Early exposure to volatile anesthetics impairs long-term associative learning and recognition memory

PLoS One. 2014 Aug 28;9(8):e105340. doi: 10.1371/journal.pone.0105340. eCollection 2014.

Abstract

Background: Anesthetic exposure early in life affects neural development and long-term cognitive function, but our understanding of the types of memory that are altered is incomplete. Specific cognitive tests in rodents that isolate different memory processes provide a useful approach for gaining insight into this issue.

Methods: Postnatal day 7 (P7) rats were exposed to either desflurane or isoflurane at 1 Minimum Alveolar Concentration for 4 h. Acute neuronal death was assessed 12 h later in the thalamus, CA1-3 regions of hippocampus, and dentate gyrus. In separate behavioral experiments, beginning at P48, subjects were evaluated in a series of object recognition tests relying on associative learning, as well as social recognition.

Results: Exposure to either anesthetic led to a significant increase in neuroapoptosis in each brain region. The extent of neuronal death did not differ between groups. Subjects were unaffected in simple tasks of novel object and object-location recognition. However, anesthetized animals from both groups were impaired in allocentric object-location memory and a more complex task requiring subjects to associate an object with its location and contextual setting. Isoflurane exposure led to additional impairment in object-context association and social memory.

Conclusion: Isoflurane and desflurane exposure during development result in deficits in tasks relying on associative learning and recognition memory. Isoflurane may potentially cause worse impairment than desflurane.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthetics, Inhalation / pharmacology*
  • Animals
  • Association Learning / drug effects*
  • Behavior, Animal / drug effects
  • Desflurane
  • Isoflurane / analogs & derivatives*
  • Isoflurane / pharmacology*
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Recognition, Psychology / drug effects*
  • Social Behavior

Substances

  • Anesthetics, Inhalation
  • Desflurane
  • Isoflurane