视交叉上核血管活性肽神经元超微结构的电镜研究

目的:本文研究血管活性肽(VIP)神经元在哺乳动物昼夜节律的起搏器(Oscillator)——视交叉上核内的超微结构。方法:用电子显微镜的技术研究血管活性肽(VIP)样免疫反应神经元在大鼠视交叉上核内的超微结构。结果表明:血管活性肽样免疫反应神经元细胞的胞体较大,胞核卵圆形,核内以常染色质为主,异染色质较少,胞质内有粗面内质网,高尔基氏复合体由多层囊泡组成,溶酶体和线粒体呈卵圆形,散在于细胞质各处。结论:血管活性肽神经元具有产生多肽物质的结构。     

三维增强T2*加权血管成像量化多发性硬化脑铁沉积的研究

目的 探讨三维增强T2*加权血管成像(ESWAN)相位值(phase)及有效横向弛豫率值(R2*)对多发性硬化(MS)患者深部灰质核团铁沉积的诊断价值,并分析测量值与扩展型残疾状态评分(EDSS)、病程相关性.方法 22例临床确诊MS患者及与之性别、年龄及教育程度相匹配的22名健康对照组行常规MRI和ESWAN扫描.测量患者及对照组深部灰质核团(双侧丘脑、尾状核头、壳核、苍白球、红核、黑质)phase值及R2*值.详细记录每例患者病程时间及EDSS评分.结果 (1)MS患者双侧深部灰质核团phase值均低于对照组,其中双侧尾状核头、壳核、红核及黑质与对照组比较差异具有统计学意义(P＜0.05).(2)MS患者双侧各个灰质核团R2*均高于对照组,差异均具有统计学意义(P＜0.05).(3)MS患者各深部灰质核团phase值、R2*值与EDSS评分、临床病程均无明显相关性(P＞0.05).结论 ESWAN序列多种测量值均能定量显示MS患者脑深部灰质核团明显铁质含量增多,有助于了解MS病理机制、研究颅内铁沉积与患者临床表现的相关性.     

下丘脑室旁核传入纤维的起源(摘要)

用电泳法将HRP导入大鼠下丘脑室旁核,标记神经元可见于端脑:外侧隔核、杏仁核群,终纹床核、海马和海马结构的下角。间脑:丘脑束旁核和连合核;下丘脑前区,视交叉上核,视上核、环状核、     

无创体核温度测量方案及其模拟研究

目的建立一种简便易行的，通过皮肤温度估计体核温度的连续、动态、长时间无创体温监测新方法．方法提出通过人为改变环境温度（咒）而获得个性化的绝热材料热阻（Re）对体表组织热阻（Rc）比值的途径，实现从皮肤温度（Ts）中扣除环境温度（Te）影响，从而达到从皮肤温度（Ts）测值中估计体核温度（Tc）的方案和具体测量方法，并用自行设计的模拟体温发生器对此方案进行了可行性和准确性验证，结果体核温度估算值和体核温度测量值的相关系数为0．996，估值误差小于0．2℃。结论该方案估计的体核温度很好地反映并跟随实际体核温度变化，在实现体温各异性测量中消除了环境温度变化所带来的影响，实现了体核温度长期、动态、无创的监测。     

扩散张量成像对多发性硬化脑深部灰质核团纵向定量研究

目的 利用3.0T MR扩散张量成像(DTI)技术纵向定量测量复发-缓解型多发性硬化(RRMS)患者脑深部灰质核团相关参数的动态变化及其与临床相关性.方法 选取RRMS患者30例及健康对照组30名,检查前根据临床残疾状态量表(EDSS)对患者进行评分.患者行间隔平均时间约2年共2次常规MRI及DTI检查,必要时行增强扫描.选取测量大脑深部灰质核团的部分各向异性分数(FA)值及平均扩散率(MD)值,比较两次测量结果的变化并评价与临床的相关性.结果 (1)与对照组相比患者脑深部部分灰质核团FA值降低,MD值增高;(2)分析各指标与EDSS评分的相关性,结果EDSS评分与丘脑(r=0.25,P=0.04)和黑质(r=0.27,P=0.046) MD值呈正相关,与丘脑(r =0.24,P=0.03)、尾状核(r=0.414,P=0.024)FA值呈负相关性.(3)患者前后两次参数对比各核团的FA值无明显变化(P＞0.05),但尾状核(=2.36,P=0.013)、丘脑(t=3.01,P=0.009)、黑质(t=2.35,P=0.015)、红核(t=2.50,P=0.012)等核团MD值增高,以丘脑增高最明显.结论 DTI能够提示RRMS患者脑深部灰质核团受累,并且在纵向观测中可以监测患者深部灰质的病理改变.     

