title: Sensitivity of temporal excitation properties to the neuronal element activated by extracellular stimulation.
abstract: Measurements of the chronaxies and refractory periods with extracellular stimuli have been used to conclude that large diameter axons are responsible for the effects of deep brain stimulation (DBS). We hypothesized that because action potential initiation by extracellular stimulation occurs in the axons of central nervous system (CNS) neurons, the chronaxies and refractory periods determined using extracellular stimulation would be similar for cells and axons. Computer simulation was used to determine the sensitivity of chronaxie and refractory period to the neural element stimulated. The results demonstrate that chronaxies and refractory periods were dependent on the polarity of the extracellular stimulus and the electrode-to-neuron distance, and indicate that there is little systematic difference in either chronaxies or refractory periods between local cells or axons of passage with extracellular stimulation. This finding points out the difficulty in drawing conclusions regarding which neuronal elements are activated based on extracellular measurements of temporal excitation properties.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Wickenden Building, Cleveland, OH 44106-4912, USA.
authors.forename: Svjetlana
authors.initials: S
authors.lastname: Miocinovic
authors.forename: Warren M
authors.initials: WM
authors.lastname: Grill
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D030161:Avian Proteins; D001369:Axons / Q000502:physiology*; D002907:Chronaxy / Q000502:physiology*; D003198:Computer Simulation; D004268:DNA-Binding Proteins; D003712:Dendrites / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods*; D004566:Electrodes; D004594:Electrophysiology; D005110:Extracellular Space / Q000502:physiology; D008959:Models, Neurological; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D011897:Random Allocation; D012032:Refractory Period, Electrophysiological / Q000502:physiology*; D012680:Sensitivity and Specificity; D014157:Transcription Factors
chemical_list: D030161:Avian Proteins; D004268:DNA-Binding Proteins; C097075:IBR protein, Gallus gallus; D014157:Transcription Factors