Washbourne, PhilipStednitz, Sarah2020-02-272020-02-272020-02-27https://hdl.handle.net/1794/25242Social behavior is arguably one of the most complex forms of behavior exhibited by animals. It requires active attention to dynamic multisnsory cues, recall of past experiences, and the generation of situationally appropriate responses. Given the swath of different cognitive systems required, it is unsurprising that social behavior is disrupted in many neurological disorders. Autism spectrum disorders (ASD) are particularly notable, as social impairment is a required diagnostic criteria. Efforts using animal models to both understand the etiology and improve behavioral outcomes for human ASD patients are complicated by the difficulty of replicating the genetic environmental causes. Similarly, measuring deficits in complex behaviors like social interaction is challenging and their neuroanatomical correlates are not yet fully described. To address these issues, I utilized the highly social and genetically tractable zebrafish (Danio rerio) as a model system. I developed a novel assay that shows social engagement requires a behavioral visual stimulus provided by another socially-engaged fish. I demonstrated that both pharmacological manipulation of dopaminergic systems and ablation of a portion of the ventral telencephalon produce predictable deficits in social behavior. Our results also provide evidence that an as yet uncharacterized population of cholinergic neurons in the ventral forebrain are critical for social interactions in zebrafish. This region corresponds to mammalian forebrain regions implicated in social behavior, suggesting an evolutionarily conserved population of cells may drive social orienting in zebrafish and mammals. Further, I identified the time points in early development when specific social behaviors are first observed, suggesting a progressive acquisition of increasingly complex social behaviors over a rapid timescale. This highly variable and early stage in development represents an opportunity to further understand how genetic and environmental factors affect the assembly of the neural circuits underlying complex behaviors.en-USAll Rights Reserved.collective behaviorneuroanatomysocial orientingzebrafishElectronic Thesis or Dissertation