月经周期对女性睡眠-觉醒和静息-活动的影响

目前有关月经周期对睡眠影响的研究结果并不一致,而对月经周期中昼夜睡眠-觉醒及静息-活动节律尚缺乏系统性的研究.本研究旨在观察正常育龄期女性月经周期中睡眠-觉醒及静息-活动昼夜节律的变化.我们采用静息-活动监测仪(actigraphy)和睡眠日志,调查了12个自然生活状态下健康育龄期妇女在月经周期不同阶段,即行经期、围排卵期、黄体早期及黄体晚期中睡眠与活动节律的变化.结果显示,睡眠-觉醒节律参数在四期之间无统计学显著差异;而静息-活动节律方面,所有受试女性静息-活动节律的平均日周期长度为(24.01±0.29)h,并且四期之间无显著性差异.行经期日间稳定系数(interdaily stability,IS)比黄体早期显著增加(P＜0.05).黄体早期日间活动开始时间明显较黄体晚期提前(P＜0.05);黄体早期的活动峰值时相比围排卵期显著提前(P＜0.05).月经周期可以影响静息-活动昼夜节律时相.而总体静息-活动数量与质量未发生显著变化;健康育龄期妇女在月经周期的各阶段中睡眠-觉醒节律亦无明显变异.     

光周期影响MT_1-R在无蹼壁虎室旁核的节律性表达(英文)

目的研究不同光周期下,MT1-R在无蹼壁虎室旁核(PVN)的节律性(昼夜节律和季节节律)表达变化。方法运用了免疫印迹、免疫组织化学和形态学计数法。结果 (1)免疫印迹结果显示MT1-R蛋白分子量为37KD,MT1-R阳性细胞主要分布在下丘脑室旁核,且有少量阳性纤维;(2)在无蹼壁虎的活动期(夏季),各光周期(DD、DL和LL)下MT1-R阳性细胞在PVN均呈明显的昼夜节律变化(P0.0001),DD、LL较DL均有时相变化;(3)在冬眠期(冬季),DL光周期下MT1-R阳性细胞在PVN无明显的昼夜节律变化(P=0.005),DD和LL光周期下MT1-R阳性细胞在PVN呈明显的昼夜节律变化(P0.0001),DD、LL较DL均有时相变化;(4)各光周期(DD、DL和LL)下MT1-R阳性细胞在PVN均呈明显的季节性节律变化(P0.0001),活动期(夏季)的MT1-R阳性细胞数较冬眠期(冬季)明显多(P0.0001),DD和LL在活动期、冬眠期的节律图形相似。结论 MT1-R在无蹼壁虎室旁核的表达有明显的节律性(昼夜节律和季节节律),不同光周期对MT1-R的节律性表达有影响,但其图形基本相似。提示光周期可能通过启动"内源性节律钟"影响MT1-R在无蹼壁虎室旁核的节律性表达,其可能调控MT1-R蛋白的表达量。     

钙结合蛋白calbindin-D28k在人输卵管组织的表达

本研究旨在探讨育龄妇女输卵管中钙结合蛋白calbindin-D28k（CaBP-D28k）的表达和变化。33例月经规律、有正常生育史的育龄妇女,因子宫肌瘤、子宫腺肌症行子宫切除术（一并切除输卵管）,输卵管取材均包括峡部、壶腹部和伞部,按月经周期分为增生早期组6例,增生中期组5例、增生晚期组5例,分泌早期组7例,分泌中期组5例和分泌晚期组5例。采用免疫组织化学法和逆转录聚合酶链反应法检测CaBP-D28k在人输卵管组织中的表达。结果显示,人输卵管组织中存在CaBP—D28k蛋白及mRNA表达。CaBP-D28k蛋白表达于输卵管上皮细胞的胞浆中,在月经周期同一时期,输卵管峡部、壶腹部、伞部的表达无明显差别（P〉0．05）。在月经周期中,CaBP-D28k蛋白表达在增生早、中期最低,而在增生晚期和分泌早期明显增高（P〈0．05）,分泌中、晚期显著下降（P〈0．05）。CaBP-D28k蛋白阳性表达分布在月经周期中出现再分布,在增生早、中期呈灶状或片状弥散分布在胞浆中,增生晚期和分泌早、中期CaBP-D28k蛋白呈聚集的颗粒状集中在细胞顶部,至分泌晚期则仍呈灶状或弥散状分布;CaBP-D28k mRNA表达也随月经周期发生变化,在增生晚期和分泌早期明显增高（P〈0．05）。结果表明,人输卵管组织中存在CaBP-D28k蛋白及mRNA表达,且具有周期性变化。     

