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。     

地下鼠视觉系统对昼夜节律调节研究进展

地下鼠由于其特殊的生活环境,视觉系统表现出明显的退化和进化镶嵌的特征:视觉器官退化,由视觉诱导产生行为反应的脑区及视觉投射严重退化,但是有关感受光周期的"非成像"视觉通路结构高度发达.即与成像和运动知觉有关的结构退化,有助于感受光周期的结构却选择性地保留.很多研究表明地下鼠的视觉系统依然保留有感知光周期节律并产生与外界昼夜循环同步的生理功能.与光周期有关的季节性繁殖、内分泌、行为活动以及体温变化等也表现出相应节律性.本文对地下鼠昼夜节律研究现状进行了综述,旨在对地下鼠的适应性进化特征加以补充,有助于开展地下啮齿类视觉系统功能的研究,更进一步阐明生物进化与环境的关系.     

尿液气味刺激后棕色田鼠主嗅球和副嗅球的神经元活动

本实验利用免疫组织化学方法,以FOS阳性反应作为神经元活动的标志,研究了棕色田鼠在受到同性和异性尿液刺激后主嗅球和副嗅球的神经元活动,表明两大嗅觉系统均有感知社会性化学信号的功能.通过比较棕色田鼠在同性和异性尿液刺激后副嗅球和主嗅球的嗅小球细胞层(GL)、僧帽细胞层(MIT)、颗粒细胞层(GRL)中FOS阳性神经元数量,发现不同性别尿液刺激后棕色田鼠的副嗅球各细胞层FOS阳性神经元数量比对照组明显增加;棕色田鼠受到异性尿液刺激后其副嗅球各细胞层的FOS阳性神经元数量均多于同性尿液刺激组.不同性别尿液刺激后棕色田鼠的主嗅球各细胞层FOS阳性神经元数量相较于对照组有增加或增加显著;异性尿液刺激组主嗅球各细胞层的FOS阳性神经元数量均多于同性尿液刺激组.说明棕色田鼠的副嗅球和主嗅球均参与了通过尿液介导的性别个体的识别.     

雌性棕色田鼠和昆明小鼠在慢性间歇性低氧条件下血象变化的比较

本文旨在对雌性棕色田鼠(Lasiopodomys mandarinus)和昆明小鼠(Mus musculus)在慢性间歇性低氧条件下血象的变化进行比较,从而为地下生活鼠种血液系统对慢性间歇性低氧的应答对策的研究提供基础数据。采用实验氧舱对棕色田鼠和昆明小鼠进行每天4h、持续28d的慢性间歇性低氧(氧浓度10.0%)处理,然后对其血象进行了比较分析。结果显示:(1)常氧下棕色田鼠的红细胞计数(red blood cell count,RBC)显著高于昆明小鼠,而红细胞平均体积(mean corpuscular volume,MCV)则显著小于昆明小鼠,慢性间歇性低氧处理后昆明小鼠的MCV和红细胞压积(hematocrit,HCT)显著增加,而棕色田鼠MCV和HCT无明显影响;(2)常氧条件下棕色田鼠的平均血红蛋白含量(mean corpuscular hemoglobin,MCH)显著低于昆明小鼠,而平均血红蛋白浓度(mean corpuscular hemoglobin concentration,MCHC)则显著高于昆明小鼠,慢性低氧处理后昆明小鼠血红蛋白(hemoglobin,HGB)含量和MCH均显著增加,而在棕色田鼠仅出现MCH的明显增加;(3)常氧条件下棕色田鼠的白细胞计数(white blood cell count,WBC)和血小板(platelet,PLT)都显著低于昆明小鼠,慢性低氧处理后棕色田鼠和昆明小鼠的WBC和PLT均未发生显著变化。以上结果表明,棕色田鼠作为地下生活鼠种,对低氧环境具有较好的耐受性,其血液系统对低氧胁迫的应答机制与地面生活鼠种昆明小鼠不同。     

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.     

