Brain cell biology最新文献

{"title":"Distribution of the scaffolding proteins PSD-95, PSD-93, and SAP97 in isolated PSDs.","authors":"Joseph A DeGiorgis,&nbsp;James A Galbraith,&nbsp;Ayse Dosemeci,&nbsp;Xiaobing Chen,&nbsp;Thomas S Reese","doi":"10.1007/s11068-007-9017-0","DOIUrl":"https://doi.org/10.1007/s11068-007-9017-0","url":null,"abstract":"<p><p>We compared the distribution of three scaffolding proteins, all belonging to a family of membrane-associated guanylate kinases, thought to have key roles in the organization of the postsynaptic density (PSD). Isolated PSDs readily adhered to treated glass coverslips where they were labeled with immunogold and rotary shadowed for analysis by EM. The distribution of proteins within individual PSDs were measured by counting and mapping individual immunogold particles. PSD-95, as previously described, is distributed evenly throughout the PSD. We find here that PSD-93 has a nearly identical distribution suggesting that PSD-95 and PSD-93 could perform similar roles. SAP97, in contrast, is concentrated near edges of cleft sides of the PSDs, and in small clumps on their cytoplasmic sides. The homogenous distribution of PSD-95 and PSD-93 throughout the PSD is consistent with their being part of a backbone that stabilizes their various binding partners within the PSD. The distribution of SAP97 confirms that this protein is actually an integral component of the PSD, and suggests that it may have a role in inserting or stabilizing its main binding partner, Glu-R1, at the edge of the PSD.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"239-50"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-007-9017-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27365938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A practical device for pinpoint delivery of molecules into multiple neurons in culture.","authors":"Chikako Hara,&nbsp;Kiyohiko Tateyama,&nbsp;Naoki Akamatsu,&nbsp;Hiroyuki Imabayashi,&nbsp;Koichi Karaki,&nbsp;Nobuo Nomura,&nbsp;Hideyuki Okano,&nbsp;Atsushi Miyawaki","doi":"10.1007/s11068-008-9021-z","DOIUrl":"https://doi.org/10.1007/s11068-008-9021-z","url":null,"abstract":"<p><p>We have developed a device for pinpoint delivery of chemicals, proteins, and nucleic acids into cultured cells. The principle underlying the technique is the flow of molecules from the culture medium into cells through a rupture in the plasma membrane made by a needle puncture. DNA transfection is achieved by stabbing the needle tip into the nucleus. The CellBee device can be attached to any inverted microscope, and molecular delivery can be coupled with conventional live cell imaging. Because the position of the needle relative to the targeted cultured cells is computer-controlled, efficient delivery of molecules such as rhodamine into as many as 100 HeLa cells can be completed in 10 min. Moreover, specific target cells within a single dish can be transfected with multiple DNA constructs by simple changes of culture medium containing different plasmids. In addition, the nano-sized needle tip enables gentle molecular delivery, minimizing cell damage. This method permits DNA transfection into specific hippocampal neurons without disturbing neuronal circuitry established in culture.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"229-37"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-008-9021-z","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27365935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Imaging synaptic inhibition in transgenic mice expressing the chloride indicator, Clomeleon.","authors":"Ken Berglund,&nbsp;Wolfram Schleich,&nbsp;Patrik Krieger,&nbsp;Li Shen Loo,&nbsp;Dongqing Wang,&nbsp;Nell B Cant,&nbsp;Guoping Feng,&nbsp;George J Augustine,&nbsp;Thomas Kuner","doi":"10.1007/s11068-008-9019-6","DOIUrl":"https://doi.org/10.1007/s11068-008-9019-6","url":null,"abstract":"<p><p>We describe here a molecular genetic approach for imaging synaptic inhibition. The thy-1 promoter was used to express high levels of Clomeleon, a ratiometric fluorescent indicator for chloride ions, in discrete populations of neurons in the brains of transgenic mice. Clomeleon was functional after chronic expression and provided non-invasive readouts of intracellular chloride concentration ([Cl(-)](i)) in brain slices, allowing us to quantify age-dependent declines in resting [Cl(-)](i) during neuronal development. Activation of hippocampal interneurons caused [Cl(-)](i) to rise transiently in individual postsynaptic pyramidal neurons. [Cl(-)](i) increased in direct proportion to the amount of inhibitory transmission, with peak changes as large as 4 mM. Integrating responses over populations of pyramidal neurons allowed sensitive detection of synaptic inhibition. Thus, Clomeleon imaging permits non-invasive, spatiotemporally resolved recordings of [Cl(-)](i) in a large variety of neurons, opening up new opportunities for imaging synaptic inhibition and other forms of chloride signaling.