Diverse actions of ovarian steroids in the serotonin neural system

Ovarian steroids decrease DNA fragmentation in the serotonin neurons of non-injured rhesus macaques

We previously found that ovarian steroids promote neuroprotection in serotonin neurons by decreasing the expression of pro-apoptotic genes and proteins in the dorsal raphe nucleus of rhesus macaques, even in the absence of overt injury. In this study, we questioned whether these actions would lead to a reduction in DNA fragmentation in serotonin neurons. Ovariectomized (OVX) rhesus monkeys were implanted with silastic capsules that were empty (placebo) or containing estradiol (E), progesterone (P) or estradiol and progesterone (E+P) for 1 month. In all animals, eight levels of the dorsal raphe nucleus in a rostral-to-caudal direction were immunostained using the terminal deoxynucleotidyl transferase nick end labeling (TUNEL) method. Two staining patterns were observed, which are referred to as type I, with complete dark staining of the nucleus, and type II, with peripheral staining in the perinuclear area. A montage of the dorsal raphe was created at each level with a Marianas Stereology Microscope and Slidebook 4.2, and the TUNEL-positive cells were counted. In direct comparison with OVX animals, P treatment and E+P treatment significantly reduced the total number of TUNEL-positive cells (Mann-Whitney test, both treatments P=0.04) and E+P treatment reduced the number of TUNEL-positive cells per mm(3) (Mann-Whitney test, P=0.04). Double immunocytochemistry for TUNEL and tryptophan hydroxylase (TPH) indicated that DNA fragmentation was prominent in serotonin neurons. These data suggest that in the absence of ovarian steroids, a cascade of gene and protein expression leads to an increase in DNA fragmentation in serotonin neurons. Conversely, ovarian steroids have a neuroprotective role in the non-injured brain and prevent DNA fragmentation and cell death in serotonin neurons of nonhuman primates.

Conceptualizing the role of estrogens and serotonin in the development and maintenance of bulimia nervosa

Serotonergic dysregulation is thought to underlie much of the pathology in bulimia nervosa (BN). The purpose of this review is to expand the serotonergic model by incorporating specific and nonspecific contributions of estrogens to the development and maintenance of bulimic pathology in order to guide research from molecular genetics to novel therapeutics for BN. Special emphasis is given to the organizing theory of general brain arousal which allows for integration of specific and nonspecific effects of these systems on behavioral endpoints such as binge eating or purging as well as arousal states such as fear, novelty seeking, or sex. Regulation of the serotonergic system by estrogens is explored, and genetic, epigenetic, and environmental estrogen effects on bulimic pathology and risk factors are discussed. Genetic and neuroscientific research support this two-system conceptualization of BN with both contributions to the developmental and maintenance of the disorder. Implications of an estrogenic-serotonergic model of BN are discussed as well as guidelines and suggestions for future research and novel therapeutic targets.

Functional characterization of rhesus embryonic stem cell-derived serotonin neurons

Optimal function of the serotonin system is essential for mental health and its role in psychopathologies is undisputed. Enhancing the ability to study primate serotonin neurons in culture would facilitate understanding of intracellular signaling pathways that mediate the action of drugs and other epigenetic or developmental factors impacting human mental health. We were the first group to report differentiation of the non-human primate rhesus monkey embryonic stem cell (ESC) line 366.4 into cultures of serotonin neurons. In this study, we optimized yield and obtained functional characteristics of the derived serotonin neurons. Sequential treatments of ESC 366.4 during expansion stage with fibroblast growth factor 4 and sonic hedgehog markedly increased the yield of serotonin neurons. These serotonin neurons propagated action potentials and expressed GABA receptors. Also, for the first time we demonstrate that these ESC-derived serotonin neurons exhibit functional high-affinity transporter sites, as well as high-affinity 5HT(1A) binding sites, which are essential targets of common psychoactive drugs. Finally, to test the generality of this method, we utilized another rhesus ESC line, ORMES-22, which efficiently differentiated into serotonin neurons. Together, these findings demonstrate the feasibility of our protocol to direct different primate ESC lines to serotonin neurons with physiological characteristics, which makes them a useful in vitro model system.

Sex hormone receptor gene polymorphisms and migraine: a systematic review and meta-analysis

BACKGROUND

Data on the association between sex hormone receptor polymorphisms and migraine are conflicting.

METHODS

We performed a systematic review and meta-analysis on this topic searching for studies published until August 2009. For each study, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) assuming additive, dominant, and recessive genetic models. We then calculated pooled ORs and 95% CIs.

RESULTS AND CONCLUSION

Among the seven genes targeted, four variants were investigated in multiple studies. Effect estimates from an additive model suggest that the ESR-1 594 G>A (pooled OR 1.37; 95% CI 1.02-1.83) and ESR-1 325 C>G (pooled OR 1.16; 95% CI 1.03-1.32) variants are associated with any migraine. This pattern does not differ between migraine with and without aura. In contrast, the ESR-1 Pvu II C>T and PGR PROGINS insert polymorphism do not appear to be associated with migraine. Results were driven by studies among Caucasians and may differ in other ethnic groups.

Estrogen therapy and cognition: a review of the cholinergic hypothesis

The pros and cons of estrogen therapy for use in postmenopausal women continue to be a major topic of debate in women's health. Much of this debate focuses on the potential benefits vs. harm of estrogen therapy on the brain and the risks for cognitive impairment associated with aging and Alzheimer's disease. Many animal and human studies suggest that estrogens can have significant beneficial effects on brain aging and cognition and reduce the risk of Alzheimer's-related dementia; however, others disagree. Important discoveries have been made, and hypotheses have emerged that may explain some of the inconsistencies. This review focuses on the cholinergic hypothesis, specifically on evidence that beneficial effects of estrogens on brain aging and cognition are related to interactions with cholinergic projections emanating from the basal forebrain. These cholinergic projections play an important role in learning and attentional processes, and their function is known to decline with advanced age and in association with Alzheimer's disease. Evidence suggests that many of the effects of estrogens on neuronal plasticity and function and cognitive performance are related to or rely upon interactions with these cholinergic projections; however, studies also suggest that the effectiveness of estrogen therapy decreases with age and time after loss of ovarian function. We propose a model in which deficits in basal forebrain cholinergic function contribute to age-related changes in the response to estrogen therapy. Based on this model, we propose that cholinergic-enhancing drugs, used in combination with an appropriate estrogen-containing drug regimen, may be a viable therapeutic strategy for use in older postmenopausal women with early evidence of mild cognitive decline.

