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15 Cards in this Set
- Front
- Back
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name the 2 types of neurotransmitter
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1) amines and maino acids 2)peptides |
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where are amines and amino acid neurotransmitters produced?
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produced in synaptic terminal using synthesising enzymes that are transported from the cell body
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are peptides or amines more effective neurotransmitters and why
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amines because they are produced locally and can be converted to other things in a single step locally by enzymes so are very fast
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name the 2 types of synaptic vesiscle, what size are they? what do they carry?
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1) small clear vesicles (40-60nm) carry amines and amino acids 2) large dense core vesicles (90-250nm) these carry peptide neurotransmitters |
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what is coexistence/ co transmission
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when a single neuron may synthesise and release more than one transmitter substance
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when the AP arrives and voltage gated CA channels open what do intracellular ca levels change to and how long does this take?
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0.0002 to 0.1mM which is a 100x increase and all this happens in 0.2 seconds
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what are snare proteins?
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they have a lipidphillic end which gets incorporated into membrane and has a cytosolic tail. they help fusion of vesicles with the membrane
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what are the 2 types of SNARE complexes and where are they found
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tSNARES = found on the plasma membrane side vSNARES |
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what is synaptobrevin, syntaxin and SNAP 25 basically
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they are all these strings of membrane proteins which help the vesicle to bind
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what is synaptotagmin
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is a ca sensory, calcium increase causes membrane juxtapositions and allows fusion
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name and describe the 2 types of neurotransmitter receptors, which one is fast response?
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1)metabolic receptors = are coupled to intracellular proteins that transduce the signal to the cell inside, its a slow response 2) inotropic receptors = these are mainly ion channels that depolarise or hyperpolarise the postsynaptic cell, its a fast resposne |
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why is rapid release of the NT from the receptor important?
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otherwise its either constantly firing which can lead to diseases or it causes desensitivity
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name 3 ways the NT is removed from the receptor
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1) diffusion of NT out of synaptic cleft where they will be degraded by enzyme proteases form the extraceullular matrix 2)vesicle recycling where reuptake of NT back into pre synaptic terminal by endocytosis and neurotransmitters 3) enzymatic breakdown of NT such as acetylcholine esterases |
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how do vesicle transporters work? do they concentrate NT? are they specifc?
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they concentrate NT into vesicles by up to 1000x, they are not specific as several NT's may use same type of transporter. they move by active transport which gets its energy from ATPase proton transpoter in surface membrane so they rely on proton gradient across membrane
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how do membrane transporters work? are they specific? where do they concentrate the NT?
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reuptake NT from synaptic cleft, they are specific for each NT. they still need active transport to move which they get their energy by na+ channels. they concentrate NT in cytoplasm
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