Definition of social interaction and the dopaminergic system Social behavior can be defined as “any modality of communication and/or interaction between two conspecifics of a given species” (1). The mesolimbic pathway plays a fundamental part in social interaction (2). It is made up of dopaminergic neurons that project from the ventral tegmental area (VTA) to the ventral striatum, which includes the nucleus accumbens (NAcc) and olfactory tubercle (3).