大鼠缰核与下丘脑外侧区在调节心血管活动方面的机能联系

电刺激大鼠下丘脑外侧区（LH）,动脉压明显升高,心率加快,在刺激电极同侧缰核（Hb)内微量注射盐酸利多卡因、电刺激LH引起的升压反应可被阻断38.9%,心率增快反应可被阻断44.4%,双侧Hb内微量注射盐酸利多卡因,电刺激LH引起的升压反应可被阻断40.7%,心率增快反应可被阻断41.2% ,单侧或双侧Hb内微量注射人工脑脊液均不能阻断电刺激LH引起的心血管反应。电刺激大鼠Hb,动脉压明显升高,心率无明显改变,在刺激电极同侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断63.2%,双侧LH内微量注射盐酸利多卡因,电刺激Hb引起的升压反应可被阻断62.6%,单侧或双侧LH内微量注射人工脑脊液均不能阻断电刺激Hb引起的心血管反应。本实验提示Hb与LH在调节心血管活动方面有协同作用。     

大鼠缰核与下丘脑外侧区在血压调节中的相互关系

电刺激乌拉坦麻醉的大鼠下丘脑外侧区(LH)可使缰核(Hb)内51.0％的单位兴奋,15.7％的单位抑制,其中发生兴奋反应的单位有15.4％可被逆行激活。双侧Hb内微量注射利多卡因,电刺激LH引起的升压反应可被阻断42.0±28.0％;反之,双侧LH内微量注射利多卡固,电刺激Hb引起的升压反应可被阻断62.0±26.4％。结果表明,LH与Hb在血压调节中相互依赖,具有协同作用。     

电刺激大鼠扣带前回对血压和心率的影响

电刺激大鼠扣带前回(ACg),血压升高,心率加快,同时缰核(Hb)内20.7％的神经元兴奋,22.4％的神经元抑制,56.9％的神经元无反应。双侧Hb内微量注射盐酸利多卡因,可明显阻断电刺激ACg引起的心血管反应。结果表明,ACg对心血管活动的调节,一部分是通过改变Hb的活动来实现的,Hb是ACg调节心血管活动的下行性通路之一。     

杏仁中央核在躯体传入冲动抑制中枢性升压反应中的作用

目的:阐明电刺激腓深神经(DPN)对下丘脑室旁核(PVN)兴奋后的心血管反应的调节作用及杏仁中央核(CeA)在此作用中的地位。方法:电刺激SD大鼠中枢核团PVN,或用核团(CeA)内微量注射法注射L-谷氨酸钠(L-Glu)或红藻氨酸(KA)。同时记录大鼠股动脉血压、平均动脉压(MAP)、心电图及心率(HR)曲线。结果:电刺激一侧PVN后,MAP升高,HR变化不一,以下降为主。电刺激腓深神经对PVN兴奋诱发的升压反应有抑制作用。在同侧CeA微量注射0.02mol/L的KA100nl,10min后刺激PVN,血压升高(13.8±3.2)mmHg,较注射KA前削弱了(6.6±1.6)mmHg(P<0.05),DPN对刺激PVN的升压反应的抑制百分比也从51.5%降为32.0%。结论:杏仁中央核部分介导了PVN兴奋后引起的升压反应。DPN传入冲动对PVN中枢性升压反应有抑制作用,其机制可能与杏仁中央核有关。     

延髓腹侧结构在刺激缰核诱发升压反应中的作用

电刺激缰核(Hb)可使大鼠血压明显升高,但心率变化不明显。电刺激Hb血压升高的同时,延髓腹侧结构(VM)中46.5％的神经元自发放电频率增加,这些神经元分布在VM的升压神经元群中,41.9％的神经元自发放电频率降低,这些神经元分布在VM的降压神经元群中,11.6%的神经元自发放电频率不变,升压和降压神经元群中均有这种神经元。单侧损毁VM的网状旁巨细胞核后,动物血压基本不变,也不影响电刺激Hb引起的升压反应。双侧损毁VM的网状旁巨细胞核后,动物血压从98.4±11.2mmHg降至45.2±10.3mmHg,阻断了电刺激Hb引起的升压反应。单侧或双恻损毁疑核及部分延髓网状核腹侧后,动物血压基本不变,且不影响电刺激Hb引起的升压反应。 上述结果表明,Hb主要通过VM中升压神经元群的网状旁巨细胞核参与心血管活动的调节。     

