Sivame ukuzwa inkulumo ethi "ukuhlala phansi" esimeni esingesihle, kukhulunywa ngayo njengembangela yempilo ebuthaka noma ukuqala kokugula. Kepha kungani impilo yokuhlala phansi iyingozi kangaka eqinisweni? Muva nje ngithole i-athikili ebingichaza kakhulu.
Kuyaziwa ukuthi ukuvivinya umzimba kungathonya ngokwakhayo isimo sobuchopho, kukhuthaze ukwakheka kwamaseli amasha futhi kubangele ezinye izinguquko. Kuvele ucwaningo olusha olukhombisa ukuthi ukunganyakazi nakho kungadala ushintsho ebuchosheni ngokukhubaza ama-neuron athile. Futhi lokhu akuthinti kuphela ubuchopho, kodwa futhi nenhliziyo.
Imininingwane enjalo itholwe ngesikhathi kwenziwa ucwaningo olwenziwe kumagundane, kepha, ngokusho kososayensi, kungenzeka ukuthi ibalulekile kubantu. Lokhu okutholakele kungasiza ekuchazeni, ngokwengxenye, ukuthi kungani izindlela zokuphila zokuhlala zingezinhle kangako emizimbeni yethu.
Uma unentshisekelo emininingwaneni yocwaningo, uzobathola ngezansi, kepha ukuze ungakhathali ngemininingwane, ngizokutshela ngomongo wayo.
Imiphumela yalolu cwaningo, eshicilelwe kwi-The Journal of Comparative Neurology, ikhombisa ukuthi ukungasebenzi komzimba kukhubaza ama-neurons kwesinye sezifunda zobuchopho. Lesi sigaba sibhekele uhlelo lwezinzwa oluzwelayo, okuthi, phakathi kwezinye izinto, lilawule umfutho wegazi ngokuguqula izinga lokuncipha kwemithambo yegazi. Eqenjini lamagundane okuhlolwa, ancishwa amandla okuhamba ngenkuthalo amasonto ambalwa, inani elikhulu lamagatsha amasha lavela kuma-neurons ale ngxenye yobuchopho. Ngenxa yalokhu, ama-neuron ayakwazi ukucasula kakhulu uhlelo lwezinzwa oluzwelayo, aphazamise ibhalansi emsebenzini wawo futhi ngaleyo ndlela abangele ukwanda kwengcindezi yegazi futhi abambe iqhaza ekuthuthukiseni izifo zenhliziyo.
Vele, amagundane akubona abantu, futhi lesi isifundo esincane, sesikhashana. Kepha esinye isiphetho sicacile: impilo yokuhlala phansi inemiphumela emikhulu yomzimba.
Kubonakala kimi ukuthi ngemuva kwesonto ngichithe emakhazeni, okungukuthi, ngeshwa, akuyona into yami futhi kukhawulela kakhulu ukuhlala kwami emoyeni omusha nomsebenzi wami ngokujwayelekile, ngizizwa ngathi ngemuva kocwaningo. Futhi ngingafinyelela eziphethweni zami siqu kulokhu kuhlolwa: ukungabi khona kokuvivinya umzimba kunomthelela omubi ngokweqile kumzwelo nasenhlalakahleni ejwayelekile. ((
Okuningi esihlokweni:
Kuze kube yiminyaka engama-20 edlule, ososayensi abaningi babekholelwa ukuthi ukwakheka kobuchopho ekugcineni kulungiswa lapho kuqala ukuba umuntu omdala, okungukuthi, ubuchopho bakho abusakwazi ukudala amangqamuzana amasha, ukushintsha ukuma kwalabo abakhona, noma nganoma iyiphi enye indlela ukuguquka komzimba isimo sobuchopho bayo ngemuva kobusha. Kepha eminyakeni yamuva nje, ucwaningo lwezinzwa lukhombisile ukuthi ubuchopho bugcina ipulasitiki, noma ikhono lokuguqula, ezimpilweni zethu zonke. Futhi, ngokusho kososayensi, ukuqeqeshwa ngokomzimba kusebenza ikakhulukazi kulokhu.
Kodwa-ke, akukho lutho olwaziwayo mayelana nokuthi ukungabi bikho kokuzivocavoca umzimba kungaba nomthelela ekuguqulweni kwesakhiwo sobuchopho, futhi uma kunjalo, imiphumela ingaba yini. Ngakho-ke, ukwenza lolu cwaningo, imininingwane ngalo esanda kushicilelwa ku-The Journal of Comparative Neurology, ososayensi abavela eWayne State University School of Medicine nakwezinye izikhungo bathathe amagundane ayishumi nambili. Bahlalisa uhhafu wabo emakhejini anamasondo ajikelezayo, lapho izilwane zingagibela khona nganoma yisiphi isikhathi. Amagundane ayakuthanda ukugijima, futhi agijime cishe amamayela amathathu ngosuku emasondweni awo. Amanye amagundane ayehlaliswe emakhejini angenamasondo futhi aphoqeleka ukuba aphile “impilo yokuzihlalela.”
