Izinzwa eziningi kakhulu Mpango Memory

Too Many Neurons Spoil the Memory

Ucwaningo olusha lembula mechanisms amaselula by ngazo inkumbulo-ngamakhodi amanethiwekhi neuronal ziyaphuma


Powered by Guardian.co.ukLesi sihloko osesikhundleni “izinzwa eziningi Too konakalisa inkumbulo” lalotshwa Mo Costandi, ngoba theguardian.com ngoLwesihlanu 12th February 2016 15.15 UTC

Ngitshele lapho ngihlale imicabango, ukhohliwe uze abize awakho? Ngitshele lapho ngihlale injabulo elidala, futhi lapho uthanda yasendulo, Futhi lapho ziyofundiswa khona ngokuziphatha, ivuselele godu, futhi ebusuku lokulibala esedlule, Ukuthi Ngingahle anqamule izikhathi futhi izikhala akude kude, futhi alethe Ukunethezeka ibe usizi samanje futhi ebusuku ubuhlungu? Kuphi Uyangaphi na, O umcabango? Ukuze lokho izwe ezicezile indiza wakho? Uma wena returnest kuze kube ngomzuzu wamanje okuhlupheka, Ngizakukubuza, wena ulethe ukunethezeka ngamaphiko akho, futhi dews noju lwezinyosi namafutha, Noma ushevu kusukela endle ugwadule, kusukela kwamehlo envier?

Enkondlweni yakhe ebonga amaqhawe, Imibono yamadodakazi Albion, William Blake nezimangaliso ngesimo inkumbulo, ikhono layo ukuthutha ngokwengqondo nathi izikhathi ezikude nezindawo, nasemizwelweni enamandla, okuhle nokubi, ukuthi izinkumbulo zethu kungaba zivuse. Inkondlo iqukethe imibuzo ezisele ofanelekayo kakhulu namuhla, ezifana kwenzekani ku izinkumbulo zethu kudala, futhi kanjani thina buyisa them?

Ngaphezu kwamakhulu amabili eminyaka kamuva, izindlela inkumbulo isitoreji kanye ukubuyisa kuyizinto okucwaningwa ngawo kakhulu wakwenza izenzakalo sciences ebuchosheni. It kunenkolelo yokuthi imemori ukubunjwa kuhilela ekuqiniseni ukuxhumana phakathi amanethiwekhi ayingcosana basakaza izinzwa isakhiwo yobuchopho okuthiwa i-hippocampus, nokuthi ukubuyisa okwalandela kuhilela ukuvuselelwa kwe-ensembles efanayo neuronal. nokho, ososayensi bezinzwa Sisehluleka ukuphendula imibuzo Blake sika nakanjani.

Manje, iqembu labacwaningi e-University of Geneva baye benza esinye kusengaphambili lebalulekile ekuvisiseni kwethu izindlela kwemizwa eziyimbangela inkumbulo kumiswa. Ukusebenzisa indlela state-of-the-art esibizwa optogenetics, babonisana kanjani ensembles neuronal ukuthi encode izinkumbulo ziyaphuma, ukuveza ukuthi ensembles equkethe izinzwa eziningi kakhulu - noma yingcosana - ona inkumbulo ukubuyisa.

optogenetics yisu enamandla kakhulu ukuthi kuhilela Wethula algal amaprotheni abizwa ngokuthi ama channelrhodopsins (ChRs) ku izinzwa. Lokhu ihumusha amangqamuzana nezinzwa ezisenza sizwele lapho ukukhanya, esingangaleso esingalotshwa amaqembu esithile kubo kungenziwa luvulwe noma ukuvala, usebenzisa pulses laser ukukhanya ikhashelwa ubuchopho nge zesivikelo sesifuba optical, on a esikaliwe of milliseconds.

Eminyakeni yakamuva, Abacwaningi baye basebenzisa optogenetics kulebula izinzwa hippocampal ukuthi babe matasa kakhulu phakathi inkumbulo kwetinhlavu ebuchosheni igundane, futhi lokuxhaphaza ensembles esinelebuli ye ngezindlela ezihlukahlukene. Ngale ndlela, bangakwazi kabusha ensembles efanayo ukuze ntombazane inkumbulo ukubuyisa; ushintshele izinkumbulo esabekayo vula noma vala; ukuguqula izinkumbulo negative ku ezitusa, kungokufanayo nangendoda; ngisho ukugxilisa izinkumbulo aluhlaza singene ubuchopho amagundane.

Ucwaningo olusha, led by Pablo Mendez futhi ngasekupheleni Dominique Muller, ngubani kabuhlungu washona engozini endiza ngo-Ephreli ngonyaka odlule, akha phezu kwaleso msebenzi ekuqaleni. They wadala amagundane izakhi ezwakalisa IziKr ezitokisini granule ngakolunye uhlangothi zobuchopho, in the isifunda dentate of hippocampus. amaseli granule yizona izinzwa isimiso kule ndawo hippocampus, okuyinto kucatshangwa esibucayi imisebenzi hippocampal ezifana inkumbulo navigation ngekwendzawo. Abeka yezilwane zingene ezinkanjini ezinkulu, ngokuvumela amanye ukuba ukuhlola indawo yabo entsha. Khonamanjalo, they optogenetically ocushiwe okungahleliwe granule amaseli ezinye amagundane, kodwa hhayi abanye.

