‘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’.