Ngo-Novemba 15th, 2011 e-Neuroscience
Ukutadisha nge-hamsters kusikisela ukuthi ukuya ocansini lapho usakhula kungaba nemiphumela emibi ehlala njalo emzimbeni kanye nokuguquguquka kube umuntu mdala
Ucwaningo olusha luveza ukuthi ucansi ngesikhathi sokuthomba lungaba nemiphumela emibi engapheli emzimbeni futhi lujule lube umuntu mdala, ikakhulukazi ngoba umsebenzi wenzeka lapho uhlelo lwezinzwa lusakhula.
Ngenkathi ucwaningo lusebenzisa izilwane zaselabhorathri, okutholakele kunikeza imininingwane engasetshenziswa ekuqondeni ukuthuthukiswa kobulili babantu.
Abaphenyi babhangqa ama-hamsters abesifazane asebekhulile nama-hamsters wesilisa lapho abesilisa benezinsuku ezingama-40 ubudala, okulingana nobusha bomuntu obuphakathi nendawo. Bathola ukuthi lezi zilwane zesilisa ezinokuhlangenwe nakho kobulili zisencane kamuva zabonisa izimpawu eziningi zokuziphatha okufana nokudana kanye nobukhulu bomzimba ophansi, izicubu ezincane zokuzala kanye nezinguquko kumaseli ebuchosheni kunama-hamsters aqale ukuvezwa ocansini kamuva impilo noma ukungayi ocansini nhlobo.
Phakathi kokushintshwa kweseli okubonwe ezilwaneni ezaziya ocansini ngesikhathi sokukhula kwakungamazinga aphezulu okuvezwa kohlobo oluhambisana nokuvuvukala ezicutshini zazo zobuchopho kanye nezakhiwo eziyinkimbinkimbi ezingamaselula ezindaweni eziyisisekelo zokubonisa ubuchopho.
Bakhombise nezimpawu zokuphendula okuqinile kwamasosha omzimba esivivinyweni sokuzwela, basikisela ukuthi amasosha abo omzimba abesesimweni sokulungela okukhulu ngaphandle kokutholakala kokutheleleka - uphawu olungaba nenkinga yokuzimela.
Ukuhlanganiswa kwezimpendulo ze-physiologic ebudaleni akusho ukuthi kubangele ukulimala, kepha phakamisa ukuthi isenzo socansi ngesikhathi sokukhula kohlelo lwezinzwa lungahunyushwa ngumzimba njengokucindezela, kusho abacwaningi.
"Ukuba nesipiliyoni kwezocansi ngalesi sikhathi, ekuqaleni kwempilo, akuyona into engenamphumela," kusho uJohn Morris, ongumbhali-mbumbulu wesifundo futhi ofundela ubudokotela kwezengqondo e-Ohio State University. "Kungaba nomthelela ekuthambekeni kwamadoda ezimpawu zokucindezeleka, futhi kungaveza abesilisa ekwandeni kokuvuvukala sebekhulile."
UMorris wethule ucwaningo ngoLwesibili (11/15) emhlanganweni waminyaka yonke weSociety for Neuroscience eWashington, DC Wenza isifundo noZachary Weil, uprofesa osizayo ocwaningweni, kanye noRandy Nelson, uprofesa kanye nosihlalo, bobabili abavela eMnyangweni Wezobuchwepheshe Nezifundo ze-Ohio State.
Ucwaningo lwangaphambilini luvame ukuhlaziya imiphumela yocansi lwentsha kwabesifazane abasebasha, futhi ngenxa yezizathu zokuziphatha kufanele lwenziwe kubantu njengokuhlaziya kabusha kokuziphatha. Ososayensi be-Ohio State basebenzise ama-hamsters, anokufana ngokomzimba kubantu, ukuze bafunde ngqo ukuthi umzimba uphendula kanjani ocansini usemncane.