大鼠松果体Clock基因和芳烷脘N-乙酰基转移酶基因的昼夜节律性表达及光照影响

探讨12h光照、12h黑暗交替(12h-light：12h-dark cycle,LD)及持续黑暗(constant darkness,DD)光制下松果体Clock基因和芳烷脘N-乙酰基转移酶基因(arylalkylamine N-acetyltransferase gene,NAT)是否存在昼夜节律性表达及其光反应变化。Sprague-Dawley大鼠在LD和DD光制下分别被饲养4周(n=36)和8周(n=36)后,在一昼夜内每隔4h采集一组松果体组织(n=6),提取总RNA,用竞争性定量RT-PCR测定不同昼夜时点样品中Clock及NAT基因的mRNA相对表达量,通过余弦法和ClockLab软件获取节律参数,并经振幅检验是否存在昼夜节律。结果如下：(1)在DD或LD光制下,松果体Clock和NAT基因mRNA的表达均呈现夜高昼低的节律性振荡(P＜0．05)。(2)与DD光制下比较,LD光制下松果体Clock和NAT基因的表达振幅及峰值相的mRNA水平均降低(P＜0．05)。(3)在DD或LD光制下,Clock和NAT基因之间显示相似的节律性表达(P＞0．05)。结果表明,Clock和NAT基因在松果体中存在同步的内源性昼夜节律表达,光照作用可使其表达下调。     

大鼠视交叉上核与松果体中Clock基因转录的昼夜节律性及不同光反应性

本研究旨在观察和比较视交叉上核（suprachiasmatic nucleus,SCN）与松果体（pineal gland,pG）中Clock基因内源性昼夜转录变化规律以及光照对其的影响。Sprague-Dawley大鼠在持续黑暗（constant darkness,DD）和12h光照：12h黑暗交替（12hourlight：12hour-darkcycle,LD）光制下分别被饲养8周（n=36）和4周n=36）后,在一昼夜内每隔4h采集一组SCN和PG组织（n=6）,提取总RNA,用竞争性定量RT-PCR测定不同昼夜时点（circadian times．CT or zeitgeber times．ZT）各样品中Clock基因的mRNA相对表达量,通过余弦法和ClockLab软件获取节律参数,并经振幅检验是否存在昼夜节律性转录变化。结果如下：（1）SCN中Clock基因mRNA的转录在DD光制下呈现昼低夜高节律性振荡变化（P〈0．05）,PG中Clock基因的转录也显示相似的内源性节律外观,即峰值出现于主观夜晚（SCN为CTl5,PG为CT18）,谷值位于主观白天（SCN为CT3,PG为CT6）（P〉0．05）。（2）LD光制下SCN中Clock基因的转录也具有昼夜节律性振荡（P〈0．05）,但与其DD光制下节律外观相比,呈现反时相节律变化（P〈0．05）,且其表达的振幅及峰值的mRNA水平均增加（P〈0．05）,而PG中Clock基因在LD光制下转录的相应节律参数变化却恰恰相反（P〈0．05）。（3）在LD光制下,光照使PG中Clock基因转录的节律外观反时相于SCN（P〈0．05）,即在SCN和PG的峰值分别出现于光照期ZT10和黑暗期ZT17,谷值分别位于黑暗期ZT22和光照期ZT5。结果表明,Clock基因的昼夜转录在SCN和PG中存在同步的内源性节律本质,而光导引在这两个中枢核团调节Clock基因昼夜节律性转录方面有着不同的作用。     

大熊猫母兽育幼早期应激水平与母幼行为的关系

大熊猫(Ailuropoda melanoleuca)属于晚熟性动物,育幼早期是幼仔存活和生长发育的关键时期,也是幼仔最易夭折时期。为了解大熊猫产后应激水平及其与母幼行为之间的关系,从行为适应机制的角度提高幼仔存活率,本研究利用酶联免疫吸附法监测7只处于育幼早期(产后0～75日)母兽粪便皮质醇含量,采用焦点动物取样法观测3对母幼个体的行为。结果显示：(1)育幼早期母兽皮质醇含量随幼仔日龄增长总体呈下降趋势(r=-0.950,P<0.001);(2)幼仔断奶前与断奶后相比,母兽皮质醇含量无显著差异(t=-0.935,P=0.361);(3)母兽皮质醇含量与母幼联系(r=0.918,P<0.001)、幼仔尖叫(r=0.777,P=0.001)和休息行为(r=0.731,P=0.002)均呈极显著正相关,与采食行为呈显著负相关(r=-0.608,P=0.016),而与舔幼仔行为不相关(r=0.366,P=0.179)。结果表明,大熊猫母兽育幼早期粪便皮质醇含量变化与幼仔生长发育有关,推测母兽的应激强度可能随幼仔御寒能力及自主活动能力的提升而降低;皮质醇可能参与母性行为调节,有助于...     

