Show simple item record

dc.contributor.authorOrmerod, Kiel G
dc.contributor.authorHadden, Julia K
dc.contributor.authorLylah D, Deady
dc.contributor.authorJoffre, Mercier
dc.contributor.authorJacob, Krans
dc.date.accessioned2015-04-30T18:41:41Z
dc.date.available2015-04-30T18:41:41Z
dc.date.issued2012-10
dc.identifier.citationAction of octopamine and tyramine on muscles of Drosophila melanogaster larvae. J Neurophysiol. 2013 Oct;110(8):1984-96. doi: 10.1152/jn.00431.2013.en_US
dc.identifier.issn00223077
dc.identifier.other10.1152/jn.00431.2013
dc.identifier.urihttp://hdl.handle.net/10464/6361
dc.description.abstractOctopamine (OA) and tyramine (TA) play important roles in homeostatic mechanisms, behavior, and modulation of neuromuscular junctions in arthropods. However, direct actions of these amines on muscle force production that are distinct from effects at the neuromuscular synapse have not been well studied. We utilize the technical benefits of the Drosophila larval preparation to distinguish the effects of OA and TA on the neuromuscular synapse from their effects on contractility of muscle cells. In contrast to the slight and often insignificant effects of TA, the action of OA was profound across all metrics assessed. We demonstrate that exogenous OA application decreases the input resistance of larval muscle fibers, increases the amplitude of excitatory junction potentials (EJPs), augments contraction force and duration, and at higher concentrations (10(-5) and 10(-4) M) affects muscle cells 12 and 13 more than muscle cells 6 and 7. Similarly, OA increases the force of synaptically driven contractions in a cell-specific manner. Moreover, such augmentation of contractile force persisted during direct muscle depolarization concurrent with synaptic block. OA elicited an even more profound effect on basal tonus. Application of 10(-5) M OA increased synaptically driven contractions by ≈ 1.1 mN but gave rise to a 28-mN increase in basal tonus in the absence of synaptic activation. Augmentation of basal tonus exceeded any physiological stimulation paradigm and can potentially be explained by changes in intramuscular protein mechanics. Thus we provide evidence for independent but complementary effects of OA on chemical synapses and muscle contractility.en_US
dc.language.isoen_USen_US
dc.subjectbiogenic amineen_US
dc.subjectfight or flighten_US
dc.subjectforceen_US
dc.subjectneuromuscular junctionen_US
dc.titleThe action of octopamine on muscles of Drosophila melanogaster larvaeen_US
dc.typePreprinten_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record