Human K-Complex Represents an Isolated Cortical Down-State

The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K-compl...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 2009-05, Vol.324 (5930), p.1084-1087
Main Authors: Cash, Sydney S, Halgren, Eric, Dehghani, Nima, Rossetti, Andrea O, Thesen, Thomas, Wang, ChunMao, Devinsky, Orrin, Kuzniecky, Ruben, Doyle, Werner, Madsen, Joseph R, Bromfield, Edward, Erőss, Loránd, Halász, Péter, Karmos, George, Csercsa, Richárd, Wittner, Lucia, Ulbert, István
Format: Article
Language:English
Subjects:
Adolescent
Adult
Anatomy & physiology
Biological and medical sciences
Brain
Cerebral Cortex - physiology
Electric current
Electrodes
Electroencephalography
Electrophysiological Phenomena
Epilepsy
Epilepsy - physiopathology
Female
Fundamental and applied biological sciences. Psychology
Humans
Medical imaging
Memory
Middle Aged
Neurology
Neuroscience
Scalp
Sleep
Sleep Stages - physiology
Sleep. Vigilance
Vertebrates: nervous system and sense organs
Waveforms
Young Adult
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
cited_by cdi_FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573
cites cdi_FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573
container_end_page 1087
container_issue 5930
container_start_page 1084
container_title Science (American Association for the Advancement of Science)
container_volume 324
creator Cash, Sydney S
Halgren, Eric
Dehghani, Nima
Rossetti, Andrea O
Thesen, Thomas
Wang, ChunMao
Devinsky, Orrin
Kuzniecky, Ruben
Doyle, Werner
Madsen, Joseph R
Bromfield, Edward
Erőss, Loránd
Halász, Péter
Karmos, George
Csercsa, Richárd
Wittner, Lucia
Ulbert, István
description The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K-complex (KC), which occurs in slow-wave sleep. Here, we show that KCs are generated in widespread cortical areas by outward dendritic currents in the middle and upper cortical layers, accompanied by decreased broadband EEG power and decreased neuronal firing, which demonstrate a steep decline in network activity. Thus, KCs are isolated "down-states," a fundamental cortico-thalamic processing mode already characterized in animals. This correspondence is compatible with proposed contributions of the KC to sleep preservation and memory consolidation.
doi_str_mv 10.1126/science.1169626
format article
fullrecord <record><control><sourceid>jstor_pubme</sourceid><recordid>TN_cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_3715654</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><jstor_id>20494002</jstor_id><sourcerecordid>20494002</sourcerecordid><originalsourceid>FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573</originalsourceid><addsrcrecordid>eNqFkc1v1DAQxS0EokvLmRMQIcEtrT_iLw5I1RZo1UqVKD1bXmdSskrirZ0U-t8zq41a4MLBsjzvN08zfoS8YvSQMa6OcmhhCIAPZRVXT8iCUStLy6l4ShaUClUaquUeeZHzmlLUrHhO9pitFKO0WpCPp1Pvh-K8XMZ-08Gv4htsEmQYxlxg_SzHzo9QF8uYxjb4rjiJP4fyasTiAXnW-C7Dy_neJ9dfPn9fnpYXl1_PlscXZVCcjyWI2viGsVoFbWrrTY0jGh2kBsWU8lYDnpVv6ioYWXvbaM1WWm97AKQW--TTznczrXqoA86WfOc2qe19unfRt-5vZWh_uJt454RmUskKDT7MBineTpBH17c5QNf5AeKUndJcaSPMf0GhuJaSCQTf_QOu45QG_AXHmcC1uLEIHe2gkGLOCZqHkRl12_TcnJ6b08OON39u-sjPcSHwfgZ8xjCa5IfQ5geOM5wOt0Hu9Y5b5zGmR51WtqJ0q7_d6Y2Pzt8k9Li-4pQJypRAQovfZgG2Qg</addsrcrecordid><sourcetype>Open Access Repository</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>213616289</pqid></control><display><type>article</type><title>Human K-Complex Represents an Isolated Cortical Down-State</title><source>American Association for the Advancement of Science</source><source>Alma/SFX Local Collection</source><creator>Cash, Sydney S ; Halgren, Eric ; Dehghani, Nima ; Rossetti, Andrea O ; Thesen, Thomas ; Wang, ChunMao ; Devinsky, Orrin ; Kuzniecky, Ruben ; Doyle, Werner ; Madsen, Joseph R ; Bromfield, Edward ; Erőss, Loránd ; Halász, Péter ; Karmos, George ; Csercsa, Richárd ; Wittner, Lucia ; Ulbert, István</creator><creatorcontrib>Cash, Sydney S ; Halgren, Eric ; Dehghani, Nima ; Rossetti, Andrea O ; Thesen, Thomas ; Wang, ChunMao ; Devinsky, Orrin ; Kuzniecky, Ruben ; Doyle, Werner ; Madsen, Joseph R ; Bromfield, Edward ; Erőss, Loránd ; Halász, Péter ; Karmos, George ; Csercsa, Richárd ; Wittner, Lucia ; Ulbert, István</creatorcontrib><description>The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K-complex (KC), which occurs in slow-wave sleep. Here, we show that KCs are generated in widespread cortical areas by outward dendritic currents in the middle and upper cortical layers, accompanied by decreased broadband EEG power and decreased neuronal firing, which demonstrate a steep decline in network activity. Thus, KCs are isolated "down-states," a fundamental cortico-thalamic processing mode already characterized in animals. This correspondence is compatible with proposed contributions of the KC to sleep preservation and memory consolidation.</description><identifier>ISSN: 0036-8075</identifier><identifier>EISSN: 1095-9203</identifier><identifier>DOI: 10.1126/science.1169626</identifier><identifier>PMID: 19461004</identifier><identifier>CODEN: SCIEAS</identifier><language>eng</language><publisher>Washington, DC: American Association for the Advancement of Science</publisher><subject>Adolescent ; Adult ; Anatomy &amp; physiology ; Biological and medical sciences ; Brain ; Cerebral Cortex - physiology ; Electric current ; Electrodes ; Electroencephalography ; Electrophysiological Phenomena ; Epilepsy ; Epilepsy - physiopathology ; Female ; Fundamental and applied biological sciences. Psychology ; Humans ; Medical imaging ; Memory ; Middle Aged ; Neurology ; Neuroscience ; Scalp ; Sleep ; Sleep Stages - physiology ; Sleep. Vigilance ; Vertebrates: nervous system and sense organs ; Waveforms ; Young Adult</subject><ispartof>Science (American Association for the Advancement of Science), 2009-05, Vol.324 (5930), p.1084-1087</ispartof><rights>Copyright 2009 American Association for the Advancement of Science</rights><rights>2009 INIST-CNRS</rights><rights>Copyright © 2009, American Association for the Advancement of Science</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573</citedby><cites>FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>230,314,780,784,885,2884,2885,27924,27925</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&amp;idt=21551672$$DView record in Pascal Francis$$Hfree_for_read</backlink><backlink>$$Uhttps://www.ncbi.nlm.nih.gov/pubmed/19461004$$D View this record in MEDLINE/PubMed$$Hfree_for_read</backlink></links><search><creatorcontrib>Cash, Sydney S</creatorcontrib><creatorcontrib>Halgren, Eric</creatorcontrib><creatorcontrib>Dehghani, Nima</creatorcontrib><creatorcontrib>Rossetti, Andrea O</creatorcontrib><creatorcontrib>Thesen, Thomas</creatorcontrib><creatorcontrib>Wang, ChunMao</creatorcontrib><creatorcontrib>Devinsky, Orrin</creatorcontrib><creatorcontrib>Kuzniecky, Ruben</creatorcontrib><creatorcontrib>Doyle, Werner</creatorcontrib><creatorcontrib>Madsen, Joseph R</creatorcontrib><creatorcontrib>Bromfield, Edward</creatorcontrib><creatorcontrib>Erőss, Loránd</creatorcontrib><creatorcontrib>Halász, Péter</creatorcontrib><creatorcontrib>Karmos, George</creatorcontrib><creatorcontrib>Csercsa, Richárd</creatorcontrib><creatorcontrib>Wittner, Lucia</creatorcontrib><creatorcontrib>Ulbert, István</creatorcontrib><title>Human K-Complex Represents an Isolated Cortical Down-State</title><title>Science (American Association for the Advancement of Science)</title><addtitle>Science</addtitle><description>The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K-complex (KC), which occurs in slow-wave sleep. Here, we show that KCs are generated in widespread cortical areas by outward dendritic currents in the middle and upper cortical layers, accompanied by decreased broadband EEG power and decreased neuronal firing, which demonstrate a steep decline in network activity. Thus, KCs are isolated "down-states," a fundamental cortico-thalamic processing mode already characterized in animals. This correspondence is compatible with proposed contributions of the KC to sleep preservation and memory consolidation.