Extracellular microelectrode sampling bias.
D000818:Animals; D002415:Cats; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D004566:Electrodes; D005071:Evoked Potentials; D009431:Neural Conduction; D009474:Neurons / Q000502:physiology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000502:physiology*