Isistimu yezinzwa yomuntu, eyinkimbinkimbi kakhulu, yakhiwa cishe ama-neurons ayizigidi eziyizinkulungwane eziyikhulu, abizwa nangokuthi amangqamuzana ezinzwa. Ama-Neuron ebuchosheni angakwazi ukuxhumana ngama-synapses adlulisa isignali yezinzwa kusuka ku-neuron eyodwa kuya kwenye.

Ama-dendrites amafushane, anezandiso ezinamagatsha ala ma-neuron. Ngempela, ama-dendrites akha ingxenye yokwamukela ye-neuron: zivame ukumelwa njengohlobo lomuthi oluvela emzimbeni we-neuronal cell. Eqinisweni, ukusebenza okunengqondo kwama-dendrites ngakho-ke kuzoba nokuqoqa imininingwane ezingeni lama-synapses abembozayo, ngaphambi kokuyidlulisela emzimbeni weseli we-neuron. 

Amaseli emizwa ahluke kakhulu kwamanye amaseli emzimbeni womuntu: ngakolunye uhlangothi, i-morphology yawo icace kakhulu futhi ngakolunye uhlangothi, isebenza ngogesi. Igama elithi dendrite livela egameni lesiGreki UDendron, okusho ukuthi "isihlahla".

Izingxenye ezintathu ezakha i-neuron

Ama-dendrites ayizingxenye eziyinhloko zokwamukela i-neuron, ebizwa nangokuthi iseli lezinzwa. Eqinisweni, ama-neurons amaningi akhiwe ngezinto ezintathu eziyinhloko:

• umzimba weseli;
• izinhlobo ezimbili zezandiso zeselula ezibizwa ngama-dendrites;
• ama-axon. 

Umzimba weseli wama-neurons, obizwa nangokuthi i-soma, uqukethe i-nucleus kanye namanye ama-organelles. I-axon iyisandiso esisodwa, esincane, esiyindilinga esiqondisa umfutho wezinzwa kwenye i-neuron noma kwezinye izinhlobo zezicubu. Eqinisweni, okuwukuphela komsebenzi onengqondo we-axon ukushayela, ukusuka endaweni eyodwa ebuchosheni kuya kwenye, umyalezo obhalwe ngendlela yokulandelana kokungenzeka kwesenzo.

Kuthiwani ngama-dendrites ngokunembile?

Isakhiwo sesihlahla esivela emzimbeni weseli

Lawa ma-dendrites amafushane, anentambo, futhi anamagatsha amakhulu, akha uhlobo lomuthi oluvela emzimbeni we-neuronal cell.

Ama-dendrites empeleni ayizingxenye zokwamukela i-neuron: empeleni, ulwelwesi lwe-plasma lwama-dendrites lunezindawo eziningi zokwamukela zokubopha izithunywa zamakhemikhali ezivela kwamanye amaseli. Irediyasi yesihlahla se-dendritic ilinganiselwa kumamilimitha owodwa. Ekugcineni, izinkinobho eziningi ze-synaptic zitholakala kuma-dendrites ezindaweni ezikude nomzimba weseli.

Ama-ramifications wama-dendrites

I-dendrite ngayinye ivela kusoma ngesigaxa esifinyelela ekwakhekeni okuyindilinga. Ngokushesha okukhulu, izobe seyihlukaniswa yaba yindodakazi yegatsha emibili. Ububanzi bawo buncane kunobo begatsha lomzali.

Ngemuva kwalokho, ukuqoqwa ngakunye kokuthola ngaleyo ndlela kutholakale ukwahlukaniswa, ngokulandelana, kwaba ezinye ezimbili, ezinhle kakhulu. Lokhu kwehlukaniswa okuqhubekayo: lesi yisona sizathu esenza abalingisi be-neurophysiology bafanise "umuthi we-dendritic we-neuron".

Umsebenzi wama-dendrites ukuqoqa imininingwane ezingeni lama-synapses (izikhala eziphakathi kwama-neurons amabili) ezimbozayo. Ngemuva kwalokho la ma-dendrites azothatha lolu lwazi aluyise emzimbeni weseli le-neuron.

Ama-Neurons ayazwela ezintweni ezahlukahlukene, aziguqula zibe amasiginali kagesi (abizwa ngokuthi amandla wesenzo sezinzwa), ngaphambi kokudlulisela la mandla esenzo kwamanye ama-neuron, izicubu zemisipha noma ngisho nasezindumbeni. Futhi empeleni, kuyilapho ku-axon, umfutho kagesi ushiya i-soma, ku-dendrite, lesi sifutho sikagesi sisakazekela ngase-soma.

Ucwaningo lwesayensi lwenze ukuthi kwenzeke, ngenxa yama-electrode amancane afakwe kuma-neuron, ukuhlola indima abanayo ama-dendrites ekudlulisweni kwemiyalezo yezinzwa. Kuvela ukuthi, kunokuba zibe yizandiso nje, lezi zinhlaka zidlala indima enkulu ekusetshenzisweni kolwazi.

