Neurotransmitters Thiab Neuromodulators: Lawv Ua Haujlwm Li Cas?

Zoo Siab

• Peb piav qhia qhov ua haujlwm yooj yim ntawm synapses.
• Qhov sib txawv ntawm neurotransmitter thiab neuromodulator
• Hom neeg txais
• Ionotropic receptors
• Metabotropic receptors
• Cov chav kawm ntawm neurotransmitters
• 1. Acetylcholine
• 2. Biogenic amines
• 3. Tshaj tawm cov amino acids
• 4. Neuropeptides

Peb piav qhia qhov ua haujlwm yooj yim ntawm synapses.

Nws tuaj yeem hais tau tias hauv txhua lub paj hlwb muaj txoj hauv kev sib txuas lus nrog ib leeg hu ua synapses.

Ntawm synapses, neurons sib txuas lus sib tham los ntawm cov neurotransmitters, uas yog cov luag haujlwm lav lub luag haujlwm xa cov cim los ntawm ib qho neuron mus rau lwm qhov. Lwm cov khoom hu ua neuromodulators tseem cuam tshuam hauv kev sib txuas lus ntawm cov leeg hlwb

Ua tsaug rau neurotransmitters thiab neuromodulators, cov neurons hauv peb lub hlwb muaj peev xwm tsim cov torrents ntawm cov ntaub ntawv uas peb hu ua "txheej txheem kev xav", tab sis cov lwg me me no tseem pom nyob ib puag ncig ntawm lub paj hlwb, nyob rau hauv cov lus sib dhos ntawm lub cev muaj zog neurons (neurons ntawm lub hauv nruab nrab lub paj hlwb uas ua haujlwm lawv cov axons rau cov leeg lossis qog), qhov uas lawv txhawb cov leeg nqaij kom cog lus.

Qhov sib txawv ntawm neurotransmitter thiab neuromodulator

Ob lossis ntau cov tshuaj neuroactive tuaj yeem nyob hauv tib lub paj hlwb thiab ib qho tuaj yeem ua haujlwm zoo li lub paj hlwb thiab lwm yam ua lub paj hlwb.

Li no lawv qhov sib txawv: cov neurotransmitters tsim lossis tsis ua qhov muaj peev xwm (hluav taws xob cuam tshuam uas tau tsim tawm hauv lub xovtooj ntawm tes), qhib cov postsynaptic receptors (receptors ntawm postsynaptic cells lossis neurons) thiab qhib ion raws (cov protein ntawm lub paj hlwb uas muaj pores uas thaum lawv qhib , lawv tso cai hla cov nqi them xws li ions), qhov neuromodulators tsis tsim cov peev txheej ua tab sis theej tswj cov haujlwm ntawm ion raws.

Ib qho ntxiv, neuromodulators hloov kho qhov ua tau zoo ntawm postsynaptic cell membrane muaj peev xwm tsim tawm ntawm ion channel-cuam tshuam cov neeg txais khoom. Qhov no tshwm sim los ntawm kev ua kom cov protein G (cov khoom uas nqa cov ntaub ntawv los ntawm tus txais rau cov protein ua kom muaj zog). Ib tus neeg xa xov paj hlwb qhib lub channel, thaum lub neuromodulator cuam tshuam rau ib lossis ob kaum ob G cov protein, uas tsim cov cAMP molecules, qhib ntau txoj hauv kev ion tib lub sijhawm.

Muaj kev sib raug zoo ntawm kev hloov pauv sai hauv lub paj hlwb thiab kev xa cov neurotransmitters thiab hloov pauv qeeb nrog neuromodulators. Ib yam li ntawd, lub sijhawm nyob ntsiag to (uas yog, kev hloov pauv hauv lub cev muaj peev xwm ua tau vim muaj kev cuam tshuam ntawm lub paj hlwb) ntawm cov neurotransmitters yog 0.5-1 milliseconds, qhov uas ntawm neuromodulators yog ob peb feeb. Tsis tas li ntawd, "kev cia siab rau lub neej" ntawm cov kab mob neurotransmitters yog 10-100 ms. thiab cov neuromodulators yog los ntawm feeb mus rau teev.