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"207-28"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-008-9019-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27371790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GABAC receptor subunit mRNA expression in the rat superior colliculus is regulated by calcium channels, neurotrophins, and GABAC receptor activity.","authors":"Britta Jost,&nbsp;Jochen Grabert,&nbsp;Silke Patz,&nbsp;Matthias Schmidt,&nbsp;Petra Wahle","doi":"10.1007/s11068-008-9020-0","DOIUrl":"https://doi.org/10.1007/s11068-008-9020-0","url":null,"abstract":"<p><p>The distribution of mRNA for the rho2 subunit of the GABA(C) receptor is much broader in organotypic SC cultures than in vivo, suggesting that GABA(C) receptor expression is regulated by environmental factors. Electrophysiological recordings indicate that neurons in SC cultures have functional GABA(C) receptors, although these receptors exhibited smaller conductance than in vivo, probably due to increased rho2 subunit expression. Adding cortical input, treatment with various neuromodulators, and blocking neuronal activity with TTX failed to affect the expression of rho2 subunits. Electrophysiological recordings revealed the presence of spontaneous Ca(2+) currents in SC cultures and preventing these, by treatment with blockers of L-type Ca(2+) channels, caused rho2 mRNA expression to decline to in vivo levels. In contrast, rho1 subunit mRNA levels remained unchanged, indicating that the two subunits are independently regulated. Surprisingly, both tonic activation and blockade of GABA(C) receptors upregulated rho1/rho2 mRNA expression. Further, NGF and BDNF promoted such expression during an early postnatal time window. In vivo, expression of the rho2 mRNA in the SC, and the rho2/rho3 mRNA in the retina increased with age. Expression of the rho2 mRNA in the visual cortex, and the rho1 mRNA in the retina and SC was constant. Subunit mRNA expression was similar in dark-reared animals, indicating that visual experience has no influence. These experiments suggest that GABA(C) receptor expression in the SC is regulated during postnatal development. While visual experience seems to have no influence on GABA(C) receptor subunits, spontaneous calcium currents selectively promote rho2 expression and both rho1 and rho2 are autoregulated both by GABA(C) receptor activity and by neurotrophic factors.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"251-66"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-008-9020-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27365936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain cell technology: a valuable new resource for novel techniques.","authors":"George J Augustine","doi":"10.1007/s11068-008-9023-x","DOIUrl":"https://doi.org/10.1007/s11068-008-9023-x","url":null,"abstract":"","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"205-6"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-008-9023-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27410339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential activation of extracellular signal-regulated kinase 1 and a related complex in neuronal nuclei.","authors":"Joseph J Lundquist, Serena M Dudek","doi":"10.1007/s11068-008-9018-7","DOIUrl":"10.1007/s11068-008-9018-7","url":null,"abstract":"<p><p>The extracellular signal-regulated kinases 1 and 2 (ERKs 1/2) are known to participate in regulating transcription in response to moderate depolarization, such as synaptic stimulation, but how the same active enzyme can differentially regulate distinct transcriptional programs induced with abnormal depolarization (high potassium) is unknown. We hypothesized that ERK1 or 2 accomplishes this differential nuclear response through close association with other proteins in stable complexes. In support of this hypothesis, we have found that immunoreactivity for an apparent high molecular weight complex containing phospho-ERK1 increased in response to synaptic stimulation, but decreased in response to high potassium; p-ERK immunoreactivity at 44/42 kDa increased in both cases. Evidence supporting the conclusion that the band of interest contained ERK1 in a complex, as opposed to it being an unrelated protein crossreacting with antibodies against p-ERK, is that ERK1 (p44 MAPK) and 14-3-3 protein were electroeluted from the 160-kDa band cut from a gel. We also found the nuclear complexes to be exceptionally durable, suggesting a role for the crosslinking enzyme, transglutaminase, in its stabilization. In addition, we found other components of the ERK pathway, including MEK, ERK2, p90RSK, and Elk-1, migrating at higher-than-expected weights in brain nuclei. These results describe a novel stable complex of ERK1 in neuronal nuclei that responds differentially to synaptic and depolarizing stimulation, and thus may be capable of mediating gene transcription in a way distinct from the monomeric protein.