Synaptic Vesicle Generation from Central Nerve Terminal Endosomes

Abstract

Central nerve terminals contain a small number of synaptic vesicles (SVs) that must sustain the fidelity of neurotransmission across a wide range of stimulation intensities. For this to be achieved, nerve terminals integrate a number of complementary endocytosis modes whose activation spans the breadth of these neuronal stimulation patterns. Two such modes are ultrafast endocytosis and activity-dependent bulk endocytosis, which are triggered by stimuli at either end of the physiological range. Both endocytosis modes generate endosomes directly from the nerve terminal plasma membrane, before the subsequent production of SVs from these structures. This review will discuss the current knowledge relating to the molecular mechanisms involved in the generation of SVs from nerve terminal endosomes, how this relates to other mechanisms of SV production and the functional role of such SVs.

Amphiphysin (BIN1) negatively regulates dynamin 2 for normal muscle maturation

“…These data call for further analysis of dynamin regulation by amphiphysins in additional physiological contexts. Whether this is also true for dynamin 1, the brain dynamin implicated in synaptic vesicle replenishment (38,39), remains to be determined.…”

Striatal dopamine neurotransmission: Regulation of release and uptake

“…In addition to flickering modes and kiss-and-run mechanisms, recycling of synaptic vesicle membrane may occur via “bulk endocytosis” of the membranes of many synaptic vesicles [58] or via smaller clathrin coated endosomal intermediates [59,60]. The involvement of dynamin on vesicle retrieval following kiss-and-run exocytosis has been demonstrated by several groups [61].…”

Synaptic vesicle generation from activity‐dependent bulk endosomes requires a dephosphorylation‐dependent dynamin–syndapin interaction

“…Clathrin‐mediated endocytosis (CME) is also triggered during mild periods of neuronal activity (Granseth et al ), however, this mode also saturates during high bursts of high‐frequency firing (Clayton et al ). During these specific periods, activity‐dependent bulk endocytosis (ADBE) is the dominant endocytosis mode (Clayton et al ), forming bulk endosomes direct from the plasma membrane from which SVs are then generated (Kokotos and Cousin ). Both ultrafast and CME refill the RRP (Granseth and Lagnado ; Watanabe et al ), whereas ADBE exclusively replenishes the reserve SV pool (Cheung et al ).…”