浙江天童常绿阔叶林演替系列植物叶片的凋落节律

叶片凋落节律是植物的主要功能策略之一,探索演替共有种(至少存在于3个阶段)和更替种(各阶段特有种)的叶片凋落节律对于理解森林演替过程中物种的更替机制具有重要意义。本研究选择浙江天童常绿阔叶林4个演替阶段,通过对4个共有种和6个更替种叶片凋落季节动态的调查,探讨了共有种的凋落节律是否在不同演替阶段存在差异,以及共有种和更替种叶片凋落节律的差异。结果显示,演替对共有种马尾松(Pinus massoniana)、木荷(Schima superba)和栲树(Castanopsis fargesii)的叶片凋落节律具有显著影响(P0.05),而对柃木(Eurya japonica)无显著影响。共有种与该演替阶段特有更替种叶片凋落节律的差异在不同演替阶段表现不同。演替第一阶段的马尾松、木荷与石栎(Lithocarpus glabra)、檵木(Loropetalum chinense)叶片凋落节律差异显著(P0.05);演替第二阶段的木荷与山矾(Symplocos caudate)叶片凋落节律有显著差异(P0.05)。栲树与苦槠(Castanopsis sclerophylla)叶片凋落节律有显著差异(P0.05);演替第四阶段的木荷、栲树、柃木与天竺桂(Cinnamomum pedunculatum)、连蕊茶(Camellia cuspidate)叶片凋落节律存在显著差异(P0.05),其他无显著差异。综上表明,部分演替共有种叶片凋落节律随森林演替发生改变,而另外部分不发生改变。在同一演替阶段,绝大部分演替共有种和更替种的叶片凋落节律存在差异。演替共有种和更替种叶片凋落节律的变化反映了植物在叶片物候方面对演替过程中微环境变化的多样适应策略。     

慢性温和应激抑郁模型大鼠5-羟色胺、色氨酸和应激激素的变化

目的：通过观察慢性温和应激对大鼠行为及5-羟色胺、色氨酸、应激激素的影响,进一步阐明应激致抑郁发生的机制。方法：利用慢性不可预计温和应激（CUMS）结合行为学指标建立大鼠抑郁动物模型;高效液相检测血浆和脑5-HT、儿荼酚胺;放免方法检测血浆皮质醇换算成皮质酮含量;氨基酸分析仪检测血清色氨酸的含量。结果：①CUMS诱导8周大鼠糖水偏爱性与对照组相比明显减低（P〈0．05）;体重和旷场实验评分下降（P〈0．05）。②CUMS诱导8周大鼠大脑和血浆5-HT含量显著下降（P〈0．05）;而血清色氨酸含量与对照组相比则明显升高（P〈0．05）。③CUMS诱导8周大鼠血浆去甲肾上腺素和肾上腺素含量与对照组相比明显升高（P〈0．05）：血浆皮质酮含量与对照组相比统计学上无显著性差异（P〉0．05）。结论：利用CUMS建立的抑郁模型大鼠存在着神经内分泌紊乱,CUMS大鼠抑郁样行为的发生可能与血浆去甲肾上腺素和肾上腺素升高对色氨酸代谢的影响有关。     

短期高浓度氟对小鼠磨牙成釉细胞形态及BMP-4表达的影响

目的:研究短期高浓度氟对小鼠磨牙成釉细胞形态及骨形成蛋白-4(BMP-4)表达的影响,探讨氟对牙本质发育的相关机制。方法:选择40只4日龄的ICR小鼠为研究对象,随机分2组各20只,每组对照鼠与实验鼠各半,对实验动物进行单次腹腔注射,剂量分别为10mg/kg和20mg/kg的Na F,对照组动物则进行单次腹腔注射等剂量的Na Cl,24小时后处死动物。采用免疫组化染色观察高浓度氟对小鼠磨牙不同分化阶段成釉细胞形态及BMP-4表达的影响。结果:成釉细胞在分泌过渡期及早、晚期对短期暴露高浓度F-敏感,与对照组小鼠相比,实验组小鼠成熟期成釉细胞无明显变化,过渡期与分泌晚期成釉细胞中BMP-4的表达显著降低,差异有统计学意义(P0.05)。结论:短期高浓度氟对分泌过渡期及晚期成釉细胞中BMP-4的表达有抑制作用。     

