Determining the role of activity-dependent bulk endocytosis via new molecules

Synaptic vesicle (SV) endocytosis is essential for the maintenance of neurotransmission, particularly during intense neuronal activity. Under these conditions the dominant endocytosis mode is activity-dependent bulk endocytosis (ADBE), suggesting it should perform a central role. However determining the physiological role of ADBE has been hindered by a limited understanding of its molecular mechanism. We propose to address these challenges by discovering presynaptic molecules with a specific and selective role in ADBE. This will be achieved by integrating functional proteomics, a spectrum of complementary SV recycling assays and detailed molecular studies to establish a mechanistic basis for key steps in ADBE. This will facilitate generation of transgenic rodents and molecular tools to disrupt / enhance specific stages of ADBE in vivo. Importantly, this research strategy is already established with a series of presynaptic molecules discovered that have specific roles in ADBE. We will exploit these findings to determine how ADBE impacts on neurotransmission at the synaptic, neuronal, circuit and behavioural level. This work will reveal fundamental mechanisms that underpin neurotransmitter release during high intensity firing, and potentially ADBE-specific interventions that will manipulate presynaptic performance exclusively during intense neuronal activity.