"Kunesikhathi ekuthuthukisweni kwesistimu yezinzwa lapho izinto zishintsha ngokushesha okukhulu, futhi ingxenye yalezo zinguquko amalungiselelo ezindlela zokuziphatha kwabantu abadala kanye ne-physiology," kusho uWeil. "Kungenzeka ukuthi okuhlangenwe nakho kanye nezimpawu zemvelo zingakhulisa imiphumela uma kwenzeka ngaphambi kokuba isimiso sezinzwa singene ebudaleni."
Ososayensi basebenzisana namaqembu amahlanu ama-hamsters angamaduna: amaqembu amabili ayelala nobudala bezinsuku ze-40 futhi ahlolwe ngezinsuku ze-40 nezinsuku ze-80 ngemuva kokuvezwa ngocansi, amaqembu amabili ayenobudala babantu abadala abaseminyakeni ye-80 futhi ahlolwa ngasikhathi sinye izikhawu, nama-hamsters angenawo umuzwa wokuya ocansini. Ama-hamsters angamaduna afinyelela ebusheni eneminyaka engu-21 yezinsuku.
Abaphenyi babeka owesilisa osemusha nowesilisa osekhulile endaweni ene-hamsters efudumele eshisayo amahora ayisithupha futhi baqopha ukuhlangana kwabo ukuqinisekisa ukuthi kwenziwa ucansi.
Izilwane zahlolwa izivivinyo ezahlukahlukene lapho zonke zase zifinyelele ebudaleni. Babekwe kumazisi ngezinketho zokuhlola izindawo ezivulekile noma ukucasha bebodwa; lezo ezikhethe ukungafuni ukuzihlola zazikhombisa izimpawu zokukhathazeka. Izilwane ezifakwe emanzini zikhombisa izimpawu zokuziphatha okucindezelayo uma ziyema ukubhukuda ngamandla.
"Womabili la maqembu ama-hamsters enza ucansi akhombise ukwanda kokuziphatha okufana nokukhathazeka uma kuqhathaniswa neqembu elilawulayo, kepha ukwanda kwempendulo efana nokudana bekucacile eqenjini lababhangqwe ngokocansi abasebasha," kusho uMorris.
Ukuhlolwa kokuzwela kwamasosha omzimba kwaphakamisa ukuthi ama-hamsters anolwazi lokuya ocansini nentsha asengozini yokulimala ngokweqile njengengxenye yokuphendula kokuzivikela komzimba okuthuthukisiwe. Ngaphezu kwalokho, la ma-hamsters afanayo ayenamazinga aphezulu e-cytokine ye-pro-inflammatory okuthiwa i-interleukin-1, noma i-IL-1, ezithweni zawo zobuchopho kunakwamanye ama-hamsters. I-IL-1 ingelinye yezithunywa zamakhemikhali eziningana ezibangela ukuvuvukala, imvamisa kakhulu ukulwa nokutheleleka noma ukulungisa ukulimala; lapho ijikeleza ngaphandle kokutheleleka ukulwa, umzimba uzwa ukuvuvukala ngokweqile.
Le nkulumo ephakeme yezakhi zofuzo yabonakala ezindaweni zobuchopho ezaziwa ukuthi zingafinyeleli ekuvuthweni kuze kube sebudaleni - kufaka phakathi i-amygdala, i-prefrontal cortex, i-hippocampus ne-striatum. Kwezinye zalezi zindawo ezifanayo zobuchopho, izilwane ezinokuhlangenwe nakho kocansi kwentsha nazo zikhombise ubunzima obuyingcosana kuma-dendrites, izingxenye zamagatsha ezivela kumaseli ezinzwa aqukethe ama-synapses, athwala amasiginali aye ebuchosheni kuwo wonke umzimba.
Ngaphandle kocwaningo olwengeziwe, ososayensi abazi kahle ukuthi lokhu kwehluka kobuchopho kusho ukuthini. Kepha ngoba zibonakala ngokugqamile ezilwaneni ezavezwa ukuya ocansini ebusheni, ososayensi bathi, kunokuhlangana okusobala nalowo msebenzi. "Ucansi lwenza okuthile ngokomzimba okusetshenzwa yilawa maseli nokuphendula ngama-dendrites amafushane," kusho uWeil.
