Functioning of Synaptic Vesicle Pools: Diversity and Organizational Principles

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• Presynaptic nerve terminals utilize synaptic vesicles (SVs) filled with neurotransmitters for neuronal signaling.
• Despite similar morphology, SVs exhibit functional heterogeneity, organized into distinct pools with varying exocytosis and recycling properties.

Purpose of the Study:

• To systematically review the organizational features of synaptic vesicle pools in central and peripheral synapses.
• To explore the implications of SV pool structure changes in synaptic plasticity, drug action, and neurological disorders.

Main Methods:

• Systematic literature review of synaptic vesicle pool organization.
• Analysis of studies on synaptic plasticity, pharmacology, and neurodegenerative diseases related to SVs.

Main Results:

• Synaptic vesicles are functionally heterogeneous, categorized into multiple pools (e.g., readily releasable, recycling, reserve, spontaneously recycling).
• Different SV pools exhibit distinct exocytosis, endocytosis, and recycling kinetics, with interpool mixing varying by synapse type and condition.
• Alterations in SV pool organization are implicated in synaptic plasticity, drug mechanisms, and the pathogenesis of neurodegenerative diseases.

Conclusions:

• The functional heterogeneity and dynamic organization of synaptic vesicle pools are fundamental to synaptic function and plasticity.
• Dysregulation of SV pool dynamics contributes to neurological disorders, highlighting them as potential therapeutic targets.