New study on pool sizes published in EMBO J.
Claudia Persoon (CNCR-FGA) & the DCV team published a study on how many secretory vesicles are found in different CNS neurons (this paper is about vesicle pools, not swimming pools!) and how many vesicles fuse upon stimulation. The paper is featured on the cover of EMBO J. this month.
Neuropeptides and neuromodulators 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. In this new study, PhD-student Claudia Persoon and colleagues of the DCV team quantified DCV pool sizes in three types of mammalian CNS neurons in vitro and in vivo. Using confocal microscopy, super-resolution microscopy and electron microscopy they show that the total vesicle pool is between 1,400-18,000 DCVs, correlating with neurite length. Excitatory hippocampal and inhibitory striatal neurons in vitro have a similar DCV density. One of the most eye-catching data sets was produced by PhD-student Joris Nassal (see banner) to quantify DCVs in thalamo-cortical axons in vivo. He observed that these axons have a slightly higher density. The authors also studied synapses and showed that they contain on average 2-3 DCVs, at the periphery of synaptic vesicle clusters. Finally, they show that DCVs distribute equally in axons and dendrites. PhD-student Alessandro Moro performed experiments to study if DCVs can secrete in both compartments. He found that the vast majority (80%) of DCV fusion events occurs at axons. The release probability of DCVs is 1-6%, depending on the stimulation.
This paper is featured on the home page of EMBO journal this month (click here to visit the EMBO J site) and is also on the cover of volume 37 of the journal.