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 4-6","pages":"267-81"},"PeriodicalIF":0.0,"publicationDate":"2006-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3755592/pdf/nihms486922.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27365937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synaptic destabilization by neuronal Nogo-A.","authors":"Elisabeth M Aloy,&nbsp;Oliver Weinmann,&nbsp;Caroline Pot,&nbsp;Hansjörg Kasper,&nbsp;Dana A Dodd,&nbsp;Thomas Rülicke,&nbsp;Ferdinando Rossi,&nbsp;Martin E Schwab","doi":"10.1007/s11068-007-9014-3","DOIUrl":"https://doi.org/10.1007/s11068-007-9014-3","url":null,"abstract":"<p><p>Formation and maintenance of a neuronal network is based on a balance between plasticity and stability of synaptic connections. Several molecules have been found to regulate the maintenance of excitatory synapses but nothing is known about the molecular mechanisms involved in synaptic stabilization versus disassembly at inhibitory synapses. Here, we demonstrate that Nogo-A, which is well known to be present in myelin and inhibit growth in the adult CNS, is present in inhibitory presynaptic terminals in cerebellar Purkinje cells at the time of Purkinje cell-Deep Cerebellar Nuclei (DCN) inhibitory synapse formation and is then downregulated during synapse maturation. We addressed the role of neuronal Nogo-A in synapse maturation by generating several mouse lines overexpressing Nogo-A, starting at postnatal ages and throughout adult life, specifically in cerebellar Purkinje cells and their terminals. The overexpression of Nogo-A induced a progressive disassembly, retraction and loss of the inhibitory Purkinje cell terminals. This led to deficits in motor learning and coordination in the transgenic mice. Prior to synapse disassembly, the overexpression of neuronal Nogo-A led to the downregulation of the synaptic scaffold proteins spectrin, spectrin-E and beta-catenin in the postsynaptic neurons. Our data suggest that neuronal Nogo-A might play a role in the maintenance of inhibitory synapses by modulating the expression of synaptic anchoring molecules.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 2-3","pages":"137-56"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-007-9014-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27066728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CD44 adhesion molecule and neuro-glial proteoglycan NG2 as invasive markers of glioma.","authors":"Marzenna Wiranowska,&nbsp;Sharron Ladd,&nbsp;Sarice R Smith,&nbsp;Paul E Gottschall","doi":"10.1007/s11068-007-9009-0","DOIUrl":"https://doi.org/10.1007/s11068-007-9009-0","url":null,"abstract":"<p><p>Glioma invasion into the CNS involves the interaction of tumor cells with the host's cells and extracellular matrix (ECM) molecules. In this study, the expression of ECM-associated and cell-associated proteins such as the transmembrane CD44 adhesion molecule and neuro-glial proteoglycan 2 (NG2), a member of the chondroitin sulfate proteoglycan family, were evaluated during glioma progression, in vitro and in vivo, using a model of a highly invasive and aggressive intracerebral mouse G-26 glioma. We found a marked increase in CD44 and NG2 expression in brain tissue containing glioma. The glioma levels of these proteins gradually increased over time to reach 3-15 times the levels in the contralateral control. NG2 and CD44 expression paralleled progression of the glioma, being higher on days 14 and 21 than on day 2 post-glioma implant. In addition, when invading glioma crossed the midline in the advanced tumor stage, levels of each of these proteins in the contralateral tissue were elevated, but were still significantly lower than in the ipsilateral, tumor-bearing hemisphere. Immunohistochemistry of advanced stage G-26 glioma (day 21) showed CD44 expression to be most prominent at the front of the glioma invasion line, sharply separated from normal brain parenchyma which expressed glial fibrillary acidic protein (GFAP). However, single CD44 positive cells that escaped the tumor mass penetrated between the astrocytes that encased the tumor at its periphery. In contrast, NG2 was expressed on nearly all glioma cells within the tumor mass but less so at the leading edge of the tumor. The NG2 positive cells were clearly demarcated and morphologically distinguishable from GFAP positive cells and only sporadic, small groups of NG2 positive cells were seen in the GFAP positive zone of the neuropil. Taken together, these data show that during glioma progression in the brain, the level and pattern of glioma-associated molecules such as CD44 and NG2 may aid in tracing and targeting the invading glioma cells.