Role of the oestrogen receptor (ESR1 PvuII and ESR1 325 C->G) and progesterone receptor (PROGINS) polymorphisms in genetic susceptibility to migraine in a North Indian population

We aimed to explore the single-locus, haplotype and epistasis patterns and the contribution of oestrogen receptor [ESR1 PvuII (rs2234693), ESR1 325 C→G (rs1801132)] and progesterone receptor [PROGINS (rs1042838)] polymorphisms in genetic susceptibility to migraine by analysing 613 subjects consisting of 217 migraine patients, 217 healthy controls (HC) and 179 patients with tension-type headache (TTH). Entire data were analysed by taking the Bonferroni corrected P-value into account. We found significant association of TT genotype [odds ratio (OR) 3.458, confidence interval (CI) 1.757, 6.806; P = 0.0003] and T allele (OR 1.729, CI 1.309, 2.284; P = 0.0001) of ESR1 PvuII single nucleotide polymorphism with migraine when compared with HC. Significant association was seen only in female migraine patients at both genotype (P = 0.002; OR 3.834, CI 1.625, 9.043) and allele level (P = 0.002; OR 1.721, CI 1.228, 2.413). Moreover, higher risk was limited to migraine with aura (MA) (in case of TT genotype, P = 0.002; OR 4.377, CI 1.703, 1.246; in case of T allele, P = 0.001; OR 1.888, CI 1.305, 2.735) rather than migraine without aura (MoA) (P-value of TT genotype = 0.003; OR 3.082, CI 1.465, 6.483; P-value T allele = 0.002; OR 1.630, CI 1.188, 2.236). In case of a recessive model, risk was seen with migraine patients (P = 0.0003; OR 2.514, CI 1.635, 3.867), MA (P = 0.0001; OR 3.583, CI 1.858, 6.909) and MoA patients (P = 0.002; OR 2.125, CI 1.304, 3.464) when compared with HC. No risk was observed when TTH patients were compared with HC. No significance of ESR 325 G→C polymorphism was seen in any of the models under study. Significant differences in genotypic (P = 0.0001) and allelic frequency (P = 0.0002) were seen in case of PROGINS polymorphism when migraine patients were compared with HC, showing a protective effect (for A1A2 genotype, OR 0.292, CI 0.155, 0.549; for A2 allele, OR 0.320, CI 0.174, 0.589). Moreover, significance was seen only in case of female migraine patients at genotype (P = 0.002; OR 0.344, CI 0.176, 0.684) as well as allele levels (P = 0.004; OR 0.379, CI 0.198, 0.727) in case of PROGINS polymorphism. ESR1 PvuII TT*ESR1 325 C→G CG genotype, PROGINS A1A2*ESR1 325 C→G CG genotype and ESR1 PvuII CT*PROGINS A1A2 interacted significantly, but significance was lost after Bonferroni correction. In conclusion, ESR1 PvuII polymorphism is a significant risk factor for migraine particularly in women and MA patients, but ESR 325 C→G polymorphism is not associated with migraine susceptibility. PROGINS polymorphism seems to play a protective role in genetic susceptibility to migraine in the North Indian population.

Sex differences in the adolescent brain

Adolescence is a time of increased divergence between males and females in physical characteristics, behavior, and risk for psychopathology. Here we will review data regarding sex differences in brain structure and function during this period of the lifespan. The most consistent sex difference in brain morphometry is the 9-12% larger brain size that has been reported in males. Individual brain regions that have most consistently been reported as different in males and females include the basal ganglia, hippocampus, and amygdala. Diffusion tensor imaging and magnetization transfer imaging studies have also shown sex differences in white matter development during adolescence. Functional imaging studies have shown different patterns of activation without differences in performance, suggesting male and female brains may use slightly different strategies for achieving similar cognitive abilities. Longitudinal studies have shown sex differences in the trajectory of brain development, with females reaching peak values of brain volumes earlier than males. Although compelling, these sex differences are present as group averages and should not be taken as indicative of relative capacities of males or females.

Interactions of corticotropin-releasing factor, urocortin and citalopram in a primate model of stress-induced amenorrhea

BACKGROUND/AIMS

We established a cynomolgus macaque model of stress-induced amenorrhea in which the application of combined metabolic and psychosocial stress suppressed ovulation in stress-sensitive (SS) individuals, but not in highly stress-resilient (HSR) individuals. We previously reported that SS monkeys have deficits in global serotonin release and serotonin-related gene expression in the raphe nucleus, and that administration of the selective serotonin reuptake inhibitor S-citalopram increased estrogen and progesterone production in SS monkeys. In this study, we questioned whether there was a difference in corticotropin-releasing factor (CRF) or urocortin (UCN) stress-related peptide systems in the midbrain raphe region when HSR and SS monkeys treated with placebo or S-citalopram are compared.

METHODS

Monkeys characterized as HSR or SS were administered placebo or S-citalopram for 15 weeks. CRF fibers in the dorsal raphe were detected with an antibody against human CRF. UCN1 fibers were immunostained in an area rostral to the dorsal raphe. The fibers were quantified by stereology and analyzed by two-way ANOVA. UCN1 cell bodies were counted in the supraoculomotor area near the Edinger-Westphal nucleus.

RESULTS

S-citalopram significantly decreased the CRF fiber density in SS animals, but not in HSR animals. SS monkeys had a significantly lower UCN1 fiber density compared to HSR monkeys, but S-citalopram treatment did not alter the UCN1 fiber density. SS animals treated with S-citalopram tended to have a higher number of UCN1-positive cell bodies than the other groups.

CONCLUSION

S-citalopram decreased CRF fiber density and appears to increase the production of UCN1 in SS individuals, indicating the likelihood that serotonin is involved in regulating CRF and UCN1 in individuals who are sensitive to the effects of serotonin.

Neuroactive steroids after estrogen exposure in depressed postmenopausal women treated with sertraline and asymptomatic postmenopausal women

Neuroactive steroids (NAS) allopregnanolone (ALLO), Allotetrahydrodeoxycorticosterone (THDOC) and dehydroepiandrosterone (DHEA) are important in the regulation of mood and behavior. Knowledge about these steroids in postmenopausal depression and the effect of estrogen on NAS is lacking. We elected to determine if there were differences in NAS between postmenopausal depressed women and age matched controls. We also investigated the effect of estradiol on NAS in post menopausal depressed women receiving a selective serotonin reuptake inhibitor (SSRI), and in non-depressed postmenopausal controls. As part of a previously published double blind study on estrogen acceleration of antidepressant action, post menopausal women with major depression receiving sertraline and healthy non depressed controls were randomized to transdermal estrogen patch 0.1 mg or placebo. NAS were measured at baseline and after 10 weeks of treatment. Depressed subjects were treated with sertraline 50 mg/day to 100 mg/day for 9 weeks. At the baseline and after treatment ALLO and DHEA were significantly lower in depressed women compared to controls. Although all depressed subjects experienced a positive clinical response, estrogen administration was not associated with changes in NAS in either the depressed or the asymptomatic postmenopausal women. The lower ALLO and DHEA in postmenopausal depressed women suggests that symptoms of depression may be influenced by the synthesis or fluctuation of these NAS. Estradiol exposure did not alter ALLO, DHEA, or THDOC, implying these NAS are unlikely to play a role in any mood changes in post menopausal women given estrogen therapy.

Gonadectomy and hormone replacement exert region- and enzyme isoform-specific effects on monoamine oxidase and catechol-O-methyltransferase activity in prefrontal cortex and neostriatum of adult male rats

Sex differences and gonadal hormone influences are well known for diverse aspects of forebrain amine and indolamine neurotransmitter systems, the cognitive and affective functions they govern and their malfunction in mental illness. This study explored whether hormone regulation/dysregulation of these systems could be related to gonadal steroid effects on catechol-O-methyltransferase and monoamine oxidase which are principal enzymatic controllers of forebrain dopamine, serotonin and norepinephrine levels. Driven by male over female differences in cortical enzyme activities, by male-specific associations between monoamine oxidase and catechol-O-methyltransferase gene polymorphisms and cognitive and dysfunction in disease and by male-specific consequences of gene knockouts in mice, the question of hormone sensitivity was addressed here using a male rat model where prefrontal dopamine levels and related behaviors are also known to be affected. Specifically, quantitative O-methylation and oxidative deamination assays were used to compare the activities of catechol-O-methyltransferase's soluble and membrane-bound isoforms and of monoamine oxidase's A and B isoforms in the pregenual medial prefrontal cortex and dorsal striatum of male rats that were sham operated, gonadectomized or gonadectomized and supplemented with testosterone propionate or with estradiol for 28 days. These studies revealed significant effects of hormone replacement but not gonadectomy on the soluble but not the membrane-bound isorfom of catechol-O-methyltransferase in both striatum and cortex. A significant, cortex-specific testosterone-but not estradiol-attenuated effect (increase) of gonadectomy on monoamine oxidase's A but not B isoform was also observed. Although none of these actions suggest potential roles in the regulation/dysregulation of prefrontal dopamine, the suppressive effects of testosterone on cortical monoamine oxidase-A that were observed could have bearing on the increased incidence of cognitive deficits and symptoms of depression and anxiety that are repeatedly observed in males in conditions of hypogonadalism related to aging, other biological factors or in prostate cancer where androgen deprivation is used as a neoadjuvant treatment.

