Pool size estimations for dense-core vesicles in mammalian CNS neurons

Claudia M. Persoon, Alessandro Moro, Joris P. Nassal, Margherita Farina, Jurjen H. Broeke, Swati Arora, Natalia Dominguez, Jan R. T. van Weering, Ruud F. Toonen, Matthijs Verhage

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Neuropeptides are essential signaling molecules transported and secreted by dense-core vesicles (DCVs), but the number of DCVs available for secretion, their subcellular distribution, and release probability are unknown. Here, we quantified DCV pool sizes in three types of mammalian CNS neurons in vitro and in vivo. Super-resolution and electron microscopy reveal a total pool of 1,400–18,000 DCVs, correlating with neurite length. Excitatory hippocampal and inhibitory striatal neurons in vitro have a similar DCV density, and thalamo-cortical axons in vivo have a slightly higher density. Synapses contain on average two to three DCVs, at the periphery of synaptic vesicle clusters. DCVs distribute equally in axons and dendrites, but the vast majority (80%) of DCV fusion events occur at axons. The release probability of DCVs is 1–6%, depending on the stimulation. Thus, mammalian CNS neurons contain a large pool of DCVs of which only a small fraction can fuse, preferentially at axons.
Original languageEnglish
Article numbere99672
JournalEMBO Journal
Volume37
Issue number20
DOIs
Publication statusPublished - 2018

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