Neuronal and hormonal control of Ca signalling in exocrine glands: insight from in vivo studies.

Fluid and enzyme secretion from exocrine glands is initiated by Ca signalling in acinar cells and is activated by external neural or hormonal signals. A wealth of information has been derived from studies in acutely isolated exocrine cells but Ca signalling has until recently not been studied in undisrupted intact tissue in live mice. Our in vivo observations using animals expressing genetically encoded Ca indicators in specific cell types in exocrine glands revealed both similarities to and differences from the spatiotemporal characteristics previously reported in isolated cells. These in vivo studies facilitate further understanding of how both neuronal and hormonal input shapes Ca signalling events in a physiological setting and how these signals are translated into the stimulation of fluid secretion and exocytosis.