Ko te takotoranga myelin o muka karere: mahi whakaora

Ko te pūnaha io o te tangata me te vertebrates i te mahere hanganga kotahi a te aroaro te pokapū - te roro, me te ua, me ngā wāhanga piringa - te whakawhānui i te tinana pokapū o te raru, e tohu tukanga o ngā pūtau io - neurons.

Ratou puka huinga kiko neural, nga mahi matua o te mea excitability me te kawe ia. E faataa te reira i enei āhuatanga runga ake te hanganga āhuatanga katoa o kiriuhi neuronal me ratou konga, arā, o te myelin taonga i huaina. I roto i tēnei tuhinga ka titiro tatou ki te hanganga me te mahi o tenei pūhui, me te kitea i roto i ngā huarahi ka taea e ia te whakahoki.

Aha neurocytes me ngā tukanga hipoki e te myelin

Ko reira kahore axons tāpiritanga me dendrites i te kahu paruru arā, o complexes lipid-pūmua. Ko te take i te institution ko te tukanga Biophysical, e hāngai ana nei i runga i te ponana hiko ngoikore. A, no te haere nāianei hiko i roto i te waea, me kia hipokina te whakamutunga ki te tuuraa i rauemi ki te whakaiti i te tohanga o ngātere hiko, me te ki te ārai i heke i roto i te amperage. Ko te taua mahi i roto i te muka io te maua e te takotoranga myelin. I tua atu, ko reira te tautoko, me whakarato hoki te muka kai.

Ko te hanganga matū o myelin

Ka rite ki te nuinga o kiriuhi pūtau, he reira he āhua lipoprotein. Ano, he nui rawa te ihirangi ngako - ki runga ki te 75%, me te pūmua - 25%. Myelin i roto i te moni iti ngā ano glycolipids me glycoproteins. Ko rerekē i roto i te raru filosilivá me cranial tona hanganga matū.

I te tuatahi i reira ko te ihirangi tiketike o phospholipids - ki runga ki te 45%, ka tae mai te toenga i cholesterol me cerebrosides. Demyelination (i.e. myelin whakakapinga mō ētahi atu matū i roto i ngā tukanga io) arata'i ki taua mate autoimmune kino, pērā i sclerosis maha.

Mai i te wāhi matū o te tirohanga, e titiro tenei tukanga rite tenei: te takotoranga myelin o muka karere te huri tona hanganga, matua te i whakakitea i roto i te hekenga i roto i te ōrau o te ihirangi lipid i roto i te pā ana ki te pūmua. I tua atu whakaiti i te nui o cholesterol me ihirangi wai nui haere. A arata'i tenei katoa ki te whakakapinga āta o te myelin kei roto oligodendrocytes ranei pūtau Schwann i macrophages, astrocytes me intercellular wai.

Ko te hua o enei huringa matüora ka waiho he hekenga koi i roto i te kaha o axons ki te whakahaere ketia tae noa oti ārai o te wahi o ponana karere.

Āhuatanga pūtau neuroglial

Ka rite ki kua whakahuatia, i hanga te takotoranga myelin o axons me dendrites te ki ngā hanganga motuhake, āhuatanga e te iti o te uruhanga hoki konutai me te konupūmā katote, a reira he moe, takoto anake (e kore e taea e ratou te whakahaere i ponana io me mahi te mahi hiko).

E huaina ēnei hanganga pūtau glial. Ko ētahi o ēnei:

• oligodendrocytes;
• astrocytes kaiota;
• pūtau ependymal;
• astrocytes wē.

Katoa o ratou e hanga e i te kahu waho o te kukune - te ectoderm me whai he ingoa noa - macroglia. Glia raru pukuaroha, parasympathetic me somatic kanohi Schwann ngā pūtau (neyrolemmotsitami).

Hanganga me te mahi o oligodendrocytes

Ko wāhanga o te pūnaha io pokapū ratou me he pūtau macroglia. Mai myelin - he hanganga pūmua-lipid, faarahi te reira i te tere o te excitation. Ko te pūtau ratou te hanga i te apa electrically tuuraa o te kūmuri karere i roto i te roro, me te ua, te hanga e kua i roto i te whanaketanga fetal. Ratou tukanga obvorachivayut i roto i ona hipi waho o neurons plasmalemma me dendrites me axons. Huri i te reira i roto i taua i te myelin - he rauemi tuuraa hiko taketake, delimiting nga tukanga karere o raru whakauru.

pūtau Schwann me ratou āhuatanga

Ko te takotoranga myelin o te pūnaha raru ko piringa i hanga neyrolemmotsitami (Schwann pūtau). Ratou āhuatanga motuhake ngā i roto i te meka e taea e ratou te hanga i tetahi anake takotoranga paruru o te axon, a kore e taea te hanga wana, rite he tūturu i roto i oligodendrocytes.

