Ni bantu ki aba 'superagers' kandi ni iki twakwigira ku bwonko bwabo?

"Igice cy'ubwonko bwe cyibutsa (hippocampus) cyari cyiza cyane" ni ko Dr Tamar Gefen yibuka.

Uyu muganga w'inzobere mu mikorere y'ubwonko yatangajwe n'imiterere idasanzwe yari muri icyo gice cy'ubwonko bw'uwo mugore yavugaga.

Ati: "Imyakura (neurons) ye yari imeze neza cyane. Ndibuka nibaza ukuntu byari ibidasanzwe uburyo iki gice cy'ubwonko bwe cyashoboraga kubika ibintu byinshi cyane."

Dr Tamar Gefen, umushakashatsi muri gahunda yiswe 'SuperAging Programme' yo muri Northwestern University y'i Illinois muri Amerika, yariho asobanura uyu muntu yize ubwonko bwe mu gihe cy'ubuzima bwe, agakomeza na nyuma y'urupfu rwe.

Uwo mugore yari mu bantu bita aba 'superagers', aba bagira ubwonko budasanzwe butuma no ku myaka y'ubusaza buba bukora neza kurusha ubwa bamwe mu bo baruta cyane.

Nubwo umugore yakoragaho ubushakashatsi yarokotse Holocaust, uyu mushakashatsi ntiyibagiwe uburyo yari umuntu wishimye, udaheranwa, kandi usetsa.

Dr Tamar ati: "Hashize imyaka irenga 10, ariko ndacyamutekereza igihe cyose".

Ibi ni ibyo Dr Tamar yabwiye Martin Wilson wanditse What We Can Learn From SuperAgers, inyandiko yatangajwe muri Northwestern Magazine.

Buriya bushakashatsi bumaze imyaka 25, bivuze ko ababukora n'ababukorerwaho bagize igihe kinini cyo kumenyana, nk'uko ibyabaye kuri Dr Tamar bibigaragaza, ubucuti bafitanye n'abatanze ubwonko bwabo ngo bukorweho ubushakashatsi burakomeye.

Ubwonko bwa mbere

Ijambo "SuperAging" ryahimbiwe ku kigo cy'ubushakashatsi cya Northwestern Alzheimer's Disease Research Center.

Mu kumenya inkomoko ya porogaramu yabo ya SuperAging tugomba gusubira inyuma mu myaka ya 1990, ubwo ikintu cy'uruhurirane cyabayeho.

Abanditse inyandiko yitwa the first 25 years of the Northwestern University SuperAging Program bagira bati: "Twakiriye post mortem (ikizami cyakorewe umurambo) yakorewe ubwonko bw'umugore w'imyaka 81.

Uwo yari umuntu wakozweho mu bundi bushakashatsi kandi utarigeze "agaragaza ikimenyetso cy'ikibazo ku mikorere y'ubwonko".

Ndetse mu kizamini cyo kwibuka yatsinze ku manota "yo hejuru" y'imyaka ye anganya n'abo mu kigero cy'imyaka 50.

Ikintu cyatunguye abashakashatsi ni uko mu bwonko bwe basanzemo 'neurofibrillary tangle' imwe gusa, mu gace k'ubwonko ka 'entorhinal cortex', agace k'amahuriro y'utunyangingo tundi dufasha kwibuka.

'Neurofibrillary tangles' ni ukwikusanya kwa 'tau protein' - y'ingenzi cyane mu mikorere y'ubwonko - iba ifatanye n'imyakura. Gukwirakwira mu bwonko kwa ziriya 'tangles' guhuzwa no kugenda bunanirwa/busaza.

Abashakashatsi bavuga ko kubona 'tangle' imwe gusa mu bwonko bw'uwo mugore byari "imbonekarimwe ku myaka ye, yewe no ku bantu bakiri bato bizwi ko nta kibazo kindi bafite ku bwonko" ntibikunze kubaho.

Mu kiganiro cya BBC cya Health Check, Dr Sandra Weintraub, umwe mu bari bayoboye buriya bushakashatsi akaba n'umwalimu muri Northwestern University yibukije intangiriro z'iriya porogaramu.

Ati: "Umu-superager wacu wa mbere yari afite 'tangle' imwe, twaribajije tuti 'oh mana! Tuvumbuye ibanga ryo guhorana ubwonko butyaye: kudakora 'tangles',".

Ariko yongeraho ati: "Umu-superager wa kabiri yari afite 'tangles' nyinshi zingana n'izaboneka nko ku muntu wishwe n'indwara ya Alzheimer."

Aba-superagers ni bantu ki?

Abahanga muri siyanse bo muri 'SuperAging Program' babasobanura nk'abantu bafite imyaka 80 kuzamura babasha kubona amanota angana n'ay'abantu barusha imyaka 30 cyangwa 20 mu bizamini byo gufata mu mutwe no kwibuka ibintu n'amagambo.

