Journal of neurobiology最新文献_第8页

Ionic currents of Drosophila embryonic neurons derived from selectively cultured CNS midline precursors. 选择性培养中枢神经系统中线前体的果蝇胚胎神经元的离子电流。

Journal of neurobiology Pub Date : 2000-09-15

H Schmidt, K Lüer, W Hevers, G M Technau

引用次数: 0

The distribution and developmental regulation of NMDA receptor subunit proteins in the outer and inner retina of the rat. NMDA受体亚基蛋白在大鼠视网膜内外的分布及发育调控。

Journal of neurobiology Pub Date : 2000-09-05

T Gründer, K Kohler, A Kaletta, E Guenther

{"title":"The distribution and developmental regulation of NMDA receptor subunit proteins in the outer and inner retina of the rat.","authors":"T Gründer, K Kohler, A Kaletta, E Guenther","doi":"","DOIUrl":"","url":null,"abstract":"In order to investigate whether N-methyl-D-aspartate (NMDA) receptors with distinct pharmacological properties are differentially distributed within the retinal layers, the spatial distribution and temporal regulation of all NMDA receptor subunits was analyzed in parallel on the protein level in the rat retina during development. Immunohistochemistry was performed on retinal sections at different developmental ages between embryonic (E) days 20/21 and the adult stage using specific antibodies against NMDA subunits (NR1, NR2A-D). All NMDA subunits were expressed in the rat retina postnatally but showed different spatial patterns. In particular, and in contrast to previous in situ hybridization studies, labeling of NR2 subunits was observed in horizontal cell bodies and in the outer plexiform layer, indicating that functional NMDA receptors are expressed in this retinal cell type in the rat. Expression of NR2D was restricted to the inner retina and seemed to be involved in neurotransmission within the rod pathway. In the inner plexiform layer (IPL), distinct patterns of labeling were observed for different NMDA subunits. NR1 was found in two bands which can be related to the off- and on-signal pathways, whereas NR2A and NR2B were located in two bands within the off-sublaminae of the IPL. The antibody against NR2C was distributed throughout the whole IPL, and NR2D was expressed exclusively in the innermost part of the IPL where rod bipolar cell terminals terminate. Distinct bands of immunoreactivity in the IPL were observed only from P14 on. In conclusion, there are clear differences in the spatial distribution and temporal expression of NMDA receptor subtypes in the rodent retina. This indicates that specific retinal cells selectively express glutamate receptors composed of different subunit combinations and thus display different pharmacological and kinetic properties.","PeriodicalId":16540,"journal":{"name":"Journal of neurobiology","volume":"44 3","pages":"333-42"},"PeriodicalIF":0.0,"publicationDate":"2000-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21780356","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}

引用次数: 0

Effects of gonadal steroids during pubertal development on androgen and estrogen receptor-alpha immunoreactivity in the hypothalamus and amygdala. 青春期性腺激素对下丘脑和杏仁核雄激素和雌激素受体免疫反应性的影响。

Journal of neurobiology Pub Date : 2000-09-05

R D Romeo, S L Diedrich, C L Sisk

{"title":"Effects of gonadal steroids during pubertal development on androgen and estrogen receptor-alpha immunoreactivity in the hypothalamus and amygdala.","authors":"R D Romeo, S L Diedrich, C L Sisk","doi":"","DOIUrl":"","url":null,"abstract":"Perinatal development is often viewed as the major window of time for organization of steroid-sensitive neural circuits by steroid hormones. Behavioral and neuroendocrine responses to steroids are dramatically different before and after puberty, suggesting that puberty is another window of time during which gonadal steroids affect neural development. In the present study, we investigated whether the presence of gonadal hormones during pubertal development affects the number of androgen receptor and estrogen receptor alpha-immunoreactive (AR-ir and ER alpha-ir, respectively) cells in limbic regions. Male Syrian hamsters were castrated either before or after pubertal development, and 4 weeks later they received a single injection of testosterone or oil vehicle 4 h prior to tissue collection. Immunocytochemistry for AR and ER alpha was performed on brain sections from testosterone-treated and oil-treated males, respectively. Adult males that had been castrated before puberty had a greater number of AR-ir cells in the medial preoptic nucleus than adult males that had been castrated after puberty. There were no significant differences in ER alpha-ir cell number in any of the brain regions examined. The demonstration that exposure to gonadal hormones during pubertal development is associated with reduced AR-ir in the medial preoptic nucleus indicates that puberty is a period of neural development during which hormones shape steroid-sensitive neural circuits.","PeriodicalId":16540,"journal":{"name":"Journal of neurobiology","volume":"44 3","pages":"361-8"},"PeriodicalIF":0.0,"publicationDate":"2000-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21780358","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}

引用次数: 0

Common mechanisms underlying growth cone guidance and axon branching. 生长锥引导和轴突分支的共同机制。

