Tyraminergic modulation of agonistic outcomes in crayfish

Abstract

Octopamine, a biogenic amine, modulates various behaviors, ranging from locomotion and aggression to learning and memory in invertebrates. Several studies recently demonstrated that tyramine, the biological precursor of octopamine, also affects behaviors independent of octopamine. Here we investigated the involvement of tyramine in agonistic interaction of the male crayfish Procambarus clarkii. When male crayfish fight, larger animals (3-7% difference in body length) are more likely to win. By contrast, direct injection of tyramine or octopamine counteracted the physical advantage of larger animals. Tyramine or octopamine-injected naive large animals were mostly beaten by untreated smaller naive animals. This pharmacological effect was similar to the loser effect in which subordinate larger animals are frequently beaten by smaller animals. Furthermore, loser effects were partly eliminated by either injection of epinastine, an octopamine blocker, or yohimbine, a tyramine blocker, and significantly diminished by injection of a mixture of both blockers. We also observed that tyramine levels in the subesophageal ganglion were remarkably increased in subordinate crayfish after losing a fight. These results suggest that tyramine modulates aggressive levels of crayfish and contributes to the loser effect in parallel with octopamine.

Neural versus alternative integrative systems: molecular insights into origins of neurotransmitters

“…Remarkably, both the formation of social relationships and complex behavioural integrations were performed by balancing similarly diverse subsets of transmitters [37,[79][80][81][82][83][84][85][86] as in early branching animal lineages. Thus, the broadest spectrum of nearly all studied behaviours is inherently traced to multiple transmitter pathways, and the transmitter organization as well as synaptic and non-synaptic integration of behaviors are intrinsically embedded in every neural circuit from a comb jelly to Octopus.…”

Survey of neurotransmitter receptor gene expression into and out of parental care in the burying beetle Nicrophorus vespilloides

“…The a priori contrast was significant for tyrr1 . Tyramine is associated with decreased aggression for arthropods (Momohara et al., 2018 ; Szczuka et al., 2013 ), so decreasing a receptor could increase aggression. We were able to recapitulate previously observed decrease between octopamine α receptor and octopamine/tyramine receptor 1 expression and a female during Resource Preparation (Cunningham et al., 2014 ).…”

Involvement of Melatonin in the Regulation of the Circadian System in Crayfish

“…Additional evidence has shown that agonistic behavior depends on the release of amines with a neurotransmitter function, such as tyramine [ 82 ], octopamine, and serotonin. Serotonin induces an increase on the number and intensity of agonistic encounters in crayfish [ 83 ].…”