视神经与视上核的传入联系

研究现神经纤维向下丘脑前区的投射,为光线通过视觉通路的介导调节昼夜节律的理论提供形态依据。采用霍乱毒素亚单位B标记的辣根过氧化物酶（CB－HRP）顺行追踪技术和免疫组化学技术。结果表明现神经纤维投射到视上核背侧区,投射到下丘脑外测区;血管加压素（VP）样免疫反应神经元见于视上核。提示视神经纤维可能与视上核内的VP样免疫反应神经元有直接联系,视上核可能是下丘脑前区昼夜节律系统的组成部分。     

猴对宇宙舱内环境的适应过程中体温昼夜节律和乳酸脱氢酶谱变化

本文从代谢方面以体温昼夜节律和乳酸脱氢酶(LDHI-5)研究猴对宇宙舱内环境适应的可能性及所需的训练次数。使用公猴(Macaca Nemeslrina)9只。设计了体温昼夜节律的拟合方程。结果表明经4次训练后的猴对宇宙舱内环境产生了基本适应。表现为体温由升高转为正常;体温昼夜节律由失同步转为再同步化;LDH5由显著升高(P<0.001)在两天内恢复到实验前水平。结果提示此种基线训练,需要较多的次数。为达到对宇宙舱内环境的完全适应,训练得少于4次。如果能结合选拔择优则可望缩短训练程序。     

基于结构MRI机器学习模型诊断帕金森病的价值

目的探讨基于多种结构MRI特征构建的机器学习模型诊断帕金森病(PD)的价值。方法回顾性分析2017年11月至2019年8月在苏州大学附属第二医院神经内科就诊的60例PD患者(PD组)和同期招募的56名社区健康老年人(NC组)的临床及影像资料。首先对所有受试者进行全脑MR扫描, 然后基于不同的脑分区模板, 从小脑、深部核团和皮层提取多种结构MRI特征, 利用Mann-WhitneyU检验和最小绝对值收缩与选择算子回归筛选一组最具诊断鉴别力的特征, 最后运用逻辑回归(LR)和线性判别分析(LDA)两种分类器, 结合5折交叉验证策略分别构建小脑、深部核团、皮层和基于所有特征的综合模型。采用受试者操作特征曲线的曲线下面积(AUC)和决策曲线分析(DCA)评价各模型的诊断效能和临床净收益。结果最终筛选出4个小脑特征(Lobule Ⅵ体积非对称指数、Lobule ⅦB皮层厚度非对称指数、灰质体积非对称指数及右侧Lobule Ⅵ灰质体积)、3个深部核团(右侧伏隔核绝对体积、伏隔核绝对和相对体积)和3个皮层(左侧PFm局部脑回指数、右侧额上回局部分形维数和左侧枕上回沟深)特征为最具诊断鉴别力的特征, ...     

1型神经纤维瘤病的皮质和皮质下区域的异常形态选择

正摘要目的1型神经纤维瘤病(NF1)是多系统神经发育障碍性疾病,有多种影像表现,包括深部灰质核团、脑干和小脑的局部一过性的髓空泡形成。本文旨在评估NF1病人的皮     

丘脑-皮质通路及其在青光眼的MRI研究进展

丘脑是最大的脑深部灰白质混合核团,也是感觉的中继核.丘脑的视觉传导通路的改变被认为在青光眼的中枢损害中起到关键性作用[1-3].近年,随着丘脑-皮质通路MRI研究的深入和MRI分析技术的快速进展,使得无创研究青光眼患者的丘脑-皮质通路成为可能.     

