title: Structural modifications in chronic microwire electrodes for cortical neuroprosthetics: a case study.
abstract: Long-term viability of chronic invasive neural probes is a necessary condition for extracting robust control signals directly from neural tissue. Although immune/tissue response is a leading factor in the degradation of single neuron recording, we investigate a second component of signal degradation connected to the structural changes associated with microwire electrodes chronically exposed to extracelluar environments in vivo. Scanning electron microscopy is used to assess the surface modifications to the electrodes after an implantation duration of four weeks in rats. The electrode developed a smooth fracture surface, a reduction of the metal diameter, and pitting in the insulation of the electrode structure. Over the duration of implantation, recording properties of the electrode were marked by a reduction in the peak-to-peak amplitude in neuronal firing.
authors.affiliation: Department of Pediatrics, Division of Neurology, University of Florida, Gainesville, FL 32611, USA. jcs77@ufl.edu
authors.forename: Justin C
authors.initials: JC
authors.lastname: Sanchez
authors.forename: Nicolas
authors.initials: N
authors.lastname: Alba
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Nishida
authors.forename: Christopher
authors.initials: C
authors.lastname: Batich
authors.forename: Paul R
authors.initials: PR
authors.lastname: Carney
mesh_terms: D000200:Action Potentials / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D003143:Communication Devices for People with Disabilities; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005071:Evoked Potentials / Q000502:physiology; D008839:Microelectrodes; D009468:Neuromuscular Diseases / Q000503:physiopathology* / Q000534:rehabilitation*; D013499:Surface Properties