Discusses two research being done on the use of fluorescent markers to examine vesicle recycling at small synapses during exocytosis, published in the 2003 issue of 'Nature.' 'Three Modes of Synaptic Vesicular Recycling Revealed by Single-Vesicle Imaging,' by S.P. Gandhi and C.F. Stevens; 'Single Synaptic Vesicles Fusing Transiently and Successively Without Loss of Identity,' by A.M. Aravanis et al.