Neuroprotective effects of estrogen therapy for cognitive and neurobiological profiles of monkey models of menopause

Many postmenopausal women question whether to start or continue hormone therapy because of recent clinical trial negative results. However, evidence from other studies of postmenopausal women, and from studies in menopausal monkeys, indicate that estrogen has neurocognitive protective effects, particularly when therapy is initiated close to the time of menopause before neural systems become increasingly compromised with age. In this review, we present studies of menopausal women and female monkeys that support the concept that estrogen therapies protect both cognitive function and neurobiological processes.

Sex hormones and mood in the perimenopause

The focus of this chapter is the relationship between the onset of depression in women and the reproductive events of the menopause transition. Epidemiologic studies have documented that the majority of women do not become depressed during the menopause transition. However, recent longitudinal studies suggest that in some women, the reproductive events related to the menopause transition could play a role in the onset of depression. No abnormality of ovarian hormones has been identified that distinguishes women with depression from those who remain asymptomatic during the menopause transition. Nonetheless, several findings suggest a role of ovarian hormones in the onset of these depressions. First, episodes of depression cluster during the stage of the menopause transition that is accompanied by estradiol withdrawal. Second, randomized controlled trials have documented the short-term (3-6 weeks) antidepressant efficacy of estradiol in depressed perimenopausal women. Third, experimentally induced estradiol withdrawal triggers mood symptoms in some women. Thus, although depression is not a uniform accompaniment of the menopause transition, in some women, age-related changes in ovarian estrogen production may alter central nervous system function and predispose them to develop depression.

Aggression is related to frontal serotonin-1A receptor distribution as revealed by PET in healthy subjects

OBJECTIVES

Various studies indicate that serotonin regulates impulsivity and the inhibitory control of aggression. Aggression is also known to be modified by sex hormones, which exert influence on serotonergic neurotransmission. The present study aimed to elucidate potential interactions between human aggression, the inhibitory serotonergic 5-HT(1A) receptor, and sex hormones.

EXPERIMENTAL DESIGN

Thirty-three healthy volunteers (16 women, aged 26.24 +/- 5.5 yr) completed a validated questionnaire incorporating five dimensions of aggression. Subsequently, all subjects underwent positron emission tomography with the radioligand [carbonyl-(11)C]WAY-100635 to quantify 5-HT(1A) binding potentials (BP(ND)s) in the prefrontal cortex, limbic areas, and midbrain. Also, plasma levels of testosterone, 17beta-estradiol and sex hormone-binding globulin (SHBG) were measured. Relations between aggression scores, regional 5-HT(1A) BP(ND)s, and hormone levels were analyzed using correlations, multivariate analyses of variance, and linear regressions.

PRINCIPAL OBSERVATIONS

Statistical analyses revealed higher 5-HT(1A) receptor BP(ND)s in subjects exhibiting higher aggression scores in prefrontal (all P < 0.041) and anterior cingulate cortices (P = 0.016). More aggressive subjects were also characterized by lower SHBG levels (P = 0.015). Moreover, higher SHBG levels were associated with lower 5-HT(1A) BP(ND)s in frontal (P = 0.048) and cingulate cortices (all P < 0.013) and in the amygdala (P = 0.03).

CONCLUSIONS

The present study provides first-time evidence for a specific interrelation between the 5-HT(1A) receptor distribution, sex hormones, and aggression in humans. Our findings point to a reduced down-stream control due to higher amounts or activities of frontal 5-HT(1A) receptors in more aggressive subjects, which is presumably modulated by sex hormones.

Estrogen and cognitive functions

Although the effects of estrogen on sexual behavior in mammals are well known, its role on other types of behavior, including cognition, have only recently been recognized. This review summarizes work conducted in our laboratory and others with the aim of identifying the effects of estrogen on cognitive functions. The first section will briefly describe the neurobiology of estrogen. The second section will discuss the effects of estrogen on cognitive behaviors in mammals, as well as the physiological relevance of these effects and their applicability to human health and disease. The third section will detail the role of estrogen on working memory in humans and nonhuman primates, and in rodents. Finally, the concluding section will briefly describe the relationship between estrogen and the aging brain.

Sex-specific associations of body mass index with mood disturbance during smoking abstinence

OBJECTIVE

Previous reports have suggested an inverse relationship between body mass index (BMI) and negative mood in women. However, little is known about the potential association of these variables under stressful conditions, such as those experienced during smoking cessation. The current investigation examined the relationship of BMI and various indices of mood in a sample of male and female cigarette smokers undergoing cessation.

METHODS

Along with baseline assessments of variables such as depression and anxiety, total mood disturbance and perceived stress were assessed via self-report during both baseline (e.g. the smoking period) and the early phases of smoking cessation.

RESULTS

Among female participants, higher BMI was associated with lower levels of mood disturbance, perceived stress and depression. Similar analyses in male participants were non-significant.

CONCLUSIONS

The results of the current study confirm previous reports regarding the relationship of BMI and mood in women and extend these findings to the early stages of smoking cessation.

Medullary serotonin defects and respiratory dysfunction in sudden infant death syndrome

Sudden infant death syndrome (SIDS) is defined as the sudden and unexpected death of an infant less than 12 months of age that occurs during sleep and remains unexplained after a complete autopsy, death scene investigation, and review of the clinical history. It is the leading cause of postneonatal mortality in the developed world. The cause of SIDS is unknown, but is postulated to involve impairment of brainstem-mediated homeostatic control. Extensive evidence from animal studies indicates that serotonin (5-HT) neurons in the medulla oblongata play a role in the regulation of multiple aspects of respiratory and autonomic function. A subset of SIDS infants have several abnormalities in medullary markers of 5-HT function and genetic polymorphisms impacting the 5-HT system, informing the hypothesis that SIDS results from a defect in 5-HT brainstem-mediated control of respiratory (and autonomic) regulation. Here we review the evidence from postmortem human studies and animal studies to support this hypothesis and discuss how the pathogenesis of SIDS is likely to originate in utero during fetal development.