光照对棕色田鼠和昆明小鼠活动性的影响

光照对啮齿动物的行为格局和活动节律有着重要的影响。本研究以比较生物学方法,以光照强度和鼠种两个因素,在实验室内利用动物行为监视系统,以焦点动物取样法( Focus animal sampling) ,在＜ 20 Lux、200 Lux、800 Lux 和1 600 Lux 等4 个水平的光照强度下,监测和记录棕色田鼠和昆明小鼠的移动和静止行为,并在实验结束时测定实验动物的体重; 在800 Lux 光照强度下,设置正常( 12L∶ 12D) 和全黑( 0L∶ 24D) 两种光照时间,连续12 h监测并记录实验动物的行为。采用双因素方差分析方法对数据进行统计分析。结果表明:1) 光强与鼠种对静止行为存在显著交互作用,棕色田鼠的静止行为与光强间存在显著的负相关关系,而昆明小鼠的静止行为则与光强无显著的相关; 2) 光强对两种动物移动行为的影响与静止行为表现方式相反; 3) 在12 h的光暴露条件下,棕色田鼠的相对活动显著强于昆明小鼠; 4) 光强对两种动物体重的影响不同,棕色田鼠体重与光强呈正相关关系,昆明小鼠与光强呈负相关关系,但差异不显著。本研究进一步验证了地面鼠与地下鼠对光强适应的差别。     

熟悉性对棕色田鼠和根田鼠择偶行为的影响

以两性配对共居至交配或生仔作不同熟悉处理,在Y字型选择箱中分别观察棕色田鼠、根田鼠的择偶行为和配偶识别.结果如下:(1)棕色田鼠雌雄两性均表现出对熟悉异性或配偶的喜好倾向;(2)在根田鼠中,只有雌性表现出对熟悉雄鼠或配偶的选择倾向,雄鼠无明确的选择取向;(3)每种雌性田鼠对2种熟悉性不同的同种雄性的嗅舔时间均有显著差异性,而每种雄性田鼠对2种熟悉性不同的同种雌性的嗅舔时间均无显著差异性.这些结果表明:(1)熟悉性对棕色田鼠择偶行为的影响大于对根田鼠的影响;(2)嗅舔时间差异可反映不同田鼠的配偶识别能力,熟悉性对棕色田鼠配偶识别能力的影响大于对根田鼠的影响;(3)2种田鼠配偶识别的性别差异的一致性,提示这2种田鼠的雌性配偶识别能力均强于雄性田鼠,而雌鼠的配偶识别能力可能取决于雌鼠受交配或分娩刺激的生理状态; (4)棕色田鼠室内所表现的择偶行为的两性熟悉性特征与其单配制有关,根田鼠所表现的择偶行为的雌性熟悉性特征与其一雄多雌制有关.     

环境光照对东方田鼠自主活动等行为的影响

目的了解不同环境光照对东方田鼠行为的影响,为制订东方田鼠环境标准提供依据。方法利用动物行为观察装置,观察三组东方田鼠在不同环境光照条件下的自主活动、玩耍、摄食、饮水等行为表现并进行定量测定和分析。结果 24 h黑暗（24D）组的东方田鼠自主活动总数最多,而24 h光照（24L）组则最少,12L/12D组跟24D组接近：无论是24L,还是24D处理,动物的相对活动没有明显的节律性,但在12L/12D条件下,动物活动节律随着光照处理而变化,呈现其一定的节律性。玩耍行为12L/12D组最多,但24D组动物玩耍行为比24L组多;当24L处理时,动物很少处于中央格,而24D处理和12L/12D处理时,动物有不同程度穿梭中央格,其中12L/12D处理时,动物穿梭次数最多;摄食与饮水次数12L/12D组次数最多,24L组次数最少。结论室内有规律的环境光照处理,可改变东方田鼠固有的依季节变化的行为规律,产生实验室控制的光周期应答行为,并表明12L/12D环境光照比24L和24D环境光照对东方田鼠造成的生活压力要小。     

光周期对棉铃虫羽化、生殖和飞行的影响

棉铃虫Helicoverpa armigera(Hübner)是世界上重要的农业害虫,探讨光周期变化对其羽化节律、生殖和飞行能力的影响,可为准确预测该虫种群动态的季节性变化提供理论依据。本文报道了,在温度为22℃±1℃,相对湿度为75%±5%的条件下,不同光周期(L∶D=24∶0、L∶D=16∶8、L∶D=12∶12、D∶L=12∶12、L∶D=8∶16和L∶D=0∶24)对棉铃虫羽化节律、成虫生殖力和飞行能力的影响。结果表明:棉铃虫的羽化活动具有节律性,不同光周期条件下棉铃虫的羽化高峰均集中在暗期,羽化活动均随光周期的光暗交替而变化。蛹期感受不同长短的暗期也会影响棉铃虫的羽化节律,暗期缩短,羽化有提前的趋势。光周期对棉铃虫产卵前期、卵孵化率和交配次数也有显著影响,但对单雌产卵量、产卵历期和交配率均无显著影响。另外,光周期对棉铃虫成虫的飞行距离和飞行时间也有显著影响,而对平均飞行速率影响不显著。上述结果表明光周期是影响棉铃虫羽化、生殖和飞行的重要环境因子。     

