Abstract:
:Intrinsic horizontal axon collaterals in the striate cortex of adult cats specifically link columns having the same preferred orientation; consequently, retrograde tracer injections result in intrinsic labeling that is sharply clustered. We have previously shown that the normal development of this circuitry involves the emergence of crude clusters from an unclustered pattern during the second postnatal week. Crude clusters are later refined to the adult level of specificity by the selective rearrangement of axonal arbors that initially project to incorrect orientation columns. Here we report that depriving animals of patterned visual experience by binocular lid suture prior to natural eye opening had no discernible effect on the emergence of crude clusters. In contrast, cluster refinement was dramatically affected by binocular deprivation. Injections of retrograde tracers in the striate cortex of animals binocularly deprived for greater than 1 month revealed only crude clusters, indicating that horizontal axon collaterals projecting to incorrect orientation columns were retained well past the age when they normally would have been eliminated. Layer 2/3 pyramidal cells from 6-week-old binocularly deprived animals had abnormal distributions of intrinsic horizontal axon collaterals that mirrored the lack of cluster refinement. The radial clustering of their horizontal collaterals was considerably less precise than normal. These cells, nevertheless, developed many of the features of normal mature arbors, including the distal axonal branches not seen in arbors from younger animals with normal visual experience. Together, these results indicate that axonal rearrangements occurred, but with reduced specificity. Thus, binocular deprivation did not simply arrest the development of this orientation-specific circuit at an immature state but limited the accuracy with which axon collaterals were added or eliminated. We suggest that development of this orientation-specific circuitry, like ocular dominance column segregation, may depend on temporal correlation of activity for regulation of axonal rearrangement. The specificity of rearrangement may be degraded in binocularly deprived cats because they do not experience sharply oriented visual stimuli necessary for concurrent activation of same-orientation columns.
journal_name
Proc Natl Acad Sci U S Aauthors
Callaway EM,Katz LCdoi
10.1073/pnas.88.3.745subject
Has Abstractpub_date
1991-02-01 00:00:00pages
745-9issue
3eissn
0027-8424issn
1091-6490journal_volume
88pub_type
杂志文章abstract::In the manufacture of chemical feedstocks and subsequent processing into derivatives and materials, the U.S. chemical industry sets the current standard of excellence for technological competitiveness. This world-class leadership is attributed to the innovation and advancement of chemical engineering process technolog...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.3.821
更新日期:1992-02-01 00:00:00
abstract::To attempt to locate functionally important regions of the interferon (IFN) molecule, recombinant human IFN-alpha 2 was subjected to proteolytic digestion. The bacterial proteinase thermolysin produced two major complementary fragments, HuIFN-alpha 2-(1-110) and HuIFN-alpha 2-(111-153). After reduction with 2-mercapto...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.4.1045
更新日期:1984-02-01 00:00:00
abstract::It is widely accepted that modern humans originated in sub-Saharan Africa approximately 150-200 thousand years ago (ka), but their route of dispersal across the currently hyperarid Sahara remains controversial. Given that the first modern humans north of the Sahara are found in the Levant approximately 120-90 ka, nort...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0804472105
更新日期:2008-10-28 00:00:00
abstract::The protein dystrophin, normally found on the cytoplasmic surface of skeletal muscle cell membranes, is absent in patients with Duchenne muscular dystrophy as well as mdx (X-linked muscular dystrophy) mice. Although its primary structure has been determined, the precise functional role of dystrophin remains the subjec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.8.3710
更新日期:1993-04-15 00:00:00
abstract::The effect of fluctuations in rate constants on the kinetic behavior of cyclic reacting systems, caused by a fluctuating external parameter, is studied. It is shown (i) that the stochastic properties of the system can be analyzed analytically by using the usual master equation approach when the external parameter is f...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.3.729
更新日期:1987-02-01 00:00:00
abstract::We describe a cell-free system in which the transcription of the yeast metallothionein gene is inducible by the addition of metal ions plus a specific regulatory protein. Efficient transcription requires the complete yeast ACE1 metalloregulatory protein, including both its DNA-binding and transactivation domains; a mo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.21.8377
