Open AccessInnate chemical, but not visual, threat cues have been co‐opted as unconditioned stimulus for social fear learning in zebrafish
Author(s) -
Pinho Julia S.,
Castilho Marisa,
Sollari Joao S.,
Oliveira Rui F.
Publication year - 2020
Publication title -
genes, brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.315
H-Index - 91
eISSN - 1601-183X
pISSN - 1601-1848
DOI - 10.1111/gbb.12688
Subject(s) - sensory cue , stimulus (psychology) , zebrafish , social cue , alarm , fear conditioning , psychology , associative learning , neuroscience , social learning , classical conditioning , cognitive psychology , odor , communication , conditioning , biology , amygdala , pedagogy , biochemistry , statistics , materials science , mathematics , composite material , gene
Animals can use social information to detect threat in the environment. In particular, social learning allows animals to learn about dangers without incurring in the costs of trial‐and‐error learning. In zebrafish, both chemical and visual social cues elicit an innate alarm response, which consists of erratic movement followed by freezing behavior. Injured zebrafish release an alarm substance from their skin that elicits the alarm response. Similarly, the sight of conspecifics displaying the alarm response can also elicit the expression of this response in observers. In this study, we investigated if these social cues of danger can also be used by zebrafish as unconditioned stimulus (US) in learning. We found that only the chemical cue was effective in the social fear conditioning. We suggest that this differential efficacy of social cues results from the fact that the alarm cue is a more reliable indicator of threat, than the sight of an alarmed conspecific. Therefore, although multiple social cues may elicit innate responses not all have been evolutionarily co‐opted to act as US in associative learning. Furthermore, the use of the expression of the immediate early genes as markers of neuronal activity showed that chemical social fear conditioning is paralleled by a differential activation of the olfactory bulbs and by a different pattern of functional connectivity across brain regions involved in olfactory processing.