Cishe ngemuva kwezinyanga ezintathu zokuhlolwa, izilwane zajovwa udayi okhethekile ongcolisa ama-neurons athile ebuchosheni. Ngakho-ke, ososayensi babefuna ukumaka ama-neurons esifundeni se-rostral ventromedial se-medulla oblongata yezilwane - ingxenye engacwaningiswanga yobuchopho elawula ukuphefumula kanye neminye imisebenzi engazi lutho edingekayo ukuze siphile.
I-rostral ventromedial medulla oblongata ilawula uhlelo oluzwelayo lomzimba lomzimba, okuthi, phakathi kwezinye izinto, lulawule ukucindezelwa kwegazi umzuzu nomzuzu ngokuguqula izinga le-vasoconstriction. Yize okuningi okutholwe yisayensi okuhlobene ne-rostral ventromedial medulla oblongata kuqhamuke ekuhlolweni kwezilwane, ucwaningo lwezithombe kubantu lukhombisa ukuthi sinesifunda esifanayo sobuchopho futhi lusebenza ngendlela efanayo.
Uhlelo lwezinzwa olulawulwa kahle luzisa ngokushesha imithambo yegazi ukuba ivuleke noma iminyanise, ivumela ukugeleza kwegazi okuyilo, ngakho-ke ungakwazi ukuthi ubalekele umgqekezi noma uphume esihlalweni sehhovisi ngaphandle kokuquleka. Kodwa ukusabela ngokweqile kohlelo lwezinzwa olunozwela kudala izinkinga, ngokusho kukaPatrick Mueller, ongusolwazi ophathelene nezomzimba eWayne University obengamele lolu cwaningo olusha. Ngokusho kwakhe, imiphumela yakamuva yesayensi ikhombisa ukuthi “isimiso sezinzwa esinozwela ngokweqile sinomthelela esifweni senhliziyo ngokubangela imithambo yegazi icindezeleke kakhulu, ibuthaka kakhulu noma ivame kakhulu, iholele ekucindezelweni umfutho wegazi ophakeme nasemonakalweni wenhliziyo.”
Ososayensi bacabanga ukuthi uhlelo lwezinzwa oluzwelayo luqala ukusabela ngokungahambi kahle nangengozi uma luthola imiyalezo eminingi kakhulu (okungenzeka ihlanekezelwe) evela kuma-neuron ku-rostral ventrolateral medulla oblongata.
Ngenxa yalokhu, lapho ososayensi bebheka ngaphakathi kobuchopho bamagundane abo ngemuva kokuthi izilwane bezisebenza noma zihlala phansi amasonto ayi-12, bathole umehluko obonakalayo phakathi kwala maqembu womabili abukeka njengamanye ama-neurons kuleso sifunda sobuchopho.
Besebenzisa uhlelo lokusiza ngekhompiyutha ukusizwa kabusha ebuchosheni besilwane, ososayensi bathola ukuthi ama-neuron ebuchosheni bamagundane asebenzayo ayesesimweni esifanayo nasekuqaleni kocwaningo futhi ayesebenza ngokujwayelekile. Kepha kuma-neurons amaningi ebuchosheni bamagundane ahlala phansi, kuvele inani elikhulu lezimpondo ezintsha, okuthiwa amagatsha. La magatsha axhuma ama-neurons aphilile ohlelweni lwezinzwa. Kepha la ma-neuron manje ayenamagatsha amaningi kunama-neurons ajwayelekile, awenza azwele ngokwengeziwe kusikhuthazo futhi athambekele ekuthumeleni imiyalezo engahleliwe ohlelweni lwezinzwa.
Eqinisweni, la ma-neuron ashintshile ngendlela yokuthi acasula kakhulu uhlelo lwezinzwa oluzwelayo, okungadala ukwanda kwengcindezi yegazi futhi kube nomthelela ekuthuthukisweni kwesifo senhliziyo.
Lokhu kutholakala kubalulekile, kusho uDkt. Müller, njengoba kujulisa ukuqonda kwethu ukuthi, ezingeni lamangqamuzana, ukungasebenzi kunokwandisa kanjani ingozi yesifo senhliziyo. Kepha okuthakazelisa nakakhulu ngemiphumela yalezi zifundo ukuthi ukunganyakazi - njengomsebenzi - kungashintsha ukwakheka nokusebenza kobuchopho.
Imithombo:
NYTimes.com/blogs
Isikhungo Sikazwelonke Semininingwane Yezebhayoloji