'Perforated patch recording' allows long-term monitoring of metabolite-induced electrical activity and voltage-dependent Ca2+ currents in pancreatic islet B cells.

We describe the application of 'perforated patch recording' using the pore-forming antibiotic nystatin, to monitor the electrical activity and underlying ionic currents of rat and human pancreatic islet B cells. We demonstrate that glucose-induced electrical activity is seen even in single B cells during current-clamp recordings lasting hours 'L-type' Ca2+-channel currents can also be monitored over this period of time. This technique may prove useful in examining hormone and neurotransmitter modulation of electrical activity in B cells, while minimizing the effects of cytoplasmic 'wash-out'.