Reversibility of the effects of acute ovarian hormone suppression on verbal memory and prefrontal function in pre-menopausal women.
BACKGROUND
Whilst acute loss of ovarian function is associated with memory deficits, the biological basis of this is poorly understood. We have previously reported that acute loss of function during Gonadotropin Hormone Releasing Hormone agonists (GnRHa) treatment is associated with impaired verbal memory and a disruption of corresponding left inferior frontal gyrus (LIFG) during the encoding stage. In the current study, we provide a critical extension to this work by determining whether this memory deficit is reversible following normalization of ovarian function. To do this we carried out a further imaging study using the same verbal memory recognition task after cessation of GnRHa-induced ovarian suppression.


METHODS
We used event-related fMRI to study verbal episodic memory performance and brain activation at the LIFG in 13 healthy pre-menopausal women pre-, during, and post-acute ovarian hormone suppression using GnRHa.


RESULTS
Following resolution of acute GnRHa-induced ovarian suppression, verbal recognition scores returned to their initial levels and this restoration was associated with a restored level of left frontal activation during successful encoding of words.


CONCLUSIONS
Our findings suggest that the memory deficits associated with acute ovarian suppression are reversed following resolution of normal ovarian function and are associated with reversible attenuation of LIFG activation during encoding. These findings lend further support to the hypothesis that memory difficulties reported by some women following acute ovarian hormone withdrawal are reversible and may have a clear neurobiological basis.
Section of Brain Maturation (PO50), Department of Psychological Medicine, Institute of Psychiatry, De Crespigny Park, Denmark Hill, London SE5 8AF, UK. m.craig@iop.kcl.ac.uk
Michael C
MC
Craig
Paul C
PC
Fletcher
Eileen M
EM
Daly
Janice
J
Rymer
Mick
M
Brammer
Vincent
V
Giampietro
Pauline M
PM
Maki
Declan G M
DG
Murphy
D000328:Adult; D004965:Estrogen Antagonists / Q000494:pharmacology*; D004967:Estrogens / Q000097:blood; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006728:Hormones / Q000097:blood; D006801:Humans; D008279:Magnetic Resonance Imaging; D008568:Memory / Q000187:drug effects*; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000187:drug effects; D021641:Recognition, Psychology / Q000187:drug effects
D004965:Estrogen Antagonists; D004967:Estrogens; D006728:Hormones; D007987:Gonadotropin-Releasing Hormone