</description><subject>Adolescent</subject><subject>Adult</subject><subject>Anatomy &amp; physiology</subject><subject>Biological and medical sciences</subject><subject>Brain</subject><subject>Cerebral Cortex - physiology</subject><subject>Electric current</subject><subject>Electrodes</subject><subject>Electroencephalography</subject><subject>Electrophysiological Phenomena</subject><subject>Epilepsy</subject><subject>Epilepsy - physiopathology</subject><subject>Female</subject><subject>Fundamental and applied biological sciences. Psychology</subject><subject>Humans</subject><subject>Medical imaging</subject><subject>Memory</subject><subject>Middle Aged</subject><subject>Neurology</subject><subject>Neuroscience</subject><subject>Scalp</subject><subject>Sleep</subject><subject>Sleep Stages - physiology</subject><subject>Sleep. Vigilance</subject><subject>Vertebrates: nervous system and sense organs</subject><subject>Waveforms</subject><subject>Young Adult</subject><issn>0036-8075</issn><issn>1095-9203</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2009</creationdate><recordtype>article</recordtype><recordid>eNqFkc1v1DAQxS0EokvLmRMQIcEtrT_iLw5I1RZo1UqVKD1bXmdSskrirZ0U-t8zq41a4MLBsjzvN08zfoS8YvSQMa6OcmhhCIAPZRVXT8iCUStLy6l4ShaUClUaquUeeZHzmlLUrHhO9pitFKO0WpCPp1Pvh-K8XMZ-08Gv4htsEmQYxlxg_SzHzo9QF8uYxjb4rjiJP4fyasTiAXnW-C7Dy_neJ9dfPn9fnpYXl1_PlscXZVCcjyWI2viGsVoFbWrrTY0jGh2kBsWU8lYDnpVv6ioYWXvbaM1WWm97AKQW--TTznczrXqoA86WfOc2qe19unfRt-5vZWh_uJt454RmUskKDT7MBineTpBH17c5QNf5AeKUndJcaSPMf0GhuJaSCQTf_QOu45QG_AXHmcC1uLEIHe2gkGLOCZqHkRl12_TcnJ6b08OON39u-sjPcSHwfgZ8xjCa5IfQ5geOM5wOt0Hu9Y5b5zGmR51WtqJ0q7_d6Y2Pzt8k9Li-4pQJypRAQovfZgG2Qg</recordid><startdate>20090522</startdate><enddate>20090522</enddate><creator>Cash, Sydney S</creator><creator>Halgren, Eric</creator><creator>Dehghani, Nima</creator><creator>Rossetti, Andrea O</creator><creator>Thesen, Thomas</creator><creator>Wang, ChunMao</creator><creator>Devinsky, Orrin</creator><creator>Kuzniecky, Ruben</creator><creator>Doyle, Werner</creator><creator>Madsen, Joseph R</creator><creator>Bromfield, Edward</creator><creator>Erőss, Loránd</creator><creator>Halász, Péter</creator><creator>Karmos, George</creator><creator>Csercsa, Richárd</creator><creator>Wittner, Lucia</creator><creator>Ulbert, István</creator><general>American Association for the Advancement of Science</general><general>The American Association for the Advancement of Science</general><scope>FBQ</scope><scope>IQODW</scope><scope>CGR</scope><scope>CUY</scope><scope>CVF</scope><scope>ECM</scope><scope>EIF</scope><scope>NPM</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7QF</scope><scope>7QG</scope><scope>7QL</scope><scope>7QP</scope><scope>7QQ</scope><scope>7QR</scope><scope>7SC</scope><scope>7SE</scope><scope>7SN</scope><scope>7SP</scope><scope>7SR</scope><scope>7SS</scope><scope>7T7</scope><scope>7TA</scope><scope>7TB</scope><scope>7TK</scope><scope>7TM</scope><scope>7U5</scope><scope>7U9</scope><scope>8BQ</scope><scope>8FD</scope><scope>C1K</scope><scope>F28</scope><scope>FR3</scope><scope>H8D</scope><scope>H8G</scope><scope>H94</scope><scope>JG9</scope><scope>JQ2</scope><scope>K9.</scope><scope>KR7</scope><scope>L7M</scope><scope>L~C</scope><scope>L~D</scope><scope>M7N</scope><scope>P64</scope><scope>RC3</scope><scope>7X8</scope><scope>5PM</scope></search><sort><creationdate>20090522</creationdate><title>Human K-Complex Represents an Isolated Cortical Down-State</title><author>Cash, Sydney S ; Halgren, Eric ; Dehghani, Nima ; Rossetti, Andrea O ; Thesen, Thomas ; Wang, ChunMao ; Devinsky, Orrin ; Kuzniecky, Ruben ; Doyle, Werner ; Madsen, Joseph R ; Bromfield, Edward ; Erőss, Loránd ; Halász, Péter ; Karmos, George ; Csercsa, Richárd ; Wittner, Lucia ; Ulbert, István</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2009</creationdate><topic>Adolescent</topic><topic>Adult</topic><topic>Anatomy &amp; physiology</topic><topic>Biological and medical