Inkqubo yoMvuzo yexesha elide yeBrain ixhomekeke kwiDopamine
Agasti 5, 2013
UBrett Smith we-redOrbit.com-Indalo yakho ekwi-Intanethi
Ukusuka ekuqhubeni kwilizwe lonke ukuya ekuphumeleleni ekholejini, iinjongo zexesha elide zihlala zinzima ukuhlala ugxile xa umvuzo wangoko ungekho emehlweni.
Iqela labaphandi abavela kwiYunivesithi yaseWashington e-Seattle kunye ne-MIT isanda kufumanisa iinkcukacha ezintsha malunga nendlela ingqondo ekwazi ngayo ukuhlala igxininisekile de kube ezi njongo zexesha elide zifezekiswe, ngokutsho kwengxelo kwiphephancwadi leNdalo.
Uphando lweqela elidibeneyo lwakha kwizifundo zangaphambili ezinxibelelanisa i-neurotransmitter dopamine kwinkqubo yomvuzo wengqondo. Ngelixa uninzi lwezifundo zangaphambili zibandakanya ukujonga i-dopamine malunga nomvuzo okhawulezileyo, isifundo esitsha safumanisa amanqanaba okwandayo e-dopamine njengoko iimpuku zaselabhoratri zisondela kumvuzo olindelekileyo emva kokulibaziseka kokwaneliseka.
Ukulinganisa amanqanaba e-dopamine ebuchotsheni beempuku, iqela lisebenzise inkqubo eyaphuhliswa sisazinzulu sokuziphatha se-UW uPaul Phillips ebizwa ngokuba yi-fast-scan cyclic voltammetry (FSCV) ebandakanya ii-electrode ezincinci, ezifakelweyo eziqhubeka zirekhoda ugxininiso lwe-dopamine ngokujonga umsayino wayo we-electrochemical.
"Silungelelanise indlela ye-FSCV ukuze sikwazi ukulinganisa i-dopamine kwiindawo ezine ezahlukeneyo engqondweni ngaxeshanye, njengoko izilwanyana zihamba ngokukhululekileyo kwi-maze," watsho umbhali-mbhali uMark Howe, ngoku i-neurobiologist yasemva kobugqirha kwiYunivesithi yaseNorthwestern. "Iprobe nganye ilinganisa ukuxinana kwe-dopamine ephuma kwi-extracellular dopamine ngaphakathi komthamo omncinci wezicubu zobuchopho, kwaye mhlawumbi ibonisa umsebenzi wamawaka ee-nerve terminals."
Izazinzulu ziqale ngokuqeqesha iimpuku ukuze zifumane indlela yazo kwimaze zikhangela umvuzo. Ngexesha lempuku nganye ibaleka kwi-maze, ithowuni yayiza kuvakala ukuyiyalela ukuba ijike ekunene okanye ekhohlo ekudibaneni kweendlela ifuna umvuzo wobisi lwetshokholethi.
Iqela lophando lathi lilindele ukubona i-pulses ye-dopamine ikhutshwa yingqondo yeempuku ngamaxesha athile ngexesha lovavanyo. Nangona kunjalo, bafumanise ukuba amanqanaba e-neurotransmitter enyuka ngokuthe chu kulo lonke ulingo-afikelela kwinqanaba eliphezulu njengoko i-rodent isondela kumvuzo wayo. Ngelixa ukuziphatha kweempuku ngexesha lolingo ngalunye bekwahluka, amanqanaba abo e-dopamine enyuka ngokuthembekileyo ngaphandle kwesantya sokubaleka okanye ukubakho komvuzo.
"Endaweni yoko, umqondiso we-dopamine ubonakala ubonisa ukuba kude kangakanani impuku kwiinjongo zayo," watsho uAnn Graybiel, oqhuba ilabhoratri yophando lwengqondo eMIT. "Okukhona isondela, kokukhona umqondiso uqina."
Iqela likwafumanise ukuba ubukhulu bomqondiso we-dopamine bunxulunyaniswa nobungakanani bomvuzo olindelekileyo. Xa iimpuku zibekwe kwimeko yokulindela ukuhanjiswa okukhulu kobisi lwetshokholethi, amanqanaba azo e-dopamine anyuka ngokukhawuleza ukuya kwincopho ephezulu.
Abaphandi baye balutshintsha olu lingelo ngokwandisa le maze ukuba ibe yimo entsonkothileyo eyenza ukuba iimpuku zibaleke ngakumbi zaza zatshintshana ukuze zifikelele ibhaso. Ngexesha lovavanyo olude, umqondiso we-dopamine unyuke kancinci kancinci, kodwa ekugqibeleni wafikelela kwinqanaba elifanayo nele-maze yangaphambili.
