Relationship of enhanced norepinephrine activity during memory consolidation to enhanced long-term memory in humans.
OBJECTIVE
The purpose of this study was to investigate the effect of enhanced noradrenergic activity on memory consolidation in humans.


METHODS
Thirty healthy subjects (21 men and nine women) viewed a series of 12 slides that depicted an emotionally arousing story. Five minutes after viewing the slides, subjects received either intravenous yohimbine or intravenous placebo in a double-blind randomized fashion. Multiple blood samples were drawn for determining plasma free 3-methoxy-4-hydroxyphenylglycol (MHPG). One week later subjects took a surprise memory test for the slides.


RESULTS
There was no significant difference in memory score between yohimbine and placebo groups. Linear regression revealed a significant effect of MHPG on memory score for the group as a whole (subjects who had received yohimbine and those who had received placebo) and for the placebo group alone.


CONCLUSIONS
These findings strengthen support for the hypothesis that enhanced memory for emotionally arousing events in humans depends critically on postlearning adrenergic modulation.
Southwick
Steven M
SM
Department of Psychiatry, Yale University School of Medicine, CT, USA. Steven.Southwick@med.va.gov
Davis
Michael
M
Horner
Beverly
B
Cahill
Larry
L
Morgan
Charles A
CA
Gold
Paul E
PE
Bremner
J Douglas
JD
Charney
Dennis C
DC
D000328:Adult; D004311:Double-Blind Method; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D016014:Linear Models; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D008734:Methoxyhydroxyphenylglycol / Q000097:blood; D008875:Middle Aged; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D010919:Placebos; D011581:Psychological Tests; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000523:psychology; D014796:Visual Perception / Q000502:physiology; D015016:Yohimbine / Q000008:administration & dosage / Q000494:pharmacology
D010919:Placebos; D015016:Yohimbine; D008734:Methoxyhydroxyphenylglycol; D009638:Norepinephrine