title: Autoregulatory and paracrine control of synaptic and behavioral plasticity by octopaminergic signaling.
abstract: Adrenergic signaling has important roles in synaptic plasticity and metaplasticity. However, the underlying mechanisms of these functions remain poorly understood. We investigated the role of octopamine, the invertebrate counterpart of adrenaline and noradrenaline, in synaptic and behavioral plasticity in Drosophila. We found that an increase in locomotor speed induced by food deprivation was accompanied by an activity- and octopamine-dependent extension of octopaminergic arbors and that the formation and maintenance of these arbors required electrical activity. Growth of octopaminergic arbors was controlled by a cAMP- and CREB-dependent positive-feedback mechanism that required Octβ2R octopamine autoreceptors. Notably, this autoregulation was necessary for the locomotor response. In addition, octopamine neurons regulated the expansion of excitatory glutamatergic neuromuscular arbors through Octβ2Rs on glutamatergic motor neurons. Our results provide a mechanism for global regulation of excitatory synapses, presumably to maintain synaptic and behavioral plasticity in a dynamic range.
authors.affiliation: Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Alex C
authors.initials: AC
authors.lastname: Koon
authors.forename: James
authors.initials: J
authors.lastname: Ashley
authors.forename: Romina
authors.initials: R
authors.lastname: Barria
authors.forename: Shamik
authors.initials: S
authors.lastname: DasGupta
authors.forename: Ruth
authors.initials: R
authors.lastname: Brain
authors.forename: Scott
authors.initials: S
authors.lastname: Waddell
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Alkema
authors.forename: Vivian
authors.initials: V
authors.lastname: Budnik
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004330:Drosophila; D006706:Homeostasis; D006815:Hunger / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009046:Motor Neurons / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology*; D009655:Octopamine / Q000378:metabolism*; D017982:Receptors, Biogenic Amine / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D017362:Cyclic AMP Response Element-Binding Protein; D017982:Receptors, Biogenic Amine; C027604:norsynephrine receptor; D009655:Octopamine; D000242:Cyclic AMP