comments: Nazarin ya bayyana yadda yawan kwayar dopamine ba zai iya karfafa kawai da'irorin "tafi da shi" a cikin buri ba, amma kuma ya raunana masu adawa da "dakatar da da'irorin."
Buɗe asirin dalilin da yasa kwayar cutar ta daskarar da marasa lafiyar Parkinson
CHICAGO - cututtukan Parkinson da jarabar shan kwayoyi cuta ce ta daban, amma duka sun dogara da kwayar dopamine a cikin kwakwalwa. Marasa lafiyar Parkinson ba su da isasshen sa; masu shan ƙwaya suna shanta da yawa. Kodayake sanannen dopamine a cikin waɗannan rikice-rikicen sananne ne, yadda yake aiki ya kasance asiri.
Sabon bincike daga Makarantar Koyon Magunguna ta Jami'ar Arewa maso Yammacin Feinberg ya bayyana cewa kwayar dopamine na karfafawa da kuma raunana da'irori biyu na farko a cikin kwakwalwa da ke kula da halayyar mu. Wannan yana ba da sabon haske game da dalilin da yasa ambaliyar dopamine na iya haifar da tilas, halayyar jaraba kuma ƙaramin maganin dopamaine na iya barin marasa lafiyar Parkinson daskarewa kuma ba sa iya motsawa.
"Binciken ya nuna yadda kwayar dopamine ke tsara manyan kekuna biyu na kwakwalwa wadanda ke kula da yadda muka zabi yin aiki da abin da ke faruwa a wadannan jihohin," in ji D. James Surmeier, marubucin marubuci da kuma farfesa Nathan Smith Davis kuma shugaban ilimin kimiyyar lissafi a Makarantar Feinberg. An buga takarda a cikin fitowar 8 ga watan Agusta na mujallar Kimiyya.
Wadannan nau'o'i biyu na kwakwalwa suna taimaka mana mu yanke shawarar ko za mu yi sha'awar ko a'a. Alal misali, kina sauka daga babban kwanciya kuma kullun zuwa kantin sayar da kayan ajiya na giya shida a rana mai zafi, ko kawai a kwanta a kan gado?
Circuitaya daga cikin da'irar shine "dakatar" wanda ke hana ku aiwatar da sha'awa; ɗayan kuma zagaye ne na "tafi" wanda ke tsokane ku ga aikatawa. Waɗannan da'irorin suna a cikin yanki, yankin ƙwaƙwalwa wanda ke fassara tunani cikin ayyuka.
A cikin binciken, masu bincike sun gwada ƙarfin maganin synapses da ke haɗuwa da gurguntaccen kwakwalwa, ɓangaren kwakwalwa yana cikin hasashe, ji da tunani, zuwa ga striatum, gidan dakatar da tafi hanyoyin da za su zabi ko hana aiki.
Masana kimiyya sun kunna zaruruwa masu amfani da wutar lantarki don yin kwatankwacin umarnin motsi da haɓaka yanayin kwayar halitta ta dopamine. Abin da ya faru a gaba ya ba su mamaki. Hanyoyin synapses masu haɗuwa da da'irar "tafi" sun zama sun fi ƙarfi da ƙarfi. A lokaci guda, dopamine ya raunana haɗin keɓaɓɓu a cikin da'irar "dakatar".
