Autism spectrum disorders (ASD) are among the most severe psychiatric disorders in childhood in terms of prevalence, outcome, impact on families and cost to society. Social dysfunctions are a core, disabling symptom of ASD. Since the neurobiology of social behavior is largely unknown, there are no drugs available to treat social dysfunctions in ASD. Although no animal model can capture all the molecular and behavioral features of ASD, animal studies of normal and abnormal social behavior can provide unique insights into the social impairments in ASD. My aim is therefore to investigate the neurobiology of social behavior in adolescent rats, in normal and impaired conditions. I will focus on the most characteristic social activity displayed by young mammals: social play behavior. Social play is highly rewarding and is essential for proper development, both in adolescent rats and human children. Importantly, social play is highly impaired in ASD children. Although the neurobiology of social play is largely unknown, my studies have shown that neurotransmitters involved in positive emotions, such as opioids, cannabinoids and dopamine, positively modulate social play. On this basis, my aims are: 1. identify the neural circuits of social play; 2. investigate whether drugs that increase social play ameliorate experimentally-induced impairments in social behavior in rat models of social dysfunction that strongly resemble ASD. By focusing on social dysfunctions as a crucial phenotype in ASD, I will investigate neurobiological aspects of ASD that cannot be studied in humans, in order to 1. understand the abnormal social behaviors that characterize ASD; 2. provide novel drug targets to treat social dysfunctions in ASD. I’ve been appointed as Assistant Professor in my Country, after a 5-year training abroad. This grant will allow me to transfer the knowledge gained abroad in my Country, and will make a substantial contribution to the scientific success of my future career.