Carter investigates signaling mechanisms regulating neuronal survival during the development of the mammalian nervous system. Programmed cell death in the nervous system is a naturally occurring process in mammalian development; however, abnormal apoptosis is the basis for many neuropathologies. The delicate balance between neuronal survival and death is regulated, in part, by a family of growth factors referred to as the neurotrophins. The neurotrophins promote neuronal survival and differentiation through binding to the Trks, a family of tyrosine kinase receptors. In addition, these factors bind to a member of the TNF receptor family, p75. This receptor has a wide variety of functions; it can promote cellular survival or induce apoptosis, regulate neurite outgrowth, and promote Schwann cell myelination, depending on the cellular context. The molecular mechanisms by which p75 mediates this variety of signals is largely unknown. Through the use of in vitro systems, as well as transgenic mice, Carter investigates the molecular components of these pathways and the physiological contexts in which they are activated.