I waenganui i ngā pūtau Schwann i te rohe 1-2 mm o e whakanohoia wahi kowaiwai o myelin, kōpuku o Ranvier pera-ka karanga. E ai ki a ia koimutu puta āriponga o ponana hiko i roto i te axon.

Lemmotsity taea ki te hanga i te muka io, me te mahi i te mahi arataukai. Ka rite ki lemmotsitov te hua o hape ira whiuwhiu timata pūtau mitotic ki wehenga whakakeke me te tupu, ai te puku whakawhanakehia i roto i ngā wāhanga rerekē o te pūnaha io - schwannoma (neurinoma).

Ko te tūranga o microglia i te whakangaromanga o te hanganga myelin

Microglia tohu macrophages nehenehe o te phagocytosis me taea ki te ite i rerekē matūriki pathogenic - antigens. Ngā mihi ki te receptors membrane, enei pūtau glial hua whākōkī - proteases me cytokines, pērā i interleukin 1. Ko ia te takawaenga o te mumura me te wātea i te mate.

Te takotoranga myelin, ko tona mahi, ko te ki te tutakina kia pakaru ai te puoto axial me whakapai ake o te karere hihiko interleukin. Ka rite ki te hua, te karere "takoto kau" me te tere o te excitation te tino heke.

Ano, cytokines, whakapataritari whakahohe receptors nui waka konupūmā katote ki te tinana o te neuron. Protease me phospholipase timata ki te piri organelles me ngā tukanga o ngā pūtau io, e tika ana ki te apoptosis - te mate o te hanganga i homai.

hinga ia, whawhati ki matūriki, e pau macrophages. huaina ana tēnei āhuatanga te excitotoxicity. ai te reira i tupu o neurons me ratou hopearaa, ārahi ki mate pērā i Alzheimer o me te mate o Parkinson.

muka io Myelinated o

Ki te tukanga neuronal - dendrites me axons, te hipoki myelin takotoranga, e huaina ratou uaua kōhiwi myelinated me innervate, tomo te wehenga somatic o te pūnaha io piringa. muka Unmyelinated hanga te pūnaha io autonomic me okana innervated.

tukanga Myelinated i te diameter nui atu i te kore-kikokiko, a kua hanga e whai ake nei: axons faaapiapi i te membrane wē o ngā pūtau glial me te puka rārangi mezaksony. Na, kua atu ratou ko Schwann pūtau toutou roropi a tawhio noa te axon, hanga papa concentric. oho te cytoplasm me karihi lemmotsita ki te paparanga waho, e kiia nei ko neurilemma Schwann takotoranga ranei.

Kei te kahu roto o te mezoksona kiri lemmotsita i huaina myelin takotoranga. e kore ko te taua tona matotoru i roto i ngā wāhanga rerekē o te karere.

Me pēhea te ki te whakahoki i te takotoranga myelin

Whakaaro i te tūranga o microglia i karere demyelination, kitea e matou e raro i te mahi o macrophages me neurotransmitters (hei tauira, interleukins), ko te whakangaromanga o myelin, i roto i te tahuri arata'i ki ino o te neurons mana tuku me ponana karere waimaero haere te axon.

Tenei māuiuitanga whakaoho pānga neurodegenerative: ino o tukanga hinengaro, rawa mahara me te whakaaro, te ahua o te kore o te ruruku o nekehanga tinana, me te pai pūkenga nekeneke.

Ka rite ki te hua, ka taea hauātanga ki tonu o te manawanui, i te mea te hua o te mate autoimmune. Na te pātai o te pehea, ki te whakahokia myelin, he tino koi tēnei wā. Taua tikanga ngā matua te kai pūmua-lipid taurite, te ora auau, ngaro o peu kino. I roto i ngā take kino, whakamahia rongoā mate, te whakaiti i te maha o ngā pūtau glial pakeke - oligodendrocytes.