Cholinergic synapses: tsarin, aiki

Cholinergic synapses ne wuri a cikin abin da akwai lamba tsakanin biyu neurons ko neuronal Kwayoyin da effector karbar siginar. A synapse aka hada biyu membranes - presynaptic da postsynaptic, kazalika daga synaptic kogon. Transmission daga jijiyar ne da za'ayi ta hanyar mai shiga tsakani, Ina nufin wani watsawa abu. Wannan na faruwa da hulda da tsoka mai amsa sigina da neurotransmitter a kan postsynaptic membrane. Wannan shi ne babban aikin da cholinergic synapses.

Matsakanci kuma rabe

A NA parasympathetic neurotransmitter ne acetylcholine rabe - da iri biyu cholinergic rabe: H (nicotine) da M (muscarine). M-cholinomimetics ciwon kai tsaye mataki irin na iya ta da rabe a postsynaptic membrane irin.

Kira na acetylcholine aka kwashe a cikin cytoplasm na cholinergic neuronal endings. An kafa daga choline da atsetilkoenzima-A, wanda yana da wani mitochondrial asalin. Kira na faruwa a karkashin mataki na cytoplasmic enzyme choline. A synaptic vesicles auku shaida na acetylcholine. A kowane daga cikin wadannan kumfa iya zama har zuwa dubu da dama kwayoyin na acetylcholine. A jijiya turu stimulates a saki acetylcholine a synaptic kogon kwayoyin. Bayan nan, ta shiga cikin hulda da acetylcholine rabe. A tsarin da cholinergic synapse musamman.

tsarin

Bisa ga bayanan, wanda suna samuwa ga biochemists, acetylcholine tsoka mai amsa sigina neuromuscular synapse iya hada biyar gina jiki subunits cewa kewaye da ion tashar da kuma mika ta hanyar dukan kauri daga cikin membrane kunshi wani sia. Biyu daga acetylcholine kwayoyin hulɗa tare da wata biyu daga α-subunits. Wannan take kaiwa zuwa da cewa yana buɗewa da ion tashar da postsynaptic membrane ne depolarized.

Iri cholinergic synapses

Cholinergic rabe ake sarrafa a cikin hanyoyi daban-daban da kuma guda a hanyoyi da dama m da sakamakon pharmacological jamiái. A daidai da wannan fifiko:

• Maskarinochuvstvitelnye cholinergic rabe - abin da ake kira M-cholinergic rabe. Shin wani alkaloid muscarine muhimmi yawan m naman kaza, Amanita misali.
• Nikotinochuvstvitelnye holinoretseptora - abin da ake kira H-cholinergic rabe. Nicotine ne wani alkaloid samu a taba ganye.

su location

A farko dake a cikin postsynaptic jikin tantanin hada da effector gabobin. Suna located a endings na postganglionic parasympathetic zaruruwa. Bugu da kari, su ma suna da, a na tsarin jijiya Kwayoyin, autonomic ganglia kuma a cikin cerebral bawo. An gano cewa M-cholinergic rabe na daban-daban sarrafawa ne iri-irin, wadda take kaiwa zuwa wani daban-daban ji na ƙwarai to dũkiyar cholinergic synapses pharmacological yanayi.

Nau'in dangane da wuri

Biochemists da dama iri M-cholinergic rabe:

• Located in autonomic ganglia da tsakiya m tsarin. A fasalin na farko shi ne cewa su suna located waje na synapses - M1-cholinergic rabe.
• Located a cikin zuciya. Wasu daga cikin su taimaka wajen rage a saki acetylcholine - M2-cholinergic rabe.
• Located in m tsoka, kuma a mafi yawan endocrine gland - da M3-cholinergic rabe.
• Located a cikin zuciya, a ganuwar da na huhu Alveoli, a cikin CNS - M4-cholinergic rabe.
• Sanya shi a cikin CNS, a cikin Iris na ido, salivary gland, a mononuclear jini Kwayoyin - M5-cholinergic rabe.

A tasiri a kan cholinergic rabe

Mafi yawa daga cikin effects bayar da sani pharmacological abubuwa da shafi da M-cholinergic rabe, saboda da hulda daga cikin wadannan abubuwa da kuma postsynaptic M2 da M3 cholinergic rabe.

Ka yi la'akari da rarrabuwa na kudi da ta da cholinergic synapses kasa.

