Oscillatory patterns in hippocampus under light and deep isoflurane anesthesia closely mirror prominent brain states in awake animals

Hippocampus. 2016 Jan;26(1):102-9. doi: 10.1002/hipo.22494. Epub 2015 Sep 17.


The hippocampus exhibits a variety of distinct states of activity under different conditions. For instance the rhythmic patterns of activity orchestrated by the theta oscillation during running and REM sleep are markedly different from the large irregular activity (LIA) observed during awake resting and slow wave sleep. We found that under different levels of isoflurane anesthesia activity in the hippocampus of rats displays two distinct states, which have several qualities that mirror the theta and LIA states. These data provide further evidence that the two states are intrinsic modes of the hippocampus; while also characterizing a preparation that could be useful for studying the natural activity states in hippocampus.

Keywords: brain state; hippocampus; isoflurane; oscillations; rat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Anesthesia
  • Anesthetics, Inhalation / pharmacology*
  • Animals
  • Dose-Response Relationship, Drug
  • Electrodes, Implanted
  • Hippocampus / drug effects*
  • Hippocampus / physiology*
  • Isoflurane / pharmacology*
  • Male
  • Rats, Long-Evans
  • Signal Processing, Computer-Assisted
  • Theta Rhythm / drug effects
  • Theta Rhythm / physiology
  • Wakefulness / physiology


  • Anesthetics, Inhalation
  • Isoflurane