Measured by in vivo microdialysis technique in relation to changes in 5-HT release. Psychopharmacology (Berl) 2004;172(2):1198. Diksic M, Young SN. Study of your brain serotonergic technique with labeled alpha-methyl-L-tryptophan. J Tropinone Biological Activity Neurochem 2001;78 (6):118500. Sneddon JM. Blood platelets as a model for monoaminecontaining neurones. Prog Neurobiol 1973;1(2):1518. Stahl SM. The human platelet. A diagnostic and research tool for the study of biogenic amines in psychiatric and neurologic issues. Arch Gen Psychiatry 1977;34(5):5096. Bianchi M, Moser C, Lazzarini C, Vecchiato E, Crespi F. Forced swimming test and fluoxetine therapy: in vivo proof thatARTICLE41467-019-11408-OPENMaintenance of cell type-specific connectivity and circuit function requires Tao kinaseFederico Marcello Tenedini1, Maria S z Gonz ez1, Chun Hu1, Lisa Hedegaard Pedersen1, Mabel Matamala Petruzzi1, Bettina Spitzweck1, Denan Wang1, Melanie Richter2, Meike Petersen1, Perospirone Purity Emanuela Szpotowicz3, Michaela Schweizer3, Stephan J. Sigrist4, Froylan Calderon de Anda2 Peter Soba1234567890():,;Sensory circuits are typically established through early development, however how circuit specificity and function are maintained for the duration of organismal development has not been elucidated. To achieve insight we quantitatively investigated synaptic growth and connectivity in the Drosophila nociceptive network in the course of larval improvement. We show that connectivity in between main nociceptors and their downstream neurons scales with animal size. We additional identified the conserved Ste20-like kinase Tao as a damaging regulator of synaptic development necessary for upkeep of circuit specificity and connectivity. Loss of Tao kinase resulted in exuberant postsynaptic specializations and aberrant connectivity throughout larval growth. Working with functional imaging and behavioral analysis we show that loss of Tao-induced ectopic synapses with inappropriate companion neurons are functional and alter behavioral responses within a connectionspecific manner. Our data show that fine-tuning of synaptic development by Tao kinase is expected for maintaining specificity and behavioral output in the neuronal network for the duration of animal growth.Patterning and Connectivity laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany. two Neuronal Development laboratory, Center for Molecular Neurobiology (ZMNH), University Medical Center HamburgEppendorf, Falkenried 94, 20251 Hamburg, Germany. three Electron microscopy unit, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany. four Institute of Biology, Free of charge University Berlin, Takustr. 6, 14195 Berlin, Germany. Correspondence and requests for components needs to be addressed to P.S. (e-mail: [email protected])NATURE COMMUNICATIONS | (2019)ten:3506 | 41467-019-11408-1 | www.nature.comnaturecommunications1 NeuronalARTICLENATURE COMMUNICATIONS | 41467-019-11408-he function of a neuronal circuit is determined by synaptic strength and patterns of connectivity that let facts to flow in a distinct manner to elicit behavior. Many circuits are formed during early improvement and undergo plastic changes such as pruning and activity-dependent refinement to establish and adjust functional connectivity1. When the mechanisms of circuit establishment and refinement have been extensively studied in lots of systems, a less well-understood method is how circuits remain.