Ngokwalolu cwaningo olushicilelwe ku- Nature, ama-dendrites ngakho-ke ngeke abe yizandiso ezilula ze-membrane ezibandakanyeka ekudluliseleni umfutho wezinzwa ku-axon: empeleni ngeke babe ngabalamuli abalula, kepha nabo bazocubungula imininingwane. Umsebenzi ongakhuphula amandla obuchopho. 

Ngakho-ke yonke idatha ibonakala ihlangana: ama-dendrites awenzi lutho, kepha, ngandlela thile, angamakhompyutha amancane ebuchosheni.

Ukusebenza okungajwayelekile kwama-dendrites kungaxhunyaniswa nokungasebenzi kahle okuphathelene nama-neurotransmitters abawathokozisayo noma, kunalokho, akuvimbele.

Okuaziwa kakhulu kulawa ma-neurotransmitters yi-dopamine, i-serotonin noma ne-GABA. Lokhu kungukungasebenzi kwemfihlo yabo, okuphezulu kakhulu noma okuphambene kakhulu kakhulu, noma okuvinjelwe, okungaba yimbangela yokungahleleki.

I-pathologies ebangelwa ukwehluleka kuma-neurotransmitters, ikakhulukazi, izifo zengqondo, ezinjengokudangala, isifo se-bipolar noma i-schizophrenia.

Ukwehluleka kwe-Psychic okuxhumene nokulawulwa okungalungile kwama-neurotransmitters ngakho-ke, ezansi nomfula, ekusebenzeni kwama-dendrites, manje kuyelapheka ngokuya ngokuya. Imvamisa, umphumela ozuzisayo wezifo zengqondo uzotholakala ngokuhlangana phakathi kokwelashwa kwezidakamizwa nokuqapha kohlobo lwe-psychotherapeutic.

Kunezinhlobo eziningana zemisinga ye-psychotherapeutic ekhona: empeleni, isiguli singakhetha uchwepheshe azizwa enokuzethemba, alalelwe kanye nendlela emfanele ngokwakudala kwakhe, isipiliyoni sakhe, nezidingo zakhe.

Kunezindlela ezithile zokwelapha ezinokuqonda, zokuziphatha, noma zokwelapha ngokwengqondo ezixhumeke kakhulu kumanje we-psychoanalytic.

Ukutholakala kwesifo sengqondo, ngakho-ke okuhambisana nokwehluleka kwesistimu yezinzwa lapho abadayisi bedlala khona indima ebalulekile, kuzokwenziwa ngudokotela wezifo zengqondo. Imvamisa kuzothatha isikhathi eside ukwenza ukuxilongwa.

Ekugcineni, kubalulekile ukwazi ukuthi isiguli akufanele sizizwe sibhajwe “kwilebula” elizomfanisa, kepha sihlale singumuntu ophelele, okuzomelwe afunde ukuphatha ukuphatha kwakhe. Ochwepheshe, odokotela bengqondo kanye nezengqondo, bazokwazi ukumsiza kule ndlela.

Usuku lokwethulwa kwegama elithi "neuron" lubekwe ngo-1891. Le adventure, empeleni eyakheka ekuqaleni, yavela ikakhulukazi ngenxa yombala omnyama wale seli, owenziwa nguCamillo Golgi. Kepha, le ngqophamlando yesayensi, kude nokugxila kuphela ezicini zokwakhiwa kwalokhu okutholakele, kancane kancane yakwenza kwaba nokwenzeka ukukhulelwa i-neuron njengeseli eliyisihlalo sezinqubo zikagesi. Kwabe sekuvela ukuthi lezi zingqondo ezilawulwayo, kanye nemisebenzi eyinkimbinkimbi yobuchopho.

Kwakukhulukazi kusukela ngawo-1950 lapho izinsimbi eziningi eziyinkimbinkimbi ze-biophysical zasetshenziswa ekutadisheni i-neuron, ku-infra-cellular nakwizinga lamangqamuzana. Ngakho-ke, i-electron microscopy yakwenza kwakwazi ukudalula isikhala somsipha we-synaptic, kanye ne-exocytosis yama-vesicles we-neurotransmitter kuma-synapses. Bese kungenzeka ukuthi kufundwe okuqukethwe kwalezi zingubo.

Ngemuva kwalokho, inqubo ebizwa nge- "patch-clamp" yenze ukuthi, kusukela ngawo-1980, ifunde ukwehluka kwamanje ngesiteshi esisodwa se-ion. Sibe sesikwazi ukuchaza izindlela eziseduze zamaseli we-neuron. Phakathi kwabo: ukusakazeka emuva kwamandla esenzo ezihlahleni ze-dendrite.

Ekugcineni, kuJean-Gaël Barbara, isazi-mlando sezinzwa nesayensi, “kancane kancane, i-neuron iba yinto yezethulo ezintsha, njengeseli elikhethekile phakathi kwabanye, ngenkathi ihlukile ngezincazelo eziyinkimbinkimbi zokusebenza kwezinqubo zayo".

Ososayensi uGolgi noRamon y Cajal baklonyeliswa ngomklomelo weNobel ngo-1906 ngomsebenzi wabo ohlobene nomqondo wama-neuron.