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Updated: May 6, 2026
Quantifying Synapses: an Immunocytochemistry-based Assay to Quantify Synapse Number
Published on: November 16, 2010
A new efficient method for synaptic vesicle quantification reveals differences between medial prefrontal cortex
Nicoletta Nava1, Fenghua Chen, Gregers Wegener
1Stereology and Electron Microscopy Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, 8000, Aarhus C, Denmark; Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, 8240, Risskov, Denmark.
Perforated synapses (PSs) have significantly more vesicles than non-perforated synapses (NPSs), correlating with larger synaptic terminal size. This suggests PSs may support higher synaptic strength in the medial prefrontal cortex.
Area of Science:
- Neuroscience
- Cell Biology
- Electron Microscopy
Background:
- Neuronal communication relies on neurotransmitter release from presynaptic vesicles.
- Understanding synaptic vesicle dynamics is crucial for synaptic function and plasticity.
Purpose of the Study:
- To quantitatively analyze synaptic vesicles in excitatory synapses using an efficient ultrastructural method.
- To compare vesicle content and terminal morphology between perforated (PSs) and non-perforated (NPSs) synapses in the medial prefrontal cortex (mPFC).
Main Methods:
- Quantitative ultrastructural analysis of serial sections from rat mPFC excitatory synapses.
- Hierarchical sampling and transmission electron microscopy.
- Cavalieri estimator for unbiased 3D volume estimation and correction factors for vesicle quantification.
Main Results:
- Perforated synapses (PSs) showed significantly higher numbers of docked (77% increase) and reserve-pool vesicles (78% increase) compared to non-perforated synapses (NPSs).
- PSs exhibited larger active zone areas (86% increase) and bouton volumes (105% increase) than NPSs.
- Positive correlations were observed between vesicle pools, active zone area, and bouton volume.
Conclusions:
- The study confirms larger sizes of mPFC PSs and a linear correlation between presynaptic features.
- A higher number of docked vesicles in PSs may contribute to enhanced synaptic strength.
- The developed method offers an efficient alternative to 3D reconstruction for vesicle quantification.
