孤束核参与刺激下丘脑室旁核的镇痛作用

本实验用电刺激鼠尾-嘶叫法测痛,观察电刺激下丘脑室旁核的镇痛效应,并采用核团损毁和核团内微量注射药物等方法分析其镇痛通路。实验结果如下:(1)电刺激下丘脑室旁核能产生明显的镇痛效应。同时,放射免疫测定发现脑干加压素含量升高。(2)损毁孤束核能取消刺激下丘脑室旁核的镇痛效应,但对基础痛阈无影响。(3)孤束核内微量注射加压素拮抗剂[d(CH_2)_5 TYr(Me)-AVP]60ng/0.6μl 和加压素抗血清0.6μl 都可明显对抗刺激下丘脑室旁核的镇痛效应。(4)直接在孤束核内微量注射加压素60ng/0.6μl,能模拟刺激下丘脑室旁核的镇痛效应。实验结果表明:电刺激下丘脑室旁核能产生镇痛效应,其机理之一可能是兴奋了下丘脑室旁核中加压素能神经元胞体,后者通过下行投射纤维在孤束核中释放加压素,影响孤束核神经元的活动,从而产生镇痛。     

糖尿病大鼠下丘脑Nesfatin-1对胃运动的影响及机制研究

目的:探讨下丘脑腹内侧核Nesfatin-1对正常大鼠及糖尿病大鼠胃运动的影响及其潜在机制。方法:正常大鼠随机分为0.08μg,0.8μg,8.0μg/0.5μL Nesfatin-1组;30μg/0.5μL astressin-B组;(0.8μg Nesfatin-1+30μg astressin-B)/0.5μL组;0.5μL生理盐水(NS)组;正常羊血清+假刺激(NR+SS)组;正常羊血清+电刺激(NR+ES)组;抗NUCB2/Nesfatin-1抗体+假刺激(anti-Nn-Ab+SS)组;抗NUCB2/Nesfatin-1抗体+电刺激(anti-Nn-Ab+ES)组。制作糖尿病大鼠模型,将糖尿病大鼠随机分为0.08μg/0.5μL Nesfatin-1组;0.8μg/0.5μLNesfatin-1组;8.0μg/0.5μL Nesfatin-1组;0.5μLNS组;NR+SS组;NR+ES组;anti-Nn-Ab+SS组;anti-Nn-Ab+ES组。大鼠胃部置入感应器后腹内侧核置管,记录清醒大鼠胃运动及电刺激海马CA1区后的胃运动。结果:与生理盐水组相比,下丘脑腹内侧核注射不同浓度Nesfatin-1,大鼠胃收缩幅度和频率显著降低,下丘脑腹内侧核注射0.5μL(0.8μg Nesfatin-1+30μg astressin-B)混合液后,相比单独给予0.8μg Nesfatin-1组,大鼠胃收缩幅度和频率显著升高。大鼠下丘脑腹内侧核注射0.5μL Nesfatin-1(0.8μg),大鼠胃收缩幅度和频率显著降低,下丘脑腹内侧核注射0.5μL(0.8μg Nesfatin-1+30μg astressin-B)混合液后,相比单独给予0.8μg Nesfatin-1组,大鼠胃收缩幅度和频率显著升高。下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与正常羊血清+电刺激组相比,大鼠胃收缩幅度和频率进一步增强,下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与单独注射抗NUCB2/Nesfatin-1抗体+假电刺激组相比,大鼠的胃收缩幅度和频率显著增高。下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再给予电刺激海马CA1区,与正常羊血清+电刺激组相比,正常大鼠和糖尿病大鼠胃运动指数均显著增加,下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与单独注射抗NUCB2/Nesfatin-1抗体+假电刺激组相比,正常和糖尿病大鼠的胃运动指数均显著增高。与正常大鼠相比,电刺激海马CA1区、下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再给予电刺激海马CA1区,或下丘脑腹内侧核微量注射抗NUCB2/Nesfatin-1抗体,糖尿病大鼠胃运动指数均无显著差异。结论:海马-下丘脑Nesfatin-1信号通路参与胃传入信息和胃运动调控,该作用可能与CRF系统活动有关。     

下丘脑下行通路及其功能

长期以来认为下丘脑室旁核和视上核神经元是通过垂体后叶分泌催产素和加压素对生殖和泌尿等功能进行调节的;但在雄性动物催产素有何生理意义,很长时间曾是个谜。近年来发现,室旁核等下丘脑结构还与脑干和脊髓有直接纤维联系,并以催产素和加压素为递质或调制物,完成对内脏活动的调节作用。这是一种神经调节,与内分泌调节并存。     

