opening of Na channels on the PSN - depolarising the PSM form an AP
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Inhibitory NT cause
opening of Cl- channels on PSN- cause hyperpolarisaion - RMP falls below normal - less likely for AP to form
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Example NTs
ACh, Biogenic amines, AAs, peptides
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Biogenic amines
can be excit or inhib. adrenaline/noradrenaline/serotinin/histamine
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AAs
E+I , examples GABA, glutamate, glycine
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Autoinhibition
NT which binds to and activates PSN also binds to PreSN and blocks Ca channels preventing vesicles fusing and preventing overstimulation of the PSN by NT
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motor end pate
the presynaptic neurone + muscle membrane
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what do many PSN mem have to prevent over stim?
enzyme which breaks down NT. NT is often retaken up by the PreSN
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Nerve gases
block action of acetylcholinesterase - casuing overstim
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Neuromuscular blockers (NMB)- botox
prevents release of ACh in NMJ, causing relaxation of muscles
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NMB - example - curare
from poison dart frog, ACh receptor blocker - relaxes muscle as less Ach binds to PSN - usfeul in surgey as can be used and subsequently reduces the amount of anesthetic req- making safer
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Myasthenia gravis
autoimmune disease, cause destruction of Ach receptors
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How can treat this ?
increase conc of NT by using enzyme inhibitor - prevent breakdown. immuno-suppressants. removal of thymus(where immune cells mature)
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Other cards in this set
Card 2
Front
Excitatory NT cause
Back
opening of Na channels on the PSN - depolarising the PSM form an AP
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