sciences</topic><topic>Brain</topic><topic>Cerebral Cortex - physiology</topic><topic>Electric current</topic><topic>Electrodes</topic><topic>Electroencephalography</topic><topic>Electrophysiological Phenomena</topic><topic>Epilepsy</topic><topic>Epilepsy - physiopathology</topic><topic>Female</topic><topic>Fundamental and applied biological sciences. Psychology</topic><topic>Humans</topic><topic>Medical imaging</topic><topic>Memory</topic><topic>Middle Aged</topic><topic>Neurology</topic><topic>Neuroscience</topic><topic>Scalp</topic><topic>Sleep</topic><topic>Sleep Stages - physiology</topic><topic>Sleep. Vigilance</topic><topic>Vertebrates: nervous system and sense organs</topic><topic>Waveforms</topic><topic>Young Adult</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Cash, Sydney S</creatorcontrib><creatorcontrib>Halgren, Eric</creatorcontrib><creatorcontrib>Dehghani, Nima</creatorcontrib><creatorcontrib>Rossetti, Andrea O</creatorcontrib><creatorcontrib>Thesen, Thomas</creatorcontrib><creatorcontrib>Wang, ChunMao</creatorcontrib><creatorcontrib>Devinsky, Orrin</creatorcontrib><creatorcontrib>Kuzniecky, Ruben</creatorcontrib><creatorcontrib>Doyle, Werner</creatorcontrib><creatorcontrib>Madsen, Joseph R</creatorcontrib><creatorcontrib>Bromfield, Edward</creatorcontrib><creatorcontrib>Erőss, Loránd</creatorcontrib><creatorcontrib>Halász, Péter</creatorcontrib><creatorcontrib>Karmos, George</creatorcontrib><creatorcontrib>Csercsa, Richárd</creatorcontrib><creatorcontrib>Wittner, Lucia</creatorcontrib><creatorcontrib>Ulbert, István</creatorcontrib><collection>AGRIS</collection><collection>Pascal-Francis</collection><collection>Medline</collection><collection>MEDLINE</collection><collection>MEDLINE (Ovid)</collection><collection>MEDLINE</collection><collection>MEDLINE</collection><collection>PubMed</collection><collection>CrossRef</collection><collection>Aluminium Industry Abstracts</collection><collection>Animal Behavior Abstracts</collection><collection>Bacteriology Abstracts (Microbiology B)</collection><collection>Calcium &amp; Calcified Tissue Abstracts</collection><collection>Ceramic Abstracts</collection><collection>Chemoreception Abstracts</collection><collection>Computer and Information Systems Abstracts</collection><collection>Corrosion Abstracts</collection><collection>Ecology Abstracts</collection><collection>Electronics &amp; Communications Abstracts</collection><collection>Engineered Materials Abstracts</collection><collection>Entomology Abstracts (Full archive)</collection><collection>Industrial and Applied Microbiology Abstracts (Microbiology A)</collection><collection>Materials Business File</collection><collection>Mechanical &amp; Transportation Engineering Abstracts</collection><collection>Neurosciences Abstracts</collection><collection>Nucleic Acids Abstracts</collection><collection>Solid State and Superconductivity Abstracts</collection><collection>Virology and AIDS Abstracts</collection><collection>METADEX</collection><collection>Technology Research Database</collection><collection>Environmental Sciences and Pollution Management</collection><collection>ANTE: Abstracts in New Technology &amp; Engineering</collection><collection>Engineering Research Database</collection><collection>Aerospace Database</collection><collection>Copper Technical Reference Library</collection><collection>AIDS and Cancer Research Abstracts</collection><collection>Materials Research Database</collection><collection>ProQuest Computer Science Collection</collection><collection>ProQuest Health &amp; Medical Complete (Alumni)</collection><collection>Civil Engineering Abstracts</collection><collection>Advanced Technologies Database with Aerospace</collection><collection>Computer and Information Systems Abstracts – Academic</collection><collection>Computer and Information Systems Abstracts Professional</collection><collection>Algology Mycology and Protozoology Abstracts (Microbiology C)</collection><collection>Biotechnology and BioEngineering