title: Recording and stimulating properties of chronically implanted longitudinal intrafascicular electrodes in peripheral fascicles in an animal model.
abstract: The purpose of this experiment was to study the recording and stimulating properties, and biocompatibility of longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model when they were chronically implanted into peripheral fascicles. LIFEs were implanted chronically into sciatic nerve fascicles of rabbits as recording and stimulating electrodes. Motor-evoked potentials (MEPs) and cortical somatosensory-evoked potentials (CSEPs) were recorded by using a transcranial stimulation system (TCS) over 6-month period to observe the change of the signals recorded. At the end of the experiment, the fascicles at the electrodes implanted site were anatomized for histological examination under light microscope and transmission electron microscope. Results showed onset latency (OL) of MEPs and CSEPs had no obvious change during the first month. However, OL significantly increased during the second month, and then became stable 3 months after implantation. The interpeak amplitudes (IPAs) of MEPs had no distinct change during the first month, but significantly decreased over the next period, and then became stable 3 months after implantation. The IPAs of CSEPs, however, decreased slowly over the 6-month period of the study. At the end of the experiment, histological examination indicated that a typical foreign body reaction developed, and electrodes caused mild damage to the fascicles, though inflammatory cells and neuroma were not seen around the electrodes. In conclusion, LIFEs have excellent recording and stimulating characters in addition to biocompatibility with peripheral fascicles. They can be implanted chronically into fascicles and record signals.
authors.affiliation: Department of Orthopedic Surgery, The Affiliated Hospital of Medical College, Qingdao University, Qingdao, People's Republic of China. xiujunzheng@hotmail.com
authors.forename: Xiujun
authors.initials: X
authors.lastname: Zheng
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Tongyi
authors.initials: T
authors.lastname: Chen
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000818:Animals; D004558:Electric Stimulation / Q000295:instrumentation*; D004567:Electrodes, Implanted / Q000009:adverse effects; D019054:Evoked Potentials, Motor; D005073:Evoked Potentials, Somatosensory; D005549:Foreign-Body Reaction / Q000209:etiology; D008422:Materials Testing; D008866:Microsurgery / Q000379:methods; D023421:Models, Animal; D009431:Neural Conduction; D011817:Rabbits; D012584:Sciatic Nerve / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D013997:Time Factors