Preliminary Data Regarding the Potential of Oxytocin to Modulate Aggressive Behaviour in a VPA-Based Animal Model of Autism Spectrum Disorder.

Background/Objectives: Aggressive behaviour is commonly associated with neurodevelopmental disorders, such as autism spectrum disorder (ASD), and could be understood as a response to daily stress routines, which negatively impacts patients' quality of life. Oxytocin (OT), a neuropeptide involved in social bonding and socio-affective regulation, has emerged as a promising candidate to enrich, rather than replace, current pharmacological approaches in managing ASD-associated aggressive behaviour. In this study, we examined the potential of OT to modulate aggressive behaviour frequency in a VPA-based animal model of ASD. Methods: Sixty adult zebrafish (1:1 sex ratio) were divided into six groups (n = 10/group) and received the following treatment for 7 consecutive days: CTR-control (no treatment); VPA (28.8 mg/L valproic acid); OT (33.2 ng/mL oxytocin); RIS (170 μg/L risperidone); VPA + OT (28.8 mg/L valproic acid and 33.2 ng/mL oxytocin); and VPA + RIS (28.8 mg/L valproic acid and 170 μg/L risperidone). The locomotor performance, and socio-affective and aggressive behaviours, were measured in the Novel Tank and Mirror Biting tests at the end of the treatments. Results: We observed that the VPA treatment led to locomotion and socio-affective impairments, as well as aggressive behaviour. Also, we found that OT and RIS had comparable potential to modulate the frequency of aggressive and anxiety-like behaviours. Conclusions: Our preliminary data showed that OT has the potential to modulate the frequency of anxiety-like and aggressive behaviours, similarly to the atypical antipsychotic, RIS, in our VPA zebrafish model. However, further studies are needed to investigate the mechanisms of action and their potential synergistic effects.