Limulus ventral photoreceptors receive synaptic input from fibers that emerge from the brain and that appear to use octopamine as a transmitter. Exogenous application of octopamine has been shown to increase levels of intracellular cAMP in ventral photoreceptors, but the resulting physiological effects have been unclear. In this report, we show that octopamine increases the rate of dark-adaptat...

In Drosophila the monoamine octopamine, through mechanisms that are not completely resolved, regulates both aggression and mating behaviour. Interestingly, our study demonstrates that the Drosophila obesity-linked homologues Transcription factor AP-2 (TfAP-2, TFAP2B in humans) and Tiwaz (Twz, KCTD15 in humans) interact to modify male behaviour by controlling the expression of Tyramine -hydroxy...

Previous findings showed that high levels of octopamine and serotonin in the antennal lobes of adult worker honey bees are associated with foraging behavior, and octopamine treatment induces precocious foraging. To better characterize the relationship between amines and foraging behavior in honey bees, we performed a detailed correlative analysis of amine levels in the antennal lobes as a funct...

Adrenergic receptors and their ligands are important regulators of synaptic plasticity and metaplasticity, but the exact mechanisms underlying their action are still poorly understood. Octopamine, the invertebrate homolog of mammalian adrenaline or noradrenaline, plays important roles in modulating behavior and synaptic functions. We previously uncovered an octopaminergic positive-feedback mech...

Efferent nerves coursing from the brain to the lateral eye of the horseshoe crab, Limulus polyphemus, increase its nighttime sensitivity to light. They release octopamine, which produces a categorical increase of photoreceptor response duration in vitro. Analogous in vivo timing effects on the electroretinogram (ERG) were demonstrated when octopamine was infiltrated into the eye of an otherwise...

An octopaminergic neurone in an insect is demonstrated. This cell (DUMETi) is the dorsal unpaired median neurone which projects to the extensor tibiae muscle of the locust metathoracic leg. Its soma was physiologically identified, isolated and shown to contain about 0.1 pmol of octopamine. Octopamine is about four times more concentrated in the axon than in the soma. The concentration in the so...

The southern cattle tick (Rhipicephalus (Boophilus) microplus) is a hematophagous external parasite that vectors the causative agents of bovine babesiosis or cattle tick fever, Babesia bovis and B. bigemina, and anaplasmosis, Anaplasma marginale. The southern cattle tick is a threat to the livestock industry in many locations throughout the world. Control methods include the use of chemical aca...

Aggression is a common behavioral strategy employed by animals to secure limited resources, but must be applied with restraint to limit potential costs including injury. How animals make the adaptive decision to fight or flee is barely known. Here, we review our work on crickets that reveals the roles of biogenic amines, primarily octopamine (the insect analog of noradrenaline) and nitric oxide...

Octopamine has been identified and measured in individual neurons from Aplysia californica. Neither dopamine nor norepinephrine was detected in these cells. Thus, in Aplysia there may be separate populations of catecholaminergic and monophenolaminergic cells. Octopamine may have functions of its own in the central nervous system of mollusks.