Sex steroid induced negative mood may be explained by the paradoxical effect mediated by GABAA modulators

Long-term administration with levonorgestrel decreases allopregnanolone levels and alters GABA(A) receptor subunit expression and anxiety-like behavior

Fluctuations in the concentrations of the neuroactive steroid allopregnanolone are thought to influence γ-amino-butyric acid type A (GABA(A)) receptor gene expression and function. Long-term treatment with ethinyl estradiol (EE) plus levonorgestrel (LNG), two of the most widely used steroids in the hormonal contraceptive pill, decreases allopregnanolone levels in rat cerebral cortex and plasma, alters GABA(A) receptor expression and induces anxiety-like behavior. We evaluated which component of the hormonal contraceptive pill is responsible for the aforementioned changes. Female rats were injected subcutaneously (s.c.) with EE (0.030 mg) or LNG (0.125 mg) once a day for 4 weeks. Compared to the respective vehicle-treated control groups, EE decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 76, 72 and 33%, respectively and hippocampal levels by 52, 56 and 50%, respectively. Likewise, LNG decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 75, 68 and 33%, respectively, and hippocampal levels by 55, 65 and 60%, respectively. Administration of LNG, but not EE, increased the abundance of the γ2 subunit peptide in cerebral cortex and hippocampus by 38 and 59%, respectively. Further, LNG, but not EE, decreased the time spent and the number of entries into the open arms of the elevated plus maze by 56 and 43%, respectively, an index of anxiety-like behavior. These results suggest that alterations in GABA(A) receptor subunit expression and anxiety-like behavior induced by long-term treatment with combined EE/LNG appear to be caused by LNG. Given that both EE and LNG decrease allopregnanolone levels in a similar manner, these results further suggest that changes in allopregnanolone levels are not associated with GABA(A) receptor expression.

[Organic and comorbid causes of depression: a first step]

The primary objective of this review is to obtain a clinical orientation as to evidence-supported common «other» causes of depressive symptomatology, which predominantly are: medical issues; life events; vitamin, mineral and diet-related deficiencies; and hormones. A secondary goal was to reflect those more frequent "other" causes in a checklist for clinical use, comprising also the preferred treatment (medical/dietary, antidepressants, or psychological) resulting from the available evidence. Medline, Cochrane and main related databases were searched from 4(th) October 2010 to 27(th) April 2011, no language limits, with keywords: depression; organic; comorbid; medication; life events; hormones; vitamin; mineral; diet; disease; as well as further searches into each upcoming possibly related issue. Total studies contemplated: 3.211; total studies reviewed: 301, with criteria of relevancy; date of study or review; size and type; journal status. Data were abstracted based upon probable clinical relevancy and use. The main results obtained were evidence-supported indications as to these other causes of depressive symptomatology, that warrant early screening, attention and treatment, possibly before antidepressant or psychological therapy is started. PRELIMINARY CONCLUSION: There appears to be a clinical rationale for early checking of a number of evidence-based causes of depressive symptoms for which first-line testing is readily available. In several cases clinical treatment may be simple, and improvements in depressive symptoms rapidly obtainable. Using a pre-treatment protocol, both patients and health systems could benefit from biological and comorbid causes of depressive symptoms being established early. An enhanced response to low-cost corrective measures can decrease the risk of suicide.

A history of depression in women is associated with an altered GABAergic neuroactive steroid profile

The 3α,5α- and 3α,5β-reduced metabolites of progesterone, deoxycorticosterone, and dehydroepiandrosterone (DHEA) have potent effects on neurotransmission mediated by GABA(A) receptors, and dysregulation of these receptors has been implicated in depression. Using gas chromatography-mass spectrometry, we compared neuroactive steroid concentrations in women with a history of depressive disorders, but who were in full remission at the time of testing (n=11) to never depressed women (n=17) both before and after a challenge with oral micronized progesterone (300 mg). Serum concentrations of the following were obtained: four progesterone-derived GABAergic neuroactive steroids, the precursor pregnenolone, androstenedione-derived neuroactive steroids, and the precursor DHEA. As an index of conversion of progesterone to neuroactive steroids, we also examined ratios of neuroactive steroids to progesterone following the oral progesterone challenge. Results indicated that both before and after oral progesterone, women with histories of depression showed lower concentrations of all GABAergic neuroactive steroids than never depressed women. Those with a history of depression also had lower cortisol concentrations. Because serum neuroactive steroids are mainly synthesized in the adrenals, we hypothesize that histories of depression may be associated with persistent adrenal suppression. Following the progesterone challenge, ratios of the progesterone-derived neuroactive steroids to plasma progesterone concentrations were elevated in women with depression histories, suggesting there may be an adaptive shift in the metabolism of progesterone that compensates for lower circulating neuroactive steroid concentrations.