排卵期生殖道局部细胞免疫与黄体功能不全患者不孕的关系研究

目的:探讨排卵期生殖道局部细胞免疫与黄体功能不全(LPD)患者不孕之间的关系,旨在为临床防治不孕不育提供依据及参考。方法:选择2014年10月~2015年10月本院确诊的LPD患者50例为观察组,同期筛选同期50例健康体检者为对照组,排卵后第4 d、6 d、8 d采用酶联免疫法检测两组排卵期血清孕酮(P)水平,采用放射免疫法(RIA)检测两组排卵期血清以及宫颈黏液中的肿瘤坏死因子-α(TNF-α)与白细胞介素1-β(IL-1β)的表达水平,对以上检测指标予以比较分析。结果:排卵后第4d、6d、8d观察组血清P明显低于对照组,比较差异均有统计学意义(P0.05)。排卵期观察组血清TNF-α及IL-1β水平与对照组比较,差异不具有统计学意义(P0.05),但观察组宫颈黏液中TNF-α及IL-1β水平显著高于对照组,差异有统计学意义(P0.05)。排卵期观察组宫颈黏液中TNF-α、IL-1β水平与血清P存在负相关关系(r=-0.879,-0.886,P0.05),且宫颈黏液中TNF-α、IL-1β二者存在显著正相关关系(r=0.768,P0.05)。结论:排卵期生殖道局部细胞免疫激活,宫颈黏液中TNF-α及IL-1β水平升高,对黄体发育产生影响,并导致LPD的发生。     

Diurnal rhythms of free estradiol and cortisol during the normal menstrual cycle in women with major depression

To investigate whether depression is accompanied by changes in diurnal rhythms of free estradiol and cortisol in different phases of the menstrual cycle, we measured these two hormone levels in saliva samples collected every 2 h for 24 h from 15 healthy normally cycling women and 12 age-matched normally cycling women suffering from major depression taking antidepressants. The assessments were repeated four times over one menstrual cycle: during menstruation and in the late follicular/peri-ovulating, early to mid-luteal and late luteal phases, respectively. Quantification with a nonlinear periodic regression model revealed distinct diurnal rhythms in free estradiol and free cortisol in all subjects. For the diurnal cortisol rhythm, significant differences were found in the peak-width and ultradian amplitude among different menstrual phases, both in controls and depressed patients, while no significant differences were found between the two groups. The diurnal estradiol rhythm, on the other hand, was quite consistent among different menstrual phases within both groups, while the depressed patients had overall larger amplitudes than controls, which is negatively correlated with disease duration. Significant positive correlations between the two hormone rhythms were found for 24-h mean level (mesor), peak, and trough in late luteal phase, and for ultradian harmonics in early to mid-luteal phase in controls, but only for ultradian harmonics in late follicular/peri-ovulating phase and for acrophase in the menstruation phase in depressed patients. A sub-analysis was also performed in patients who received Fluoxetine (n = 7). The findings implicate a close correlation between the hypothalamic-pituitary-adrenal axis and the hypothalamic-pituitary-gonadal axis, both of which may be involved in depression.     

Is Cortisol Excretion Independent of Menstrual Cycle Day? A Longitudinal Evaluation of First Morning Urinary Specimens

Background

Cortisol is frequently used as a marker of physiologic stress levels. Using cortisol for that purpose, however, requires a thorough understanding of its normal longitudinal variability. The current understanding of longitudinal variability of basal cortisol secretion in women is very limited. It is often assumed, for example, that basal cortisol profiles do not vary across the menstrual cycle. This is a critical assumption: if cortisol were to follow a time dependent pattern during the menstrual cycle, then ignoring this cyclic variation could lead to erroneous imputation of physiologic stress. Yet, the assumption that basal cortisol levels are stable across the menstrual cycle rests on partial and contradictory evidence. Here we conduct a thorough test of that assumption using data collected for up to a year from 25 women living in rural Guatemala.