下丘脑背内侧核在缰核兴奋诱发的心血管反应及腓深神经抑制中的作用

目的 :阐明下丘脑背内侧核 (DMH)在缰核 (Hb)兴奋诱发的心血管反应中的作用及DMH在腓深神经 (DPN)传入冲动调节Hb兴奋诱发的心血管活动中的作用及机制。方法 :脲酯和氯醛糖混合静脉麻醉的家兔 ,电刺激Hb、腓深神经 ,记录股动脉血压及心外膜电图 ,DMH内微量注射受体拮抗剂。结果 :同侧DMH微量注射谷氨酸受体阻断剂Kynurenicacid ,部分取消了电刺激Hb兴奋诱发的升压反应及缺血性心电变化反应。同侧DMH微量注射纳洛酮对腓深神经传入冲动抑制Hb兴奋诱发的上述反应有削弱作用。结论 :DMH及其中的谷氨酸受体参与电刺激缰核兴奋诱发的心血管反应 ,DMH及其中的阿片受体参与了DPN传入冲动对上述心血管反应的抑制作用     

孤束核内注NPY抗体对电刺激室旁核引起心血管反应的影响

本实验在乌拉坦麻醉的大鼠上进行。电刺激下丘脑室旁核（ＰＶＨ）使动脉血压升高,心率加快,并伴有瞳孔扩大,胡须抖动等交感反应。向孤束核（ＮＴＳ）微量注射神经肽Ｙ（ＮＰＹ）抗体后,电刺激ＰＶＨ引起的升压反应被阻断５３．８％,心率加快被阻断５７．１％,交感反应也被减弱。兴奋缰核（Ｈｂ）可对抗孤束核内注射ＮＰＹ抗体对室旁核引起的心血管反应的影响。结果提示：孤束核参与电刺激ＰＶＨ引起的心血管作用,其间有ＮＰＹ纤维的参与,同时证明Ｈｂ在其中起一定的作用。     

去甲肾上腺素在大鼠缰核引起的心血管效应及其机制

在乌拉坦麻醉的大鼠,研究了去甲肾上腺素(NE)在缰核(Hb)引起的心血管效应及其机制。Hb内微量注射NE使平均动脉压和心率呈剂量依赖性增加。用α受体阻断剂酚妥拉明预处理Hb,可明显减弱NE在Hb引起的心血管效应,但β受体阻断剂心得安或生理盐水不引起任何影响。Hb内微量注射海人酸使平均动脉压和心率明显增加,但Hb内微量注射利多卡因则不能引起明显的心血管效应。上述结果表明,Hb内NE在调节心血管活动中起重要作用,而这种效应可能是通过激活α受体使Hb兴奋的结果。     

阻断缰核或内侧前脑束对 L-谷氨酸刺激隔区引起的镇痛作用的影响

以辐射热-甩尾潜伏期作为测定大鼠痛阈的指标,用向隔区内微量注射 L-谷氨酸和向缰核或内侧前脑束微量注射利多卡因,可逆性刺激和阻断上述核团。L-谷氨酸刺激隔区使大鼠痛阈明显提高,并且在13.6—100nmol 呈现剂量-效应关系。利多卡因阻断缰核,使隔区的镇痛作用明显减弱(P<0.001)。而阻断内侧前脑束对隔区的镇痛作用无明显影响(P>0.05)。结果表明隔区在脊髓水平抑制痛觉信息的传导主要是下行通过缰核实现的。     