Ekugcineni, ama-hamsters ayenze ucansi lwentsha aba nesisindo esincane somzimba kanye nokwehla kwezicubu zokuzala ezifakiwe, kufaka phakathi i-seminal vesicles, vas deferens kanye ne-epididymis, njengabantu abadala.
"Lokhu kusikhombisa ukuthi mhlawumbe le nqubo idala ukuthi izilwane zithole impendulo engafanele ngokuzala," kusho uMorris.
Inikezwe yi-The Ohio State University
"Ucansi lwentsha oluxhunyaniswe nomzimba wabantu abadala, izinkinga zemizwelo, esifundweni sezilwane." Novemba 15th, 2011. http://medicalxpress.com/news/2011-11-adolescent-sex-linked-adult-body.html
UKUFINYELELA KWE-ADULT, IMMUNE, KANYE NEMPENDULO EBONAKALAYO IYAFANELE
abstract
Okuhlangenwe nakho kokuphila kwasekuqaleni kunomthelela ohlala njalo ku-physiology nokuziphatha. Ubusha yisikhathi esibucayi sokuthuthuka lapho ukujikeleza kwe-neural kulungiswa kakhulu, futhi okuhlangenwe nakho ngalesi sikhathi kungaguqula unomphela ukukhula nentuthuko. Ezifundweni zabantu, ubulili obutholakale ngesikhathi sobusha bungakhuphula ukuthambekela kokuphazamiseka kwengqondo, kuguqule ukusebenza komzimba, futhi kuguqule ukucindezelwa kabusha. Kulolu cwaningo sihlolisise umthelela wokuxhumana okubalulekile kwezenhlalo, ikakhulukazi ulwazi lwezocansi, ekuziphatheni kwabantu abadala, ekuzivocavoca umzimba nasekuziphatheni ngokuzala kuma-hamsters. Lapho kuzalwa, ama-hamsters wesilisa aseSiberia abelwa ngokungahleliwe kwelinye lamaqembu amathathu: (1) ukuxhumana ngokocansi ne-ovariectomized, estrogen-primed, owesifazane omdala ngesikhathi sokuthomba ngosuku lwangemva kokubeletha 40 (P40), (2) ukuxhumana ngokocansi ne-ovariectomized, estrogen -kunciphisiwe, owesifazane omdala lapho esemdala ngosuku lwangemva kokubeletha 80 (P80), noma (3) akukho ukuxhumana ngokocansi. Ezinsukwini ezingama-120 ubudala, ama-hamsters ahlolwa ngokuziphatha, kanye nezimpendulo zomzimba ezivikelwe ngamaseli (ukubambezeleka kohlobo lwe-hypersensitivity; i-DTH) kwahlolwa. Uma kuqhathaniswa nama-hamsters angenakho okuhlangenwe nakho ngokocansi noma isipiliyoni sabantu abadala kwezocansi, ama-hamsters anokuhlangenwe nakho kobulili kwentsha akhombise izimpendulo ze-DTH ezikhuphuke kakhulu, kanye nokukhathazeka okuphezulu nezimpendulo zokuziphatha ezicindezelayo. Lezi zilwane zikhombise nokwehliswa kobukhulu bomzimba jikelele kanye nesisindo sezicubu zokuzala zokufinyelela. Uma ihlanganiswa, le miphumela iphakamisa ukuthi isipiliyoni sobulili sentsha esencane sinemiphumela yesikhathi eside ezimpendulweni ezithintekayo, imiphumela ebekezelayo ekusebenzeni komzimba womuntu omdala, kanye nemiphumela ehlala njalo kwizicubu zokuzala. Lo msebenzi ungaba wusizo ekuqondeni imiphumela yesikhathi eside yezempilo yomzimba nengqondo yocansi lwentsha kubantu.
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