Hais txog qhov sib txawv ntawm cov neurotransmitters thiab neuromodulators raws li lawv lub cev, cov neurotransmitters zoo ib yam li cov me me 50-mm vesicles. hauv txoj kab uas hla, tab sis hais tias ntawm neuromodulators yog qhov loj ntawm 120-mm vesicles. txoj kab uas hla

Hom neeg txais

Cov tshuaj tsis muaj zog tuaj yeem khi rau ob hom kev txais, uas yog cov hauv qab no:

Ionotropic receptors

Lawv yog cov txais tos uas qhib cov ion. Feem ntau, pom cov neurotransmitters.

Metabotropic receptors

Cov neeg txais kev khi rau G cov protein. Ntawm metabotropic receptors, neuromodulators feem ntau khi.

Kuj tseem muaj lwm hom receptors uas yog tus neeg txais tos lossis presynaptic receptors uas koom nrog kev sib xyaw ntawm cov tshuaj tso tawm ntawm lub davhlau ya nyob twg. Yog tias muaj kev tso tawm ntau dhau ntawm cov tshuaj neuroactive, nws khi rau cov neeg txais kev xav thiab ua rau muaj kev txwv tsis pub ua ke kom tsis txhob qaug zog ntawm lub cev.

Cov chav kawm ntawm neurotransmitters

Neurotransmitters tau muab cais ua pawg: acetylcholine, biogenic amines, xa cov amino acids, thiab neuropeptides.

1. Acetylcholine

Acetylcholine (ACh) yog tus xa xov ntawm lub paj hlwb sib txuas, nws tau sib sau ua ke hauv septal nuclei thiab lub qhov ntswg ntawm Meynert (nuclei ntawm lub paj hlwb yav dhau los), nws tuaj yeem yog ob qho tib si hauv nruab nrab lub paj hlwb (qhov chaw uas lub paj hlwb thiab tus txha caj qaum nyob) zoo li nyob rau hauv lub paj hlwb sab hauv (seem) thiab ua rau muaj kab mob xws li myasthenia gravis (kab mob neuromuscular uas yog vim qhov tsis muaj zog ntawm cov leeg pob txha) thiab cov leeg dystonia (teeb meem tshwj xeeb los ntawm kev txav mus los yam tsis xav tau).

2. Biogenic amines

Biogenic amines yog serotonin thiab catecholamines (epinephrine, norepinephrine, thiab dopamine) thiab ua feem ntau los ntawm cov neeg txais khoom metabotropic.

3. Tshaj tawm cov amino acids

Qhov tseem ceeb tshaj plaws excitatory transmitter amino acids yog glutamate thiab aspartate, thiab cov tshuaj tiv thaiv yog GABA (gamma immunobutyric acid) thiab glycine. Cov neurotransmitters no tau faib thoob plaws hauv lub hlwb thiab koom nrog yuav luag txhua qhov sib txuas hauv CNS, qhov uas lawv khi rau ionotropic receptors.

4. Neuropeptides

Neuropeptides yog tsim los ntawm cov amino acids thiab ua feem ntau ua neuromodulators hauv CNS. Cov txheej txheem ntawm kev sib txuas tshuaj synaptic tuaj yeem cuam tshuam los ntawm cov tshuaj psychoactive uas cuam tshuam rau lub hlwb yog txhawm rau hloov kho qhov ua tau zoo uas cov tshuaj siv tshuaj sib txuas lus tshwm sim, thiab qhov no yog vim li cas qee qhov ntawm cov tshuaj no yog siv los kho cov cuab yeej. hauv kev kho mob ntawm kev puas siab puas ntsws thiab kab mob neurodegenerative.