Research Interests

As a physiologist, I have studied exocytosis and endocytosis, two processes fundamental to every cell. During exocytosis, vesicles fuse with the plasma membrane and secrete their contents into the extracellular space. During endocytosis, the membrane thus added to the cell surface is taken back into the cell. In high-speed recordings, we observed the exocytosis of single vesicles, and discovered that membrane fusion starts with the opening of a pore no larger than that formed by some ion channels. Fusion often proceeds no further, and the vesicle simply re-seals. We wonder how such re-sealing is molecularly related to endocytosis. Now we image single vesicles by evanescent field fluorescence microscopy, and track their membranes through exo- and endocytosis. By labeling individual proteins in different colors, we observe their recruitment and release by single organelles, and also record the minute movements executed by the organelles as they fuse with, or separate from, the plasma membrane. Such observations will detect the mechanical forces accompanying membrane fusion and fission, and their relationship to the proteins that may cause them.

Membership Type


Election Year


Primary Section

Section 24: Cellular and Molecular Neuroscience

Secondary Section

Section 23: Physiology and Pharmacology