Chapter 14 - Octopaminergic and Tyraminergic Signaling in the Honeybee (Apis mellifera) Brain: Behavioral, Pharmacological, and Molecular Aspects

Abstract

The central nervous system is exquisitely tuned to provide an organism with the ability to respond and adapt dynamically to changing environmental stimuli. An important group of compounds controlling neuronal and physiological activity is the biogenic amines. Notably, adrenergic transmitters present in deuterostomes are functionally substituted by octopamine and tyramine in protostomes. These phenolamines control and modulate various physiological processes and behaviors in insects. The honeybee, Apis mellifera, with its rich behavioral repertoire, proved to be excellently suited to uncover the functions of phenolamines in behavior. Both amines bind to specific receptors located in the cell’s surface membrane. All honeybee phenolamine receptors belong to the superfamily of G-protein-coupled receptors. Activation of these receptors leads to transient changes in concentrations of intracellular second messengers. We will summarize current knowledge on behavioral effects of octopamine and tyramine in the honeybee and on the molecular identity, properties, and distribution of the respective receptors.