Leucokinin and Associated Neuropeptides Regulate Multiple Aspects of Physiology and Behavior in Drosophila

Leucokinins (LKs) constitute a family of neuropeptides identified in numerous insects and many other invertebrates. LKs act on G-protein-coupled receptors that display only distant relations to known receptors. In adult Drosophila, 26 neurons/neurosecretory cells three main types express LK. The four brain interneurons are two types, these implicated several important functions the fly’s behavior physiology, including feeding, sleep–metabolism interactions, state-dependent memory formation, as well modulation gustatory sensitivity nociception. 22 neurosecretory (abdominal LK neurons, ABLKs) abdominal neuromeres co-express diuretic hormone (DH44), together, regulate water ion homeostasis associated stress food intake. Drosophila larvae, neurons modulate locomotion, escape responses aspects ecdysis behavior. A set lateral cells, ALKs (anterior neurons), but inconsistently so adults. These homeostasis, drinking, specific role is not yet known. This review summarizes data embryonic lineages functional roles individual neuron interactions with peptidergic systems, orchestrating