Functional Hippocampal Assessment with Depth Electrodes

  • David W. Loring
  • Kimford J. Meador
  • Gregory P. Lee
Chapter
Part of the Critical Issues in Neuropsychology book series (CINP)

Abstract

Mesial temporal lobe (MTL) structures, from which seizures commonly originate, are crucial for acquisition of new material into memory. The reason for this relationship is unknown but may be related to the tissue excitability necessary for memory encoding. For information to be encoded into memory and the recent memory systems (i.e., episodic memory) to be constantly updated, a system with sufficient sensitivity and constant, active processing of the environment is necessary to allow continual information updating. However, a balance between the sensitivity and stability of functionally connected cell assemblies is also required (Freeman, 1975). As neurons become excited by background input, the neural gain increases, driving the neurons to an operating point closer to their firing threshold; subsequent input is more likely to trigger a response. However, as sensitivity increases, there is a concomitant increase in instability. Thus, the requirement for a memory system to possess the ability to rapidly lay down memory traces makes it less stable and perhaps predisposed to develop seizures.

Keywords

Verbal Memory Seizure Onset Temporal Lobectomy Recent Memory Depth Electrode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Springer Science+Business Media New York 1992

Authors and Affiliations

  • David W. Loring
    • 1
  • Kimford J. Meador
    • 2
  • Gregory P. Lee
    • 3
  1. 1.Section of Behavioral Neurology, Department of NeurologyMedical College of GeorgiaAugustaUSA
  2. 2.Section of Behavioral Neurology, Department of NeurologyMedical College of GeorgiaAugustaUSA
  3. 3.Department of Psychiatry, and Section of Neurosurgery, Department of SurgeryMedical College of GeorgiaAugustaUSA

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