The lonely fish is not a loner fish: whole-brain mapping reveals abnormal activity in socially isolated zebrafish

The zebrafish is used to assess the impact of social isolation on behaviour and brain function. As in humans and other social species, early social deprivation reduces social preference in juvenile zebrafish. Whole-brain functional maps of anti-social isolated fish were distinct from anti-social fish found in the normal population. These isolation-induced activity changes revealed profound disruption of neural activity in brain areas linked to social behaviour, such as the preoptic area and hypothalamus. Several of these affected regions are modulated by serotonin, and we found that social preference in isolated fish could be rescued by acutely reducing serotonin levels.