@article {477, title = {A genetic RNAi screen for IP$_{3}$/Ca{\texttwosuperior}$^{+}$ coupled GPCRs in Drosophila identifies the PdfR as a regulator of insect flight. [Drosophila facility]}, journal = {PLoS Genet}, volume = {9}, year = {2013}, month = {2013}, pages = {e1003849}, abstract = {

Insect flight is regulated by various sensory inputs and neuromodulatory circuits which function in synchrony to control and fine-tune the final behavioral outcome. The cellular and molecular bases of flight neuromodulatory circuits are not well defined. In Drosophila melanogaster, it is known that neuronal IP3 receptor mediated Ca{\texttwosuperior}$^{+}$ signaling and store-operated Ca{\texttwosuperior}$^{+}$ entry (SOCE) are required for air-puff stimulated adult flight. However, G-protein coupled receptors (GPCRs) that activate intracellular Ca{\texttwosuperior}$^{+}$ signaling in the context of flight are unknown in Drosophila. We performed a genetic RNAi screen to identify GPCRs that regulate flight by activating the IPIP$_{3}$ receptor. Among the 108 GPCRs screened, we discovered 5 IPIP$_{3}$/Ca{\texttwosuperior}$^{+}$ linked GPCRs that are necessary for maintenance of air-puff stimulated flight. Analysis of their temporal requirement established that while some GPCRs are required only during flight circuit development, others are required both in pupal development as well as during adult flight. Interestingly, our study identified the Pigment Dispersing Factor Receptor (PdfR) as a regulator of flight circuit development and as a modulator of acute flight. From the analysis of PdfR expressing neurons relevant for flight and its well-defined roles in other behavioral paradigms, we propose that PdfR signaling functions systemically to integrate multiple sensory inputs and modulate downstream motor behavior.

}, keywords = {Adult, Animals, Calcium Signaling, Drosophila melanogaster, Drosophila Proteins, Flight, Animal, Humans, Inositol 1,4,5-Trisphosphate Receptors, Neurons, Receptors, G-Protein-Coupled, RNA Interference, Signal Transduction}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003849}, author = {Agrawal, Tarjani and Sadaf, Sufia and Hasan, Gaiti} } @article {721, title = {Synaptic activity in serotonergic neurons is required for air-puff stimulated flight in Drosophila melanogaster.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e46405}, abstract = {

BACKGROUND: Flight is an integral component of many complex behavioral patterns in insects. The giant fiber circuit has been well studied in several insects including Drosophila. However, components of the insect flight circuit that respond to an air-puff stimulus and comprise the flight central pattern generator are poorly defined. Aminergic neurons have been implicated in locust, moth and Drosophila flight. Here we have investigated the requirement of neuronal activity in serotonergic neurons, during development and in adults, on air-puff induced flight in Drosophila.

METHODOLOGY/PRINCIPAL FINDINGS: To target serotonergic neurons specifically, a Drosophila strain that contains regulatory regions from the TRH (Tryptophan Hydroxylase) gene linked to the yeast transcription factor GAL4 was used. By blocking synaptic transmission from serotonergic neurons with a tetanus toxin transgene or by hyperpolarisation with Kir2.1, close to 50\% adults became flightless. Temporal expression of a temperature sensitive Dynamin mutant transgene (Shi(ts)) suggests that synaptic function in serotonergic neurons is required both during development and in adults. Depletion of IP(3)R in serotonergic neurons via RNAi did not affect flight. Interestingly, at all stages a partial requirement for synaptic activity in serotonergic neurons was observed. The status of serotonergic neurons was investigated in the central nervous system of larvae and adults expressing tetanus toxin. A small but significant reduction was observed in serotonergic cell number in adult second thoracic segments from flightless tetanus toxin expressing animals.

CONCLUSIONS: These studies show that loss of synaptic activity in serotonergic neurons causes a flight deficit. The temporal focus of the flight deficit is during pupal development and in adults. The cause of the flight deficit is likely to be loss of neurons and reduced synaptic function. Based on the partial phenotypes, serotonergic neurons appear to be modulatory, rather than an intrinsic part of the flight circuit.

}, keywords = {Animals, Cell Count, Central Nervous System, DNA-Binding Proteins, Drosophila melanogaster, Drosophila Proteins, Dynamins, Flight, Animal, Gene Expression Regulation, Developmental, Larva, Potassium Channels, Inwardly Rectifying, Pupa, Saccharomyces cerevisiae Proteins, Serotonergic Neurons, Synaptic Transmission, Tetanus Toxin, Transcription Factors, Transgenes, Tryptophan Hydroxylase}, issn = {1932-6203}, doi = {10.1371/journal.pone.0046405}, author = {Sadaf, Sufia and Birman, Serge and Hasan, Gaiti} }