Maitiro Ekuita Zvinogona Kuitika Mumasero Etsinga
Pendauluan
Masero etsinga, kana kuti ma neuron, ndiwo hwaro hwehurongwa hwetsinga uye basa rekutumira ruzivo mumuviri wese. Imwe yenzira huru dzinoita kuti kufambisa ruzivo uku kuve kugona kwekuita. Simba rekuita kuchinja nekukurumidza uye kwenguva pfupi mumagetsi emembrane yesero retsinga rinobvumira chiratidzo chemagetsi kufamba neaxon kubva kumugumo mumwe wetsinga kuenda kune mumwe. Chinyorwa chino chichaongorora zvakakwana nzira dzekutanga, maitiro ekuyerera kwemaion ari pasi, uye matanho anobatanidzwa mukuita simba rekuita.
Chimiro Chekutanga cheNeurons
Usati wanzwisisa mashandiro anoita simba rekuita, zvakakosha kuti unzwisise chimiro chemasero etsinga. Matsinga ane zvikamu zvitatu zvikuru: soma (muviri wesero), dendrites, uye axons.
– Soma: Uyu ndiwo muviri mukuru we neuron, une nucleus nedzimwe organelles. Soma ndiyo nzvimbo iri pakati pebasa re neuron rekugadzirisa mashandiro emasero etsinga.
– Dendrites: Idzi ishinda pfupi, dzine matavi dzinogamuchira zviratidzo kubva kune mamwe ma neuron uye dzinozvitumira ku soma.
– Axon: Chimiro chakareba, chakatetepa chinotumira masaini kubva ku soma kuenda kune mamwe ma neuron kana kuti kumasero anobatsira.
Kumagumo kweaxon kune axon terminal, uko ma neurotransmitters anoburitswa mu synapse, ayo anobva akanganisa neuron iri kutaurwa.
Electrophysiology Yekutanga
Voltage yeMembrane chinhu chakakosha mukuita kwesimba rekuita. Mumamiriro ekuzorora, ma neuron ane simba rekuzorora remembrane rinosvika -70 mV. Izvi zvinoreva kuti mukati mesero mune negative kupfuura kunze. Simba iri rinogadzirwa nekupararira kwemaion akadai sesodium (Na+), potassium (K+), chloride (Cl-), uye organic anions mukati nekunze kwesero, iyo inodzorwa neplasma membrane inopindika zvishoma nezvishoma.
Pombi yesodium-potassium (Na+/K+ ATPase) inoita basa rakakosha mukuchengetedza kugoverwa kwemaion uku. Morekuru yega yega yeATP inonyungudutsa maion matatu esodium kubva musero uye maion maviri epotassium musero, zvichichengetedza gradient yemagetsi.
Maitiro Ekuita Zvinogona Kuitika
Danho 1: Kubvisa polarization
Simba rekuita rinotanga kana neurite (dendrite kana muviri wesero) ikagamuchira simba rakasimba rekuti isvike pamucheto (-55 mV). Sezvo simba remembrane richisvika pamucheto uyu, nzira dzesodium dzakavharirwa nemagetsi dziri mu axon membrane dzinotanga kuvhurika. Maion eSodium, aripo muhuwandu hwakawanda kunze kwesero, anopinda nekukurumidza mu neuron, zvichikonzera kukurumidza kudzima kwe membrane ye neuronal. Izvi zvinoita kuti mukati me neuron muve nepfungwa dzakanaka, kusvika pa +30 mV.
Danho rechipiri: Kukwanisa Kuita Chinhu Nesimba
Kana membrane yasvika pa +30 mV, nzira dze sodium dzinotanga kuvhara dzoga uye nzira dze potassium dzinotanga kuvhurika. Panguva iyi, simba rekuita basa rasvika padanho repamusoro.