Failed lactation and perinatal depression: common problems with shared neuroendocrine mechanisms?

In the early postpartum period, mother and infant navigate a critical neuroendocrine transition from pregnancy to lactation. Two major clinical problems that occur during this transition are failed lactation and perinatal mood disorders. These disorders often overlap in clinical settings. Failed lactation is common. Although all major medical organizations recommend 6 months of exclusive breastfeeding, only 13% of women in the United States achieve this recommendation. Perinatal mood disorders affect 10% of mothers, with substantial morbidity for mother and child. We hypothesize that shared neuroendocrine mechanisms contribute to both failed lactation and perinatal mood disorders. In this hypothesis article, we discuss data from both animal models and clinical studies that suggest neuroendocrine mechanisms that may underlie these two disorders. Research to elucidate the role of these underlying mechanisms may identify treatment strategies both to relieve perinatal depression and to enable women to achieve their infant feeding goals.

How reward and emotional stimuli induce different reactions across the menstrual cycle

Despite widespread belief that moods are affected by the menstrual cycle, researchers on emotion and reward have not paid much attention to the menstrual cycle until recently. However, recent research has revealed different reactions to emotional stimuli and to rewarding stimuli across the different phases of the menstrual cycle. The current paper reviews the emerging literature on how ovarian hormone fluctuation during the menstrual cycle modulates reactions to emotional stimuli and to reward. Behavioral and neuroimaging studies in humans suggest that estrogen and progesterone have opposing influences. That is, it appears that estrogen enhances reactions to reward, but progesterone counters the facilitative effects of estrogen and decreases reactions to rewards. In contrast, reactions to emotionally arousing stimuli (particularly negative stimuli) appear to be decreased by estrogen but enhanced by progesterone. Potential factors that can modulate the effects of the ovarian hormones (e.g., an inverse quadratic function of hormones' effects; the structural changes of the hippocampus across the menstrual cycle) are also discussed.

Endocrine modulation of the adolescent brain: a review

Neurophysiological and behavioral development is particularly complex in adolescence. Youngsters experience strong emotions and impulsivity, reduced self-control, and preference for actions which offer immediate rewards, among other behavioral patterns. Given the growing interest in endocrine effects on adolescent central nervous system development and their implications on later stages of life, this article reviews the effects of gonadal steroid hormones on the adolescent brain. These effects are classified as organizational, the capacity of steroids to determine nervous system structure during development, and activational, the ability of steroids to modify nervous activity to promote certain behaviors. During transition from puberty to adolescence, steroid hormones trigger various organizational phenomena related to structural brain circuit remodelling, determining adult behavioral response to steroids or sensory stimuli. These changes account for most male-female sexual dimorphism. In this stage sex steroids are involved in the main functional mechanisms responsible for organizational changes, namely myelination, neural pruning, apoptosis, and dendritic spine remodelling, activated only during embryonic development and during the transition from puberty to adolescence. This stage becomes a critical organizational window when the appropriately and timely exerted functions of steroid hormones and their interaction with some neurotransmitters on adolescent brain development are fundamental. Thus, understanding the phenomena linking steroid hormones and adolescent brain organization is crucial in the study of teenage behavior and in later assessment and treatment of anxiety, mood disorders, and depression. Adolescent behavior clearly evidences a stage of brain development influenced for the most part by steroid hormones.

AKR1C4 gene variant associated with low euthymic serum progesterone and a history of mood irritability in males with bipolar disorder

BACKGROUND

Irritable mood during mood elevation is common in bipolar disorder. The progesterone metabolite allopregnanolone (ALLO) has been implicated in other disorders presenting with irritability. This study aimed to test whether a history of manic/hypomanic irritability is associated with low serum progesterone levels; and whether single nucleotide polymorphisms (SNPs) in gene coding for steroidogenetic enzymes (HSD3B2, SRD5A1 and AKR1C4 were coupled to previous manic irritability and/or with serum progesterone concentrations.

METHODS

Morning serum progesterone concentrations during euthymic phase of bipolar illness types 1 and 2 were assessed in 71 males and 107 females. Previous manic/hypomanic irritability was assessed using the Affective Disorders Evaluation. Selected SNPs were analyzed: i) aldoketoreductase-type-4 (AKR1C4 - rs17306779, rs3829125, rs10904440, rs12762017, and rs11253048), ii) 3-β-hydroxysteroid-dehydrogenase (HSD3B2 - rs4659174, rs2854964, and rs3765948), iii) steroid-5-α-reductase (SRD5A1 - rs8192139, rs181807, rs3822430, and rs3736316).

RESULTS

In males, progesterone concentrations were lower in those who had shown manic/hypomanic irritability compared with nonirritable (F=7.05, p=0.0099). SNPs rs17306779, rs3829125, and rs10904440 were associated with manic/hypomanic irritability. A cystine to serine change at position 145 in AKR1C4 (rs3829125) was associated with lower serum progesterone (F=6.34, p=0.014). There were no associations in females.

LIMITATIONS

Relatively small sample sizes.

CONCLUSION

Low progesterone levels and a cystine to serine change at position 145 in AKR1C4 gene are associated with manic/hypomanic irritability in males. Given that the enzyme AKR1C4 has both dehydrogenating and reductive activities in the steroidogenetic pathway, a missense variation in the gene may predispose to manic/hypomanic irritability by altering the relationship between progesterone and ALLO concentrations in the brain.

Susceptibility to the long-term anxiogenic effects of an acute stressor is mediated by the activation of the glucocorticoid receptors

The specificity of the response of an organism is an important variable influencing stress-related parameters and psychopathological states. We have shown that trait anxiety in C57BL/6 mice, determined by their emergence latencies in the free choice open field test, positively correlates with the long-term behavioral and neuroendocrinological changes induced by a stressor. Here, we show that this interindividual variability is caused by a different reactivity of the hypothalamus-pituitary-adrenal (HPA) axis upon exposure to a stressor. Mice with high trait anxiety (long emergence latency, LEL) display a more pronounced stress-induced activation of the HPA axis than mice with low trait anxiety (short emergence latency, SEL). Moreover, stress-induced activation of tyrosine hydroxylase and corticotropin-releasing hormone occurred in LEL but not SEL mice. In search of the molecular mechanisms underlying these differences, we found that under non-stressed conditions mRNA and protein levels of the glucocorticoid receptor in the hippocampus were higher in LEL mice compared to SEL mice. Also, systemic injection of the glucocorticoid receptor antagonist RU486 decreased the stress-induced activation of the HPA axis and the long-term anxiogenic effects of stress observed in LEL mice. Finally, the rewarding properties of cocaine were enhanced in LEL mice compared to SEL mice, suggesting a causal link between trait anxiety, stress activity and the behavioral responses to drugs of addiction.

Progesterone turnover to its 5α-reduced metabolites in the ventral tegmental area of the midbrain is essential for initiating social and affective behavior and progesterone metabolism in female rats

BACKGROUND

Among women and female rodents, progesterone (P) influences social affiliation and affect. These effects may be partly due to formation of its 5α-reduced, 3α- hydroxylated metabolite, 5α-pregnan-3α-ol-20-one (3α,5α- THP).

AIM

To elucidate whether actions of 3α,5α-THP in the midbrain ventral tegmental area (VTA) are both necessary and sufficient to enhance non-sexual and sexual social behaviors, affect, and central 3α,5α-THP metabolism.

MATERIALS AND METHODS

P and 3α,5α-THP formation were unperturbed or blocked in VTA via infusions of vehicle, PK11195 (400 ng), and/or indomethacin (10 μg). Rats then received subsequent infusions of vehicle or 3α,5α-THP (100 ng) and were assessed in a battery of tasks that included open field (exploration), elevated plus maze (anxiety behavior), social interaction (social affiliation), and paced mating (sexual behavior) or were not tested. Metabolic turnover of P to its 5α-reduced metabolites was assessed in plasma, midbrain, hippocampus, frontal cortex, diencephalon, and remaining subcortical tissues (control interbrain).

RESULTS

Infusions of any combination of inhibitors significantly reduced social and affective behavior in all tasks compared to vehicle, concomitant with reduced turnover of P to its 5α-reduced metabolites, in midbrain only. Subsequent infusions of 3α,5α-THP significantly reinstated/enhanced anti- anxiety behavior, lordosis, and P turnover to its 5α-reduced metabolites in midbrain, as well as hippocampus, cortex, and diencephalon (but not plasma or interbrain).

CONCLUSIONS

These data are the first to provide direct evidence that actions of 3α,5α-THP in the VTA are both necessary and sufficient for social and affective behavior, as well as initiation of central 5α-reduction.

Reduced maladaptive behavior and improved social function in a child with PDD-NOS treated with progesterone

This case report presents the use of progesterone for the regulation of an atypical menstrual cycle in a girl, aged 11 years, who is also diagnosed with Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS). The progesterone injections alleviated the prolonged, heavy monthly blood flow, but also caused significant improvements in the patient's mood, behavior, and cognition within four weeks following the initial injections. The use of hormonal treatments, such as progesterone, to effect mood, behavior, and cognition should be further researched to determine other potential therapeutic uses.

Hormesis and Female Sex Hormones

Hormone replacement after menopause has in recent years been the subject of intense scientific debate and public interest and has sparked intense research efforts into the biological effects of estrogens and progestagens. However, there are reasons to believe that the doses used and plasma concentrations produced in a large number of studies casts doubt on important aspects of their validity. The concept of hormesis states that a substance can have diametrically different effects depending on the concentration. Even though estrogens and progestagens have proven prone to this kind of dose-response relation in a multitude of studies, the phenomenon remains clearly underappreciated as exemplified by the fact that it is common practice to only use one hormone dose in animal experiments. If care is not taken to adjust the concentrations of estrogens and progestagens to relevant biological conditions, the significance of the results may be questionable. Our aim is to review examples of female sexual steroids demonstrating bidirectional dose-response relations and to discuss this in the perspective of hormesis. Some examples are highlighted in detail, including the effects on cerebral ischemia, inflammation, cardiovascular diseases and anxiety. Hopefully, better understanding of the hormesis phenomenon may result in improved future designs of studies of female sexual steroids.

Anxiolytic properties of a 2-phenylindolglyoxylamide TSPO ligand: Stimulation of in vitro neurosteroid production affecting GABAA receptor activity

A number of neurosteroids have been demonstrated to exert anxiolytic properties by means of a positive modulation of inhibitory GABAergic neurotransmission. The observation that neurosteroid synthesis can be pharmacologically regulated by ligands to the mitochondrial translocator protein (TSPO) has prompted the search for new, more selective TSPO ligands able to stimulate steroidogenesis with great efficacy. In the present study, the potential anxiolytic activity of a selective TSPO ligand, N,N-di-n-propyl-2-(4-methylphenyl)indol-3-ylglyoxylamide (MPIGA), was tested by means of the elevated plus maze paradigm. Moreover, the in vitro effects on synaptoneurosomal GABA(A) receptor (GABA(A)R) activity exerted by the conditioned salt medium from MPIGA-treated ADF human glial cells were investigated. MPIGA (30mg/kg) was found to affect rats' performance in the elevated plus maze test significantly, leading to an increase in both entries and time spent in the open arms. This same dose of MPIGA had no effect on rats' spontaneous exploratory activity. The conditioned salt medium from MPIGA-treated ADF cells potentiated the (36)Cl(-) uptake into cerebral cortical synaptoneurosomes. The exposure of ADF cells to MPIGA stimulated the production of pregnelonone derivatives including allopregnanolone, one of the major positive GABA(A)R allosteric modulator. In conclusion, the TSPO ligand MPIGA is a promising anxiolytic drug. The mechanism of action by which MPIGA exerts its anxiolytic activity was identified in the stimulation of endogenous neurosteroid production, which in turn determined a positive modulation of GABA(A)R activity, thus opening the way to the potential use of this TSPO ligand in anxiety and depressive disorders.

Brain-derived neurotrophic factor plasma variation during the different phases of the menstrual cycle in women with premenstrual syndrome

Premenstrual syndrome (PMS) is characterized by a cluster of psychological and somatic symptoms that begin during the late luteal phase of the menstrual cycle and disappear after the onset of menses. Since PMS might be caused by an alteration in the cyclical hormonal modifications and ovarian steroids are directly involved in the regulation of mood, affective and cognitive functions and influence neurotrophins expression, in particular the brain-derived neurotrophic factor (BDNF), we aimed to evaluate whether plasma BDNF levels in women with PMS differ from those of normally menstruating women without PMS. Sixty-two women were divided into two groups: one group of women (n=35) with PMS and one group (n=27) composed by normally menstruating women. Plasma samples were collected at day 7 (follicular phase) and day 21 (luteal phase) of the menstrual cycle. Plasma BDNF of the control group significantly increased (p<0.001) from the follicular phase (402.90±74.41pg/ml) to the luteal phase (1098.79±146.49pg/ml). On the other hand, in the PMS group plasma BDNF levels significantly decreased (p<0.001) from the follicular phase (412.45±78.35pg/ml) to the luteal phase (233.03±75.46pg/ml) Luteal BDNF levels of the PMS women were significantly lower than those of the control group (p<0.001). In women with PMS, plasma BDNF followed a decreasing trend during the ovarian cycle, in opposition to the increasing trend observed in women without PMS. The lower luteal BDNF levels of the PMS women might be a consequence of an altered hormonal response and might play a role in the onset of the symptoms PMS related.

Neurosteroid and GABA-A receptor alterations in Alzheimer's disease, Parkinson's disease and multiple sclerosis

Steroid hormones (e.g. estrogens, androgens, progestagens) which are synthesized de novo or metabolized within the CNS are called neurosteroids. There is substantial evidence from animal studies suggesting that these steroids can affect brain function by modulating neurotransmission, and influence neuronal survival, neuronal and glial differentiation and myelination in the CNS by regulating gene expression of neurotrophic factors and anti-inflammatory molecules. Indeed, evidence is emerging that expression of the enzymes responsible for the synthesis of neurosteroids changes in neurodegenerative diseases. Some of these changes may contribute to the pathology, while others, conversely, may represent an attempted rescue program in the diseased brain. Here we review the data on changes in neurosteroid levels and neurosteroid synthesis pathways in the human brain in three neurodegenerative conditions, Alzheimers's (AD) and Parkinson's (PD) diseases and Multiple Sclerosis (MS) and the extent to which these findings may implicate protective or pathological roles for neurosteroids in the course of these diseases.Some neurosteroids can modulate neurotransmitter activity, for example, the pregnane steroids allopregnanolone and 3α5α-tetrahydro-deoxycorticosterone which are potent positive allosteric modulators of ionotropic GABA-A receptors. Therefore, neurosteroid-modulated GABA-A receptor subunit alterations found in AD and PD will also be discussed. These data imply an involvement of neurosteroid changes in the neurodegenerative and neuroinflammatory processes and suggest that they may deserve further investigation as potential therapeutic agents in AD, PD and MS. Finally, suggestions for therapeutic strategies will be included. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

Towards a consensus on diagnostic criteria, measurement and trial design of the premenstrual disorders: the ISPMD Montreal consensus

Premenstrual disorders (PMD) are characterised by a cluster of somatic and psychological symptoms of varying severity that occur during the luteal phase of the menstrual cycle and resolve during menses (Freeman and Sondheimer, Prim Care Companion J Clin Psychiatry 5:30-39, 2003; Halbreich, Gynecol Endocrinol 19:320-334, 2004). Although PMD have been widely recognised for many decades, their precise cause is still unknown and there are no definitive, universally accepted diagnostic criteria. To consider this issue, an international multidisciplinary group of experts met at a face-to-face consensus meeting to review current definitions and diagnostic criteria for PMD. This was followed by extensive correspondence. The consensus group formally became established as the International Society for Premenstrual Disorders (ISPMD). The inaugural meeting of the ISPMD was held in Montreal in September 2008. The primary aim was to provide a unified approach for the diagnostic criteria of PMD, their quantification and guidelines on clinical trial design. This report summarises their recommendations. It is hoped that the criteria proposed here will inform discussions of the next edition of the World Health Organisation's International Classification of Diseases (ICD-11), and the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V) criteria that are currently under consideration. It is also hoped that the proposed definitions and guidelines could be used by all clinicians and investigators to provide a consistent approach to the diagnosis and treatment of PMD and to aid scientific and clinical research in this field.

Beyond the HPA Axis: Progesterone-Derived Neuroactive Steroids in Human Stress and Emotion

Stress and social isolation are well-known risk factors for psychopathology. However, more research is needed as to the physiological mechanisms by which social support buffers the impacts of stress. Research in animal models suggests important roles for progesterone (P) and its product, the neuroactive steroid allopregnanolone (ALLO), in stress and psychopathology. These hormones are produced in brain and periphery during stress in rodents, and down-regulate anxiety behavior and hypothalamic-pituitary-adrenal axis activity. Human clinical populations, including depressed patients, have alterations in ALLO levels, but it is unclear whether these basal hormone level differences have clinical import. To begin to address this question, this review examines the role of P and ALLO in stress physiology, and the impact of these hormones on mood, in healthy humans. Evidence largely supports that P and ALLO increase during stress in humans. However, P/ALLO administration appears to cause only mild effects on mood and subjective anxiety, while exerting effects consistent with gamma-aminobutyric acid receptor modulation. Additionally, P is linked to motivation for affiliation/social contact; P (and ALLO) release may be especially responsive to social rejection. These observations lead to the novel hypothesis that stress-related P/ALLO production functions not only to down-regulate stress and anxiety, but also to promote social contact as a long-term coping strategy. Malfunctioning of the P/ALLO system could therefore underlie depression partly by decreasing propensity to affiliate with others.

Neurosteroids in clinical practice: implications for women’s health

The steroidogenic endocrine glands and local synthesis both contribute to the pool of steroids present in the central nervous system (CNS) and peripheral nervous system (PNS). Although the synthesis of neurosteroids in the nervous system is now well established, the spectrum of respective functions in regulating neuronal and glial functions remains to be fully elucidated. From the concept of neurosteroids derives another therapeutical strategy: the use of pharmaceutical agents that increase the synthesis of endogenous neurosteroids within the nervous system. This approach is so far hampered by the lack of knowledge concerning the regulation of the biosynthetic pathways of neurosteroids and their relationship with sex steroids produced by peripheral glands. The present review summarizes some of the available clinical and experimental findings supporting the critical role of neuro-steroids during the fertile life and reproductive aging and their relationship with endogenous and exogenous sex steroids. Brain metabolism of synthethic progestins and the implication of dehydroepiandrosterone (DHEA) treatment in post-menopausal women will be also discussed.

One woman's low is another woman's high: Paradoxical effects of the menstrual cycle

Although past research on affective changes associated with the menstrual cycle has focussed on a specific pattern commonly referred to as Premenstrual Syndrome, there are compelling reasons to hypothesize that an opposite pattern, with a mid-cycle increase and a premenstrual low in symptoms, may also exist. Focusing on depression and anxiety, the present study tested whether this mid-cycle pattern of symptoms could be identified, using a sample of 213 female university students, who completed daily questionnaires for two menstrual cycles. Results confirmed the existence of a group of women who demonstrate the mid-cycle pattern of symptom changes (13%), in addition to the classic PMS pattern (61%), and individuals demonstrating no cyclical pattern of symptoms (26%). Moreover, women with a strong PMS pattern showed lower average levels of depression/anxiety than women with no cyclical changes. These findings require that current conceptions of menstrual-cycle related psychological changes be redefined to include the mid-cycle pattern, and suggest that women with strong PMS symptoms may actually benefit from a mid-cycle sense of wellness.

Progesterone level predicts serotonin-1a receptor binding in the male human brain

BACKGROUND

Progesterone (P) is thought to influence mood and affective states. Alterations of the inhibitory serotonin-1A (5-HT(1A)) receptor distribution are associated with depression and anxiety. This study evaluates the influence of plasma P levels on the 5-HT(1A) receptor binding in healthy male subjects.

METHODS

Molecular neuroimaging of the 5-HT(1A) receptor distribution using positron emission tomography and hormone assays for total plasma P and cortisol were done in a sample of 18 healthy men.

RESULTS

Plasma P levels explained up to 65% of the variability in 5-HT(1A) receptor binding in limbic regions including the amygdala, orbitofrontal cortex and retrosplenial cortex. When controlling for cortisol in the model, there was an expected decline in explained variances of 5-HT(1A) binding attributed to P.

CONCLUSIONS

The results of this study provide further support for the effect of P on 5-HT(1A) receptor expression and raise the possibility that P mediates the vulnerability to mood disorders by affecting the serotonergic system.

Brain distribution and behavioral effects of progesterone and pregnenolone after intranasal or intravenous administration

Neurosteroids hold great promise for the treatment of diseases of the central nervous system (CNS). We compared the uptake by 11 brain regions and appearance in blood of tritium-labeled pregnenolone and progesterone after intranasal and intravenous (IV) injection. Both neurosteroids appeared in blood and brain after either method of administration, but with important differences in uptake. Bioavailability based on appearance in arterial serum showed that about 23% and 14% of the intranasal administered doses of pregnenolone and progesterone, respectively, entered the blood. Brain levels were about two fold lower after intranasal administration for the two neurosteroids. With intranasal administration, brain levels of the two steroids did not vary over time (2-120 min), whereas brain levels were higher early (10 min or less) after i.v. administration. With i.v. administration, uptake by brain regions did not vary, whereas the olfactory bulb, hippocampus, and hypothalamus had high uptake rates after intranasal administration. Intranasal administration of prenenolone improved memory, whereas progesterone decreased anxiety, thus demonstrating that therapeutic levels of neurosteroids can be delivered to the brain by intranasal administration. The neurosteroids were rapidly degraded after i.v. or intranasal delivery, but pregnenolone was more resistant to degradation in the brain after intranasal administration and in serum after i.v. administration. These results show that either the i.v. or intranasal routes of administration can deliver neurosteroids to blood and brain, but that the two routes have significant differences with intranasal administration favoring some brain regions.

Forced swim test behavior in postpartum rats

This study was undertaken to determine whether depression-like behavior can be observed in gonadally intact females that have experienced normal pregnancy. When tested on the forced swim test (FST) on postpartum days 1-7, previously pregnant rats spent slightly more time immobile, significantly less time swimming and diving, and defecated more than virgin controls. Subchronic treatment with nomifensine (DA reuptake inhibitor, 2.5mg/kg) but not sertraline (serotonin reuptake inhibitor, 10mg/kg) or desipramine (norepinephrine reuptake inhibitor, 10mg/kg) significantly decreased immobility on postpartum day 2. In rats pre-exposed to the FST in mid-pregnancy, neither subchronic nor chronic treatment with desipramine or sertraline decreased immobility on postpartum day 2; in contrast, chronic desipramine significantly decreased immobility in virgin controls. These results indicate that postpartum female rats, compared to virgin controls, show a reduction in some "active coping behaviors" but no significant increase in immobility when tested during the early postpartum period, unlike ovariectomized females that have undergone hormone-simulated pregnancy (HSP). Additionally, immobility that is increased by FST pre-exposure is not readily prevented by treatment with standard antidepressant medications in postpartum females. Depression-like behaviors previously observed in females that have undergone HSP may result from the more dramatic changes in estradiol, prolactin or corticosterone that occur during the early "postpartum" period, compared to the more subtle changes in these hormones that occur in actual postpartum females.

Approach to premenstrual dysphoria for the mental health practitioner

As many as 7% of women experience significant social or occupational dysfunction as a result of severe premenstrual mood disturbance. Biological, psychological, and sociocultural factors are implicated in the cause of premenstrual dysphoric disorder, but the interaction between these factors remains to be elucidated. Mental health practitioners can aid women by providing diagnostic clarity and by initiating an integrated step-wise management approach.

Flunitrazepam in combination with alcohol engenders high levels of aggression in mice and rats

RATIONALE

Higher doses of benzodiazepines and alcohol induce sedation and sleep; however, in low to moderate doses these drugs can increase aggressive behavior.