"Wannan na iya zama abin da ke haifar da jaraba," in ji Surmeier. “Dopamine da aka fitar ta hanyar magunguna tana haifar da rashin ƙarfi na synapses masu motsa jiki da ke haifar da da'irorin 'tafi', yayin da raunana synapses a adawa da 'dakatar' da'irorin. A sakamakon haka, lokacin da al'amuran da ke tattare da shan kwayoyi - inda kuka sha kwayar, abin da kuka ji - suka faru, akwai hanyar da ba za a iya shawo kanta ba don zuwa neman kwayoyi. ”
"Duk ayyukanmu a cikin ƙoshin lafiyayyiyar kwakwalwa an daidaita su da buƙatar yin wani abu da kuma buƙatar tsayawa," in ji Surmeier. “Aikinmu ya nuna cewa ba wai kawai karfafar da’irar kwakwalwa ke taimakawa wajen zabar ayyuka ba ne ke da matukar muhimmanci ga tasirin kwayar cutar ta dopamine, rashin karfin hanyoyin ne ke taimaka mana mu ma mu tsaya. ”
A kashi na biyu na gwajin, masana kimiyya sun kirkiro samfurin dabba na cutar Parkinson ta hanyar kashe kwayoyin halittar dopamine. Sannan sun kalli abin da ya faru lokacin da suka kwaikwayi dokokin kwatankwacin motsawa. Sakamakon: haɗin haɗin da ke cikin "dakatar" ya ƙarfafa, kuma haɗin haɗin a cikin "tafi" kewaye ya yi rauni.
Surmeier ya ce "Binciken ya haska dalilin da ya sa marasa lafiyar na Parkinson ke da matsala wajen gudanar da ayyukan yau da kullun kamar kaiwa tebur sama don daukar gilashin ruwa yayin da suke kishin ruwa."
Surmeier ya bayyana abin da ya faru ta amfani da kwatancen mota. "Nazarinmu ya nuna cewa rashin iya motsawa cikin cutar ta Parkinson ba abu ne mai wuce gona da iri kamar motar da ke cikin gas ba," in ji shi. “Maimakon haka, motar ba 'motsawa saboda ƙafarku ta matse a birki. Dopamine koyaushe yana taimaka maka daidaita matsin lamba a kan birki da gas. Yana taimaka muku koya cewa lokacin da kuka ga jan wuta a wani mararraba, kuna birki kuma idan koren hasken ya haskaka, sai ku cire ƙafarku daga birkin kuma ku ɓata fatar gas don tafiya. Marasa lafiyar Parkinson, waɗanda suka rasa jijiyoyin da ke sakin dopamine, suna da ƙafarsu har abada a kan birki. ”
Fahimtar tushen waɗannan canje-canje a cikin kewayen kwakwalwa yana motsa masana kimiyya kusa da sabbin dabarun magani don sarrafa waɗannan cututtukan ƙwaƙwalwar da sauran abubuwan da ke tattare da dopamine kamar schizophrenia, Ciwon Tourette da dystonia.
TASKIYA: Gwajin Kwayoyin Gudanar da Harkokin Kasuwanci na Synaptic
Abstract
A synapses tsakanin ƙwayoyin cuta na pyramidal da ƙananan ƙananan ƙananan ƙwayoyin cuta (MSNs), masu karɓa na postynaptic D1 da D2 dopamine (DA) an sanya su don zama wajibi don ƙaddamar da ƙarfin aiki na dogon lokaci da baƙin ciki, bi da bi-nau'i-nau'i na filastik da ake tsammani don haifar da tarayya koyo. Saboda waɗannan masu karɓar an ƙayyade su zuwa yawan mutanen MSN guda biyu, wannan wakilin yana buƙatar cewa filastik ɗin synaptic ba shi da ma'ana a cikin kowane nau'in kwayar halitta. Amfani da sassan kwakwalwa daga DA mai karɓar ɓerayen ƙwayoyin cuta, muna nuna cewa wannan ba haka bane. Maimakon haka, DA tana taka rawa a cikin waɗannan nau'ikan nau'ikan MSN guda biyu don tabbatar da cewa filastik ɗin synaptik yana da fa'ida da Hebbian. A cikin sifofin cutar ta Parkinson, wannan tsarin an watsar da shi daga daidaituwa, wanda ke haifar da canje-canje mara izini a cikin filastik wanda zai iya haifar da cututtukan hanyoyin sadarwa da alamomi.
- PMID 18687967
- PMCID: PMC2833421
- DOI: 10.1126 / kimiyya.1160575
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