Serotonin and vasotocin function in territoriality

Area of Science:

• Ethopharmacology
• Neuroendocrinology
• Animal Behavior

Background:

• Territoriality is crucial for social systems and resource defense.
• The roles of neuroendocrine systems, specifically serotonergic and vasotonergic systems, in modulating territorial behavior are not fully understood.

Purpose of the Study:

• To investigate the ethopharmacological effects of arginine vasotocin (AVT) and serotonin (5HT) on territorial behavior in male coquí frogs (Eleutherodactylus coqui).
• To determine the specific influences of AVT and 5HT on components of territoriality, including calling, displays, and movement.

Main Methods:

• A long-term field study involving adult male coquí frogs, both territorial and non-territorial.
• Intraperitoneal injections of AVT, 5HT agonists (DOI and 8-OH-DPAT), or saline (control).
• Two-injection protocol where males received different drug classes sequentially, followed by detailed observation of behaviors and vocalizations.

Main Results:

• AVT significantly activated the initiation of advertisement calling, dominant physical displays, and movement associated with territorial behavior.
• 5HT significantly suppressed advertisement calling and dominant physical displays, while affecting calling rate.
• Opposing effects of AVT and 5HT on key territorial behaviors were observed.

Conclusions:

• Both 5HT and AVT profoundly impact territoriality in Eleutherodactylus coqui.
• These neuroendocrine systems play fundamental, often opposing, roles in governing territorial behavior in social systems.
• The findings highlight the complex interplay between neurochemistry and social behavior regulation.