Estrogen and Mood in Women:

Performance of fine motor and spatial tasks during the menstrual cycle

Various studies have shown fluctuations in task performance during the menstrual cycle. The aim of this study was to see the effects of the menstrual cycle on performing fine motor and spatial tasks of different level of complexity in twenty students aged 18 to 21 years, with regular menstrual cycle (28 to 30 days). The students performed O'Connor Finger Dexterity Test and mental rotation test during the menstrual, late follicular, and midluteal phase. Before the tests were performed, we administered Spielberger's State-Trait Anxiety Inventory for each phase. After the tasks were completed, the subjects ranked their difficulty on Borg's scale.The results showed the best performance in both tests in the midluteal phase (with sex hormones at their peak). The anxiety level and task difficulty ranking were the highest in the menstrual phase, when the hormone levels were the lowest.

Sex Hormones and Cognitive Functioning of Women

U radu se raspravlja o organizirajućim i aktivirajućim učincima spolnih hormona te o njihovu utjecaju na kognitivno funkcioniranje. Dosadašnja su istraživanja pokazala spolne razlike u nekim specifičnim kognitivnim sposobnostima. Žene su u prosjeku bolje u verbalnoj fluentnosti, perceptivnoj brzini i točnosti, kao i finijoj motorici, dok su muškarci u prosjeku bolji u prostornim i matematičkim sposobnostima. Ove razlike u kognitivnom funkcioniranju dovode se u vezu s izlaganjem mozga fetusa različitim razinama spolnih hormona tijekom prenatalnog života. Studije na skupinama rođenim s genskim poremećajima, kao što su sindrom neosjetljivosti na androgene, kongenitalna adrenalna hiperplazija i Turnerov sindrom također upućuju na organizirajuće učinke spolnih hormona na kognitivno funkcioniranje.

Nadalje, dosadašnja istraživanja pokazuju da povišene razine ženskih spolnih hormona u kasnoj folikularnoj i/ili lutealnoj fazi menstrualnog ciklusa potenciraju tipičan ženski kognitivni obrazac funkcioniranja, koji karakterizira veća učinkovitost u zadacima koje u prosjeku bolje rješavaju žene. Niske pak razine ovih hormona, koje karakteriziraju menstrualnu fazu ciklusa, potenciraju tipičan muški obrazac funkcioniranja, koji uključuje bolju učinkovitost u zadacima koje u prosjeku bolje rješavaju muškarci.

U radu se također raspravlja o metodološkim razlikama u dosadašnjim istraživanjima organizirajućih i aktivirajućih učinaka spolnih hormona na kognitivno funkcioniranje, kao i o smjernicama za buduća istraživanja.

Ovarian hormones modulate 'compulsive' lever-pressing in female rats

Life events related to the female hormonal cycle may trigger the onset of obsessive-compulsive disorder (OCD) or exacerbate symptoms in women already suffering from it. These observations suggest a possible role for ovarian hormones in the course of this disorder. Yet, the mechanisms that may subserve the modulatory effect of ovarian hormones are currently unknown. The aim of the present study was therefore to test the role of ovarian hormones in the signal attenuation rat model of OCD. Experiment 1 compared the behavior of pre-pubertal and adult male and female rats in the model, and found no age and sex differences in compulsive responding. Experiment 2 found that compulsive responding fluctuates along the estrous cycle, being highest during late diestrous and lowest during estrous. Acute administration of estradiol to pre-pubertal female rats was found to attenuate compulsive behavior (Experiment 3), and withdrawal from chronic administration of estradiol was shown to increase this behavior (Experiment 4). These findings extend the use of the signal attenuation model of OCD to female rats, and by demonstrating that the model is sensitive to the levels of ovarian hormones, provide the basis for using the model to study the role of ovarian hormones in OCD. In addition, the present findings support the hypothesis that the increased risk of onset and exacerbation of OCD in women post-partum may be a result of the decrease in the level of estradiol, which was elevated during pregnancy.

Effects of long-term hormone treatment and of tibolone on monoamines and monoamine metabolites in the brains of ovariectomised, Cynomologous monkeys

The effects of long-term hormone treatment on monoamines and monoamine metabolites in different regions of the primate brain were examined and compared. Ovariectomised Cynomologous monkeys received daily oral administration of either conjugated equine oestrogens (CEE), CEE + medroxyprogesterone acetate (MPA), or a low or high dose of tibolone, for a period of 2 years. Tissue punches collected from frozen sections through various regions of the forebrain, midbrain, and hindbrain were assayed for levels of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, 5-hydroxyindole acetic acid (5-HIAA), and norepinephrine by high-performance liquid chromatography. Few differences between hormone-treated animals and ovariectomised controls were observed. No statistically significant effects of CEE relative to controls were detected in any of the seven brain regions analysed. Animals treated with CEE + MPA showed significant reductions in 5-HIAA in the dorsal raphe nucleus, a significant reduction in dopamine in the hypothalamus, and a significant reduction in serotonin (5-HT) levels in area 8AD of the frontal cortex. Similar to CEE, no significant effects of tibolone relative to controls were detected; however, animals treated with high-dose tibolone showed a decrease in 5-HT levels in the frontal cortex that approached significance and was similar to the effect of CEE + MPA. Collectively, the findings suggest that long-term oral administration of these compounds has relatively few effects on the levels of dopamine, serotonin, and their primary metabolites in the primate brain. This differs from the significant effects on serotonergic and dopaminergic systems detected following parenteral treatment with oestradiol and progesterone, and likely reflects differences between the effects of treating with CEE + MPA versus oestradiol and progesterone on brain monoaminergic systems.