus MeSH
- konexiny nedostatek genetika MeSH
- lac operon MeSH
- morfogeneze MeSH
- myši knockoutované MeSH
- myši transgenní MeSH
- myši MeSH
- penetrance MeSH
- převodní systém srdeční embryologie metabolismus MeSH
- srdeční komory embryologie metabolismus MeSH
- vývojová regulace genové exprese MeSH
- zobrazování pomocí barviva citlivého na potenciál MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- mozkové okruhy,
- MeSH
- chování zvířat MeSH
- Diptera MeSH
- elektrická stimulace MeSH
- genetické jevy MeSH
- mapování mozku * metody MeSH
- mozek * fyziologie MeSH
- nervové vedení fyziologie genetika MeSH
- neurony fyziologie MeSH
- optogenetika * MeSH
- signální transdukce MeSH
- světelná stimulace MeSH
- výzkum MeSH
- zobrazování pomocí barviva citlivého na potenciál MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
