Axonal Endoplasmic Reticulum Ca²⁺ Content Controls Release Probability in CNS Nerve Terminals.

ABSTRACT: Although the endoplasmic reticulum (ER) extends throughout axons and axonal ER dysfunction is implicated in numerous neurological diseases, its role at nerve terminals is poorly understood. We developed novel genetically encoded ER-targeted low-affinity Ca²⁺ indicators optimized for examining axonal ER Ca²⁺. Our experiments revealed that presynaptic function is tightly controlled by ER Ca²⁺ content. We found that neuronal activity drives net Ca²⁺ uptake into presynaptic ER although this activity does not contribute significantly to shaping cytosolic Ca²⁺ except during prolonged repetitive firing. In contrast, we found that axonal ER acts as an actuator of plasma membrane (PM) function: [Ca²⁺]_ER controls STIM1 acti

SUBMITTER: de Juan-Sanz J 

PROVIDER: S-EPMC5325711 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature