Monoamines and ovarian hormone-linked sexual and emotional changes: A review

Serotonergic Modulation of Nigrostriatal and Mesolimbic Dopamine and Motor/Exploratory Behaviors in the Rat

Purpose: The 5-HT_2A receptor (R) is known to modulate dopamine (DA) release in the mammalian brain. Altanserin (ALT) and 2,5-dimethoxy-4-iodoamphetamine (DOI) act as 5-HT_2AR antagonist and agonist, respectively. In the present study, we assessed the effects of ALT and DOI on motor and exploratory behaviors and on D_2/3R binding in the rat brain with in vivo imaging methods.

Methods: D_2/3R binding was determined after systemic application of ALT (10 mg/kg) or DOI (0.5 mg/kg) and the respective vehicles [dimethyl sulfoxide (DMSO) and 0.9% saline (SAL)] with [¹²³I]IBZM as a single-photon emission computed tomography (SPECT) radioligand. Anatomical information for the delineation of the target regions was obtained with dedicated small animal MRI. Immediately after 5-HT_2AR antagonistic or agonistic treatment, motor/exploratory behaviors were assessed for 45 (ALT) or 30 min (DOI) in an open field. Additional rats underwent behavioral measurements after injection of DMSO or SAL.

Results: ALT increased D_2/3R binding in the ventral hippocampus relative to vehicle, while DOI augmented D_2/3R binding in caudate putamen, frontal cortex, motor cortex, and ventral hippocampus. The 5-HT_2AR agonist as well as antagonist decreased parameters of motor activity and active exploration. However, ALT, in contrast to DOI, decreased explorative head–shoulder motility and increased sitting.

Conclusions: The regional increases of D_2/3R binding after ALT and DOI (90 and 75 min post-challenge) may be conceived to reflect decreases of synaptic DA. The reductions of motor/exploratory activities (min 1–45 and min 1–30 after challenge with ALT and DOI, respectively) contrast the regional reductions of D_2/3R binding, as they indicate elevated DA levels at the time of behavioral measurements. It may be concluded that ALT and DOI modulate DA in the individual regions of the nigrostriatal and mesolimbocortical pathways differentially and in a time-dependent fashion.

Ovarian steroids and premenstrual symptoms: a comparison of group differences and intra-individual patterns

To examine the relationship of gonadal hormone and symptom patterns across the menstrual cycle, women screened for 2-3 cycles completed an intensive study cycle; 26 had a low-severity symptoms (LS), 20, a premenstrual syndrome (PMS), and 26, a premenstrual magnification pattern (PMM). All completed daily symptom diaries and collected late afternoon urine samples which were assayed for pregnanediol and estradiol for that cycle. The PMS and PMM groups had significantly more positive cross-correlations of pregnanediol and symptoms than the LS group. Women in all groups had similar levels of estradiol and pregnanediol. Women with PMS and PMM patterns responded to progesterone differently than women with LS patterns: thus the former groups may not benefit from hormone therapies.

Exploratory study of premenstrual symptoms and serotonin variability

Premenstrual symptoms can pose significant problems for a large number of women; this small exploratory study was designed to investigate biological markers that may provide etiological clues. Using an algorithm based on daily symptom charting for two months, 15 participants were assigned to one of three study groups: non-symptomatic (n = 9), probable PMS (n = 3) and probable PMDD (n = 3). During two overnight admissions, one prior to and one following the onset of menses, participants had blood drawn to assess the level of available serotonin via one of its metabolites, 5-HIAA. The three groups exhibited potentially significant differences in several biological markers. This study's results are consistent with a hypothesis implicating serotonin in the generation of premenstrual symptomology.

The neurobiology of depression: perspectives from animal and human sleep studies

This article reviews human and animal studies in the neurobiology of depression. The etiology of the illness, associated neurotransmitter dysregulation, sex steroids, the role of stress, and sleep regulation are discussed. It is suggested that the genesis of depression is related to homeostatic maladaptation that is sexually dimorphic. The authors propose that depressed females are hyperresponsive to stress, whereas depressed males are hyporesponsive to stress. This divergence reflects the exaggeration of naturally occurring differences between males and females, which are most obvious under challenge conditions. The authors conclude that future work in this area should fully evaluate sexual dimorphism, neural plasticity, critical periods, and individual differences in vulnerability.

Historical studies of premenstrual tension up to 30 years ago: implications for future research

The biology and treatment of premenstrual tension syndrome has advanced significantly in the past 30 years. Newer research expands on earlier literature that has been accumulated before 1972. This review selectively considers this earlier literature, because it defines the nature and impact of what was then considered to be premenstrual tension syndrome. The authors consider a set of earlier studies that suggest a role for personality, psychodynamics, and cultural variables in the etiology, impact, and treatment of the cyclic disorders. This review also considers studies of the biology of premenstrual tension that suggest a role for sodium and water fluctuations, the renin-angiotensin-aldosterone system, ovarian hormones, monoamines, and acetylcholine. Current applications and potential research directions based on this information are also discussed.

Assessment of sexual functioning during the menstrual cycle

In a study of 115 women who presented with complaints of premenstrual symptoms, we investigated the relationship between the menstrual cycle and different aspects of sexual functioning, using the Changes in Sexual Functioning Questionnaire. Women who were assessed at the screening visit during the late luteal phase of their menstrual cycle reported less desire to engage in sexual activity and less frequent sexual activity than women who were assessed during other phases of the menstrual cycle. The 24 women who returned for the second and third visits reported less frequent orgasms and less satisfaction from their orgasms premenstrually than during midcycle.

Long-term in vivo desipramine or estrogen treatment fails to affect serotonin-induced outward current in hippocampal pyramidal cells of the rat

The effect of castration combined with either long-term treatment with the tricyclic antidepressant drug desipramine or the sex steroid 17 beta-estradiol on serotonin responses in area CA1 of the hippocampus of male and female rats was examined. Using single-electrode current and voltage-clamp techniques serotonin-induced hyperpolarizations and outward currents were recorded from hippocampal pyramidal cells. Neither in male nor in female castrated rats treatment effects were observed on the magnitude of the 5-hydroxytryptamine 1A mediated outward currents (0.26 nA) and membrane hyperpolarizations (11 mV) induced by superfusion of serotonin (15 microM), or on the effect of serotonin on the afterhyperpolarization and extracellularly recorded population spike. In voltage-clamp experiments using microelectrodes filled with potassium-chloride, but not with potassium-acetate, the sole observable effect was that the membrane resistance drop due to application of serotonin was significantly larger in the ovariectomized group (31% approximately 19 M omega) as compared to the ovariectomized/estrogen supplemented group (23% approximately 15 M omega). Spiperone (3 microM) completely antagonized the serotonin-induced outward currents and input resistance changes under all treatments. Apart from these changes the majority of passive and active membrane properties of cells from ovariectomized animals were not affected by chronic desipramine or steroid treatment. Neither did castration alone, nor in combination with long-term 17 beta-estradiol treatment, affect CA1 pyramidal cell membrane properties of male rats. Since we attained physiological levels of 17 beta-estradiol in the blood plasma (30-50 pg/ml) using subcutaneous silastic implants containing a mixture of cholesterol/estrogen, we conclude that both long-term estrogen and long-term desipramine treatment do not affect serotonergic neurotransmission in CA1 of the rat hippocampus.

Increased imidazoline and alpha 2 adrenergic binding in platelets of women with dysphoric premenstrual syndromes

An association between dysphoric premenstrual syndromes (PMS) and a lifetime history of major depressive disorders has previously been documented. Other studies have demonstrated an increase in the binding of radiolabeled imidazoline compounds to platelets of depressed patients. Clonidine and related imidazoline compounds interact with alpha 2 adrenoceptors to inhibit neuronal noradrenergic activity and in higher concentrations, they stimulate noradrenergic activity through their interaction with imidazoline receptors. Here we report increased 3H para-aminoclonidine binding to high affinity alpha 2 adrenoceptor sites as well as to nonadrenergic imidazoline binding sites in platelets of women with dysphoric PMS. This higher binding was most pronounced during the late-luteal-symptomatic phase of the menstrual cycle and, to a lesser degree, during the non-symptomatic mid-follicular phase. Binding to the imidazoline site distinguished women with dysphoric PMS from women with no such symptoms, was highly positively correlated with the severity of symptoms, and was negatively correlated with plasma levels of progesterone. These findings suggest that platelet imidazoline binding sites might be a biological marker for dysphoric states in PMS or for the vulnerability to develop them. These findings also point to a possible biological link between dysphoric PMS and major depressive disorders.

Premenstrual tension: a placebo-controlled efficacy study with spironolactone and medroxyprogesterone acetate

Forty-three healthy women with a characteristic history of premenstrual tension participated in a placebo controlled, crossover study. The effects of spironolactone (Aldactone) and medroxyprogesterone acetate (Gestapuran) on ten symptoms of premenstrual tension were evaluated. Placebo tablets as well as spironolactone and medroxyprogesterone acetate significantly improved a mood index score (which is a generally accepted method to measure premenstrual symptoms). Spironolactone and medroxyprogesterone acetate were however both significantly (P less than 0.05) better than placebo in relieving the symptoms.

Sexuality and pregnancy: a review

Marital success and failure may be related to sexual satisfaction, including orgasmic capability. Pregnancy represents a life crisis to the pregnant woman and her husband. Complex psychosocial and physiological demands may produce insecurities, anxieties, and somatic complaints. The expectant mother may seek to fulfill increasing nurturant needs through increased physical contact such as cuddling or being held. A pregnant woman's interest in sexual activity may be affected by her changing physical appearance and the hormonal milieu of pregnancy. Although there are marked individual variations and methodological biases and differences among empirical studies, pregnancy appears to be usually accompanied by a decrease in sexual desire, coital frequency, and orgasm. Sexual behavior in pregnancy has been traditionally restricted and is currently poorly defined. Sexual proscriptions may precipitate sexual frustration and marital estrangement. Abortion is only rarely caused by coitus. The relationship of coitus and orgasm to prematurity and distress of the fetus and newborn has not been clearly established. Coitus can indirectly result in maternal, fetal, and neonatal morbidity and mortality through the spread of sexually transmitted diseases. Deaths from air embolism in pregnancy associated with cunnilingus and vaginal insufflation have been reported.

Comparison of spontaneous and contraceptive menstrual cycles on a visual discrimination task

21 women with spontaneous ovulatory menstrual cycles, and 7 women who were regular users of oral contraceptives were investigated over two consecutive menstrual cycles. There two groups were compared on their two flash threshold performance and on mood ratings. It was found that, for women with ovulatory menstrual cycles, visual sensitivity was enhanced during the late follicular phase of the cycle, as ovulation approached. At other phases of the menstrual cycle (paramenstrual and luteal) visual sensitivity remained constant and comparable to the values found in women who were taking to the values found in women who were taking contraceptives. Women who were taking contraceptives showed no significant variation in visual sensitivity with phase of the menstrual cycle. The overall level of anxiety, as reflected by mood ratings was higher in women with spontaneous cycles compared to those taking contraceptives. Neither group, however, showed significant variation in anxiety with phase of the cycle.

Sex specific differences in chlorimipramine inhibition of serotonin uptake in human platelets

The uptake of 14C-serotonin in platelet-rich plasma was similar in clinically healthy men and women. Serotonin uptake inhibition by chlorimipramine was significantly less in women than in men, the extent of inhibition correlating with the stage of the menstrual cycle.