Key words:  Gene expression, Neurotransmitter release, Behaviour, Development.

Inositol-1,4,5 trisphosphate (IP3) is a key cellular signaling molecule that functions downstream of specific G-protein coupled receptors and links GPCR activation to changes in intracellular Ca2+.  My group studies the primary cellular target of IP3, which is the endoplasmic reticulum localized ligand-gated calcium channel, the IP3 receptor (IP3R).  We also study the consequences of store-operated calcium entry (SOCE), which is stimulated upon IP3-mediated Ca2+ release from the ER-store. Our interest is to understand the developmental and physiological consequences of IP3 signaling and SOCE in neurons in the context of the whole organism. This requires that we perturb IP3R function and SOCE specifically in neurons and not in other cell types. The ubiquitous expression of the IP3R as well as the key SOCE components, STIM and Orai, in multiple cell types in all multicellular organisms is a challenge for achieving this aim. Traditionally, cellular functions of ubiquitous proteins have been addressed using pharmacological methods on cells in culture. However, this approach does not allow an understanding of the physiological and/or developmental function of the targeted protein in the context of the whole organism. Sophisticated genetic tools, either available or developed by us in the fruit fly Drosophila melanogaster, have helped understand the consequences of cell and tissue specific abrogation of IP3R function as well as SOCE. I will present our recent findings in this area.