Androgens enhance plasticity of an electric communication signal in female knifefish, Brachyhypopomus pinnicaudatus

Sex steroids were initially defined by their actions shaping sexually dimorphic behavioral patterns. More recently scientists have begun exploring the role of steroids in determining sex differences in behavioral plasticity. We investigated the role of androgens in potentiating circadian, pharmacological, and socially-induced plasticity in the amplitude and duration of electric organ discharges (EODs) of female gymnotiform fish. We first challenged female fish with injections of serotonin (5-HT) and adrenocorticotropic hormone (ACTH), and with social encounters with female and male conspecifics to characterize females' pre-implant responses to each treatment. Each individual was then implanted with a pellet containing dihydrotestosterone (DHT) concentrations of 0.0, 0.03, 0.1, 0.3, or 1.0 mg 10 g(-1) body weight. We then repeated all challenges and compared each female's pre- and post-implant responses. The highest implant dose enhanced EOD duration modulations in response to all challenge types, responses to male challenge were also greater at the second highest dose, and responses to ACTH challenge were enhanced in females receiving all but the smallest dose (and blank) implants. Alternatively, amplitude modulations were enhanced only during female challenges and only when females received the highest DHT dose. Our results highlight the differential regulation of EOD duration and amplitude, and suggest that DHT enhanced the intrinsic plasticity of the electrogenic cells that produce the EOD rather than modifying behavioral phenotypes. The relative failure of DHT to enhance EOD amplitude plasticity also implies that factors other than androgens are involved in regulating/promoting male-typical EOD circadian rhythms and waveform modulations displayed in social contexts.

Protective actions of ovarian hormones in the serotonin system of macaques

The serotonin neurons of the dorsal and medial raphe nuclei project to all areas of the forebrain and play a key role in mood disorders. Hence, any loss or degeneration of serotonin neurons could have profound ramifications. In a monkey model of surgical menopause with hormone replacement and no neural injury, E and P decreased gene expression in the dorsal raphe nucleus of c-jun n-terminal kinase (JNK1) and kynurenine mono-oxygenase (KMO) that promote cell death. In concert, E and P increased gene expression of superoxide dismutase (SOD1), VEGF, and caspase inhibitory proteins that promote cellular resilience in the dorsal raphe nucleus. Subsequently, we showed that ovarian steroids inhibit pivotal genes in the caspase-dependent and caspase-independent pathways in laser-captured serotonin neurons including apoptosis activating factor (Apaf1), apoptosis-inducing factor (AIF) and second mitochondria-derived activator of caspases (Smac/Diablo). SOD1 was also increased specifically in laser-captured serotonin neurons. Examination of protein expression in the dorsal raphe block revealed that JNK1, phosphoJNK1, AIF and the translocation of AIF from the mitochondria to the nucleus decreased with hormone therapy, whereas pivotal execution proteins in the caspase pathway were unchanged. In addition, cyclins A, B, D1 and E were inhibited, which would prevent re-entry into the cell cycle and catastrophic death. These data indicated that in the absence of gross injury to the midbrain, ovarian steroids inhibit the caspase-independent pathway and cell cycle initiation in serotonin neurons. To determine if these molecular actions prevented cellular vulnerability or death, we examined DNA fragmentation in the dorsal raphe nucleus with the TUNEL assay (terminal deoxynucleotidyl transferase nick end labeling). Ovarian steroids significantly decreased the number of TUNEL-positive cells in the dorsal raphe. Moreover, TUNEL staining prominently colocalized with TPH immunostaining, a marker for serotonin neurons. In summary, ovarian steroids increase the cellular resilience of serotonin neurons and may prevent serotonin neuron death in women facing decades of life after menopause. The survival of serotonin neurons would support cognition and mental health.

Gender and the use of hormonal contraception in women are not associated with cerebral cortical 5-HT 2A receptor binding

Gender influences brain function including serotonergic neurotransmission, which may play a role in the well-known gender variations in vulnerability to mood and anxiety disorders. Even though hormonal replacement therapy in menopause is associated with globally increased cerebral 5-HT(2A) receptor binding it is not clear if gender or use of hormonal contraception exhibits associations with 5-HT(2A) receptor binding. We found no significant effect of gender on cortical 5-HT(2A) receptor binding (P=0.15, n=132). When adjusting for the personality trait neuroticism, known to be positively correlated to frontolimbic 5-HT(2A) receptor binding and to be more pronounced in women, again, the effect of gender was not significant (P=0.42, n=127). Also, the use of hormonal contraception (n=14) within the group of pre-menopausal women (total n=29) was not associated with cortical 5-HT(2A) receptor binding (P=0.31). In conclusion, neither gender, nor the use of hormonal contraception in premenopausal women was associated with cortical 5-HT(2A) receptor binding.

Oestrogen receptors in the central nervous system and evidence for their role in the control of cardiovascular function

Oestrogen is considered beneficial to cardiovascular health through protective effects not only on the heart and vasculature, but also on the autonomic nervous system via actions on oestrogen receptors. A plethora of evidence supports a role for the hormone within the central nervous system in modulating the pathways regulating cardiovascular function. A complex interaction of several brainstem, spinal and forebrain nuclei is required to receive, integrate and co-ordinate inputs that contribute appropriate autonomic reflex responses to changes in blood pressure and other cardiovascular parameters. Central effects of oestrogen and oestrogen receptors have already been demonstrated in many of these areas. In addition to the classical nuclear oestrogen receptors (ERalpha and ERbeta) a recently discovered G-protein coupled receptor, GPR30, has been shown to be a novel mediator of oestrogenic action. Many anatomical and molecular studies have described a considerable overlap in the regional expression of these receptors; however, the receptors do exhibit specific characteristics and subtype specific expression is found in many autonomic brain areas, for example ERbeta appears to predominate in the hypothalamic paraventricular nucleus, whilst ERalpha is important in the nucleus of the solitary tract. This review provides an overview of the available information on the localisation of oestrogen receptor subtypes and their multitude of possible modulatory actions in different groups of neurochemically and functionally defined neurones in autonomic-related areas of the brain.

Dissecting natural sensory plasticity: hormones and experience in a maternal context

There is a growing consensus that the auditory system is dynamic in its representation of behaviorally relevant sounds. The auditory cortex in particular seems to be an important locus for plasticity that may reflect the memory of such sounds, or functionally improve their processing. The mechanisms that underlie these changes may be either intrinsic because they depend on the receiver's physiological state, or extrinsic because they arise from the context in which behavioral relevance is gained. Research in a mouse model of acoustic communication between offspring and adult females offers the opportunity to explore both of these contributions to auditory cortical plasticity in a natural context. Recent works have found that after the vocalizations of infant mice become behaviorally relevant to mothers, auditory cortical activity is significantly changed in a way that may improve their processing. Here we consider the hypothesis that maternal hormones (intrinsic factor) and sensory experience (extrinsic factor) contribute together to drive these changes, focusing specifically on the evidence that well-known experience-dependent mechanisms of cortical plasticity can be modulated by hormones.

What causes hot flushes? The neuroendocrine origin of vasomotor symptoms in the menopause

Vasomotor symptoms (VMS) such as hot flushes and night sweats are frequently encountered during menopause and can greatly reduce the quality of life. These symptoms are causally related to decreasing estradiol concentrations, mainly in the serum and subsequently also in the hypothalamic temperature regulating centre. The lack of estrogens alters neurotransmitter activity, especially in the serotonergic and noradrenergic pathways. Because sex steroids act as potent neuromodulators, the substitution of ovarian sex steroids by hormone replacement therapy is the most effective treatment option for VMS. When contraindications exist for the use of sex steroids, steroid-free drugs are a possible alternative. A better understanding of the physiology of thermoregulation, thermoregulatory dysfunction and adaptive processes of the brain may facilitate the development of new therapeutic approaches. Such drugs could then be used to treat vasomotor disorders even when the use of steroid hormones is contraindicated. This review article summarises our knowledge on the mechanisms of temperature regulation and describes deviations from this regulation during altered sex steroid conditions. Our current knowledge on neuroendocrinology of thermoregulation may serve as a basis for the use of steroid-free pharmacological intervention.