更新日期:1989-11-01 00:00:00
abstract::IL-17-producing CD27(-) γδ cells (γδ(27-) cells) are widely viewed as innate immune cells that make critical contributions to host protection and autoimmunity. However, factors that promote them over IFN-γ-producing γδ(27+) cells are poorly elucidated. Moreover, although human IL-17-producing γδ cells are commonly imp...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1204327109
更新日期:2012-10-23 00:00:00
abstract::Climate change, water supply limits, and continued population growth have intensified the search for measures to conserve water in irrigated agriculture, the world's largest water user. Policy measures that encourage adoption of water-conserving irrigation technologies are widely believed to make more water available ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0805554105
更新日期:2008-11-25 00:00:00
abstract::The identity of cells that mediate positive selection of CD8(+) T cells was investigated in two T cell receptor (TCR) transgenic systems. Irradiated beta(2)-microglobulin mutant mice or mice with mutations in both the K(b) and D(b) genes were repopulated with fetal liver cells from class I(+) TCR transgenic mice. In t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.20.11470
更新日期:1999-09-28 00:00:00
abstract::Oligosaccharyltransferase transfers an oligosaccharide chain to the asparagine residues in proteins. The archaeal and eubacterial oligosaccharyltransferases are single subunit membrane enzymes, referred to as "AglB" (archaeal glycosylation B) and "PglB" (protein glycosylation B), respectively. Only one crystal structu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1309777110
更新日期:2013-10-29 00:00:00
abstract::Activation-induced cytidine deaminase (AID) is essential to class-switch recombination (CSR) and somatic hypermutation (SHM) in both V region SHM and S region SHM (s-SHM). Uracil DNA glycosylase (UNG), a member of the base excision repair (BER) complex, is required for CSR. Strikingly, however, UNG deficiency causes a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1402391111
更新日期:2014-03-18 00:00:00
abstract::Coincidence cloning allows the isolation of sequences held in common by two genomic DNA populations. Human DNA from two human-hamster hybrid cell lines was amplified by Alu-repeat primers (Alu PCR) and the products originating from the shared human chromosomal region were cloned. To achieve this, human sequences were ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.15.6765
更新日期:1991-08-01 00:00:00
abstract::The cat-86 gene in plasmid pPL603 specifies chloramphenicol acetyltransferase (CAT) and is selectively expressed in Bacillus subtilis at a stage in sporulation in which internal spores are first observed (approximately T8). The gene is unexpressed in vegetatively growing cells. cat-86 expression and spore formation ar...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.11.3457
更新日期:1984-06-01 00:00:00
abstract::Patients with hematological malignancies can be successfully treated with HLA-matched T cell-depleted allogeneic stem cell transplantation (alloSCT) and subsequent donor lymphocyte infusions (DLIs). The efficacy of DLI is mediated by donor T cells recognizing minor histocompatibility antigens (mHags) on malignant reci...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0712250105
更新日期:2008-03-11 00:00:00
abstract::Thymidine kinase-deficient mouse L cells have been transformed with plasmid DNAs carrying 8-base-pair Xho I linker insertion mutations in the coding region of the herpes simplex virus type 1 thymidine kinase gene. When the mutant plasmids are introduced individually into LTK- cells, transformation efficiencies are gre...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.15.4827
更新日期:1983-08-01 00:00:00
abstract::Seasonal oxygen depletion (hypoxia) in coastal bottom waters can lead to the release and persistence of free sulfide (euxinia), which is highly detrimental to marine life. Although coastal hypoxia is relatively common, reports of euxinia are less frequent, which suggests that certain environmental controls can delay t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1510152112
更新日期:2015-10-27 00:00:00
abstract::Karrikins are a class of seed germination stimulants identified in smoke from wildfires. Microarray analysis of imbibed Arabidopsis thaliana seeds was performed to identify transcriptional responses to KAR(1) before germination. A small set of genes that are regulated by KAR(1), even when germination is prevented by t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0911635107
更新日期:2010-04-13 00:00:00
abstract::Infection of cultured cells with lytic animal viruses often results in the selective inhibition of host protein synthesis, whereas viral mRNA is efficiently translated under these circumstances. This phenomenon, known as "shut off," has been well described at the molecular level for some viruses, but there is not yet ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1004110107
更新日期:2010-05-25 00:00:00
abstract::Antibodies to chromatin proteins of Novikoff hepatoma cells formed precipitin bands in the double-diffusion immunoprecipitation assay with chromatin proteins of Novikoff hepatoma, Walker 256 carcinosarcoma, and 18-day fetal rat liver. The antigen used for preparation of antiserum was the chromatin proteins initially e...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.73.9.3258
更新日期:1976-09-01 00:00:00
abstract::Cooperativity in oligonucleotide-directed sequence-specific recognition of DNA by triple helix formation can be enhanced by the addition of discrete dimerization domains. The equilibrium association constants for cooperative binding of oligonucleotides that dimerize by Watson-Crick hydrogen bonds and occupy adjacent s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.4.1179
更新日期:1993-02-15 00:00:00
abstract::Stepwise, synthetic alteration of oxytocin, guided by conformational and enzymological considerations, has led to analogs with specifically modified activity profiles and resistance to enzymatic inactivation. General requirements for the design of peptides with therapeutic value are discussed. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.5.1901
更新日期:1974-05-01 00:00:00
abstract::The human CMV UL37x1-encoded protein, also known as the viral mitochondria-localized inhibitor of apoptosis, traffics to the endoplasmic reticulum and mitochondria of infected cells. It induces the fragmentation of mitochondria and blocks apoptosis. We demonstrate that UL37x1 protein mobilizes Ca(2+) from the endoplas...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0609353103
更新日期:2006-12-12 00:00:00
abstract::DNA repair alkyltransferases protect organisms against the cytotoxic, mutagenic, and carcinogenic effects of alkylating agents by transferring alkyl adducts from DNA to an active cysteine on the protein, thereby restoring the native DNA structure. We used random sequence substitutions to gain structure-function inform...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.12.6124
更新日期:1996-06-11 00:00:00
abstract::We recently developed the electron force field (eFF) method for practical nonadiabatic electron dynamics simulations of materials under extreme conditions and showed that it gave an excellent description of the shock thermodynamics of hydrogen from molecules to atoms to plasma, as well as the electron dynamics of the ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1110322108
更新日期:2011-09-13 00:00:00
abstract::Gonadotropin-releasing hormone (GnRH) is important in reproduction, although the mechanism of central hypogonadism in humans remains unclear. Because the GnRH neuron originates from the olfactory placode and migrates to the hypothalamus during development, central hypogonadism in humans could be caused by failure in n...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.8.3402
更新日期:1991-04-15 00:00:00
abstract::We examined the effect of the inhibition of initiation of DNA replication on the membrane association of the chromosomal origin of replication of Bacillus subtilis and the Staphylococcus aureus-Bacillus pumilus chimeric plasmid pSL103, using temperature-sensitive mutants of B. subtilis that have specifically affected ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.5.2834
更新日期:1980-05-01 00:00:00
abstract::Assessing temporal variability in extreme rainfall events before the historical era is complicated by the sparsity of long-term "direct" storm proxies. Here we present a 2,200-y-long, accurate, and precisely dated record of cave flooding events from the northwest Australian tropics that we interpret, based on an integ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1422270112
更新日期:2015-04-14 00:00:00
abstract::A photoreactive derivative of epidermal growth factor (EGF) has been used to identify and specifically label a membrane receptor for EGF on mouse 3T3 cells. Photoactivable EGF, labeled with 125I, was incubated with 3T3 cells and then photolyzed in situ to generate a nitrene capable of reacting with a wide variety of c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.7.2790
更新日期:1977-07-01 00:00:00
abstract::Ultraviolet irradiation of the [3H]colchicine-tubulin complex leads to direct photolabeling of tubulin with low but practicable efficiency. The bulk (70% to greater than 90%) of the labeling occurs on beta-tubulin and appears early after irradiation, whereas alpha-tubulin is labeled later. The labeling ratio of beta-t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.7.2820
更新日期:1991-04-01 00:00:00
abstract::We describe a strategy to "revive" putatively pathogenic T cells from frozen specimens of human inflammatory target organs. To distinguish pathogenic from irrelevant bystander T cells, we focused on cells that were (i) clonally expanded and (ii) in direct morphological contact with a target cell. Using CDR3 spectratyp...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0604247103
更新日期:2006-08-08 00:00:00