Unexpected Mobility Variation among Individual Secretory Vesicles Produces an Apparent Refractory Neuropeptide Pool

Most stored neuropeptide cannot be released from nerve terminals suggesting the existence of a refractory pool of dense core vesicles (DCVs). Past fluorescence photobleaching recovery, single particle tracking and release experiments suggested that the refractory neuropeptide pool corresponds to a d...

Full description

Saved in:
Bibliographic Details
Published in:Biophysical journal 2003-06, Vol.84 (6), p.4127-4134
Main Authors: Ng, Yuen-Keng, Lu, Xinghua, Gulacsi, Alexandra, Han, Weiping, Saxton, Michael J., Levitan, Edwin S.
Format: Article
Language:English
Subjects:
Animals
Cell Biophysics
Cell Movement - physiology
Computer Simulation
Diffusion
Endocrine system
Microscopy, Fluorescence - methods
Models, Biological
Nerve Growth Factors - metabolism
Nerve Growth Factors - secretion
Nervous system
Neurology
Neuropeptides - metabolism
PC12 Cells
Peptides
Protein Transport - physiology
Rats
Reproducibility of Results
Secretory Vesicles - physiology
Secretory Vesicles - ultrastructure
Sensitivity and Specificity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Most stored neuropeptide cannot be released from nerve terminals suggesting the existence of a refractory pool of dense core vesicles (DCVs). Past fluorescence photobleaching recovery, single particle tracking and release experiments suggested that the refractory neuropeptide pool corresponds to a distinct immobile fraction of cytoplasmic DCVs. However, tracking of hundreds of individual green fluorescent protein-labeled neuropeptidergic vesicles by wide-field or evanescent-wave microscopy shows that a separate immobile fraction is not evident. Instead, the DCV diffusion coefficient ( D) distribution is unusually broad and asymmetric. Furthermore, the distribution shifts with a release facilitator. This unexpected variation, which could reflect heterogeneity among vesicles or in their medium, is shown to generate the appearance of a regulated refractory neuropeptide pool.
ISSN:0006-3495
1542-0086
DOI:10.1016/S0006-3495(03)75137-6