Presynaptic morphology and vesicular composition determine vesicle dynamics in mouse central synapses

Area of Science:

• Neuroscience
• Cell Biology
• Synaptic Physiology

Background:

• Synaptic vesicle (SV) transport is vital for maintaining neurotransmission.
• Understanding factors that modulate SV movement is key to comprehending synaptic function.

Purpose of the Study:

• To investigate the dynamics of SV movements in different nerve terminal types.
• To identify molecular and morphological factors influencing SV mobility.

Main Methods:

• Real-time imaging analysis of fluorescently labeled SVs.
• Comparison of SV movement in giant calyceal and conventional hippocampal terminals.
• Assessment of SVs over-expressing vesicular glutamate transporter 1 (VGLUT1) and VGLUT2.
• Pharmacological disruption of the presynaptic microtubule network.

Main Results:

• SV movements were faster, longer, and more heterogeneous in giant calyceal terminals compared to hippocampal terminals.
• Terminal maturation reduced SV mobility and displacement heterogeneity.
• VGLUT1-expressing SVs exhibited higher mobility than VGLUT2-expressing SVs.
• Microtubule disruption impaired long-directional SV movements.

Conclusions:

• Nerve terminal morphology and vesicle molecular identity (e.g., VGLUT1 vs. VGLUT2) are critical determinants of vesicular dynamics.
• These factors influence SV mobility and movement patterns in central synapses.
• Understanding these dynamics provides insights into neurotransmission regulation.