Bakoresha ikizwi nka 'Rey Auditory Verbal learning Test', iki gikoreshwa n'abavura indwara z'ubwonko mu gupima kwibuka, n'ibindi. Hamwe n'ibindi bikoreshwa mu gupima ubushobozi bw'ubwonko.

Rero mu gushyira umuntu muri kiriya kiciro cy'aba 'superager', abahanga bashyiraho amanota yo hejuru rwose - icyo ni ukugira ubwonko bwibuka nk'ubw'umuntu urusha imyaka 30.

Ibyavuyemo byari bitangaje.

"Ni igitangaza kugira umuntu uri mu myaka 90 ushobora kwibuka amakuru angana atyo, ayo abantu bamwe bari mu myaka za 50 cyangwa 60 bagorwa no kwibuka" ni ko Molly A Mather, umwalimu wa Psychiatry and Behavioral Sciences muri Northwestern University yabwiye BBC Mundo.

Ubwonko bwabo butaniye he n'ubusanzwe?

Aba 'Superagers' batuma dukemanga ingingo isanzweho yo gutakara k'ubushobozi bw'ubwonko uko umuntu agenda akura.

Abashakashatsi babashije kubona imiterere y'uduce tw'ubwonko twitwa 'phenotype' aba 'superagers' bihariye ugereranyije n'abandi b'ikigero cyabo.

Urugero, baba bafite "cortical volumes" itangukanye n'iy'abantu barusha imyaka hagati ya 20 na 30.

"Cortical volume" ni umubare w'imikaya iba muri ka gace ka 'cerebral cortex', agace k'ubwonko k'ingenzi cyane mu gutekereza no kwibuka.

Nka kimwe mu byo gakora, uduce twinshi tugize aka gace turahura tugafasha kwibuka cyangwa gutunganya ururimi ugiye kuvuga.

Ikindi abashakashatsi bavumbuye ni uko aba 'superagers' ubwonko bwabo bufite imyakura myinshi ya 'Von Economo neurons' barusha cyane abo banganya imyaka ndetse n'abo baruta cyane ubukuru.

Ubu bwoko bw'imyakura bufatwa nk'ubugira uruhare runini mu buryo umuntu abana n'abandi ndetse no kugira imico runakana itandukanye.

Mather arasobanura ati: "Icyo ntekereza ko kigaragara cyane ku ba 'superagers' ni uko benshi muri bo bari mu myaka za 80 na 90, rimwe na rimwe no hejuru ya 100, kandi bakagira za 'tangles' nkeya cyane ugereranyije n'iziba zitezwe".

Abahanga kugeza ubu ntibazi impamvu ndetse bibaza ikintu cyaba kibuza izo 'tangles' kwirema kimwe no ku bandi bantu.

Naho ku ba 'superagers' bafite 'tangles', uburyo babasha kugira ubwonko butyaye bwibuka neza biracyari inshoberabahanga.

Imibereho itandukanye

Ralph Rehbock, wavutse mu 1934, ni umwe mu bakorerabushake bakozweho ubushakashatsi.

"Ntewe ishema cyane no kuba umu 'SuperAger'," ni ko avuga mu mashusho yakozwe na Northwestern University.

Kuva iriya porogaramu yatangira, aba 'superagers' 290 bayigiyemo kandi ubwonko 77 bwakozweho ibizami bya 'autopsie' kugira ngo bagerageze kumenya impamvu budasaza nk'ubw'abandi.

Ubu, hari 133 barimo gukorwaho ubushakashatsi.

Mu nyandiko yabo, abashakashatsi bavuga ko aba bantu usanga barabayeho ubuzima butandukanye.

Bati: "Bamwe mu ba 'superagers' basa n'abakurikije inama zose zitangwa ku kugira ubuzima bwiza. Abandi bo ntibariye neza, baryohewe n'itabi n'inzoga, nta myitozo ngororamubiri, barwaye umujagararo (stress) mu buzima, ndetse ntibaryamaga neza".

Aba bahanga bavuga ko mu by'ukuri nta kintu gifatika gisobanura impamvu umuntu yisanga muri iki gice cy'aba 'superagers', kandi ko bari "kure cyane" yo kumenya impamvu yabyo.

Dr Tamar Gefen ariko aburira abantu ko kurya neza, kuruhuka bihagije, kwirinda inzoga n'itabi n'ibindi byangiza ubuzima nubwo bitatuma umuntu aba umu-'superager' "ariko tuzi ko iyo myifatire myiza nanone igabanya ibyago byo kwangirika k'ubwonko uko ugenda usaza. Rero ubutumwa bwacu ni ukugabanya ibyo byago uko ushoboye kose."