Qhov sib txawv tseem ceeb ntawm GABA A thiab GABA B yog tias GABA A receptors yog ligand-gated ion channels thaum GABA B receptors yog G protein-coupled receptors.
Gamma-aminobutyric acid (GABA) yog ib qho inhibitory neurotransmitter hauv lub hlwb. Muaj cov receptors rau GABA no. GABA A thiab GABA B yog ob hom receptors. Thaum GABA A receptors yog ligand-gated ion channels, GABA B receptors yog G protein-coupled receptors. GABA A thiab GABA B txawv ntawm ib leeg vim muaj ntau yam ntxwv, raws li tau tham hauv kab lus no.
GABA A yog dab tsi?
GABA A yog ib qho ntawm ob hom receptors uas khi nrog GABA. Nws yog ligand-gated Cl– ion channel. Hauv lwm lo lus, nws yog ib qho ionotropic receptor faib feem ntau hauv postsynaptic membrane ntawm CNS. Tsis tas li ntawd, GABA A yog ib qho transmembrane receptor uas yog pentameric, muaj tsib subunits nyob ib ncig ntawm lub hauv paus tseem ceeb. Lub tsib subunits yog ob subunits ntawm α, ob subunits ntawm β thiab ib tug subunit ntawm γ.
Daim duab 01: GABA A
GABA A yog xaiv permeable rau Cl– ions. Thaum cov receptor no khi nrog nws cov ligand GABA, nws ua haujlwm thiab qhib nws qhov pore thiab tso cai rau Cl– ions hla dhau. Txawm li cas los xij, nyob ntawm qhov muaj peev xwm ua tau ntawm tes, Cl– ions yuav ntws tawm ntawm / mus rau hauv lub cell. Tsis tas li ntawd, kev nkag mus ntawm Cl-ions ua rau hyperpolarization ntawm lub paj hlwb, ua rau muaj kev cuam tshuam ntawm neurotransmission.
GABA B yog dab tsi?
GABA B yog lwm hom GABA receptors tam sim no hauv lub hlwb. Lawv yog cov metabotropic receptors, uas yog G protein-coupled receptors. Nws yog dimeric muaj ob subunits.
Daim duab 02: GABA B
GABA B receptors yog tam sim no ob qho tib si ua ntej thiab postsynaptically. Zoo ib yam li GABA A, GABA B kuj yog ib qho transmembrane receptor. Ntawm no, tus receptor no inhibits calcium channels thiab activates potassium raws. Ntxiv mus, nws inhibits adenyl cyclase.
Dab tsi zoo sib xws ntawm GABA A thiab GABA B?
- GABA A thiab GABA B yog ob chav kawm ntawm GABA receptors.
- Lawv khi nrog neurotransmitter gamma-aminobutyric acid.
- Ntxiv mus, ob lub receptors no muaj nyob rau hauv lub hauv paus paj hlwb.
- Lawv yog transmembrane receptors.
- Kuj, ob qho tib si dav.
- Dhau li ntawm, khi ntawm GABA rau ob qho tib si receptors ua rau inhibition ntawm neurotransmission.
Qhov txawv ntawm GABA A thiab GABA B yog dab tsi?
GABA A thiab GABA B yog ob chav kawm ntawm GABA binding receptors. GABA A yog ligand-gated ion channel thaum GABA B yog G protein-coupled receptor. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm GABA A thiab GABA B. Tus qauv tsim, GABA A yog pentamer thaum GABA B yog dimer. Yog li, peb tuaj yeem xav txog qhov no kuj yog qhov sib txawv ntawm GABA A thiab GABA B.
Ntxiv mus, qhov sib txawv ntxiv ntawm GABA A thiab GABA B yog qhov hnyav molecular ntawm GABA A yog 300 kDa, thaum qhov hnyav molecular ntawm GABA B yog 80 kDa.
Cov lus qhia hauv qab no qhia txog qhov sib txawv ntawm GABA A thiab GABA B.
Summary – GABA A vs GABA B
GABA A thiab GABA B yog ob lub GABA khi receptors. GABA A yog ligand-gated ion channel thaum GABA B yog G protein-coupled receptor. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm GABA A thiab GABA B. Tsis tas li ntawd, GABA A yog pentamer tsim los ntawm tsib subunits, thaum GABA B yog ib qho dimer muaj li ntawm ob subunits. Tsis tas li ntawd, GABA A tau faib tawm tom qab-synaptically hauv CAS thaum GABA B raug faib ua ntej thiab tom qab-synaptically hauv CNS. Yog li, qhov no qhia txog qhov sib txawv ntawm GABA A thiab GABA B.
