Serotonin blockade delays learning performance in a cooperative fish
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Animals use learning and memorizing to gather information that will help them to make ecologically relevant decisions. Neuro-modulatory adjustments enable them to make associations between stimuli and appropriate behavior. A key candidate for the modulation of cooperative behavior is serotonin. Previous research has shown that modulation of the serotonergic system spontaneously affects the behavior of the cleaner wrasse Labroides dimidiatus during interactions with so-called ‘client’ reef fish. Here, we asked whether shifts in serotonin function affect the cleaners’ associative learning abilities when faced with the task to distinguish two artificial clients that differ in their value as a food source. We found that the administration of serotonin 1A receptor antagonist significantly slowed learning speed in comparison with saline treated fish. As reduced serotonergic signaling typically enhances fear, we discuss the possibility that serotonin may affect how cleaners appraise, acquire information and respond to client-derived stimuli via manipulation of the perception of danger.
KeywordsSerotonin Learning Cooperation Serotonin 1A receptor WAY 100.635
We thank the Oceanário de Lisboa staff for logistical support, Mariana Ramos, Andreia Teixeira for assistance during experimental trails. We also thank Sónia Cardoso for designing Fig. 1.
MSC was supported by Fundação para a Ciência e Tecnologia (PTDC/MAR/105276/2008) and RB by Swiss Science Foundation 31003AB grant. MSC is currently supported by SFRH/BPD/109433/2015.
Compliance with ethical standards
Human and animal rights statement
Animal procedures used in this study have been approved by the Portuguese Veterinary Office (#0420/000/000/2009).
- Bshary R (2001) The cleaner fish market. In: Noë R, Van Hooff JARAM, Hammerstein P (eds) Economics in nature. Cambridge University Press, Cambridge, pp 146–172Google Scholar
- Davis M (1992) The amygdala: neurobiological aspects of emotion. In: Aggleton JP (ed) Memory, and mental dysfunction. Wiley, NewYork, pp 255–306Google Scholar
- Oliveira RF (2013) Mind the fish: zebrafish as a model in cognitive social neuroscience. Front Neural Circuits 7:e131Google Scholar
- Rogers RD, Blackshaw AJ, Middleton HC, Matthews K, Deakin JFW, Sahakian BJ, Robbins TW (1999) Tryptophan depletion impairs stimulus-reward learning while methylphenidate disrupts attentional control in healthy young adults: implications for the monoaminergic basis of impulsive behaviour. Psychopharmacology 146:482–491CrossRefPubMedGoogle Scholar