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《Cell》2022,185(2):328-344.e26
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人睫状神经营养因子的原核表达,纯化及其生物效应 总被引:2,自引:0,他引:2
人睫状神经营养因子(hCNTF)克隆入pBV220中,在DH5α菌株中表达,重组蛋白以包含体的形式存在,表达量为菌体总蛋白的50%左右。经比较发现用2mol/L脲洗涤包含体可溶解大量可溶性细菌蛋白,且包含体损失较小。在高浓度变性剂条件下进行sepharcylS-200凝胶过滤,解决了纯化中hCNTF易聚合的问题,在低浓度变性剂条件下进行DEAE离子交换,有利于蛋白活性的保持。经两步纯化后得到均一性hCNTF,纯度达95%以上。在自然状态下使hCNTF复性。纯化复性后的hCNTF对无血清培养的鸡胚背根节神经元和脊髓腹角运动神经元有明显的维持存活和促进生长发育的生物效应。 相似文献
4.
J. T. Watson R. E. Ritzmann 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,182(1):23-33
We have combined kinematic and electromyogram (EMG) analysis of running Blaberus discoidalis to examine how middle and hind leg kinematics vary with running speed and how the fast depressor coxa (Df) and fast extensor
tibia (FETi) motor neurons affect kinematic parameters. In the range 2.5–10 Hz, B. discoidalis increases step frequency by altering the joint velocity and by reducing the time required for the transition from flexion
to extension. For both Df and FETi the timing of recruitment coincides with the maximal frequency seen for the respective
slow motor neurons. Df is first recruited at the beginning of coxa-femur (CF) extension. FETi is recruited in the latter half
of femur-tibia (FT) extension during stance. Single muscle potentials produced by these fast motor neurons do not have pronounced
effects on joint angular velocity during running. The transition from CF flexion to extension was abbreviated in those cycles
with a Df potential occurring during the transition. One effect of Df activity during running may be to phase shift the beginning
of joint extension so that the transition is sharpened. FETi is associated with greater FT extension at higher running speeds
and may be necessary to overcome high joint torques at extended FT joint angles.
Accepted: 24 May 1997 相似文献
5.
Nervous system development in the fairy shrimp Branchinella sp. (Crustacea: Branchiopoda: Anostraca): Insights into the development and evolution of the branchiopod brain and its sensory organs 下载免费PDF全文
Using immunohistochemical labeling against acetylated a‐tubulin and serotonin in combination with confocal laser scanning microscopy and 3D‐reconstruction, we investigated the temporary freshwater pond inhabitant Branchinella sp. (Crustacea: Branchiopoda: Anostraca) for the first time to provide detailed data on the development of the anostracan nervous system. Protocerebral sense organs such as the nauplius eye and frontal filament organs are present as early as the hatching stage L0. In the postnaupliar region, two terminal pioneer neurons grow from posterior to anterior to connect the mandibular neuromeres. The first protocerebral neuropil to emerge is not part of the central complex but represents the median neuropil, and begins to develop from L0+ onwards. In stage L3, the first evidence of developing compound eyes is visible. This is followed by the formation of the visual neuropils and the neuropils of the central complex in the protocerebrum. From the deutocerebral lobes, the projecting neuron tract proceeds to both sides of the lateral protocerebrum, forming a chiasma just behind the central body. In the postnaupliar region, the peripheral nervous system, commissures and connectives develop along an anterior–posterior gradient after the fasciculation of the terminal pioneer neurons with the mandibular neuromere. The peripheral nervous system in the thoracic segments consists of two longitudinal neurite bundles on each side which connect the intersegmental nerves, together with the ventral nervous system forming an orthogon‐like network. Here, we discuss, among other things, the evidence of a fourth nauplius eye nerve and decussating projecting neuron tract found in Branchinella sp., and provide arguments to support our view that the crustacean frontal filament (organ) and onychophoran primary antenna are homologous. J. Morphol. 277:1423–1446, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
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Changiz Geula Sara R. Dunlop Ivan Ayala Allegra S. Kawles Margaret E. Flanagan Tamar Gefen Marek-Marsel Mesulam 《Journal of neurochemistry》2021,158(6):1394-1411
8.
Summary Neck muscles of Calliphora erythrocephala, situated in the anterior prothorax, are innervated on each side by 8 motor neurons arising in the brain (cervical nerve neurons, CN1–8) and at least 13 motor neurons arising in the prothoracic ganglion (anterior dorsal and frontal nerve neurons, ADN1,2 and FN1-11). Three prominent motor neurons (CN6 and FN1,2) are described in detail with special emphasis on their relationships with giant visual interneurons from the lobula plate, haltere interneurons, and primary afferents from the prosternal organs and halteres. These sensory organs detect head movement and body yaw, respectively. Neuronal relationships indicate that head movement is under multimodal sensory control that includes giant motion-sensitive neurons previously supposed to mediate the optomotor response in flying flies. The described pathways provide anatomical substrates for the control of optokinetic and yaw-incurred head movements that behavioural studies have shown must exist. 相似文献
9.
A. Falconi D. Lorenzo S. Curti F. R. Morales M. Borde 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,181(2):143-151
The present study was designed to examine the synaptic events in neurons of the pacemaker nucleus of Gymnotus carapo during the increase in rate of the electric organ discharge following activation of Mauthner cells. Pacemaker and relay cells
were investigated using intracellular recordings which were performed under two different conditions: (1) with the pacemaker
nucleus spontaneously discharging and (2) after its activity was abolished by anesthesia. Mauthner axon activation induced
an increase in the rate of pacemaker cell discharges. This response was accompanied by an increase in the slope of the pacemaker
potential (up to 110%) and a depolarization of these cells. The discharges of relay cells followed one to one those of pacemaker
cells. In contrast to that observed in pacemaker cells, only brief depolarizing antidromic effects could be evoked in relay
cells after Mauthner axon activation. In quiescent pacemaker cells, Mauthner cell activation induced a prolonged (up to 500 ms)
depolarizing potential with an average amplitude of 1.92 ± 0.82 mV; its latency was 4.43 ± 1.14 ms. Our data indicate that,
within the pacemaker nucleus, the population of pacemaker cells is the only target for Mauthner cell-evoked, short-latency
excitatory synaptic actions.
Accepted: 1 March 1997 相似文献
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