Danho rechitatu: Kudzoreredza polarization
Mushure mekunge simba rekuita rasvika padanho repamusoro, neuron inotanga kudzorera simba rayo remembrane kumamiriro ayo ekuzorora. Kana nzira dze potassium dzakavharirwa ne voltage dzichivhurwa, ma potassium ions, aripo muhuwandu hwakawanda mukati me cell, anotanga kubuda mu neuron. Kuburitswa uku kwe K+ kunoita kuti membrane ye neuron ive negative zvakanyanya, maitiro anozivikanwa se repolarization.
Danho rechina: Hyperpolarization uye Restitution
Dzimwe nguva, kubuda kwemaion epotassium kwakawandisa kunoita kuti membrane ive negative kupfuura kugona kwayo kwekuzorora kwakajairika (pasi pe -70 mV), chikamu chinozivikanwa se hyperpolarization. Munguva ye hyperpolarization, neuron inopinda munguva yekusagadzikana kwemuviri uye yozopedzisira yava nenguva yekusagadzikana, panguva iyo inenge isingachapinduri zvakanyanya kune zvitsva. Pombi ye sodium-potassium inobva yadzorera zvinobudirira kugoverwa kwemaion kune mamiriro ekuzorora akagadzikana.
Danho rechishanu: Chiito Chinogona Kuitwa
Mushure mekunge chikamu chimwe che axon membrane chapera simba, simba rekuita rinopararira pamwe chete ne axon semafungu. Nzira dzesodium muzvikamu zvinotevera zve axon membrane dzinovhurika zvakateerana. Maitiro aya anobvumira chiratidzo chemagetsi kuti chipararire zvinobudirira kuenda kumagumo e axon.
Muma neuron ane myelin sheaths, action potential conduction inoshanda zvakanyanya kuburikidza nemaitiro anonzi saltatory conduction, umo action potential "inosvetuka" kubva pane imwe node yeRanvier kuenda kune inotevera. Myelin inoshanda seinsulator, ichidzivirira kubuda kwemaion, nokudaro ichikurumidzisa kutapurirana kwemasaini.
Kukosha Kwemuviri uye Kliniki
Maitiro ekuita haangobatsiri chete pakushanda kwehurongwa hwetsinga asiwo anobatsira mumamiriro akasiyana-siyana ekurapa uye emuviri. Semuenzaniso, kukanganiswa kwenzira dze ion kunogona kutungamira kuzvirwere zvakasiyana-siyana zvetsinga zvakaita se multiple sclerosis, pfari, uye mamwe marudzi e neuropathy.
Multiple Sclerosis (MS): MuMS, sheath inofukidza ma axons inokuvadzwa nemasoja emuviri. Izvi zvinokanganisa kufambiswa kwemunyu, zvichiita kuti masaini etsinga afambe zvishoma nezvishoma kana kutomira zvachose.
Pfari: Chirwere ichi chinowanzo kukonzerwa nekusashanda zvakanaka kwenzira dzemaion izvo zvinoita kuti mashandiro etsinga dzemaneuron ashande zvakanyanya uye asingadzoreki, zvichikonzera pfari.
Neuropathy: Mamwe marudzi e neuropathy anokonzerwa nekukuvara kana kusashanda zvakanaka kwe myelin sheath kana masero etsinga pachawo, izvo zvinokanganisa kutapurirana kwesimba rekuita, zvichikonzera zviratidzo zvakaita sekurwadziwa, kusanzwa kana kushaya simba.
Mhedziso
Simba rekuita chinhu chakaoma asi chakakosha pakushanda kwetsinga. Maitiro aya anosanganisira matanho akasiyana-siyana kubva pakubvisa polarization, simba rekuita zvakanyanya, repolarization, uye hyperpolarization, zvese zvinodzorwa ne ion channel dynamics. Kunzwisisa mashandiro aya hakungopi ruzivo rwakakosha rwekuti ruzivo runotapurirwa sei mutsinga asiwo kunopa hwaro hwekunzwisisa nekugadzira mishonga yezvirwere zvakasiyana-siyana zvetsinga.
Neruzivo rwuri kuramba ruchikura munyaya iyi, mukana wekuwana nzira dzekurapa dzinoshanda dzezvirwere zvetsinga uri kukura, zvichiunza tariro itsva kuvarwere vazhinji pasi rese.
