title: Comprehensive chronic laminar single-unit, multi-unit, and local field potential recording performance with planar single shank electrode arrays.
abstract: BACKGROUND
  Intracortical electrode arrays that can record extracellular action potentials from small, targeted groups of neurons are critical for basic neuroscience research and emerging clinical applications. In general, these electrode devices suffer from reliability and variability issues, which have led to comparative studies of existing and emerging electrode designs to optimize performance. Comparisons of different chronic recording devices have been limited to single-unit (SU) activity and employed a bulk averaging approach treating brain architecture as homogeneous with respect to electrode distribution.
  
  
  METHODS
  In this study, we optimize the methods and parameters to quantify evoked multi-unit (MU) and local field potential (LFP) recordings in eight mice visual cortices.
  
  
  RESULTS
  These findings quantify the large recording differences stemming from anatomical differences in depth and the layer dependent relative changes to SU and MU recording performance over 6-months. For example, performance metrics in Layer V and stratum pyramidale were initially higher than Layer II/III, but decrease more rapidly. On the other hand, Layer II/III maintained recording metrics longer. In addition, chronic changes at the level of layer IV are evaluated using visually evoked current source density.
  
  
  CONCLUSIONS
  The use of MU and LFP activity for evaluation and tracking biological depth provides a more comprehensive characterization of the electrophysiological performance landscape of microelectrodes.
  
  
  CONCLUSIONS
  A more extensive spatial and temporal insight into the chronic electrophysiological performance over time will help uncover the biological and mechanical failure mechanisms of the neural electrodes and direct future research toward the elucidation of design optimization for specific applications.
authors.affiliation: Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States. Electronic address: tdk18@pitt.edu.
authors.forename: Takashi D Y
authors.initials: TD
authors.lastname: Kozai
authors.affiliation: Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
authors.forename: Zhanhong
authors.initials: Z
authors.lastname: Du
authors.affiliation: Bioengineering, University of Pittsburgh, United States; Division of Biology and Biological Engineering, California Institute of Technology, United States.
authors.forename: Zhannetta V
authors.initials: ZV
authors.lastname: Gugel
authors.affiliation: Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States; Ophthalmology, University of Pittsburgh, United States.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Smith
authors.affiliation: Center for the Neural Basis of Cognition, United States; Biomedical Engineering, Carnegie Mellon University, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Chase
authors.affiliation: Neurological Surgery, University of Pittsburgh, United States.
authors.forename: Lance M
authors.initials: LM
authors.lastname: Bodily
authors.affiliation: Neurological Surgery, University of Pittsburgh, United States.
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Caparosa
authors.affiliation: Neurological Surgery, University of Pittsburgh, United States.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Friedlander
authors.affiliation: Bioengineering, University of Pittsburgh, United States; Center for the Neural Basis of Cognition, United States; McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States.
authors.forename: X Tracy
authors.initials: XT
authors.lastname: Cui
mesh_terms: D000818:Animals; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D004567:Electrodes, Implanted; D005071:Evoked Potentials; D007150:Immunohistochemistry; D008810:Mice, Inbred C57BL; D008839:Microelectrodes; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D012146:Rest; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
keywords: Electrochemical impedance spectroscopy; Electrophysiology; Firing rate; Gamma oscillations; Microelectrode arrays; Power density spectra; Signal-to-noise; Visual cortex; Visual evoked activity