Mechanisms of action of estrogen in the brain: insights from human neuroimaging and psychopharmacologic studies

Use of estrogen therapy in the perimenopausal and postmenopausal periods has been shown in several clinical trials to help women maintain a premenopausal level of cognitive function. What is not yet fully understood is how the neurobiological effects of estrogen contribute to these cognitive effects. This review explores data from two related bodies of human literature that provide compelling evidence in support of the biological plausibility that estrogen treatment can benefit cognition. The first half of the literature review focuses on studies from the estrogen neuroimaging literature, and the second half focuses on pharmacologic challenge studies assessing estrogen-neurotransmitter interactions. We integrate these two bodies of literature by focusing on the neurophysiologic underpinnings of estrogen effects on cognition and linking these clinical studies to preclinical studies. The focus on verbal memory is important because it is a cognitive function that has been shown to change with estrogen treatment and predict Alzheimer's disease risk but is not addressed by preclinical studies. Overall, we conclude that estrogen interacts with cholinergic and serotonergic systems to affect hippocampal and frontal cortical brain areas and thereby enhance memory, particularly at the retrieval stage.

Estradiol increases Pet-1 and serotonin transporter mRNA in the midbrain raphe nuclei of ovariectomized rats

Previous research has shown that estradiol increases the anorexia associated with serotonin (5-HT) neurotransmission. To examine further the putative relationship between estradiol and 5-HT, we investigated whether estradiol increases the expression of Pet-1 and the 5-HT transporter (5-HTT), two genes implicated in the development and regulation of the 5-HT system. Ovariectomized (OVX) rats (n=5-6/group) were treated with 0, 2, or 10 microg estradiol benzoate (EB) in sesame oil on 2 consecutive days. Food intake and body weight were recorded 2 days later when EB-treated rats typically display signs of behavioral estrus (e.g., reduced feeding). Following the collection of behavioral data, rats were perfused, brains were removed, and coronal sections were cut through the midbrain raphe nuclei. Pet-1 and 5-HTT mRNA levels were quantified throughout the dorsal and median raphe nuclei (DRN and MRN) by conducting in situ hybridization on free-floating tissue sections using (35)S-labeled cDNA probes. As expected, EB treatment decreased food intake and body weight on the day that modeled estrus. At this same time, EB treatment increased Pet-1 and 5-HTT mRNA levels within the DRN and MRN. We conclude that a physiologically relevant regimen of estradiol treatment in OVX rats increases Pet-1 and 5-HTT mRNA levels in the midbrain raphe nuclei at a time when the anorexigenic effect of estradiol is apparent. Further studies are required to determine whether the increased expression of Pet-1 and 5-HTT mRNA plays a causal role in the anorexigenic effect of estradiol.

Serotonergic projections from the caudal raphe nuclei to the hypoglossal nucleus in male and female rats

The respiratory control system is sexually dimorphic. In many brain regions, including respiratory motor nuclei, serotonin (5HT) levels are higher in females than in males. We hypothesized that there could be sex differences in 5HT input to the hypoglossal nucleus, a region of the brainstem involved in upper airway control. Adult Fischer 344 rats were anesthetized and a retrograde transsynaptic neuroanatomical tracer, Bartha pseudorabies virus (PRV), was injected into the tongue. Sections through the medulla were reacted immunocytochemically for the presence of (i) PRV, (ii) tryptophan hydroxylase (TPH; marker of 5HT neurons), (iii) PRV combined with TPH, and (iv) 5HT. Sex hormone levels were measured in female rats and correlated with TPH immunoreactivity, as hypoglossal 5HT levels vary with the estrous cycle. The number of PRV neurons was comparable in male and female rats. The number and distribution of TPH immunoreactive neurons in the caudal raphe nuclei were similar in male and female rats. The subset of 5HT neurons that innervate hypoglossal motoneurons was also similar in male and female rats. With the exception of the ventrolateral region of the hypoglossal nucleus, 5HT immunoreactivity was similar in male and female rats. These data suggest that sex differences in 5HT modulation of hypoglossal motoneurons in male and female rats are not the result of sex differences in TPH or 5HT, but may result from differences in neurotransmitter release and reuptake, location of 5HT synaptic terminals on hypoglossal motoneurons, pre- and postsynaptic 5HT receptor expression, or the distribution of sex hormone receptors on hypoglossal or caudal raphe neurons.

Migraine in postmenopausal women and the risk of invasive breast cancer

BACKGROUND

The frequency of migraine headache changes at various times of a woman's reproductive cycle. Menarche, menses, pregnancy, and perimenopause may carry a different migraine risk conceivably because of fluctuating estrogen levels, and in general, migraine frequency is associated with falling estrogen levels. Given the strong relationship between endogenous estrogen levels and breast cancer risk, migraine sufferers may experience a reduced risk of breast cancer.

METHODS

We combined data from two population-based case-control studies to examine the relationship between migraine and risk of postmenopausal invasive breast cancer among 1,199 ductal carcinoma cases, 739 lobular carcinoma cases, and 1,474 controls 55 to 79 years of age. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Women who reported a clinical diagnosis of migraine had reduced risks of ductal carcinoma (OR, 0.67; 95% CI, 0.54-0.82) and lobular carcinoma (OR, 0.68; 95% CI, 0.52-0.90). These associations were primarily limited to hormone receptor-positive tumors as migraine was associated with a 0.65-fold (95% CI, 0.51-0.83) reduced risk of estrogen receptor-positive (ER+)/progesterone receptor-positive (PR+) ductal carcinoma. The reductions in risk observed were seen among migraine sufferers who did and did not use prescription medications for their migraines.

CONCLUSIONS

These data suggest that a history of migraine is associated with a decreased risk of breast cancer, particularly among ER+/PR+ ductal and lobular carcinomas. Because this is the first study to address an association between migraine history and breast cancer risk, additional studies are needed to confirm this finding.

Sex differences in response to citalopram: a STAR*D report

OBJECTIVE

Controversy exists as to whether women with depression respond better to selective serotonin reuptake inhibitors (SSRIs) than men. The purpose of this report was to determine whether men and women differ in their responses to treatment with the SSRI citalopram using a large sample of real world patients from primary and psychiatric specialty care settings.

METHOD

As part of the sequenced treatment alternatives to relieve depression (STAR *D) study, 2876 participants were treated with citalopram for up to 12-14 weeks. Baseline demographic and clinical characteristics and outcomes were gathered and compared between men and women.

RESULTS

At baseline, women were younger, had more severe depressive symptoms and were more likely to have: early onset; previous suicide attempt(s); a family history of depression, alcohol abuse or drug abuse; atypical symptom features; and one or more of several concurrent psychiatric disorders. Despite greater baseline severity and more Axis I comorbidities, women were more likely to reach remission and response with citalopram than men.

CONCLUSIONS

Women have a better response to the SSRI citalopram than men, which may be due to sex-specific biological differences particularly in serotonergic systems.