棕色田鼠和沼泽田鼠雄性社会行为与嗅觉相关脑区性激素受体表达之间的关系

应用行为聚焦取样观察和免疫组织化学相结合的方法 ,比较研究了棕色田鼠 (Microtusmandarinus)(n =15 )和沼泽田鼠 (M .fostis) (n =15 )在同种雄雄交往中的行为差异 ,及在雄雄交往前后雌激素 β受体(ERβ)和雄激素受体 (AR)表达的差异。在 2h的雄雄交往中 ,前 1h棕色田鼠对同性入侵者有较多的攻击和防御行为 ,后 1h攻击行为较少 ,沼泽田鼠前后 1h差异不大 ,整个 2h期间 ,棕色田鼠较沼泽田鼠对同性入侵者有较多的攻击、防御行为 ,较少的非社会行为。经过免疫组织化学检测 ,没有社会交往时棕色田鼠主嗅球系统投射区和犁鼻系统投射区ERβ免疫阳性细胞 (ERβ IRs)明显少于沼泽田鼠 ,且显色淡 ,AR免疫阳性细胞(AR IRs)在两种鼠间差异不大 ,且都明显少于各自的ERβ IRs。 2h交往后 ,棕色田鼠主嗅球投射区和犁鼻系统投射区的ERβ IRs细胞数明显少于交往前 ,AR IRs细胞数明显多于交往前 ;沼泽田鼠交往前与交往后ERβ IRs和AR IRs细胞数均无显著差异 ,且显著多于交往后棕色田鼠ERβ IRs细胞数 ,显著少于交往后棕色田鼠AR IRs细胞数。以上结果表明 :两种田鼠在社会交往中社会行为不同 ;ERβ的减少和AR的增多可能在社会识别及攻击行为中均起一定的作用 ,可能也是引起两种田鼠社会行为发生差异的原因之一     

三种啮齿类动物前肢挖掘效率分析

以甘肃鼢鼠(Myospalax cansus)、棕色田鼠(Lasiopodomys mandarinus)和小鼠(Mus musculus)为对象,对其尺骨、桡骨和肱三头肌结构进行了比较,并通过力学模型,对这三种生活类型鼠类前肢的挖掘效率进行分析。结果显示,甘肃鼢鼠肘关节位置大幅度前移,尺骨鹰嘴特化突出,形成更加省力的骨学杠杆基础,其中甘肃鼢鼠的鹰嘴尺骨比例达0.40;棕色田鼠和小鼠的鹰嘴尺骨比例分别约为0.19和0.18。此外,甘肃鼢鼠提供挖掘动力的肱三头肌近体端长头覆盖整个肩胛骨下缘,外侧头和内侧头覆盖桡神经沟到肱骨肘关节髁附近区域,远体端扁腱附着于尺骨鹰嘴,整块肌肉非常发达,棕色田鼠和小鼠均无此特化现象。说明甘肃鼢鼠前肢结构更加适应地下掘土生活,其挖掘效率远大于棕色田鼠和小鼠。     

Circadian Rhythms of Plasma Concentrations of Na+ and K+ and Their Urinary Excretion in Normal and Diabetic Rats

The effects of streptozotocin induced diabetes (50 mg/Kg) on the circadian rhythms in the excretion of sodium and potassium as well as their plasma concentration rhythms were investigated. Control (C) and diabetic (D) rats were studied during a light-dark (12h:12h) cycle and fed ad libitum. Statistically significant circadian rhythms were found for sodium and potassium excretion in C rats. The orthophases of both rhythms occurred in the dark phase, the potassium one occurring before that of sodium. In D rats there is increased excretion of both sodium and potassium with the rhythmicity maintained for sodium excretion only, which has an earlier orthophase than in the C rats. Plasma sodium and potassium concentrations showed a statistically significant circadian pattern in C rats, with orthophase in the light phase. This rhythmicity only appears in plasma potassium concentration for D rats, with orthophase at the end of the dark phase. The results in diabetic rats may suggest that the glomerular filtration rate (GFR) and/or tubular reabsorption rhythms are still contributing to the sodium excretory rhythm, and that the loss of the circadian rhythm in sodium plasma concentration has no influence on the sodium excretion rhythm. Nevertheless, the loss of the potassium excretion rhythm may suggest a disruption of the variations in the secretory process, as this excretion seems to be independent of the plasma potassium concentration rhythm, which is not lost in D rats.     