空间时间生物学:航天飞行近日节律与导引的研究进展

目的 综述空间时间生物学中航天飞行近日节律研究进展,并探讨飞行中近日节律的导引问题. 资料来源与选择国内外相关研究领域的科技报告、学术论文和学术论著等. 资料引用引用文献资料53篇. 资料综合空间时间生物学中的近日节律系统由感受器-起搏器-效应器组成.哺乳动物的起搏器位于下丘脑的视交叉上核(SCN).通过神经元与感受器和效应器相连接.参与连接的有3种神经递质和1种激素.这些物质的分泌与光或暗和非光环境某些因子相关,在地球光或暗环境下近日节律系统运行周期约为24 h.空间环境时间暗示条件的改变使得这些物质的分泌发生变化,从而影响近日节律的正常运转. 结论 根据航天飞行光或暗与非光时间暗示条件的变化规律与特点,总结了近日节律的导引问题.     

模拟失重条件下体温调节的特点

为观察模拟失重条件下体温调节的特点，５名健康男性－６°头低卧床７ｄ、对照３ｄ、恢复２ｄ。结果表明：卧床中体温保持了觉醒－睡眠的昼变化规律，但节律发生了一定改变，直肠温度昼夜节律的改变主要出现在卧床初期。头颈部皮肤温度明显升高，温度分布改变。     

昼夜节律在代谢调控中的作用

昼夜节律的产生和维持依赖于内源性生物钟调控系统,其遗传基础是由一系列生物钟基因(bmal1、clock、cry、per)和钟控基因(rev-erbα、rorα、dbp、tef、hlf等)组成的反馈调控环路.昼夜节律与机体代谢功能密切相关,参与机体糖、脂肪等营养物质的代谢过程.当饮食时间、睡眠障碍、作息颠倒等外源因素引起机体昼夜节律发生紊乱,可显著增加诱发代谢综合征的风险.该文将着重阐述昼夜节律及生物钟系统对机体代谢功能的影响,以及昼夜节律失调在诱发代谢综合征中的作用.     

Fos expression in the suprachiasmatic nucleus in rats following high altitude exposure

INTRODUCTION: Disturbances of circadian rhythms occur at high altitude. We examined the suprachiasmatic nucleus (SCN), considered to be the biological clock in mammals that regulates circadian rhythmicity, in adult rats following an exposure to simulated high altitude. METHODS: Male adult Wistar rats weighing 250 g were exposed to an altitude of 8000 m in an altitude chamber, following which they were sacrificed at various time intervals ranging from 45 min to 3 d. Normal rats of similar weight kept outside the chamber were used as controls. Sections of hypothalamus containing the suprachiasmatic nucleus were processed immunohistochemically for expression of Fos, neuronal nitric oxide synthase (nNOS), and endothelial nitric oxide synthase (eNOS). RESULTS: At 45 min, 4 h, and 24 h following the altitude exposure, a large number of Fos-positive neurons were detected as compared with the control rats in which occasional Fos-positive neurons were observed. Increased expression of nNOS and eNOS was also observed at 45 min and 4 h following the altitude exposure. CONCLUSIONS: It is suggested that the neuronal activation indicated by upregulated expression of Fos and nitric oxide (NO) generated by nNOS may be involved in the disturbed circadian rhythms of the cardiovascular system (e.g., heart rate and BP), hormone secretion, and sleep-wake cycle which occur frequently during sojourns to high altitude. Increased eNOS expression also indicates excess production of NO, which may be involved in vasodialation and increased blood flow to the SCN following the exposure and may also be involved in modulating the circadian rhythms at high altitude.     

Circadian rhythms in two types of anaerobic cycle leg exercise: force-velocity and 30-s Wingate tests

Previous studies investigating the impact of circadian rhythms on performance during anaerobic cycle leg exercise have yielded conflicting results. The purpose of the present investigation was firstly, to determine the effect of the time of day on anaerobic performance during a force-velocity test on a cycle ergometer (F-V) and the Wingate test and secondly, to relate any changes in anaerobic performance to the circadian rhythm in oral temperature. Nineteen subjects volunteered to take part in the study. In a balanced and randomized study design, subjects were measured for maximal power (P (max)) (force-velocity test), peak power (P (peak)) and mean power (P (mean)) (Wingate test) on six separate occasions. These were at 02 : 00, 06 : 00, 10 : 00, 14 : 00, 18 : 00 and 22 : 00 hours on separate days. There was an interval of 28 h between two successive tests. Oral temperature and body mass were measured before each test. Body mass did not vary during the day but a significant time of day effect was observed for the oral temperature with an acrophase at 18 : 22 +/- 00 : 34 hours. A significant circadian rhythm was found for P (max) with an acrophase at 17 : 10 +/- 00 : 52 hours and an amplitude of 7 %. A time-of-day effect was significant for F (0) and V (0). Also a significant circadian rhythm was observed for P (peak) with an acrophase at 17 : 24 +/- 00 : 36 hours and an amplitude of 7.6 % and for P (mean) with an acrophase at 18 : 00 +/- 01 : 01 hours and an amplitude of 11.3 %. The results indicated that oral temperature, P (peak), P (mean) and P (max) varied concomitantly during the day. These results suggest that there was a circadian rhythm in anaerobic performance during cycle tests. The recording of oral temperature allows one to estimate the time of occurrence of maximal and minimal values in the circadian rhythm of anaerobic performance.     

