Axonal Trafficking of Synaptic Vesicles is Dynamically Modulated to During Synaptic Plasticity

Neurons use neurotransmitter carrying synaptic vesicles to transmit information at specialized locations called presynapses. Synapses must maintain their connections over long times (stability) but also dynamically change them in response to activity (plasticity). The underlying molecular mechanisms that balance stability/plasticity have long been an open problem. These competing processes also require up/down regulation of proteins and vesicles via intracellular transport across dynamically changing time/space scales. Here we will present our recent work investigating mechanisms of vesicle turnover during plasticity. Specifically, we study dynamic changes in vesicle axonal trafficking using cultured hippocampal neurons and high-resolution fluorescence microscopy. We use this approach to distinguish the rate of vesicle turnover as a function of time after plasticity induction. We show that turnover is dynamically modulated. Our findings, therefore, shed light on the intricate processes that determine how presynapses balance between stability and plasticity.