伏核在躯体传入冲动抑制防御性心血管反应中的作用及机制

损毁伏核可明显削弱电刺激腓深神经（ＤＰＮ）对兴奋下丘脑背内侧核诱发的升压反应和心肌缺血的抑制作用（Ｐ＜０．０５,Ｐ＜０．０１）。电刺激伏核可引起明显的降压效应。中脑中央灰质腹侧部（ｖＰＡＧ）微量注射纳洛酮可明显衰减伏核的减压效应;损毁ｖＰＡＧ甚至可翻转伏核的减压效应,引起轻度升压（Ｐ＜０．０１）。损毁弓状核后伏核的减压效应基本消失,弓状核内微量注射纳洛酮明显衰减伏的的减压效应。故ＤＰＮ传入冲动可能     

Causality, randomness, intelligibility, and the epistemology of the cell

Because the basic unit of biology is the cell, biological knowledge is rooted in the epistemology of the cell, and because life is the salient characteristic of the cell, its epistemology must be centered on its livingness, not its constituent components. The organization and regulation of these components in the pursuit of life constitute the fundamental nature of the cell. Thus, regulation sits at the heart of biological knowledge of the cell and the extraordinary complexity of this regulation conditions the kind of knowledge that can be obtained, in particular, the representation and intelligibility of that knowledge. This paper is essentially split into two parts. The first part discusses the inadequacy of everyday intelligibility and intuition in science and the consequent need for scientific theories to be expressed mathematically without appeal to commonsense categories of understanding, such as causality. Having set the backdrop, the second part addresses biological knowledge. It briefly reviews modern scientific epistemology from a general perspective and then turns to the epistemology of the cell. In analogy with a multi-faceted factory, the cell utilizes a highly parallel distributed control system to maintain its organization and regulate its dynamical operation in the face of both internal and external changes. Hence, scientific knowledge is constituted by the mathematics of stochastic dynamical systems, which model the overall relational structure of the cell and how these structures evolve over time, stochasticity being a consequence of the need to ignore a large number of factors while modeling relatively few in an extremely complex environment.     

The tree, the network, and the species

To enrich the Hennigian internodal conception of species, a new formalization of the definition of the species concept is proposed. This rigorous definition allows for considerable unification of the various, and sometimes conflicting, techniques of species delimitation used in practice. First, the domain of such a definition is set out, namely, the set of all organisms on Earth, past, present, and future. Next, the focus is on the genealogical relationship among organisms, which provides the key to analysing the giant or global genealogical network (GGN) connecting all these organisms. This leads to the construction of an algorithm revealing the topological structure of the GGN, from families to lineages, ending up with a definition of species as equivalence classes of organisms corresponding to branches of the 'tree of life'. Such a theoretical definition of the species concept must be accompanied by various recognition criteria to be operational. These criteria are, for example, the ill-named 'biological species concepts', 'phylogenetic species concepts', etc., usually, but wrongly, presented as definitions of the species concept. Besides clarifying this disputed point, the definition in the present study displays the huge diversity of the scales (time-scale and population size) involved in actual species, thus explaining away the classical problems raised by previous attempts at defining the species concept (uniparental reproduction, temporal depth of species, and hybridization).  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 509–521.     

Diacylglycerol, phosphatidic acid, and the converting enzyme, diacylglycerol kinase, in the nucleus

There exists phosphoinositide (PI) cycle in the nucleus, which is operated differentially from the classical PI cycle at the plasma membrane. Evidence has been accumulated that nuclear PIs and the related enzymes are closely involved in a variety of nuclear processes, although the details remain to be elucidated. In this mini review, some components of PI cycle, i.e., diacylglycerol, phosphatidic acid, and the converting enzyme, diacylglycerol kinase, in the nucleus are discussed with focusing on the lipid metabolism, cell cycle regulation, and animal models.