Figure 4

The use of pHlourin tags to image surface receptors and receptor exocytosis. (A) pHlourin fluorescence is quenched within the acidic domain of the endosome, ensuring that only surface receptors are imaged. (B) pHlourins report surface GluR1-containing AMPA receptors in a transfected hippocampal neuron in dissociated cell culture. Fluorescence of pHlourin-tagged GluR1 subunits prior to, 2 minutes, and 8 minutes following photobleaching. Fluorescence recovery is mediated primarily by newly exocytosed receptors, as lateral exchange of bleached and unbleached surface receptors is limited under these conditions. Induction of chemical LTP results in a greater number of labelled puncta after photobleaching. Figure 4B: Reprinted from Neuron, 64 (3), Makino, H. and R. Malinow, AMPA receptor incorporation into synapses during LTP: the role of lateral movement and exocytosis, p381-90., Copyright (2009), with permission from Elsevier.