Methodology

We apply a linear mixed model to describe longitudinal first morning urinary cortisol profiles, accounting for differences in both mean and standard deviation of cortisol among women. To that aim we evaluate the fit of two alternative models. The first model assumes that cortisol does not vary with menstrual cycle day. The second assumes that cortisol mean varies across the menstrual cycle. Menstrual cycles are aligned on ovulation day (day 0). Follicular days are assigned negative numbers and luteal days positive numbers. When we compared Models 1 and 2 restricting our analysis to days between −14 (follicular) and day 14 (luteal) then day of the menstrual cycle did not emerge as a predictor of urinary cortisol levels (p-value >0.05). Yet, when we extended our analyses beyond that central 28-day-period then day of the menstrual cycle become a statistically significant predictor of cortisol levels.

Significance

The observed trend suggests that studies including cycling women should account for day dependent variation in cortisol in cycles with long follicular and luteal phases.     

Menstrual Cycle Phase Modulates Emotional Conflict Processing in Women with and without Premenstrual Syndrome (PMS) – A Pilot Study

Background

Premenstrual syndrome (PMS) is characterized by a cluster of psychological and somatic symptoms during the late luteal phase of the menstrual cycle that disappear after the onset of menses. Behavioral differences in emotional and cognitive processing have been reported in women with PMS, and it is of particular interest whether PMS affects the parallel execution of emotional and cognitive processing. Related to this is the question of how the performance of women with PMS relates to stress levels compared to women without PMS. Cortisol has been shown to affect emotional processing in general and it has also been shown that women with severe PMS have a particular cortisol profile.

Methods

We measured performance in an emotional conflict task and stress levels in women with PMS (n = 15) and women without PMS (n = 15) throughout their menstrual cycle.

Results

We found a significant increase (p = 0.001) in the mean reaction time for resolving emotional conflict from the follicular to the luteal cycle phase in all subjects. Only women with PMS demonstrated an increase in physiological and subjective stress measures during the luteal menstrual cycle phase.

Conclusions

Our findings suggest that the menstrual cycle modulates the integration of emotional and cognitive processing in all women. Preliminary data are supportive of the secondary hypothesis that stress levels are mediated by the menstrual cycle phase only in women with PMS. The presented evidence for menstrual cycle-specific differences in integrating emotional and cognitive information highlights the importance of controlling for menstrual cycle phase in studies that aim to elucidate the interplay of emotion and cognition.     

Psychosocial stress and the menstrual cycle.

The relationship between mood states, urinary stress hormone output (adrenaline, noradrenaline and cortisol) and adequacy of the menstrual cycle was examined in 120 recorded non-conception cycles from 34 women. It was hypothesized that women with higher stress levels would be more likely to experience abnormal cycles and that within women higher stress levels would positively relate to follicular phase length and inversely relate to luteal phase length. There was a non-significant trend for women to report higher stress levels during oligomenorrhoeic and unclear cycles compared with normal cycles. Analysis of covariance indicated that there was no consistent relationship between the measures of stress used here and follicular or luteal phase length within women. There was also no consistent pattern of relationship between reported mood states and stress hormone excretion within women. Further research is warranted to understand the role of stress and subtle menstrual cycle abnormalities in female fertility.     

The diurnal rhythm in isometric muscular performance differs with eumenorrheic menstrual cycle phase

The aim of this study was to examine the effect of the interaction of circamensal and diurnal rhythms in temperature upon the production of maximal voluntary muscle force. Ten eumenorrheic females (mean age: 24 +/- 3 yr mean body mass: 58.4 +/- 6.9 kg) participated in the experiment at both 06:00 and 18:00h at the mid-point of both the follicular and luteal phases of the menstrual cycle. Subjects performed tasks of maximal isometric lifting strength (MILS) at knee height, and endurance time (t) for lifting 45% of MILS, upon an isometric lift dynamometer. Body temperature was elevated at 18:00h and in the luteal phase by 0.52 +/- 0.4 and 0.26 +/- 0.35 degrees C, respectively. The amplitude of the diurnal variation in temperature was blunted by 0.3 degrees C within the luteal phase. Maximal isometric performance was elevated by 8% at 18:00h in the luteal phase of the cycle (p < 0.05 interaction for MILS) but unaffected by time of day in the follicular phase. Endurance time was unaffected by time or phase (p > 0.05). It should be noted that the classic diurnal rhythm in maximal voluntary isometric muscle force may not be evident in all phases of the female menstrual cycle.     