Abstracts</collection><collection>Genetics Abstracts</collection><collection>MEDLINE - Academic</collection><collection>PubMed Central (Full Participant titles)</collection><jtitle>Science (American Association for the Advancement of Science)</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Cash, Sydney S</au><au>Halgren, Eric</au><au>Dehghani, Nima</au><au>Rossetti, Andrea O</au><au>Thesen, Thomas</au><au>Wang, ChunMao</au><au>Devinsky, Orrin</au><au>Kuzniecky, Ruben</au><au>Doyle, Werner</au><au>Madsen, Joseph R</au><au>Bromfield, Edward</au><au>Erőss, Loránd</au><au>Halász, Péter</au><au>Karmos, George</au><au>Csercsa, Richárd</au><au>Wittner, Lucia</au><au>Ulbert, István</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Human K-Complex Represents an Isolated Cortical Down-State</atitle><jtitle>Science (American Association for the Advancement of Science)</jtitle><addtitle>Science</addtitle><date>2009-05-22</date><risdate>2009</risdate><volume>324</volume><issue>5930</issue><spage>1084</spage><epage>1087</epage><pages>1084-1087</pages><issn>0036-8075</issn><eissn>1095-9203</eissn><coden>SCIEAS</coden><abstract>The electroencephalogram (EEG) is a mainstay of clinical neurology and is tightly correlated with brain function, but the specific currents generating human EEG elements remain poorly specified because of a lack of microphysiological recordings. The largest event in healthy human EEGs is the K-complex (KC), which occurs in slow-wave sleep. Here, we show that KCs are generated in widespread cortical areas by outward dendritic currents in the middle and upper cortical layers, accompanied by decreased broadband EEG power and decreased neuronal firing, which demonstrate a steep decline in network activity. Thus, KCs are isolated "down-states," a fundamental cortico-thalamic processing mode already characterized in animals. This correspondence is compatible with proposed contributions of the KC to sleep preservation and memory consolidation.</abstract><cop>Washington, DC</cop><pub>American Association for the Advancement of Science</pub><pmid>19461004</pmid><doi>10.1126/science.1169626</doi><tpages>4</tpages><oa>free_for_read</oa></addata></record>
fulltext fulltext
identifier ISSN: 0036-8075
ispartof Science (American Association for the Advancement of Science), 2009-05, Vol.324 (5930), p.1084-1087
issn 0036-8075
1095-9203
language eng
recordid cdi_pubmedcentral_primary_oai_pubmedcentral_nih_gov_3715654
source American Association for the Advancement of Science; Alma/SFX Local Collection
subjects Adolescent
Adult
Anatomy & physiology
Biological and medical sciences
Brain
Cerebral Cortex - physiology
Electric current
Electrodes
Electroencephalography
Electrophysiological Phenomena
Epilepsy
Epilepsy - physiopathology
Female
Fundamental and applied biological sciences. Psychology
Humans
Medical imaging
Memory
Middle Aged
Neurology
Neuroscience
Scalp
Sleep
Sleep Stages - physiology
Sleep. Vigilance
Vertebrates: nervous system and sense organs
Waveforms
Young Adult
title Human K-Complex Represents an Isolated Cortical Down-State
url http://sfxeu10.hosted.exlibrisgroup.com/loughborough?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-01T10%3A13%3A17IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-jstor_pubme&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Human%20K-Complex%20Represents%20an%20Isolated%20Cortical%20Down-State&rft.jtitle=Science%20(American%20Association%20for%20the%20Advancement%20of%20Science)&rft.au=Cash,%20Sydney%20S&rft.date=2009-05-22&rft.volume=324&rft.issue=5930&rft.spage=1084&rft.epage=1087&rft.pages=1084-1087&rft.issn=0036-8075&rft.eissn=1095-9203&rft.coden=SCIEAS&rft_id=info:doi/10.1126/science.1169626&rft_dat=%3Cjstor_pubme%3E20494002%3C/jstor_pubme%3E%3Cgrp_id%3Ecdi_FETCH-LOGICAL-c622t-e3d8af11d6c78d9a8d10987c57e6166a97ea97bafd4c85da9f771b77af11ee573%3C/grp_id%3E%3Coa%3E%3C/oa%3E%3Curl%3E%3C/url%3E&rft_id=info:oai/&rft_pqid=213616289&rft_id=info:pmid/19461004&rft_jstor_id=20494002&rfr_iscdi=true