“Kuba ngathi isilwanyana silungisa ulindelo lwaso, sisazi ukuba kuseza kufuneka sihambe ngakumbi,” utshilo uGraybiel.
Uye wacebisa ukuba amaphononongo exesha elizayo kufuneka ajonge kwesi siganeko sifanayo ebantwini.
“Ndingothuka ukuba into efanayo ibingenzeki ezingqondweni zethu,” utshilo uGraybiel.
Uphando lutyhila indlela ingqondo egcina ngayo amehlo emvuzweni
Mon, 08/05/2013 - 10:15am
McGovern Institute for Brain Research
"Ngaba sisekhona?"
Njengoko nabani na okhe wahamba nabantwana abancinane esazi, ukugcina ingqalelo kusukelo olukude kunokuba lucelomngeni. Uphononongo olutsha oluvela kwiMassachusetts Institute of Technology (MIT) lucebisa ukuba ingqondo iwufezekisa njani lo msebenzi, kwaye ibonisa ukuba i-neurotransmitter dopamine inokubonisa ixabiso lemivuzo yexesha elide. Iziphumo zinokucacisa ukuba kutheni abaguli abanesifo sikaParkinson-apho ukubonakaliswa kwe-dopamine kungasebenzi kakuhle-kaninzi banobunzima bokugcina inkuthazo yokugqiba imisebenzi.
Umsebenzi uchazwe kwiNdalo.
Izifundo zangaphambili zidibanise i-dopamine nemivuzo, kwaye zibonise ukuba i-dopamine neurons ibonisa ugqabhuko olufutshane lomsebenzi xa izilwanyana zifumana umvuzo ongalindelekanga. Ezi zibonakaliso ze-dopamine kukholelwa ukuba zibalulekile ekufundiseni ukomeleza, inkqubo apho isilwanyana sifunda ukwenza izenzo ezikhokelela emvuzweni.
Ukuthatha umbono omde
Kwizifundo ezininzi, loo mvuzo unikezelwe kwimizuzwana embalwa. Kubomi benene, nangona kunjalo, ulwaneliseko alusoloko lukhawuleza: Izilwanyana kufuneka zisoloko zihamba zikhangela ukutya, kwaye kufuneka zigcine inkuthazo yenjongo ekude ngelixa zikwasabela kwiingcebiso ezikhawulezayo. Kunjalo ke nakubantu: Umqhubi kuhambo olude lwendlela umele ahlale enikel’ ingqalelo ekufikeleleni kwindawo yokugqibela ngoxa ekwasabelana nezithuthi, emisa amashwamshwam, yaye esonwabisa abantwana kwisihlalo esingasemva.
Iqela le-MIT, elikhokelwa liZiko uNjingalwazi u-Ann Graybiel-okwangumphandi kwi-MIT's McGovern Institute for Brain Research-ligqibe ekubeni lifunde indlela i-dopamine etshintsha ngayo ngexesha lomsebenzi we-maze omalunga nomsebenzi wokulibaziseka kokwanelisa. Abaphandi baqeqeshe iimpuku ukuba zihambe kwimaze ukuze zifumane umvuzo. Ngexesha lolingo ngalunye impuku iva ithowuni eyiyalela ukuba ijike nokuba ngasekunene okanye ngasekhohlo ekudibaneni kweendlela ukufumana umvuzo wobisi itshokolethi.
Endaweni yokulinganisa nje umsebenzi we-dopamine-equlathe i-neurons, abaphandi be-MIT bafuna ukulinganisa ukuba ingakanani i-dopamine ekhutshiweyo kwi-striatum, isakhiwo sobuchopho esaziwa ngokuba sibalulekile ekomelezeni ukufunda. Badibana noPaul Phillips weUniv. waseWashington, othe waphuhlisa itekhnoloji ebizwa ngokuba yi-fast-scan cyclic voltammetry (FSCV) apho i-electrode encinci, efakwe, i-carbon-fiber fiber ivumela imilinganiselo eqhubekayo yoxinaniso lwe-dopamine olusekwe kwiminwe ye-electrochemical fingerprint.
