Morgane Rosendale, Damien Jullié, Daniel Choquet & David Perrais
Endocytosis in neuronal dendrites is known to play a critical role in synaptic transmission and plasticity such as long term depression (LTD). However, the inability to detect endocytosis directly in living neurons has hampered studies of its dynamics and regulation. Here we visualized the formation of individual endocytic vesicles containing pHluorin tagged receptors with high temporal resolution in dendrites of cultured hippocampal neurons. We show that transferrin receptors (TfRs) are constitutively internalized at optically static clathrin coated structures. These structures are slightly enriched near synapses which represent preferential sites for the endocytosis of postsynaptic AMPA-type receptors (AMPARs), but not for non-synaptic TfRs. Moreover, the frequency of AMPAR endocytosis events increases after induction of NMDAR-dependent chemical LTD but the activity of perisynaptic endocytic zones is not differentially regulated. We conclude that endocytosis is a highly dynamic and stereotyped process which internalizes receptors in precisely located endocytic zones.