Progesterone reduces the effect of the serotonin 1B/1D receptor antagonist, GR 127935, on lordosis behavior

Ovariectomized rats were hormonally primed with 10 microg estradiol benzoate or with estradiol benzoate plus 500 microg progesterone. Rats received a bilateral infusion with 200 ng of the 5-HT(1B/1D) receptor antagonist, N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-1-1'-biphenyl-4-carboxamide hydrochloride (GR 127935), into the ventromedial nucleus of the hypothalamus (VMN), followed by a 5 min restraint or home cage experience. In estrogen-primed females that had experienced minimal handling between ovariectomy and use in the experiment, infusion with the water vehicle transiently inhibited lordosis behavior, and the 5-HT(1B/1D) receptor antagonist amplified this inhibition. There were no effects in rats hormonally primed with estrogen and progesterone. Handling for two days before the experiment reduced the effects of the infusions in estrogen-primed rats. However, when a 5 min restraint experience followed infusion with GR 127935, there was a significant decline in lordosis behavior that persisted for 10 to 15 min after the experience. Regardless of the prior experience or type of infusion, the addition of progesterone to the hormonal priming completely prevented the lordosis inhibition. These findings are consistent with prior evidence that progesterone protects against the inhibitory effects of a 5 min restraint experience on lordosis behavior. Moreover, these are the first experiments to demonstrate an inhibitory effect of a selective 5-HT(1B/1D) receptor antagonist in the VMN on lordosis behavior of estrogen primed, but not estrogen and progesterone primed, ovariectomized rats.

Update on research and treatment of premenstrual dysphoric disorder

Many women in their reproductive years experience some mood, behavioral. or physical symptoms in the week prior to menses. Variability exists in the level of symptom burden in that some women experience mild symptoms, whereas a small minority experience severe and debilitating symptoms. For an estimated 5%-8% of premenopausal women, work or social functioning are affected by severe premenstrual syndrome. Many women in this group meet diagnostic criteria for premenstrual dysphoric disorder (PMDD). Among women who suffer from PMDD, mood and behavioral symptoms such as irritability, depressed mood, tension, and labile mood dominate. Somatic complaints, including breast tenderness and bloating, also can prove disruptive to women's overall functioning and quality of life. Recent evidence suggests that individual sensitivity to cyclical variations in levels of gonadal hormones may predispose certain women to experience these mood, behavioral, and somatic symptoms. Treatments include: antidepressants of the serotonin reuptake inhibitor class, taken intermittently or throughout the menstrual cycle; medications that suppress ovarian cyclicity; and newer oral contraceptives with novel progestins.

Neurobiology of stress-induced reproductive dysfunction in female macaques

It is now well accepted that stress can precipitate mental and physical illness. However, it is becoming clear that given the same stress, some individuals are very vulnerable and will succumb to illness while others are more resilient and cope effectively, rather than becoming ill. This difference between individuals is called stress sensitivity. Stress sensitivity of an individual appears to be influenced by genetically inherited factors, early life (even prenatal) stress, and by the presence or absence of factors that provide protection from stress. In comparison to other stress-related diseases, the concept of sensitivity versus resilience to stress-induced reproductive dysfunction has received relatively little attention. The studies presented herein were undertaken to begin to identify stable characteristics and the neural underpinnings of individuals with sensitivity to stress-induced reproductive dysfunction. Female cynomolgus macaques with normal menstrual cycles either stop ovulating (stress sensitive) or to continue to ovulate (stress resilient) upon exposure to a combined metabolic and psychosocial stress. However, even in the absence of stress, the stress-sensitive animals have lower secretion of the ovarian steroids, estrogen and progesterone, have higher heart rates, have lower serotonin function, have fewer serotonin neurons and lower expression of pivotal serotonin-related genes, have lower expression of 5HT2A and 2C genes in the hypothalamus, have higher gene expression of GAD67 and CRH in the hypothalamus, and have reduced gonadotropin-releasing hormone transport to the anterior pituitary. Altogether, the results suggest that the neurobiology of reproductive circuits in stress-sensitive individuals is compromised. We speculate that with the application of stress, the dysfunction of these neural systems becomes exacerbated and reproductive function ceases.

Characterization of a functional polymorphism in the 3' UTR of SLC6A4 and its association with drinking intensity

BACKGROUND

The propensity for severe drinking is hypothesized to be regulated by differential expression of serotonin transporter gene (SLC6A4) in the human brain. The SLC6A4 promoter region 5-HTTLPR has been examined previously as a candidate polymorphic variant associated with severe drinking. In this study, we investigated whether other SLC6A4 single nucleotide polymorphisms (SNPs) are associated with drinking intensity among treatment-seeking alcoholics and whether these polymorphic variants result in differential SLC6A4 expression levels.

METHODS

We analyzed associations of drinking intensity in 275 (78.5% male) treatment-seeking alcoholics of Caucasian and Hispanic origin, with 6 SLC6A4 polymorphisms. Next, to examine the functionality of the SNP that showed a significant association with drinking intensity, we transfected the 2 alleles of rs1042173 into HeLa cell cultures and measured serotonin transporter mRNA and protein expression levels by using qRT-PCR and western blotting techniques.

RESULTS

One of the 6 polymorphisms we examined, rs1042173 in the 3' untranslated region (3'-UTR) of SLC6A4, showed a significant association with drinking intensity. The G allele carriers for rs1042173 were associated with significantly lower drinking intensity (p = 0.0034) compared to T-allele homozygotes. In HeLa cell cultures, the cells transfected with G allele showed a significantly higher mRNA and protein levels than the T allele-transfected cells.

CONCLUSION

These findings suggest that the allelic variations of rs1042173 affect drinking intensity in alcoholics possibly by altering serotonin transporter expression levels. This provides additional support to the hypothesis that SLC6A4 polymorphisms play an important role in regulating propensity for severe drinking.

Depression during menopausal transition: a review of treatment strategies and pathophysiological correlates

It has long been recognized that women are at a higher risk than men to develop depression and that such risk is particularly associated with reproductive cycle events. Recent long-term, prospective studies have demonstrated that the transition to menopause is associated with higher risk for new onset and recurrent depression. A number of biological and environmental factors are independent predictors for depression in this population, including the presence of hot flushes, sleep disturbance, history of severe premenstrual syndrome or postpartum blues, ethnicity, history of stressful life events, past history of depression, body mass index, socioeconomic status and the use of hormones and antidepressants. Accumulated evidence suggests that ovarian hormones modulate serotonin and noradrenaline neurotransmission, a process that may be associated with underlying pathophysiological processes involved in the emergence of depressive symptoms during periods of hormonal fluctuation in biologically predisposed subpopulations. Transdermal estradiol and serotonergic and noradrenergic antidepressants are efficacious in the treatment of depression and vasomotor symptoms in symptomatic, midlife women. The identification of individuals whom might be at a higher risk for depression during menopausal transition could guide preventive strategies for this population.

Expression profile of differentiating serotonin neurons derived from rhesus embryonic stem cells and comparison to adult serotonin neurons

The rhesus monkey embryonic stem cell line 366.4 differentiates into serotonin neurons. We examined the genetic cascade during differentiation and compared ESC-derived serotonin neurons to adult monkey serotonin neurons. RNA was extracted from ESC colonies, embryoid bodies (EBs), neurospheres in selection (N1) and proliferation stages (N2), differentiated serotonin neurons (N3) and from laser captured (LC) serotonin neurons of spayed female macaques treated with placebo, estrogen (E), progesterone (P) or E+P. The RNA was labeled and hybridized to Rhesus Monkey Affymetrix Gene Chips (n=1 per stage and 2 per animal treatment). Gene expression was examined with GeneSifter software. 545 genes that were related to developmental processes showed a threefold or greater change between stages. TGFb, Wnt, VEGF and Hedgehog signaling pathways showed the highest percent of probe set changes during differentiation. Genes in the categories (a) homeobox binding and transcription factors, (b) growth factors and receptors, (c) brain and neural specific factors and (d) serotonin specific factors are reported. Pivotal genes were confirmed with quantitative RT-PCR. In the serotonin developmental cascade, FGFR2 was robustly expressed at each stage. GATA3 was robustly expressed in EBs. Sonic hedgehog (Shh), PTCH (Shh-R) and Fev1 transcription factor expression coincided with the induction of serotonin specific marker genes during N1-selection. A majority of the examined genes were expressed in adult serotonin neurons. However, in the ESC-derived neurons, there was significant over-representation of probe sets related to cell cycle, axon guidance & dorso-ventral axis formation. This analysis suggests that the 366.4 cell line possesses cues for serotonin differentiation at early stages of differentiation, but that ESC-derived serotonin neurons are still immature.

