Serotonin Increases Flexion And Excitatory Junction Potential Amplitude While Octopamine Decreases Average Excitatory Junction Potential Amplitude In Crayfish

Abstract

Serotonin and octopamine are biogenic amines that cause postural changes in crayfish. Their effectiveness is related to the social experience of the animal. In this study, the effect of serotonin and octopamine on postural changes of socially isolated crayfish was analyzed after injecting the amines into the hemolymph at the abdominal thoracic junction. Serotonin increased flexion of the tail, claws, and legs of the crayfish after 30 minutes. However, octopamine treated crayfish showed no significant postural changes. In addition, our study investigated the effects of serotonin and octopamine on excitatory junction potential amplitude (EJP) by stimulating the fast extensor muscles of the crayfish abdomen. Serotonin significantly increased and octopamine significantly decreased average EJP amplitude.