Administration of Stephania tetrandra to Drosophila melanogaster to create obsessive compulsive disorder model

Obsessive compulsive disorder (OCD) is a neuropsychiatric condition that affects 2-3% of the world population, with more research needed to better understand its mechanisms. Theories positing the involvement of neurotransmitters like serotonin, dopamine, and glutamate in OCD have gained traction, however no specific cause has been identified. There are currently no research models of OCD in invertebrates, and existing vertebrate models fail to accurately model the disorder. Often, these existing models exhibit abnormal behaviors not associated with OCD, or do not respond appropriately to OCD treatments. The current study aimed to create a model of OCD in Drosophila melanogaster through administration of Stephania tetrandra extract. S. tetrandra extract is a plant extract with antiserotonergic and antidopaminergic properties similar to those of second-generation antipsychotics, a class of drugs that can induce obsessive compulsive symptoms (OCS). We hypothesized that flies administered the extract would display more OCS than control flies. We determined the highest non-lethal dose of S. tetrandra in Drosophila and administered it in two assays for OCS: a locomotion assay that measured movement as a metric of anxiety, and a grooming assay that quantified repetitive grooming behavior. These two assays were selected because OCD is characterized by repetitive behaviors and anxiety. Administration of the S. tetrandra extract significantly increased both anxiety and repetitive behavior, suggesting that flies administered the extract had increased OCS and that S. tetrandra treatment could serve as a potential model of OCD in Drosophila.