刺激大鼠尾壳核对脑内脑啡肽含量的影响

为确定刺激某一脑区时,远隔脑区脑啡肽含量是否改变;如有改变,甲-脑啡肽和亮-脑啡肽的变化是否一致。本工作在乌拉坦麻醉大鼠上,用放射免疫测定方法测定了电刺激尾壳核对六个脑区(下丘脑、纹状体、丘脑、海马、皮层及脑干)两种脑啡肽含量的影响。放射免疫测定的结果表明:(1)动物经乌拉坦麻校舍醉及手术操作后,除纹状体外,其它五个脑区亮-脑啡肽含量均明显降低,甲-脑啡肽含量只有下丘脑和丘脑明显降低,其它脑区无显著变化。(2)在乌拉坦麻醉及手术的基础上,再刺激尾壳核,除丘脑无显著变化外,其它五个脑区甲-脑啡肽含量均明显降低,亮-脑啡肽含量均明显升高,甲-脑啡肽/亮-脑啡肽比值减少(其中纹状体的比值改变无统计学显著性)。以上结果表明,刺激大鼠尾壳核可明显影响远隔脑区脑啡肽含量。关于甲-脑啡肽和亮-脑啡肽反向变化的意义有待进一步研究。     

缰核、弓状核对大鼠痛阈和针刺镇痛的影响

形态学资料和电生理实验证明,缰核是前脑边缘结构至脑干的中间枢纽,它接受隔区、视前区、海马、伏隔核等的抑制性作用,进而对脑干的有关核团如中缝核、蓝斑核的活动进行调节,从而加强针刺镇痛效应。本实验以整体动物的甩尾阈值为指标,确定并衡量缰核对基础痛阈的影响和在针刺镇痛中的作用。     

嗅觉与摄食行为的相互调节及其神经机制

嗅觉与摄食相互关联和相互调节。在摄食过程中,体内的代谢信号及食物刺激产生的进食信号首先被下丘脑的弓状核及脑干的孤束核感受到,进一步投射到下丘脑室旁核,室旁核再将信号传递到与摄食相关的其他脑区,调控摄食行为。在此过程中,嗅觉信号可以通过嗅球及嗅皮层投射到下丘脑,调节摄食行为。与此同时,摄食过程中产生的胃肠激素(促生长激素释放素、胰岛素、瘦素等)和体内的一些神经递质(乙酰胆碱,去甲肾上腺素、五羟色胺、内源性大麻素等)又作用于嗅觉系统,对嗅觉功能进行调节,反过来影响摄食本身。本综述从神经调节、激素调节等方面总结了近年嗅觉与摄食之间的相互作用及其内在机制的研究进展。     

半导体激光对机体中枢神经递质影响的初步观察

本工作报道了血管内照射（６５０ｎｍ,５ｍＷ,ｃｗ）对家兔尾核、下丘脑ＤＡ和ＮＥ的影响,发现ＤＡ在尾核和下丘脑中均有下降现象,但均Ｐ＞０．０５。在大鼠光照“扶突”穴中亦发现ＤＡ在脑干和尾核中,亦有下降倾向,ＮＥ有脑干和尾核中则有上升倾向。５—ＨＴ则均下降,但亦均未达显著性差异,（Ｐ＞０．０５）。另发现在人体血管内照射时,血液中ＮＯ·含量随照射次数增加而递减倾向。这些变化作者认为与光照的光化学反应引发的神经体液性调控有关。在本工作中还发现光照后神经未梢中的线粒体有肿胀现象。     

Ghrelin和脑功能

Ghrelin是首先从大鼠胃粘膜发现的一种新的脑-肠肽激素,具有促进生长激素释放的作用。它经辛酰化修饰具有生物学活性后可以通过血脑屏障发挥作用。研究发现,Ghrelin及其受体在脑组织(如下丘脑、大脑皮质、脑干、海马等)分布较广泛。近几年来,人们对Ghrelin和脑功能的研究也越来越多。本文就Ghrelin在学习和记忆、睡眠、焦虑、应激及神经保护等脑功能中所发挥的作用作一综述。     

糖皮质激素对胎儿下丘脑-垂体-肾上腺皮质轴的印迹效应

现已发现,糖皮质激素（glucocorticoids,GC)参与神经细胞的发生、分化、成熟及死亡。在胎儿脑发育的关键时期,接触过高浓度的GC将会影响其出生后的下丘脑－垂体－肾上腺轴（HPA轴）的功能。HPA轴与应激反应密切相关,对孕期暴露于高浓度的GC非常敏感。GC主要是通过以下三点来编程成年HPA轴功能的：（1）脑干神经系统的发育和功能;（2）海马皮质类固醇受体发育状态;（3）室旁核神经元的发育和功能。孕期接触高浓度的GC还可以直接影响脑结构的发育。GC对HPA轴功能及脑结构的影响则导致了成年行为的改变及一系列疾病的发生。     

下丘脑Orexin神经元对呼吸活动的调节

半个世纪前,就有报道提示来自下丘脑外侧区的电脉冲可刺激呼吸。近年研究显示,下丘脑对呼吸的调节可能起源于下丘脑的Orexin神经元,其神经纤维投射到有Orexin受体分布的脑干呼吸中枢,微量注射Orexin于脑干呼吸中枢可刺激呼吸。在Orexin基因敲除的小鼠上,CO2引起呼吸增加的反应变弱,且使自发性睡眠呼吸暂停发生的频率增加。更有意义的发现是,下丘脑Orexin神经元能感受细胞外H+和CO2的变化,起到中枢化学感受器的作用而调节呼吸活动。本文简述Orexin的生物学特点,着重对呼吸活动的调节,以及参与相关呼吸系统疾病的病理生理过程作一综述。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism