Dynamics of protein aggregation and a neuron-silicon interface

Our work in experimental biophysics has attempted to contribute at both the technique application and the technique development levels to two different biological problems:; The first part of this tally describes the application of a relatively new technique (atomic force microscopy - AFM) to the study of protein aggregation. The large-scale aggregation of proteins is responsible for a number of human and animal diseases. Because the resulting fibrils are anisotropic, it is impossible to use crystal x-ray diffraction as a way of resolving structure. We use AFM for the task. Based on our measurements of different protein aggregate structures that were grown in vitro, we propose a general model of fibril formation. We also observe the binding of antibodies to amyloid fibrils, giving insight into the specificity of the antibodies and the mechanism for inhibiting fibril formation.; The second part of this tally relates the development of a novel technique for neuroscience. A long-standing problem in neuroscience has been the inability to probe networks of interconnected neurons. While a number of theories have been developed as to the behavior of neuronal networks, there has been a lack of experimental validation due to the difficulties associated with simultaneous recording of neurons in a network. This thesis describes our work on the development of a system for recording action potentials from neurons cultured on microfabricated electrode arrays.