Internal desynchronization of the circadian activity and feeding rhythm in an owl monkey (Aotus lemurinus griseimembra): a case study

In the free-running circadian locomotor activity rhythm of a 7-year-old male owl monkey (Aotus lemurinus griseimembra) kept under constant light and climatic conditions (LL 0.2 lux, 25°C ± 1°C, 60 ± 5% relative humidity [RH]), a second rhythm component developed that showed strong relative coordination with the free-running activity rhythm of 24.4h and a 24h rhythm. The simultaneously recorded feeding activity rhythm strongly resembled this rhythm component. Therefore, it seems justified to infer that there was an internal desynchronization between the two behavioral rhythms or their circadian pacemakers, that is, between the light-entrainable oscillator located in the suprachiasmatic nuclei (SCN) and a food-entrainable oscillator located outside the SCN. This internal desynchronization may have been induced and/or maintained by a zeitgeber effect of the (irregular) 24h feeding schedule on the food-entrainable oscillator. The weak relative coordination shown by the activity rhythm indicates a much weaker coupling of the light-entrainable oscillator to the food-entrainable oscillator than vice versa. (Chronobiology International, 17(2), 147-153, 2000)     

RNAi of the circadian clock gene period disrupts the circadian rhythm but not the circatidal rhythm in the mangrove cricket

The clock mechanism for circatidal rhythm has long been controversial, and its molecular basis is completely unknown. The mangrove cricket, Apteronemobius asahinai, shows two rhythms simultaneously in its locomotor activity: a circatidal rhythm producing active and inactive phases as well as a circadian rhythm modifying the activity intensity of circatidal active phases. The role of the clock gene period (per), one of the key components of the circadian clock in insects, was investigated in the circadian and circatidal rhythms of A. asahinai using RNAi. After injection of double-stranded RNA of per, most crickets did not show the circadian modulation of activity but the circatidal rhythm persisted without a significant difference in the period from controls. Thus, per is functionally involved in the circadian rhythm but plays no role, or a less important role, in the circatidal rhythm. We conclude that the circatidal rhythm in A. asahinai is controlled by a circatidal clock whose molecular mechanism is different from that of the circadian clock.     

Pace‐of‐life: Relationships among locomotor activity,life history,and circadian rhythm in the assassin bug,Amphibolus venator

The pace‐of‐life syndrome (POLS) hypothesis means that animal behavior is correlated with life history strategies. Studies have reported that the free‐running period of the circadian rhythm (length of the period) is correlated with life history strategies in some animals. Although the length of the circadian rhythm may be associated with the POLS hypothesis, few studies have investigated the relationships among animal behavior, life history traits, and circadian rhythm. We tested the POLS hypothesis in the assassin bug, Amphibolus venator, which shows individual variation in locomotor activity. We found higher repeatability of differences in locomotor activity between individuals. Moreover, we found a trade‐off between locomotor activity and developmental period such that active individuals developed faster. However, locomotor activity was not correlated with the length of the circadian rhythm in A. venator. Therefore, this study suggests that the length of the circadian rhythm in A. venator does not support the POLS hypothesis.     

Characteristics of the circadian activity rhythm in common marmosets (Callithrix j. jacchus)

The circadian activity rhythm of the common marmoset, Callithrix j. jacchus was investigated by long-term recording of the locomotor activity of 15 individuals (5 males, 10 females) from 1.5 to 8 years old, both under constant illumination and under LD 12:12. The mean period of the spontaneous circadian rhythm was 23.2 ± 0.3 h. Neither sex-specific differences nor a systematic influence of light intensity on the spontaneous period were observed, but the period was dependent on the duration of the trial and on the age of the individual. Due to the short spontaneous period, in LD 12:12 there was a distinct advance of the activity phase with respect to the light time and a masking of the true onset of activity by the inhibitory direct effect of low light intensity during the dark time. After an 8 h delay shift of the LD 12:12, re-entrainment of the circadian activity rhythm required an average of 6.8 ± 0.7 days; the average re-entrainment time after an 8 h phase advance of the LD cycle was 8.6 ± 1.3 day. This directional effect is ascribed to characteristics of the phase-response curve. No ultradian components were observed, either in the LD-entrained or the free-running circadian activity rhythm.     