Journal of neurobiology Pub Date : 2000-08-01

K Kalil, G Szebenyi, E W Dent

{"title":"Common mechanisms underlying growth cone guidance and axon branching.","authors":"K Kalil, G Szebenyi, E W Dent","doi":"","DOIUrl":"","url":null,"abstract":"During development, growth cones direct growing axons into appropriate targets. However, in some cortical pathways target innervation occurs through the development of collateral branches that extend interstitially from the axon shaft. How do such branches form? Direct observations of living cortical brain slices revealed that growth cones of callosal axons pause for many hours beneath their cortical targets prior to the development of interstitial branches. High resolution imaging of dissociated living cortical neurons for many hours revealed that the growth cone demarcates sites of future axon branching by lengthy pausing behaviors and enlargement of the growth cone. After a new growth cone forms and resumes forward advance, filopodial and lamellipodial remnants of the large paused growth cone are left behind on the axon shaft from which interstitial branches later emerge. To investigate how the cytoskeleton reorganizes at axon branch points, we fluorescently labeled microtubules in living cortical neurons and imaged the behaviors of microtubules during new growth from the axon shaft and the growth cone. In both regions microtubules reorganize into a more plastic form by splaying apart and fragmenting. These shorter microtubules then invade newly developing branches with anterograde and retrograde movements. Although axon branching of dissociated cortical neurons occurs in the absence of targets, application of a target-derived growth factor, FGF-2, greatly enhances branching. Taken together, these results demonstrate that growth cone pausing is closely related to axon branching and suggest that common mechanisms underlie directed axon growth from the terminal growth cone and the axon shaft.","PeriodicalId":16540,"journal":{"name":"Journal of neurobiology","volume":"44 2","pages":"145-58"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21773104","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}

引用次数: 0

Mechanisms of growth cone guidance and motility in the developing grasshopper embryo. 蝗虫胚胎发育过程中生长锥引导和运动的机制。

Journal of neurobiology Pub Date : 2000-08-01

C M Isbister, T P O'Connor

引用次数: 0

Substrate-cytoskeletal coupling as a mechanism for the regulation of growth cone motility and guidance. 底物-细胞骨架偶联作为生长锥运动调控和引导的机制。

Journal of neurobiology Pub Date : 2000-08-01

D M Suter, P Forscher

{"title":"Substrate-cytoskeletal coupling as a mechanism for the regulation of growth cone motility and guidance.","authors":"D M Suter, P Forscher","doi":"","DOIUrl":"","url":null,"abstract":"Growth cones are highly motile structures at the end of neuronal processes, capable of receiving multiple types of guidance cues and transducing them into directed axonal growth. Thus, to guide the axon toward the appropriate target cell, the growth cone carries out different functions: it acts as a sensor, signal transducer, and motility device. An increasing number of molecular components that mediate axon guidance have been characterized over the past years. The vast majority of these molecules include proteins that act as guidance cues and their respective receptors. In addition, more and more signaling and cytoskeleton-associated proteins have been localized to the growth cone. Furthermore, it has become evident that growth cone motility and guidance depends on a dynamic cytoskeleton that is regulated by incoming guidance information. Current and future research in the growth cone field will be focussed on how different guidance cues transmit their signals to the cytoskeleton and change its dynamic properties to affect the rate and direction of growth cone movement. In this review, we discuss recent evidence that cell adhesion molecules can regulate growth cone motility and guidance by a mechanism of substrate-cytoskeletal coupling.","PeriodicalId":16540,"journal":{"name":"Journal of neurobiology","volume":"44 2","pages":"97-113"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21773101","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}

引用次数: 0

Regulation of growth cone behavior by calcium: new dynamics to earlier perspectives. 钙对生长球果行为的调节:早期观点的新动态。

Journal of neurobiology Pub Date : 2000-08-01

T M Gomez, N C Spitzer

引用次数: 0

The receptor tyrosine phosphatase CRYPalpha affects growth cone morphology. 受体酪氨酸磷酸酶CRYPalpha影响生长锥形态。

Journal of neurobiology Pub Date : 2000-08-01

B K Mueller, M M Ledig, S Wahl

{"title":"The receptor tyrosine phosphatase CRYPalpha affects growth cone morphology.","authors":"B K Mueller, M M Ledig, S Wahl","doi":"","DOIUrl":"","url":null,"abstract":"During development of the nervous system receptor tyrosine kinases and receptor protein tyrosine phosphatases act in a coordinate way during axon growth and guidance. In the developing avian retinotectal system, many different receptor protein tyrosine phosphatases are expressed. Most of them have unknown functions. Retinal ganglion cells express at least three different members of this receptor family on their axons and growth cones: CRYPalpha, CRYP-2 and PTPmu. CRYPalpha interacts heterophilically with at least two different ligands found in the basal membranes of the retina and the optic tectum. To analyze the role of the CRYPalpha-ligand interaction, retinal ganglion cell axons were grown on retinal basal membranes (inner limiting membrane) and the receptor-ligand interaction was blocked from both the receptor side (by receptor specific antibodies) and from the ligand side by using a receptor-alkaline phosphatase fusion protein. Both of these treatments reduced average retinal axon length and induced a dramatic change in morphology of retinal ganglion cell growth cones on basal membranes, but not on other substrates like laminin, N-cadherin, matrigel- and detergent-treated basal membranes. These results suggest that CRYPalpha and its ligand act as growth-promoting molecules during intraretinal axon growth.","PeriodicalId":16540,"journal":{"name":"Journal of neurobiology","volume":"44 2","pages":"204-18"},"PeriodicalIF":0.0,"publicationDate":"2000-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21772486","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}

引用次数: 0

The multiple decisions made by growth cones of RGCs as they navigate from the retina to the tectum in Xenopus embryos. 爪蟾胚胎中RGCs的生长锥在从视网膜到顶盖的过程中所做的多个决定。

Journal of neurobiology Pub Date : 2000-08-01

K S Dingwell, C E Holt, W A Harris

引用次数: 0

Genetic analysis of growth cone migrations in Caenorhabditis elegans. 秀丽隐杆线虫生长锥迁移的遗传分析。

Journal of neurobiology Pub Date : 2000-08-01

D C Merz, J G Culotti

引用次数: 0