Amangqamuzana Hippocampal granule ezwakalisa Channelrhodopsin (ngombala obomvu).
Amangqamuzana Hippocampal granule ezwakalisa Channelrhodopsin (ngombala obomvu). Image: Pablo Mendez

Uma they dissected futhi lahlola ubuchopho izilwane 45 Ngemva kwemizuzu engu-, abacwaningi bathola lwezendawo ukuhlola umsebenzi yabangela e ensembles izinzwa hippocampal, njengoba kunqunywa amazinga cFos, okuthiwa 'ngokushesha ekuqaleni' isakhi esithile sisebenza esitshalweni ngokushesha lapho izinzwa ukuqala nomlilo. Okubalulekile, amagundane bavunyelwe ukuba ukuhlola ezinkanjini zawo zazingeke izinombolo ephakeme ka cFos-ezwakalisa amaseli granule kunalabo abababusayo kwesokunxele emzini wabo ezinkanjini isikhathi ukuhlola, nalabo abamukela ukushukuma optogenetic ngesikhathi ukuhlola kwadingeka izinombolo eliphezulu kakhulu cFosizinzwa -positive kunalawo elalinge.

Lokhu kwabonisa ukuthi ukuhlola ngekwendzawo liletha umsebenzi e ensembles lamaseli dentate granule, nokuthi nemiyalezo ukuma umsebenzi lezi amanethiwekhi ne ukushukuma optogenetic kwandisa ubukhulu ensembles, noma inani lamaseli ngaphakathi kubo.

Kodwa ingabe ukuxhaphaza usayizi ensembles ibe nanoma imuphi umthelela ukuziphatha? Ukuthola, Mendez nozakwabo ibekwe amagundane ezwakalisa IziKr e hippocampi yabo kolunye yezinyoni, futhi wabanika omnene uthuthumele eziningana kagesi. Nge ukuphindaphindwa lokhu kwelashwa, amagundane ngokushesha bafunde ukwesaba yezinyoni, futhi ngokushesha kwi freezer lapho wabuya kuwo, ngisho nalapho benganikezwa uthuthumele okwengeziwe.

Ngalesi sikhathi, abacwaningi optogenetically kwavusa okungahleliwe granule amaseli ezinye amagundane, kodwa hhayi abanye, phakathi ukuqeqeshwa, ukuze andise ubukhulu Ensemble neuronal ukuthi buqonda imemori ukwesaba. Lezi amagundane embukisweni ngaphansi kwezinga-qhwa ukuziphatha lapho wabuyela yezinyoni efanayo kunabanye abathola kungekho ukushukuma. Kodwa ezishukumisayo futhi wadala yokufakelwa yokwesaba izinkumbulo, yokuthi izilwane eba yiqhwa kwezinye izimo, kakhulu.

Okusithiyayo lamaseli okungahleliwe granule aba nethonya elifanayo, esikisela ukuthi nje ukuma inani izinzwa e-Ensemble liphazamisa ikhono izilwane kokukhumbula izinkumbulo ukwesaba. Le miphumela uhambisane nalezo Ekuhloleni kwangaphambili, okuyinto wabonisa nokuthi ezivimbela noma inkanuko granule cell umsebenzi ikhono lokufunda zesimo.

Ukuze uqonde ukuthi kungani lokhu kungase kube, abacwaningi wenza esinye uchungechunge ucwaningo, usebenzisa microelectrodes ukurekhoda umsebenzi izinzwa tincetu izicubu hippocampal. Lezi ucwaningo lwabonisa ukuthi ukushukuma optogenetic ka granule amaseli ukhiqiza impendulo asiqinile interneurons engumakhelwane, akhiphela inhibitory neurotransmitter Gaba.

Ngakho, the labadubuli ka granule amaseli kuholela interneurons inhibitory, okuyinto kuyidambise eduze granule amaseli futhi zingaphinde ngokufaka Ensemble. Ngale ndlela, interneurons avele ekulinganiseni izinkumbulo osanda kusungulwa ngokulawula inombolo nokusatshalaliswa granule amaseli ehilelekile wekhodi izinkumbulo. Ukwenza noma ukuthulisa amaseli okungahleliwe granule kuyabacasula le nqubo futhi okushintsha inani granule amaseli, okungase kwenze izinkumbulo ezintsha engazinzile.

"Kulesi sifundo, thina babesebenzisa uhlobo okulula inkumbulo, inkumbulo umongo ngekwendzawo, kodwa inselele ukutadisha indlela nakho eziyinkimbinkimbi kuthiwa ngekhanda, futhi indlela ubuchopho iphatha isitoreji nakho okuningi,"Kusho Mendez. "Ukuqonda le mibuzo zingasisiza ukuba baqonde imikhawulo isitoreji umthamo ebuchosheni."

Izikhombo

Stefanelli, T., et al. (2016). Hippocampal Somatostatin Interneurons Lawula Usayizi neuronal Memory Ensembles. namangqamuzana ezinzwa, 89: 1-12. Doi: 10.1016/j.neuron.2016.01.024 [abstract]

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