Comments: Kudzidza kunotsanangura kuti kuwedzeredza dopamine hakugone chete kusimbisa "kuenda kwazviri" maseketi muropa, asi zvakare kunetesa kupikisa "kumisa maseketi."
Kuvhura chakavanzika chekuti nei dopamine ichiomesa varwere vaParkinson
CHICAGO - Chirwere chaPasinson uye kupindwa muropa nezvinodhaka ndezvepachirwere chakatarisana nepolar, asi zvese zviri zviviri zvinoenderana nedopamine muuropi. Varwere vaParkinson havana zvakakwana zvacho; vakapindwa muropa nezvinodhaka vanowana yakawandisa yacho. Kunyangwe kukosha kwedopamine mumatambudziko aya kwave kuzivikanwa, mashandiro ainoita anga asingazivikanwe.
Tsvagurudzo nyowani kubva kuNorthwestern University yeFeinberg Chikoro cheMishonga yakaratidza kuti dopamine inosimbisa uye inoderedza maseketi maviri ekutanga muuropi ayo anodzora maitiro edu. Izvi zvinopa nzwisiso nyowani yekuti nei mafashama edopamine angatungamira mukumanikidza, maitiro ekurwisa uye dopamaine shoma inogona kusiya varwere vaParkinson vaine chando uye vasingakwanise kufamba.
"Chidzidzo ichi chinoratidza mashandiro anoita dopamine matunhu makuru europi ayo anotonga maitiro atinosarudza kuita uye zvinoitika mumatunhu aya," akadaro D. James Surmeier, munyori anotungamira uye naNathan Smith Davis Muzvinafundo uye sachigaro wezve physiology ku Chikoro cheFeinberg. Iyo bepa rakaburitswa mune yaAugust 8 nyaya yemagazini Sayenzi.
Iyi idzi mbiri huru dzeuropi dzinotibatsira kusarudza kana tingaita chido kana kwete. Somuenzaniso, unoburuka pamubhedha uye unofambisa kuchitoro nokuda kwechando chinokonzerwa nematare matanhatu emusi weusiku wechando, kana kungovata pamubhedha?
Dunhu rimwe "denderedzwa" redunhu rinokutadzisa kuita pane chishuwo; imwe ndeye "enda" dunhu rinokuchidzira iwe kuita chiito. Aya macircuit ari mune iyo striatum, iyo dunhu reropi iyo inoshandura pfungwa kuita zviito.
Muchidzidzo chacho, vatsvakurudzi vakaongorora simba remashirasiki achibatanidza cerebral cortex, nzvimbo yeuropi inobatanidzwa mumafungiro, manzwiro nemafungiro, kusvika ku-striatum, pamba rekumira uye kuenda kumatunhu anosarudza kana kudzivirira chiito.
Masayendisiti emagetsi akagonesa iyo cortical fibers kutevedzera mafambiro ekufambisa uye yakawedzera iyo yakasikwa nhanho yedopamine. Zvakazoitika zvakazovashamisa. Iwo macortical synapses anobatana ne "enda" wedunhu akasimba uye akasimba. Panguva imwecheteyo, dopamine yakanetesa macortical kubatana mu "mira" dunhu.
"Izvi zvinogona kunge zviri izvo zvinokonzeresa kupindwa muropa," akadaro Surmeier. “Dopamine yakaburitswa nemishonga inotungamira mukusimbisa zvisina kujairika kweiyo cortical synapses inotyaira masekete anouraya 'go', uku ichinetesa ma synapses kumakwikwi e 'stop'. Nekuda kweizvozvo, kana zviitiko zvine chekuita nekutora zvinodhaka - kwawakatora mushonga, zvawanga uchinzwa - zvikaitika, pane kutyaira kusingadzorwi kwekuenda kunotsvaga zvinodhaka. ”
"Zvese zvatinoita muhuropi hune hutano zvakaenzana nechishuwo chekuita chimwe chinhu uye chishuwo chekumira," akadaro Surmeier. "Basa redu rinoratidza kuti hakusi kungosimbisa maseketi ehuropi achibatsira kusarudza zviito zvakakoshesa mhedzisiro yedopamine, ndiko kushomeka kwekubatana kunotigonesa kumira zvakare. ”
Muchikamu chechipiri chekuyedza, masayendisiti akagadzira mhando yemhuka yechirwere chaParkinson nekuuraya dopamine neurons. Vakabva vatarisa pane zvakaitika pavakafananidza mirairo yekortical yekufamba. Mhedzisiro yacho: kubatana mu "stop" dunhu kwakasimbiswa, uye kubatana mu "go" dunhu kwakashayiwa simba.
"Chidzidzo chinovhenekera kuti nei varwere vaParkinson vachinetseka kuita mabasa ezuva nezuva sekusvikira patafura kunotora girazi remvura kana vaine nyota," akadaro Surmeier.
Surmeier akatsanangura chiitiko ichi achishandisa fananidzo yemotokari. "Chidzidzo chedu chinoratidza kuti kusakwanisa kufamba muchirwere chaParkinson hakusi kungoita semota irikupera gasi," akadaro. “Asi, mota 'haifambe nekuti tsoka yako yakatsika pabhureki. Dopamine inowanzo kubatsira iwe kugadzirisa kumanikidza pamabhureki uye gasi pedals. Zvinokubatsira iwe kudzidza kuti kana iwe ukaona mwenje mutsvuku pamharadzano, unotyoka uye kana mwenje wegirini wasvika, unobvisa rutsoka rwako pabhureki uye unodzvinyirira peturu kuti uende. Varwere vechirwere chePasinson, avo vakarasikirwa nemitsipa inoburitsa dopamine, tsoka dzavo dzinoramba dzakanamatira paakavhuna. ”
Kunzwisisa hwaro hweiyi shanduko muhuropi wedunhu kunofambisa masayendisiti padhuze nemaitiro matsva ekurapa ekudzora kusagadzikana kwehuropi uye zvimwe zvinosanganisira dopamine senge schizophrenia, Tourette's syndrome uye dystonia.
DZOKUDZIDZA: Dophotomous Dopaminergic Kudzora kweStriatal Synaptic Plasticity
ngovepo
Panopindirana pakati pekortical pyramidal neurons uye chikuru chinouraya svikiro spiny neurons (MSNs), postynaptic D1 uye D2 dopamine (DA) zvinogamuchirwa zvinotumirwa kuve zvakakosha pakuiswa kweyakareba-nguva kugona uye kushushikana, zvichiteerana-mafomu epurasitiki anofungidzirwa kuti asimbise kushamwaridzana. kudzidza. Nekuti izvi zvinogamuchirwa zvinorambidzwa kune maviri akasarudzika eMMSN vanhu, izvi zvinoratidzira zvinoda kuti synaptic plasticity ive unidirectional mune yega sero mhando. Tichishandisa zvidimbu zvehuropi kubva kuDA receptor transgenic mbeva, tinoratidza kuti izvi handizvo. Asi, DA inotamba zvinowirirana mumhando mbiri idzi dzeMSN kuona kuti synaptic plasticity iri bidirectional uye Hebbian. Mune mhando dzechirwere chaPasinson, ino sisitimu inokandwa kunze kwekuyerwa, zvichitungamira kune unidirectional shanduko mupurasitiki inogona kukonzeresa hutachiona hwehutachiona nezviratidzo.
- PMID 18687967
- PMCID: PMC2833421
- DOI: 10.1126 / science.1160575
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