H-cholinergic rabe dake a cikin membrane na postsynaptic neurons a ganglia endings na kowane preganglionic zaruruwa (a parasympathetic kuma m ganglia), a yankin na carotid sinus, a cikin adrenal medulla, a neurohypophysis, a Renshaw Kwayoyin a kwarangwal tsoka. Ji na ƙwarai daga daban-daban H-cholinergic rabe dabam domin abubuwa. Alal misali, H-cholinergic rabe a autonomic ganglia Tsarin (tsaka tsaki irin rabe) da gagarumin bambanci daga H-cholinergic rabe a kwarangwal tsoka (tsoka-type rabe). Yana da wannan yanayin ba su zuwa selectively toshe ganglia musamman abubuwa. Alal misali, kurarepodnye abu iya tarewa neuromuscular watsa.

Presynaptic cholinergic rabe da adrenoceptors suna da hannu a cikin tsari aiwatar da acetylcholine saki a synapse neuroeffector yanayi. Ruri daga wadannan rabe zai hana a saki acetylcholine.

Acetylcholine reacts tare da H-acetylcholine rabe da kuma canza su conformation, qara matakin na permeability na postsynaptic membrane. Acetylcholine yana da wani ya haramta motsa sakamako a kan sodium ions, wanda sa'an nan shiga cikin cell, da kuma wannan take kaiwa zuwa gaskiya cewa postsynaptic membrane ne depolarized. Da farko akwai wani gida synaptic m cewa ya kai wani daraja, da kuma fara aiwatar da samar da aikin m. Bayan haka, na gida da tashin hankali, wanda aka iyakance zuwa synaptic yanki fara watsa a fadin jikin tantanin. Idan akwai ruri na M-choline tsoka mai amsa sigina, da gagarumin irin rawa da na biyu da manzanni da kuma G-sunadarai a cikin siginar watsa.

Acetylcholine abubuwa a wani dan kankanin lokacin. Wannan shi ne saboda da cewa shi ne hanzari hydrolyzed da enzyme acetylcholinesterase. Choline, wanda aka kafa a lokacin da hydrolysis da acetylcholine a rabin girma na presynaptic m aka kama da kuma hawa zuwa cytoplasm ga m biosynthesis na acetylcholine.

Abubuwa da aiki a kan cholinergic synapses

Pharmacological kuma da dama sunadarai zai iya tasiri a yawan matakai da ake dangantawa da synaptic watsa:

• Tsari acetylcholine kira.
• Tsari matsakanci saki. Alal misali, carbacholine iya inganta acetylcholine saki tsari, wani botulinum toxin iya hana neurotransmitter saki tsari.
• Kan aiwatar da hulda tsakanin acetylcholine kuma choline tsoka mai amsa sigina.
• Hydrolysis da acetylcholine enzymatic yanayi.
• Kame choline, kafa ta hydrolysis da acetylcholine presynaptic m. Alal misali, za a iya hana gemiholiny na neuron kama da sufuri da na choline a cikin cell cytoplasm.

rarrabuwa

Yana nufin stimulating da cholinergic synapses, za a iya samar da ba kawai da sakamako, amma anticholinergic (yanã raunanar) sakamako. A matsayin dalilin da rarrabuwa na irin wannan abubuwa biochemists amfani da shugabanci na mataki na wadannan mahadi a kan daban-daban cholinergic rabe. Idan bi don irin wannan manufa, da abubuwa da shafi cikin cholinergic rabe za a iya classified kamar haka:

• Abubuwa da samun wani tasiri a kan M-cholinergic rabe da kuma N-cholinergic rabe: a holinomimetikami ne acetylcholine da carbacholine kuma holinoblokatoram - tsiklodol.
• anticholinesterase yanayi nufi. Wadannan sun hada da salicylate, physostigmine, Neostigmine, galantamine hydrobromide, Armin.
• Abubuwa da shafi cholinergic synapses. By cholinomimetics hada pilocarpine hydrochloride da aceclidine zuwa holinoblokatoram - atropine sulfate, matatsin, tartrate platifillina, ipratropium bromide, hydrobromide skopalamina.

• Abubuwa da vlinyanie H-cholinergic rabe. By holinomimetikami ne tsititon da lobeline hydrochloride. H blockers nicotinic acetylcholine tsoka mai amsa sigina za a iya raba kungiyoyin biyu. A farko - a na nufin ganglioblokiruyuschimi hali. Wadannan sun hada da benzogeksony, gigrony, pentamin, arfonad, pyrylium. Na biyu kungiyar vkulyuchaet a Curariform abu. Wadannan sun hada da tsoka relaxants, samar da gefe mataki kamar tubocurarine chloride, pancuronium bromide, bromide pipekuroniya.

Mun yi nazari a daki-daki da wajen shafi cholinergic synapses.