Circadian and ultradian (12 h) rhythms of hepatic thiosulfate sulfurtransferase (rhodanese) activity in mice during the first two months of life

Thiosulfate sulfurtransferase (TST) is an important 'enzyme of protection,' that accelerates the detoxification of cyanide, converting it into thiocyanate. The TST physiological rhythm was investigated at wks 2, 4, and 8 of post-natal development (PND) in the mouse. The results revealed a statistically significant gender-related difference, with the highest activity in females, at all the documented PND stages. In the second week of PND (pre-weaning time), the circadian rhythm of the enzyme activity was associated with ultradian components. The prominent circadian rhythm (τ=24 h) peaked at the beginning of the light span, more precisely ∼3 HALO (Hours After Light Onset). A week after weaning (wk 4 of PND), an impairment of the rhythm, with the peak shifted toward the second half of photophase, was recorded. Four to 6 wks later, about wk 8 of PND, the circadian rhythm pattern was stabilized, with its peak then located at the beginning of the dark span (13 HALO). The obtained results showed a 12 h phase-shift of the circadian TST peak time during PND, suggesting that the rhythm stabilization is age-dependent.     

Deriving the reference value from the circadian motor active patterns in the “non-dementia” population,compared to the “dementia” population: What is the amount of physical activity conducive to the good circadian rhythm

Background: The circadian rhythm in older adults is commonly known to change with a decrease in physical activity. However, the association between circadian rhythm metrics and physical activity remains unclear. The objective of this study was to examine circadian activity patterns in older people with and without dementia and to determine the amount of physical activity conducive to a good circadian measurement. Method: Circadian parameters were collected from 117 older community-dwelling people (66 subjects without dementia and 52 subjects with dementia); the parameters were measured continuously using actigraphy for 7 days. A receiver operating characteristic (ROC) curve was applied to determine reference values for the circadian rhythm parameters, consisting of interdaily stability (IS), intradaily variability (IV), and relative amplitude (RA), in older subjects. Results: The ROC curve revealed reference values of 0.55 for IS, 1.10 for IV, and 0.82 for RA. In addition, as a result of the ROC curve in the moderate-to-vigorous physical Activity (MVPA) conducive to the reference value of the Non-parametric Circadian Rhythm Analysis per day, the optimal reference values were 51 minutes for IV and 55 minutes for RA. However, the IS had no classification accuracy. Conclusions: Our results demonstrated the reference values derived from the circadian parameters of older Japanese population with or without dementia. Also, we determined the MVPA conducive to a good circadian rest–active pattern. This reference value for physical activity conducive to a good circadian rhythm might be useful for developing a new index for health promotion in the older community-dwelling population.     

Silencing the circadian clock gene Clock using RNAi reveals dissociation of the circatidal clock from the circadian clock in the mangrove cricket

Whether a clock that generates a circatidal rhythm shares the same elements as the circadian clock is not fully understood. The mangrove cricket, Apteronemobius asahinai, shows simultaneously two endogenous rhythms in its locomotor activity; the circatidal rhythm generates active and inactive phases, and the circadian rhythm modifies activity levels by suppressing the activity during subjective day. In the present study, we silenced Clock (Clk), a master gene of the circadian clock, in A. asahinai using RNAi to investigate the link between the circatidal and circadian clocks. The abundance of Clk mRNA in the crickets injected with double-stranded RNA of Clk (dsClk) was reduced to a half of that in control crickets. dsClk injection also reduced mRNA abundance of another circadian clock gene period (per) and weakened diel oscillation in per mRNA expression. Examination of the locomotor rhythms under constant conditions revealed that the circadian modification was disrupted after silencing Clk expression, but the circatidal rhythm remained unaffected. There were no significant changes in the free-running period of the circatidal rhythm between the controls and the crickets injected with dsClk. Our results reveal that Clk is essential for the circadian clock, but is not required for the circatidal clock. From these results we propose that the circatidal rhythm of A. asahinai is driven by a clock, the molecular components of which are distinct from that of the circadian clock.