Research in Ess’s laboratory is focused on deciphering the molecular mechanisms required for typical brain development and how disruptions of these processes lead to malformations of the cerebral cortex. Children with such aberrations typically suffer from severe seizure disorders (epilepsy) as well as severe cognitive and behavioral problems such as autism. To approach these complex neurologic disorders, Ess has been studying tuberous sclerosis complex (TSC), a disease that prominently features cortical malformations and is caused by loss of either the TSC1 or TSC2 genes. TSC is quite prevalent and is the most common genetic cause of seizures and autism in children. To study these complicated abnormalities of the human brain, Ess has generated experimental models of TSC using genetically engineered mice as well as in vitro progenitor cell systems. Ess’s long-term goal is to use these models to precisely define the molecular pathways used by the TSC1/2 genes during human brain development. This knowledge will facilitate the development of more efficacious therapies for children who have epilepsy or autism.