Serotonin 1A receptor messenger RNA regulation in the hippocampus after acute stress.
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.
López
J F
JF
Mental Health Research Institute, University of Michigan, Ann Arbor 48109, USA.
Liberzon
I
I
Vázquez
D M
DM
Young
E A
EA
Watson
S J
SJ
D000208:Acute Disease; D000704:Analysis of Variance; D000818:Animals; D003345:Corticosterone / Q000097:blood / Q000502:physiology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D044263:Receptors, Serotonin, 5-HT1; D012720:Severity of Illness Index; D013315:Stress, Psychological / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology
D012333:RNA, Messenger; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D003345:Corticosterone