I worked in the laboratory of Richard Ambron as an undergraduate and research technician at Columbia University. The focus of this research was the identification of intrinsic nerve injury signals. In addition to growth factor and electrophysiological responses, neurons posses axonal proteins with a masked nuclear localization sequence (NLS) that serve as a sensor for injury. These injury signals are activated and rapidly retrogradely transported to the neuronal cell body and into the nucleus following nerve crush injury. In the nucleus they function to initiate the transcriptional program for repair. My research focused on the identification of an NF-κB-like transcription factor in Aplysia and its function in nerve injury. Nerve regeneration following injury requires transcriptional activation of repair genes. Members NF-κB family of transcription factors are well-suited to play a role in nerve injury since they contain and masked NLS and are localized to the cytoplasm until activated. This work identified by electrophoretic mobility shift assay an NF-κB-like activity in axoplasm. Contrary to what was expected, this activity was rapidly inactivated in injured neurons. We hypothesized that in these neurons, NF-κB functions as a signal of homeostasis and must be inactivated following injury since it regulates genes that are incompatible with repair.
