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M. Ghirardi A. Casadio L. Santarelli P. G. Montarolo 《Invertebrate neuroscience : IN》1996,2(1):41-49
Hemolymph of adultAplysia californica significantly affects neurite outgrowth of identified neurons of the land snailHelix pomatia. The metacerebral giant cell (MGC) and the motoneuron C3 from the cerebral ganglion and the neuron B2 from the buccal ganglion
ofH. pomatia were isolated by enzymatic and mechanical dissociation and plated onto poly-l-lysine-coated dishes either containing culture medium conditioned byHelix ganglia, or pre-treated withAplysia hemolymph. To determine the extent of neuronal growth we measured the neurite elongation and the neuritic field of cultured
neurons at different time points.Aplysia hemolymph enhances the extent and rate of linear outgrowth and the branching domain ofHelix neurons. With the hemolymph treatment the MGC neuron more consistently forms specific chemical synapses with its follower
cell B2, and these connections are more effective than those established in the presence of the conditioned medium. 相似文献
64.
胡启明 《热带亚热带植物学报》1996,4(3):15-17
本文对过去一直认为是日本特有的两种珍珠菜属植物作了归并和组合:将Lysimachia,tashiroiMakino归并作L.patungensisHand.-Mazz.的异名,将L.tanakaeMaxim.降级作L.christinaeHance的亚种处理.对此间植物在中国和日本的地理替代现象作了讨论. 相似文献
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Human Microtubule-Associated Protein-2c Localizes to Dendrites and Axons in Fetal Spinal Motor Neurons 总被引:2,自引:0,他引:2
Joanna S. Albala Yvonne Kress Wan-Kyng Liu Karen Weidenheim Shu-Hui C. Yen Bridget Shafit-Zagardo 《Journal of neurochemistry》1995,64(6):2480-2490
Abstract: Microtubule-associated protein-2 (MAP-2) functions to maintain neuronal morphology by promoting the assembly of microtubules. MAP-2c is an alternately spliced form of MAP-2, containing the first 151 amino acids of high-molecular-weight (HMW) MAP-2 joined to the last 321 amino acids, eliminating 1,352 amino acids specific to HMW MAP-2. A polyclonal antibody generated to the splice site of human MAP-2c was used to determine its cellular localization. The MAP-2c antiserum was depleted of any HMW MAP-2 reactivity by absorption with HMW MAP-2 fusion protein. Western blot analysis of human fetal spinal cord homogenates demonstrated that the antibody is specific for human MAP-2c. MAP-2c immunoreactivity was found in the perinuclear cytoplasm and processes of anterior motor neurons and large processes of the posterior column in sections from 22–24-week human fetal spinal cord. Double-label confocal microscopy was performed using the MAP-2c polyclonal antibody and either a HMW MAP-2 or a neurofilament protein (highly phosphorylated 160- and 200-kDa protein) monoclonal antibody to identify these processes as dendrites or axons, respectively. HMW MAP-2 and MAP-2c colocalized in cell bodies and dendrites of anterior motor neurons, demonstrating for the first time the presence of native MAP-2c within dendrites. In addition, immunoelectron microscopy showed MAP-2c associated with microtubules in dendrites of motor neurons. MAP-2c and the neurofilament proteins were found in axons of the dorsal and ventral roots. The presence of MAP-2c within axons and dendrites suggests that MAP-2c contributes to neuronal plasticity during human fetal development. 相似文献
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Abstract: We examined the ability of ceramide and sphingomyelinase (SMase) to prevent neuronal programmed cell death (PCD). We found that a cell-permeable ceramide analogue prevented neuronal PCD when applied to established sympathetic neuron primary cultures at the time of nerve growth factor (NGF) deprivation. Other amphiphilic lipids such as oleic acid failed to prevent cell death. Exogenous SMase also showed the same effect, probably by raising the intracellular ceramide level by sphingomyelin (SM) breakdown. Phosphocholine, another hydrolytic product of SM by SMase, did not prevent cell death. Other phospholipases, such as phospholipase C and phospholipase A2 , could not prevent cell death. Given the recent findings that the SM cycle is activated to increase the intracellular ceramide level on NGF binding to the low-affinity NGF receptor (LNGFR) and that NGF binding to LNGFR suppresses apoptosis in neural cell lines, our results suggest the possibility of the SM cycle as a signaling mechanism transducing the PCD-preventing activity of NGF. 相似文献
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对我国文献中记载的前原鹅观草(Roegneriamayebarana(Honda)Ohwi)的标本和植物,与原产于日本的该种进行了比较形态学、细胞学研究,二者差异显著。作者认为我国所记载的该种种名应是山东鹅观草(Roegneriashandongensis(B.Salomon)J.L.Yang,Y.H.ZhouetYen),其内稃先端钝圆,长为外稃的3/4,染色体数为2n=4x=28,具SY染色体组,结实率达90%以上,过去被错定为R.mayebarana。而R.mayebarana在日本系一天然杂种,其内稃先端尖,与外稃等长或稍短,染色体数为2n=6x=42,具HSY染色体组,结实率极低,仅0.2%~0.4%。 相似文献
70.
Double-gating mechanism and diversity of an adenosine triphosphate (ATP)-sensitive K~ channel in neurons acutely dissociated from rat neocortex 总被引:2,自引:0,他引:2
Classically, ion channels are classified into 2 groups: chemical-sensitive (ligand-gated) and voltage-sensitive channels. Single ATP-sensitive K (K-ATP) channel currents were recorded in acutely dissociated rat neo-cortical neurons using patch clamp technique. A type of K-ATP channel has been found to be gated not only by intra-cellular ATP, but also by membrane potential ( Vm) , and proved to be a novel mechanism underlying the gating of ion channels, namely bi-gating mechanism. The results also show that the K-ATP channels possess heterogeneity and di-versity. These types of K-ATP channels have been identified in 40.12% of all patches, which are different in activa-tion-threshold and voltage-sensitivity. The present experiment studied the type-3 K-ATP channel with a unitary con-ductance of about 80 pS in detail ( n = 15). Taking account of all the available data, a variety of K-ATP channels are suggested to exist in body, and one type of them is bi-gated by both chemical substances and membrane poten 相似文献