Exocytosis of peptides and steroids stored in a dense core vesicular (DCV) form is the final step of every secretory pathway, indispensable for the function of nervous, endocrine and immune systems. The lack of live imaging techniques capable of direct, label‐free visualisation of DCV release makes many aspects of the exocytotic process inaccessible to investigation. We describe the application of correlative scanning ion conductance and fluorescence confocal microscopy (SICM‐FCM) to study the exocytosis of individual granules of insulin from the top, non‐adherent, surface of pancreatic β‐cells. Using SICM‐FCM, we were first to directly follow the topographical changes associated with physiologically‐induced release of insulin DCVs. This allowed us to report the kinetics of the full fusion of the insulin vesicle as well as the subsequent solubilisation of the released insulin crystal.
Bibliographical noteFunding Information:
This work was supported by BBSRC funding to A.S. (BB/M022080/1). P.N. acknowledges support from the Russian Science Foundation (grant no. 19‐79‐30062). Y.K. acknowledges support from the World Premier International Research Center Initiative (WPI), MEXT, Japan.
© 2020 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society
Copyright 2020 Elsevier B.V., All rights reserved.
- dense core vesicle
- fusion pore