Estrogen receptor-alpha immunoreactive neurons in the brainstem and spinal cord of the female rhesus monkey: species-specific characteristics

The distribution pattern of estrogen receptors in the rodent CNS has been reported extensively, but mapping of estrogen receptors in primates is incomplete. In this study we describe the distribution of estrogen receptor alpha immunoreactive (ER-alpha IR) neurons in the brainstem and spinal cord of the rhesus monkey. In the midbrain, ER-alpha IR neurons were located in the periaqueductal gray, especially the caudal ventrolateral part, the adjacent tegmentum, peripeduncular nucleus, and pretectal nucleus. A few ER-alpha IR neurons were found in the lateral parabrachial nucleus, lateral pontine tegmentum, and pontine gray medial to the locus coeruleus. At caudal medullary levels, ER-alpha IR neurons were present in the commissural nucleus of the solitary complex and the caudal spinal trigeminal nucleus. The remaining regions of the brainstem were devoid of ER-alpha IR neurons. Spinal ER-alpha IR neurons were found in laminae I-V, and area X, and were most numerous in lower lumbar and sacral segments. The lateral collateral pathway and dorsal commissural nuclei of the sacral cord and the thoracic intermediolateral cell column also contained ER-alpha IR neurons. Estrogen treatment did not result in any differences in the distribution pattern of ER-alpha IR neurons. The results indicate that ER-alpha IR neurons in the primate brainstem and spinal cord are concentrated mainly in regions involved in sensory and autonomic processing. Compared with rodent species, the regional distribution of ER-alpha IR neurons is less widespread, and ER-alpha IR neurons in regions such as the spinal dorsal horn and caudal spinal trigeminal nucleus appear to be less abundant. These distinctions suggest a modest role of ER-alpha in estrogen-mediated actions on primate brainstem and spinal systems. These differences may contribute to variations in behavioral effects of estrogen between primate and rodent species.

The unique challenges of managing depression in mid-life women

Throughout most of their lives, women are at a greater risk of becoming depressed than men. Some evidence suggests that this heightened risk is associated with increased sensitivity to the hormonal changes that occur across the female reproductive lifecycle. For some women, the peri-menopause and early post-menopausal years may constitute a "window of vulnerability" during which challenging physical and emotional discomforts could result in significant impairment in functioning and poorer quality of life. A number of biological and environmental factors are independent predictors for depression in this population, including the presence of hot flashes, sleep disturbance, history of severe premenstrual syndrome or postpartum blues, ethnicity, history of stressful live events, past history of depression, body mass index and socioeconomic status. This paper explores the current knowledge on the complex associations between mood changes and aging in women. More specifically, the biological aspects of reproductive aging and their impact on mood, psychosocial factors, lifestyle, and overall health are reviewed. In addition, evidence-based hormonal and non-hormonal therapies for the management of depression and other complaints in midlife women are discussed. Ultimately, this article should help clinicians and health professionals to address a challenging clinical scenario: a preventive and effective strategy for the management of depression in the context of the menopausal transition and beyond.

Regulation of pseudosexual behavior in the parthenogenetic whiptail lizard, Cnemidophorus uniparens

Neuroendocrine mechanisms underlying complementary behaviors like male-typical mounting and female-typical receptivity are most often studied independently in males and females, respectively. Cnemidophorus uniparens is a unisexual lizard species consisting only of females that alternately express male- and female-like pseudosexual behavior across the ovarian cycle. Intact, postovulatory (PostOv), and ovariectomized (OVX), androgen-implanted animals [OVX plus testosterone (T)] exhibit male-like mounting, but not receptivity, whereas intact, preovulatory (PreOv), and OVX lizards injected with estradiol [OVX plus estrogen (E)] express receptivity, but not mounting. We tested whether the serotonergic system in the preoptic area (POA) and ventromedial nucleus of the hypothalamus (VMN) gates the reciprocal inhibition characterizing this alternating expression of mounting and receptivity. Serotonergic signaling at the POA appears to be key to gating male-like behavior. Postovulatory and OVX plus T animals have lower intracellular serotonin (5-HT) levels, and greater abundance of inhibitory 5-HT1A receptor mRNA in the POA compared with both PreOv and OVX plus E lizards. Moreover, injecting 5-HT into the POA of OVX plus T animals suppresses mounting, whereas injection into VMN of OVX plus E lizards suppresses receptivity. Although 5-HT levels in the VMN do not differ across the ovarian cycle or between hormonally manipulated animals, PreOv and OVX plus E lizards have a lower abundance of 5-HT2A mRNA in the VMN. Stimulating 5-HT1A receptors using systemic drug administration inhibits mounting, whereas activating 5-HT2A receptors facilitates receptivity. This study illuminates how male- and female-typical sexual behaviors share common neural circuits, and that 5-HT regulates these naturally complementary, and mutually exclusive, behaviors.

Working memory for emotional facial expressions: role of the estrogen in young women

Physiological hormonal fluctuations during the menstrual cycle, postpartum, and menopause have been implicated in the modulation of mood, cognition, and affective disorders. Taking into account that women's performance in memory tasks can also fluctuate with circulating hormones levels across the menstrual cycle, the cognitive performance in a working memory task for emotional facial expressions, using the six basic emotions as stimuli in the delayed matching-to-sample, was evaluated in young women in different phases of the menstrual cycle. Our findings suggest that high levels of estradiol in the follicular phase could have a negative effect on delayed matching-to-sample working memory task, using stimuli with emotional valence. Moreover, in the follicular phase, compared to the menstrual phase, the percent of errors was significantly higher for the emotional facial expressions of sadness and disgust. The evaluation of the response times (time employed to answer) for each facial expression with emotional valence showed a significant difference between follicular and luteal in reference to the emotional facial expression of sadness. Our results show that high levels of estradiol in the follicular phase could impair the performance of working memory. However, this effect is specific to selective facial expressions suggesting that, across the phases of the menstrual cycle, in which conception risk is high, women could give less importance to the recognition of the emotional facial expressions of sadness and disgust. This study is in agreement with research conducted on non-human primates, showing that fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors. Moreover, our data could also represent a useful tool for investigating emotional disturbances linked to menstrual cycle phases and menopause in women.

