The axon initial segment and node of Ranvier: Mechanisms of excitable membrane assembly and disassembly

Date of Completion

January 2008


Biology, Neuroscience




The action potential (AP) is fundamental to nervous system function. The axon serves as a conduit by which this electrical activity can be initiated and transmitted from one neuron to the next. The axon initial segment (AIS) and node of Ranvier are the domains within axons necessary for initiation and propagation of this signal. The functional similarity between these two domains is reflected in a nearly identical molecular composition. As a result, mechanisms underlying development, maintenance, and function may be common. I have chosen to focus on three distinct aspects related to the AIS and/or node of Ranvier: (1) identification of additional molecular components, (2) formation during nervous system development and (3) mechanisms of disassembly and reassembly following injury/disease. The AIS and node are critical to proper nervous system function. As a result, the ultimate goal and theme of this thesis is using insights from each of these areas of focus to better understand how disruptions of these domains contribute to the underlying mechanisms of nervous system dysfunction. ^