The role of the adenylyl cyclase system in the regulation of corpus luteum function in the human and in nonhuman primates

We have reviewed the properties of luteinizing hormone/human chorionic gonadotropic (LH/hCG)-sensitive adenylyl cyclase (AC) of human corpus luteum (CL) and its regulation by several hormones and nonhormonal activators. We have also described the changes in enzyme activity in membrane preparations of human and cynomolgus monkey CL obtained at various stages of the menstrual cycle and pregnancy. The data have been analyzed with respect to the functional status of the luteal tissue and to the species differences among primate CL. In the menstrual cycle, luteal AC responsiveness to LH/hCG was detectable during the midluteal phase, but not during the late luteal phase or in the follicular phase of the following cycle. In addition, nonhormonal stimulation was high in CL obtained during the midluteal and late luteal phases, but declined drastically by the follicular phase of the next cycle. In early pregnancy, the enzyme was unresponsive to LH/hCG stimulation, yet its sensitivity to nonhormonal stimulation was similar, if not identical, to that of midluteal phase CL. Functional activity was also evident at the end of pregnancy. These results demonstrate that expression of AC activity in primate luteal membrane changes significantly with varying hormonal status under physiologic conditions. It is concluded that the AC system in luteal membranes is an effective model to study the mechanisms that regulate function and life span of the human and nonhuman primate CL.     

Expression of mRNA and proteins for GnRH I and II and their receptors in primate corpus luteum during menstrual cycle

The differential expression of mRNA and protein of GnRH I, II and their receptors (RI and RII) in the monkey corpus luteum (CL) were measured during different stages of the luteal phase of the menstrual cycle as an initial step towards considering the role and regulation of GnRH (I and II) system during luteinization and luteolysis in primates. RT-PCR confirmed the sequence identity of PCR products and real time PCR quantified specific mRNA expressions. Proteins were localized by immunohistochemistry (IHC). Changes in mRNA expression patterns of GnRH I and II (increased) and GnRH RII (decreased) were maximal at mid-late to late stages, that is, at CL regression, where as GnRH RI was low during the entire luteal phase. However, RT-PCR and IHC studies confirmed the presence of GnRH RI at both mRNA and protein levels, respectively. IHC results showed the presence of GnRH I, II and their receptors in steroidogenic cells (granulose-luteal cells and thecal-luteal cells) across the luteal phase. Hence, GnRH I and II systems may have a role on both luteinization (from early to mid stages of CL) and luteolysis (from mid-late to very-late stages of CL). These novel findings suggest that monkey luteal GnRH system may have a role in fertility regulation in paracrine and/or autocrine manner.     

Menstrual cycle variation in spatial ability: relation to salivary cortisol levels

This study examined whether menstrual cycle phase was associated with performance on the Primary Mental Abilities Test of Spatial Relations, a test of mental rotation, in undergraduate students (N = 82). As cortisol levels also vary across the menstrual cycle under conditions of stress and influence cognitive performance, saliva samples were obtained before and after the test session to examine whether cortisol levels were related to between- and within-group differences in spatial performance. Men scored higher on the spatial test than all the groups of women, although the difference between men and women in the menstrual phase was not significant. Women in the luteal phase scored lower than the menstrual, follicular, and oral contraceptive user groups of women. There were no sex or menstrual cycle differences in cortisol levels, and no association between cortisol levels and spatial performance. The poorer performance of women in the luteal phase was not related to differences in ratings of perceived stress, perceived success on the test, or mood. Although menstrual cycle phase accounted for a significant proportion of the variance (15%) in performance on the spatial test, this does not explain why men outperformed women regardless of the phase of the cycle. Thus, there are clearly several other variables, sociocultural and physiological, involved in mediating individual differences in spatial performance.     

Features of cardiovascular functioning during different phases of the menstrual cycle

The purpose of the present study was to determine whether there is a menstrual cycle effect on heart rate, blood pressure and heart rate variability. 10 healthy regularly cycling females (age 19-23 years) were studied during the follicular phase and luteal phase over two month. We found significant changes in heart rate, AMo and stress index during the menstrual cycle with a minimum in the follicular phase and maximum in the luteal phase. The HF and LF components decreased more during the luteal phase than during the follicular phase (p < 0.05), whereas a tendency for increase LF/HF was observed in the luteal phase. In the follicular phase SDNN, pNN50, Mo, MxDMn were significantly higher than in the luteal phase. Furthermore, the VIK was higher in the luteal phase compared to the follicular phase (p = 0.003). Blood pressure did not show any significant change during both these phases of the menstrual cycle. These findings indicate that sympathetic nervous activity in the luteal phase is greater than in the follicular phase, whereas parasympathetic nervous activity is predominant in the follicular phase. A difference of the balance of ovarian hormones may be responsible for these changes of autonomic functions during the menstrual cycle.