The effects of metergoline and 8-OH-DPAT injections into arcuate nucleus and lateral hypothalamic area on feeding in female rats during the estrous cycle

The present study examined the effects of local injections of metergoline (MET, an antagonist of 5-HT1/2 receptors, 2 and 20 nmol) and 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT, selective 5-HT1A receptor agonist, 0.6 and 6 nmol) into the arcuate nucleus (ARC) and the lateral hypothalamus (LH), on ingestive and non-ingestive behaviors of female rats. These effects were examined during the diurnal periods of diestrus and estrus in rats adapted to eat a wet mash diet (enriched with 10% sucrose) during 1h for 3 consecutive days at the recording chamber. The results showed that 8-OH-DPAT injected into the LH significantly reduced food intake at all doses and both cycle stages, while in the ARC these treatments evoked hypophagia only at the highest 8-OH-DPAT dose and only at the estrous phase. MET administered into the ARC (at all doses) failed to affect food intake during both estrous stages. On the other hand, food intake decreased after injection of both doses of MET into the LH of rats during estrous and diestrus phases. In estrus stage, injections of the higher dose of 8-OH-DPAT into the ARC and into the LH decreased the duration of feeding. Latency to start feeding, drinking, and non-ingestive behaviors were not affected by 8-OH-DPAT or MET treatments in the ARC or the LH in both cycle phases. These results indicated that 5-HT1A receptors participate in the serotonergic control of feeding-related mechanisms located at the ARC and the LH. These feeding-related serotonergic circuits in both areas are possibly affected by ovarian hormones that could increase sensitivity of ARC neurons to the hypophagic effects of 8-OH-DPAT or increase the efficacy of satiety signals that terminate feeding. In addition, the present data indicated that serotonergic inputs do not exert a tonic inhibitory activity on the ARC and the LH feeding-related circuits.

Headache and pregnancy

BACKGROUND

Many women who suffer from migraine and tension-type headaches (TTHs) have an improvement in the frequency of these headaches during pregnancy. At the same time pregnancy predisposes women to a number of potentially life-threatening conditions which can present with headache. Accurate diagnosis and treatment of headache during pregnancy is essential.

REVIEW SUMMARY

The primary objectives of this review are to: (1) Summarize the natural history of primary headache disorders, including migraine, tension-type, and cluster headaches during pregnancy, as well as the impact of migraine on pregnancy outcomes and complications.(2) Summarize the therapeutic options and strategies for managing headaches in pregnancy and (3) Discuss the causes of secondary headaches and the diagnostic evaluation for new onset headache during pregnancy.

CONCLUSION

Primary headache disorders, in particular TTHs and migraines, generally improve during pregnancy. However the frequency of improvement varies greatly. Because the pathophysiology of both migraines and TTHs is poorly understood, this limits our ability to predict improvement. Future research should be focused on headache pathophysiology and the effect of ovarian hormones and the pregnant state on headache pathogenesis.

Sequential serotonin and noradrenalin associated processes involved in postpartum blues

OBJECTIVE

We investigated whether postpartum blues was related to changes in parameters of noradrenergic and serotonergic functioning.

METHODS

From 26 healthy pregnant women blood was collected at the end of pregnancy and 5 days and 6 weeks postpartum. Serotonergic parameters were: platelet serotonin content; paroxetine binding to platelet membranes as an index of serotonin transporter activity; the serotonin precursor tryptophan in proportion to the large neutral amino acids, as an estimate of its cerebral influx. Noradrenergic indices were the noradrenaline precursor tyrosine and its metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). The Kennerly and Gath blues questionnaire was applied at day five postpartum.

RESULTS

The incidence of postpartum blues was 30%. The tryptophan ratio and serotonin content of platelets were decreased (p<0.01) at day five postpartum in all women. Bmax paroxetine at day five was correlated with blues score (beta=0.460; p=0.031). MHPG levels at 6 weeks were increased in women with blues (p<0.001). In a regression model MHPG at 6 weeks was related to blues score (beta=0.477; p=0.002) and MHPG at day five (beta=0.550; p=0.001), explaining >50% of the variation (R2=0.588; p<0.001).

CONCLUSIONS

A decreased serotonergic activity was found at the fifth day postpartum in all subjects. Increased SERT activity, reflected by higher paroxetine binding to platelets might be involved in the onset of blues. The elevated MHPG levels in women with blues are compatible with a higher stress sensitivity, or a decreased stress coping in those and is suggested to be involved with the onset of depression.

The serotonin-1A receptor distribution in healthy men and women measured by PET and [carbonyl-11C]WAY-100635

PURPOSE

The higher prevalence rates of depression and anxiety disorders in women compared to men have been associated with sexual dimorphisms in the serotonergic system. The present positron emission tomography (PET) study investigated the influence of sex on the major inhibitory serotonergic receptor subtype, the serotonin-1A (5-HT(1A)) receptor.

METHODS

Sixteen healthy women and 16 healthy men were measured using PET and the highly specific radioligand [carbonyl-(11)C]WAY-100635. Effects of age or gonadal hormones were excluded by restricting the inclusion criteria to young adults and by controlling for menstrual cycle phase. The 5-HT(1A) receptor BP(ND) was quantified using (1) the 'gold standard' manual delineation approach with ten regions of interest (ROIs) and (2) a newly developed delineation method using a PET template normalized to the Montreal Neurologic Institute space with 45 ROIs based on automated anatomical labeling.

RESULTS

The 5-HT(1A) receptor BP(ND) was found equally distributed in men and women applying both the manual delineation method and the automated delineation approach. Women had lower mean BP(ND) values in every region investigated, with a borderline significant sex difference in the hypothalamus (p = 0.012, uncorrected). There was a high intersubject variability of the 5-HT(1A) receptor BP(ND) within both sexes compared to the small mean differences between men and women.

CONCLUSIONS

To conclude, when measured in the follicular phase, women do not differ from men in the 5-HT(1A) receptor binding. To explain the higher prevalence of affective disorders in women, further studies are needed to evaluate the relationship between hormonal status and the 5-HT(1A) receptor expression.

Differential effects of ovarian steroids and raloxifene on serotonin 1A and 2C receptor protein expression in macaques

To further understand the role of ovarian hormones in the function of the serotonin neural system, we investigated the effects of estradiol (E), progesterone (P), and raloxifene on 5HT 1A and 2C receptor protein expression in the dorsal raphe region using Western blot analysis. Adult rhesus macaques (Macaca mulatta) were ovariectomized (Ovx) and implanted with Silastic capsules containing E or P. In the first paradigm, animals that had been Ovx for 6-16 months were treated for 1 month with E (El) or E + P (EP1) and compared to animals that were untreated and Ovx for 5 months (n = 4 per group). In the second paradigm, comparisons were made between animals that were Ovx and untreated for 5 months, or Ovx and immediately implanted with Silastic capsules containing E or E + P for 5 months (E5, EP5), or administered raloxifene in the diet for 5 months (Ral5) (n = 4 per group). The dorsal raphe region was harvested, homogenized and a crude membrane fraction was obtained for examination of receptor proteins. In the first paradigm, 5HT1A receptor protein expression was significantly lower in E1 and EPI treatment groups compared to the Ovx-control group (ANOVA P = 0.01; posthoc P < 0.03), but 5HT2C receptor expression was unaffected by 1 month of E or EP treatment. In the second paradigm, there was no difference in 5HT1A receptor expression between the Ovx-control group and the E5 group, but 5HT1A receptor expression was significantly suppressed in the EP5 group (ANOVA P = 0.04; posthoc P < 0.05). In addition, 5HT2C expression increased in the E5 treatment group relative to the Ovx-control group. Addition of P to the E5 regimen prevented the E5-induced increase in 5HT2C receptor expression and significantly reduced 5HT2C receptor expression to a level below that observed in the Ovx-control group (ANOVA P = 0.001; posthoc P < 0.05). Thus, 5HT1A receptor may lose sensitivity to the suppressive effect of E after 5 months, whereas the 5HT2C receptor increases. However, addition of P in the EP5 regimen maintains the regulatory effects observed with 1 month of treatment. 5HT1A receptor protein levels were higher with raloxifene treatment than in Ovx-control animals (P < 0.01), suggesting that raloxifene may antagonize residual E in Ovx animals.