Tuberous sclerosis complex is a genetic disorder caused by mutations in the gene TSC2. Many people who suffer from tuberous sclerosis complex also develop autism, but it is not understood how mutations in TSC2 cause autism. Autism is thought to be caused at least in part by changes in the development and function of synapses, or the connections between neurons in the brain. During the first few years of life, the number of synapses between neurons increases dramatically, and over time these connections are edited so that any incorrect synapses are removed and only correctly made synapses remain. In this research project, the fellow will test the hypothesis that TSC2 is involved in this process of synaptic editing, and that loss of TSC2 causes neurons to have too many synapses. To study the effects of the TSC2 gene product on synaptic editing, Dr. Williams will examine synaptic development in neurons from rats that have been genetically engineered to lack TSC2. She will determine whether the loss of TSC2 causes changes in the numbers of synapses made by these neurons. She will also examine the development of synapses in real time, to explore the possibility that TSC2 affects the dynamics of synapse formation and editing. This study will help us further understand the function of the disease-causing gene TSC2 in neurons, and may point towards the development of new therapies in the treatment of autism and tuberous sclerosis complex.