Abstract
Associative learning, such as classical or operant conditioning, has never been unequivocally associated with animals outside bilatarians, e.g., vertebrates, arthropods, or mollusks. Learning modulates behavior and is imperative for survival in the vast majority of animals. Obstacle avoidance is one of several visually guided behaviors in the box jellyfish, Tripedalia cystophora Conant, 1897 (Cnidaria: Cubozoa), and it is intimately associated with foraging between prop roots in their mangrove habitat. The obstacle avoidance behavior (OAB) is a species-specific defense reaction (SSDR) for T. cystophora, so identifying such SSDR is essential for testing the learning capacity of a given animal. Using the OAB, we show that box jellyfish performed associative learning (operant conditioning). We found that the rhopalial nervous system is the learning center and that T. cystophora combines visual and mechanical stimuli during operant conditioning. Since T. cystophora has a dispersed central nervous system lacking a conventional centralized brain, our work challenges the notion that associative learning requires complex neuronal circuitry. Moreover, since Cnidaria is the sister group to Bilateria, it suggests the intriguing possibility that advanced neuronal processes, like operant conditioning, are a fundamental property of all nervous systems.
Originalsprog | Engelsk |
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Tidsskrift | Current Biology |
Vol/bind | 33 |
Udgave nummer | 19 |
Sider (fra-til) | 4150-4159.e5 |
Antal sider | 10 |
ISSN | 0960-9822 |
DOI | |
Status | Udgivet - 2023 |
Bibliografisk note
Funding Information:The authors are grateful for the technical assistance offered by Mathias Hoppe, Ingo Klein, Olaf Wendt, and Holger Voigt (Kiel University) and the help from the members of the Sensory Biology Group (University of Copenhagen) with maintaining the cultures. We acknowledge the three anonymous reviewers who helped tighten the manuscript. Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation ) – Project-ID 434434223 – SFB 1461 (J.B.), Danish Research Council (DFF) – grant no. 4181-00398 (A.G.), and The Villum Foundation – grant no. 40837 (A.G.).
Publisher Copyright:
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