Serotonin 1A receptor messenger RNA regulation in the hippocampus after acute stress

Biol Psychiatry. 1999 Apr 1;45(7):934-7. doi: 10.1016/s0006-3223(98)00224-8.


Background: When rats are subjected to chronic stress for 2 weeks, a significant decrease in hippocampal serotonin (5-HT)1A messenger RNA (mRNA) is observed. We wanted to investigate whether stress, administered for shorter periods of time, would result in decreases in 5-HT1A gene expression in hippocampus.

Methods: In one experiment, rats were either stressed daily for 1 week or implanted with two corticosterone pellets to produce elevated corticosterone levels. In another experiment, rats were subjected to a severe acute stressor and sacrificed 1 day or 1 week after the stressor.

Results: We found that 24 hours after the acute stress, rats showed a significant decrease in 5-HT1A mRNA levels in CA1 and the dentate gyrus compared to controls. No significant changes in 5-HT1A mRNA levels were detected in any of the other groups.

Conclusions: Although 1 week of chronic stress is not sufficient to cause significant decreases in hippocampal 5-HT1A mRNA levels, a severe and prolonged acute stress is capable of down-regulating, at least transiently, 5-HT1A mRNA gene expression in hippocampus.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Analysis of Variance
  • Animals
  • Corticosterone / blood
  • Corticosterone / physiology
  • Down-Regulation / drug effects
  • Down-Regulation / physiology*
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Male
  • RNA, Messenger / analysis
  • RNA, Messenger / drug effects
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Serotonin / biosynthesis*
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / genetics
  • Receptors, Serotonin, 5-HT1
  • Severity of Illness Index
  • Stress, Psychological / chemically induced
  • Stress, Psychological / metabolism*
  • Stress, Psychological / physiopathology
  • Time Factors
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / physiology


  • RNA, Messenger
  • Receptors, Serotonin
  • Receptors, Serotonin, 5-HT1
  • Corticosterone