Circadian rhythms and temperature homeostasis in monkeys during a flight on the Kosmos 1514 biosatellite

In the course of a 5-day space flight of two rhesus-monkeys the following parameters were recorded at an interval of 16 min: core body temperature (Tc), skin temperature (Ts), and motor activity (MA). The telemetric Tc sensor was implanted subcutaneously in the right axilla, Ts thermistor was attached to the right ankle, and the MA piezotape was fixed to the inner side of the vest. Circadian rhythms of Tc varied with a period of 24 hours in one monkey and 25 hours in the other. The daily Tc decreased on the average by 0.5 degrees C, Ts fell immediately after launch and remained close to the lower limit throughout the flight. The Ts amplitude decreased 5-fold. Phases of the circadian rhythms of Ts changed and circadian rhythms of MA remained unchanged and equal to 24 hours.     

Circadian rhythm of rectal temperature during sleep deprivation with modafinil

BACKGROUND: Sleep deprivation (SD) induces many adverse psychological and physiological effects, particularly on vigilance and the thermoregulatory system. The drug modafinil appears to suppress or diminish the harmful effects on vigilance. However, the effects of modafinil combined with SD on the circadian rhythm of core temperature are not well established. HYPOTHESIS: We studied the circadian rhythm of rectal temperature (CRTre) during 62 h of SD alone or with three dosage levels of modafinil. METHODS: Six men underwent repeated SD experiments lasting 7 d each, including a 24-h control period, 62 h of SD, and a 24-h recovery period. Experiments were repeated four times in mixed order for placebo and three levels of modafinil (50, 150, or 300 mg x 24 h(-1)). The Tre was recorded each minute throughout the experiment and the CRTre was studied by the single cosinor method. RESULTS: Independent of modafinil, SD increased the mesor (p < 0.05) and reduced the amplitude (p < 0.01) of the CRTre without changing the acrophase. During the recovery period, a rebound increase was seen in the amplitude of the CRTre (p < 0.01). The 50 mg x 24 h(-1) dose of modafinil, but not the higher doses, induced a lower mesor (p < 0.01) independent of SD. CONCLUSIONS: The observed changes may reflect a threshold for the central action of modafinil on core temperature. The hyperthermic effect reported in the literature for SD with modafinil may actually result from the sleep deprivation alone.     

Some circulatory responses to exercise at different times of day

Circadian rhythms in heart rate were examined at rest, immediately pre-exercise, during submaximal and maximal exercise on a cycle ergometer, and during recovery post-exercise (N = 10). Observations were made under controlled conditions at 0300, 0900, 1500, and 2100 hours. A significant circadian rhythm was found for resting heart rate lying supine and sitting pre-exercise (P less than 0.05), peak values being measured at 1500 hours. The acrophase in the oral temperature rhythm at 1739 hours was not significantly out of phase with that of resting heart rate (P greater than 0.05). The rhythm in heart rate persisted during submaximal exercise (150 W) and at the maximal rate (P less than 0.05); the amplitude of the rhythm was attenuated at maximum. Ratings of perceived exertion at submaximal and maximal exercise intensities, and time of day (P greater than 0.05). The increment of 0.2 degrees C in oral temperature during exercise did not exhibit circadian variation (P greater than 0.05). A significant rhythm was found for recovery heart rates in minutes 2, 3, 4, and 5 post-exercise (P less than 0.05). Observations of systolic and diastolic pressures pre- and post-exercise were inconclusive. Therefore, the circadian rhythm in heart rate responses to exercise should be considered when a heart rate variable is used as a criterion in fitness testing or as an index of physiological strain.