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 2-3","pages":"159-72"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-007-9009-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27066729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beta-amyloid enhances intracellular calcium rises mediated by repeated activation of intracellular calcium stores and nicotinic receptors in acutely dissociated rat basal forebrain neurons.","authors":"James H Chin,&nbsp;Frederick W Tse,&nbsp;Kim Harris,&nbsp;Jack H Jhamandas","doi":"10.1007/s11068-007-9010-7","DOIUrl":"https://doi.org/10.1007/s11068-007-9010-7","url":null,"abstract":"<p><p>Beta-amyloid, a 39-43 amino acid peptide, may exert its biological effects via neuronal nicotinic acetylcholine receptors. Using the ratiometric dye, fura-2, we examined the effect of soluble beta-amyloid(1-42) on the concentration of intracellular Ca(2+) ([Ca(2+)](i)) in acutely dissociated rat basal forebrain neurons. Focal applications of nicotine (0.5-20 mM), evoked dose-dependent increases in intracellular [Ca(2+)](i) that were mediated by the entry of extracellular Ca(2+) via nicotinic acetylcholine receptors, and the release of intracellular Ca(2+) from stores. With repeated nicotine challenges, the nicotinic responses were potentiated by 98 +/- 12% (P < 0.05) while beta-amyloid(1-42)(100 nM) was present for approximately 5 min. This potentiation became larger during the subsequent washout of beta-amyloid(1-42), which was associated with a gradual rise in baseline [Ca(2+)](i). Application of beta-amyloid(1-42)by itself did not alter [Ca(2+)](i), and beta-amyloid(1-42)also had no significant effect on the response to repeated KCl challenges. Therefore, beta-amyloid(1-42) caused neither gross disturbance of cellular Ca(2+) homeostasis nor enhancement of voltage-gated Ca(2+) channels. Interestingly, beta-amyloid(1-42) transiently potentiated the response to repeated caffeine challenges, which was also associated with a transient rise in baseline [Ca(2+)](i). beta-amyloid(1-42) potentiation of nicotine-evoked rises in [Ca(2+)](i) was reversed by the SERCA pump inhibitor, thapsigargin, and the mitochondrial Na(+)/Ca(2+) exchanger inhibitor, CGP-37157. These results suggest that the dysregulation of [Ca(2+)](i) by beta-amyloid(1-42) during multiple challenges with nicotine or caffeine involved the sensitization or overfilling of intracellular stores that are maintained by SERCA pump and Ca(2+) efflux from the mitochondria.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 2-3","pages":"173-86"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-007-9010-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27066730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the distribution of calcium calmodulin-dependent protein kinase II at the presynaptic bouton after depolarization.","authors":"Jung-Hwa Tao-Cheng,&nbsp;Ayse Dosemeci,&nbsp;Christine A Winters,&nbsp;Thomas S Reese","doi":"10.1007/s11068-007-9012-5","DOIUrl":"https://doi.org/10.1007/s11068-007-9012-5","url":null,"abstract":"<p><p>Phosphorylation of synapsin I by CaMKII has been reported to mobilize synaptic vesicles from the reserve pool. In the present study, the distributions of alpha-CaMKII and of synapsin I were compared in synaptic boutons of unstimulated and stimulated hippocampal neurons in culture by immunogold electron microscopy. CaMKII and synapsin I are located in separate domains in presynaptic terminals of unstimulated neurons. Label for alpha -CaMKII typically surrounds synaptic vesicle clusters and is absent from the inside of the cluster in control synapses. In contrast, intense labeling for synapsin I is found within the vesicle clusters. Following 2 minutes of depolarization in high K(+), synaptic vesicles decluster and CaMKII label disperses and mingles with vesicles and synapsin I. These results indicate that, under resting conditions, CaMKII has limited access to the synapsin I in synaptic vesicle clusters. The peripheral distribution of CaMKII around vesicle clusters suggests that CaMKII-mediated declustering progresses from the periphery towards the center, with the depth of penetration into the synaptic vesicle cluster depending on the duration of CaMKII activation. Depolarization also promotes a significant increase in CaMKII immunolabel near the presynaptic active zone. Activity-induced redistribution of CaMKII leaves it in a position to facilitate phosphorylation of additional presynaptic proteins regulating neurotransmitter release.</p>","PeriodicalId":72445,"journal":{"name":"Brain cell biology","volume":"35 2-3","pages":"117-24"},"PeriodicalIF":0.0,"publicationDate":"2006-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s11068-007-9012-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"27066203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}