Junctional Cleft [Ca ²⁺ ] _i Measurements Using Novel Cleft-Targeted Ca ²⁺ Sensors

Abstract

We have developed junctional cleft-targeted sensors to measure [Ca(2+)]Cleft versus [Ca(2+)]Bulk and demonstrated dynamic differences during electric excitation and a standing diastolic [Ca(2+)]i gradient, which could influence local Ca(2+)-dependent signaling within the junctional cleft.