Maxi-anion channel activity localized in specific regions on freshly isolated adult rat cardiomyocytes. a Topographic image of the area indicated by a white rectangle in the optical image shown at the bottom part on the surface of a cardiomyocyte obtained using scanning ion conductance microscopy (SICM) with a fine nanopipette. The maxi-anion channel activity in patches excised from Z-grooves, T-tubule openings, and scallop crests using the “smart-patch” technique are shown on the right side. b Swelling-induced activation of the maxi-anion channel activity in sarcolemma of adult cardiomyocytes. Mean patch currents recorded at +50 mV (open circles) and −50 mV (filled circles) in a cell-attached patch before and during (horizontal bar) exposure to hypotonic solution. Single-channel I–V relationship for these on-cell events is shown on the lower panel. Each symbol represents the mean ± SEM (vertical bar). Modified from Dutta et al.