Meeting Abstract
Grouping behaviour has many benefits for individuals, such as reducing the costs of finding new foraging locations or reducing predation risk. Guppies (Poecilia reticulata) are social fish that live in groups in the rivers of Trinidad. Guppies, like many fish, prefer to join a larger shoal over a less numerous one. However, little is known about the brain regions that are active in teleosts during social exposure. Here, after confirming that wild-type guppies do indeed prefer to join a larger shoal, we investigated the activation of four brain regions proposed to be involved in social behaviour and reward. Subjects were exposed to a large shoal, a small one, or an empty tank, and we used immediate early gene expression (egr1) to assess neuronal activation. We found increased activation in the Preoptic Area when the fish were exposed to a large shoal compared to the control that had no social exposure. There were no significant differences in activation with social exposure within the other brain areas examined (dorsal and ventral parts of the ventral telencephalon, and ventral pallium). Our findings suggest possibilities for future work on social information processing in the Preoptic Area, known to be involved in the production of nonapeptides that modulate vertebrate social behaviour.
