Asunto(s)
Investigación Biomédica/historia , Cardiología/historia , Enfermedades Cardiovasculares/historia , Imagen de Colorante Sensible al Voltaje/historia , Potenciales de Acción , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Historia del Siglo XXI , HumanosRESUMEN
Optical mapping of Ca(2+)-sensitive fluorescence probes has become an extremely useful approach and adopted by many cardiovascular research laboratories to study a spectrum of myocardial physiology and disease conditions. Optical mapping data are often displayed as detailed pseudocolor images, providing unique insight for interpreting mechanisms of ectopic activity, action potential and Ca(2+) transient alternans, tachycardia, and fibrillation. Ca(2+)-sensitive fluorescent probes and optical mapping systems continue to evolve in the ongoing effort to improve therapies that ease the growing worldwide burden of cardiovascular disease. In this technical review we provide an updated overview of conventional approaches for optical mapping of Cai (2+) within intact myocardium. In doing so, a brief history of Cai (2+) probes is provided, and nonratiometric and ratiometric Ca(2+) probes are discussed, including probes for imaging sarcoplasmic reticulum Ca(2+) and probes compatible with potentiometric dyes for dual optical mapping. Typical measurements derived from optical Cai (2+) signals are explained, and the analytics used to compute them are presented. Last, recent studies using Cai (2+) optical mapping to study arrhythmias, heart failure, and metabolic perturbations are summarized.
Asunto(s)
Señalización del Calcio , Calcio/metabolismo , Colorantes Fluorescentes/metabolismo , Miocardio/metabolismo , Imagen de Colorante Sensible al Voltaje/métodos , Potenciales de Acción , Animales , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatología , Colorantes Fluorescentes/historia , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/fisiopatología , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Cinética , Procesamiento de Señales Asistido por Computador , Imagen de Colorante Sensible al Voltaje/historiaRESUMEN
Voltage imaging was first conceived in the late 1960s and efforts to find better organic voltage sensitive dyes began in the 1970s and continue until today. At the beginning it was difficult to measure an action potential signal from a squid giant axon in a single trial. Now it is possible to measure the action potential in an individual spine. Other chapters will discuss advances in voltage imaging technology and applications in a variety of biological preparations. The development of genetically encoded voltage sensors has started. A genetically encoded sensor could provide cell type specific expression and voltage recording (see Chap. 20). Optimizing the signal-to-noise ratio of an optical recording requires attention to several aspects of the recording apparatus. These include the light source, the optics and the recording device. All three have improved substantially in recent years. Arc lamp, LED, and laser sources are now stable, more powerful, and less expensive. Cameras for recording activity have frames rates above 1 kHz and quantum efficiencies near 1.0 although they remain expensive. The sources of noise in optical recordings are well understood. Both the apparatus and the noise sources are discussed in this chapter.