OBJECTIVES

To assess firstly the effects of ethanol, secondly the effects of flunitrazepam, a so-called club drug, and thirdly the effects of flunitrazepam plus alcohol on aggression in mice and rats.

METHODS

Exhaustive behavioral records of confrontations between a male resident and a male intruder were obtained twice a week, using CF-1 mice and Wistar rats. The salient aggressive and non-aggressive elements in the resident's repertoire were analyzed. Initially, the effects of ethanol (1.0g/kg), and secondly flunitrazepam (0; 0.01; 0.1; and 0.3mg/kg) were determined in all mice and rats; subsequently, flunitrazepam or vehicle, given intraperitoneally (0; 0.01; 0.1; and 0.3mg/kg) was administered plus ethanol 1.0g/kg or vehicle via gavage.

RESULTS

The most significant finding is the escalation of aggression after a moderate dose of ethanol, and a low dose of flunitrazepam. The largest increase in aggressive behavior occurred after combined flunitrazepam plus ethanol treatment in mice and rats.

CONCLUSIONS

Ethanol can heighten aggressive behavior and flunitrazepam further increases this effect in male mice and rats.

Low doses of cocaine decrease, and high doses increase, anxiety-like behavior and brain progestogen levels among intact rats

There are sex and hormonal differences in response to cocaine that have been demonstrated in people and animal models. Cocaine can alter secretion of progestogens, such as progesterone (P), and its neuroactive metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP). However, little research has been done on the neuroendocrine effects in the initiation phase of cocaine use. We hypothesize that some sex/hormonal differences in initiation phase responses to cocaine may be related to formation of progestogens. To investigate the role of progestogens in sex differences in response to acute cocaine, male and female rats in the high (proestrous) or low (diestrous) progestogen phase of the estrous cycle were administered cocaine (0, 5, 10, or 20mg/kg, IP). We examined cocaine's acute neuroendocrine effects on P and 3alpha,5alpha-THP levels, as well as its effects on acute psychomotor stimulation, anxiety, and sexual behaviors. Among rats that had P and/or 3alpha,5alpha-THP levels increased in response to cocaine, enhanced acute psychomotor stimulation was observed. Results suggest that cocaine produces U-shaped curves for progestogens, and anxiety-like behaviors. Male rats were less susceptible to these effects of cocaine than were proestrous or diestrous female rats. However, cocaine's disruption of sexual behaviors was similar among males and proestrous females. These data suggest a complex interaction between hormonal milieu and the neuroendocrine and behavioral effects of cocaine.

Effects of acute progesterone administration upon responses to acute psychosocial stress in men

Animal studies suggest that neuroactive steroids, in particular progesterone and its metabolites, have stress-dampening effects. However, few studies have explored these effects in humans. In this study, we investigated the effects of acute progesterone administration on responses to the Trier Social Stress Test (TSST). Healthy men participated in the TSST 3.5 hrs after intramuscular injection of 0, 50, or 100 mg progesterone (N = 16, 14, and 14). We measured cardiovascular (heart rate, blood pressure), hormonal (plasma adrenocorticotrophic hormone, cortisol, and noradrenaline), and subjective (e.g., anxiety, arousal) responses to stress in the three groups. Before the TSST, progesterone injections increased plasma levels without altering physiological or subjective states. Stress produced its expected physiological and subjective effects among placebo-treated individuals. Progesterone 50 mg attenuated peak increases in plasma cortisol and reduced changes in negative mood and alertness after stress, yet it increased plasma noradrenaline and systolic blood pressure. Progesterone 100 mg also attenuated stress-induced increases in alertness and arousal, yet it potentiated stress-induced increases in diastolic pressure. Thus, progesterone dampened some of the psychological effects of stress but produced inconsistent effects on physiological stress responses.

Understanding and treating premenstrual dysphoric disorder: an update for the women's health practitioner

Up to 7% of women report premenstrual symptoms severe enough to impair daily function, and are said to suffer from premenstrual dysphoric disorder (PMDD). Although PMDD is predominately regarded as a biologically based condition, sociocultural factors, and particularly life stress, past sexual abuse, and cultural socialization, likely interact with hormonal changes. This integrative model has implications for etiology and treatment of PMDD.