Arginine vasotocin modulates associative learning in a mutualistic cleaner fish

Stimulation of dopamine D 1 receptor improves learning capacity in cooperating cleaner fish

“…This study followed the experimental design of Cardoso et al [40] in which two plates with different patterns are presented simultaneously; only one of these plates offers a food reward and, when ignored by the cleaner, is immediately removed (representing the real-life situation where when a visitor client is ignored, it swims away [41]). Two tasks were designed that differed in terms of the cues available to identify the correct choice: in the first task, cleaners needed to identify a specific pattern that consistently provided food, whereas in the second task, they had to identify the site where food was consistently provided.…”

“…Because cleaners eat exclusively off the surface of clients, which vary in terms of parasite or mucus distribution, regardless of location (with clients themselves being mobile), the first task (cue or pattern discrimination) was deemed to be socioecologically more meaningful than the second (side/spatial discrimination). These two different learning situations putatively rely on different neural substrates, with cue learning being Dm dependent and spatial learning being Dl dependent [40]. DA is an appropriate candidate to affect these learning tasks because it is generally linked to the learning process and due to a wide distribution of dopaminergic receptors (D 1 and D 2 in teleost fish) in the forebrain area [24].…”

Using fish models to investigate the links between microbiome and social behaviour: The next step for translational microbiome research?

“…In recent years, a priority has been identification of neurohormonal candidates that may modulate behavioural changes in marine cleaning mutualisms, allowing us to relate social cognition to the underlying mechanistic and neural mechanisms (Soares, ). These studies have highlighted the importance of neuromodulators such as nonapeptide arginine‐vasotocin (AVT), which has substantial motivational and learning effects on cleaners (Cardoso, Paitio, Oliveira, Bshary, & Soares, ; Cardoso, Bshary, et al., ; Soares, Bshary, Mendonça, Grutter, & Oliveira, ). Monoamines such as serotonin and dopamine (DA) also have a crucial impact, with serotonin increases being responsible for changes in motivation to engage mutualistically (Paula, Messias, Grutter, Bshary, & Soares, ), while disruption in dopamine transmission leads the cleaner to anticipate a lower probability of feeding or, alternatively, a higher likelihood of being punished by being chased or the client leaving (Messias, Paula, Grutter, Bshary, & Soares, ).…”

The integration of sociality, monoamines and stress neuroendocrinology in fish models: applications in the neurosciences

“…Thus, different stress response magnitudes, appear to produce significant behavioural responses. Small variations of cortisol produce new metabolic‐dietary demands which justify a change in behavioural pursuit (Soares et al ., ) and the mediation of AVT on the structural, life history changes between cleaning and non‐cleaning, ultimately underlying a switch in social and cognitive output (Soares et al ., , , Cardoso et al ., , ).…”

“…Individual recognition/familiarity (L. dimidiatus) (Tebbich et al, 2002) Alterations in stimulus-outcome expectancies, predicted to vary amongst cleaner species and according to site context, as some species may respond to putative cortisol variations by changing strategic behaviour (also known as manipulatory strategies; Binning et al, 2017) Partner value assessment (L. dimidiatus) (Soares et al, 2008) Eavesdropping and image scoring (L. dimidiatus) (Bshary, 2002;Bshary & Grutter, 2006) Learning and memory Cue and spatial stimuli learning (L. dimidiatus) (Cardoso et al, 2015a) Expected memory biases in stress-related social treatments, both in acquisition and consolidation stages. Reversal learning (L. dimidiatus) (Salwiczek & Bshary, 2011;Salwiczek et al, 2012) Pavlovian conditioning (L. dimidiatus) (Soares et al, 2017a) Reverse reward contingency (L. dimidiatus) (Danisman et al, 2010) Keeping track of when and what (L. dimidiatus) (Salwiczek & Bshary, 2011) Repeated interactions delay (L. bicolor) (Oates et al, 2010) Bonding Pair association (L. dimidiatus) (Cardoso et al, 2015b) Changes in dominance and pair dynamics are expected, which should ultimately alter the service quality provided to clients.…”