"Silungelelanise indlela yeFSCV ukuze sikwazi ukulinganisa i-dopamine kwiindawo ezine ezahlukeneyo ebuchotsheni ngaxeshanye, njengoko izilwanyana zihamba ngokukhululekileyo kwi-maze," uyachaza umbhali wokuqala uMark Howe, owayesakuba ngumfundi ophumeleleyo noGraybiel ngoku ongumfundi we-postdoc. iSebe leNeurobiology eNorthwestern Univ. "Iprobe nganye ilinganisa ukuxinana kwe-dopamine ephuma kwi-extracellular dopamine ngaphakathi komthamo omncinci wezicubu zobuchopho, kwaye mhlawumbi ibonisa umsebenzi wamawaka ee-nerve terminals."
Ukunyuka kancinci kwi-dopamine
Ukusuka kumsebenzi wangaphambili, abaphandi bebelindele ukuba babone i-pulses ye-dopamine ekhutshwe ngamaxesha ahlukeneyo kulingo, "kodwa eneneni sifumene into eyothusa kakhulu," uGraybiel uthi: Inqanaba le-dopamine landa ngokuthe ngcembe kulo lonke ulingo, liphezulu njengoko isilwanyana safikelela usukelo lwaso—ngokungathi silindele umvuzo.
Ukuziphatha kweempuku kwahluka ukusuka ekulingweni ukuya ekulingweni-ezinye zibaleka ngokukhawuleza kunabanye, kwaye ngamanye amaxesha izilwanyana zaziyeka kancinci-kodwa isibonakaliso se-dopamine azange hluke ngesantya sokubaleka okanye ubude belingo. Kwaye kwakungaxhomekekanga kumathuba okufumana umvuzo, into eyayicetyiswe zizifundo zangaphambili.
Endaweni yoko, umqondiso we-dopamine ubonakala ubonisa ukuba kude kangakanani impuku kwiinjongo zayo, utshilo uGraybiel. "Okukhona isondela, kokukhona umqondiso uqina." Abaphandi baphinde bafumanisa ukuba ubungakanani bomqondiso wawunxulumene nobungakanani bomvuzo olindelekileyo: Xa iimpuku zaziqeqeshelwa ukuqikelela ubisi lwetshokholethi enkulu, uphawu lwe-dopamine lwenyuka ngomnqantsa ukuya kugxininiso oluphezulu lokugqibela.
Kwezinye iimvavanyo imaze emile okwe-T yandiswa yaya kwimo entsonkothileyo, ifuna ukuba izilwanyana ziqhubele phambili kwaye zenze iinguqu ezongezelelweyo phambi kokufikelela emvuzweni. Ngexesha lezi zilingo, umqondiso we-dopamine unyuke kancinci kancinci, wade wafikelela kwinqanaba elifanayo nele-maze emfutshane. UGraybiel uthi: “Kuba ngathi isilwanyana sihlengahlengisa ulindelo lwaso, sisazi ukuba kwakuseza kufuneka sihambe.
'Inkqubo yesikhokelo yangaphakathi'
"Oku kuthetha ukuba amanqanaba e-dopamine angasetyenziselwa ukunceda isilwanyana ukuba senze ukhetho kwindlela eya enjongweni kunye nokuqikelela umgama oya kwinjongo," utsho uTerrence Sejnowski weSalk Institute, isazi se-neuroscientist esiqhelene neziphumo kodwa ngubani. akazange abandakanyeke kwisifundo. "Le 'nkqubo yesikhokelo yangaphakathi' inokuba luncedo nakubantu, nabo kufuneka benze ukhetho kwindlela enokuba lusukelo olukude."
Umbuzo omnye uGraybiel anethemba lokuwuvavanya kuphando lwexesha elizayo yindlela umqondiso ovela ngayo ngaphakathi kwengqondo. Iimpuku kunye nezinye izilwanyana zenza iimephu zengqondo zendawo yazo, kunye nezinto ezibizwa ngokuba "iiseli zendawo" ezisebenzayo xa isilwanyana sikwindawo ethile. Uthi: “Njengoko iimpuku zethu ziphindaphinda le ngxaki, sikrokrela ukuba zifunda ukunxulumanisa indawo nganye kudederhu lweempuku kunye nomgama eziwufumene kwixesha elidluleyo.”
Ngokuphathelele ukubaluleka kolu phando ebantwini, uGraybiel uthi, "Ndingothuka ukuba into efanayo ibingenzeki kwiingqondo zethu." Kuyaziwa ukuba izigulana zikaParkinson, apho umqondiso we-dopamine uphazamisekile, uhlala ubonakala ngathi awunamdla, kwaye unobunzima bokugcina inkuthazo yokugqiba umsebenzi omde. "Mhlawumbi kungenxa yokuba abanako ukuvelisa olu phawu lucothayo lwe-dopamine," utshilo uGraybiel.
Umthombo: Massachusetts Institute of Technology
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