S-117 | Effect of early social isolation on risk assessment in zebrafish

Sensory and Motor Systems
Author: Valentin Azar | Email: azarvalentin8@gmail.com

Valentin Azar^1°, Valentin Agulló^1°, Nicolás Martorell^1°,  Violeta Medan^1°

^1° FCEN-UBA / IFIBYNE – CONICET

Early postnatal social interaction is critical for establishing proper behavioral patterns, while social isolation during early development is a risk factor for depression, anxiety and autistic-type disorders. Zebrafish (ZF) are social vertebrates that aggregate in groups both in nature and in the laboratory and are susceptible to social isolation. In this work, we asked whether early social isolation affects risk assessment, multisensory integration of danger stimuli and social preference for other conspecifics. Taking advantage that ZF do not require parental care, we kept ZF in groups of 50 individuals or in individual opaque containers since egg fertilization and tested their behavior 10-30 days post fertilization. We evaluated ZF escape behavior in response to visual, acoustic or multisensory stimuli. Isolated ZF showed lower escape thresholds than control ZF. However, while the combination of an auditory and a visual (multisensory) stimulus increases the probability of escape in control ZF, isolated ZF did not show significant multisensory integration. We analyzed visual preference for conspecifics by offering the focal fish two options: either to look at other fish or to observe an empty chamber. We found that isolated ZF exhibited a lower visual preference index compared to control ZF. Our results suggest that social isolation leads to hyper-reactivity to threatening stimuli and reduces multisensory integration, while abolishing visual preference for conspecifics.