Term
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Definition
1. Compounds made by special metabolic pathways (ACh, GABA, catecholamines)
2. compounds made by standard metabolic pathways (glutamate (ex), glycine (inhib) ATP)
3. unconventional compounds (not stored in vesicles, act as retrograde messengers - work in opposite direction) |
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Term
| Inactivation of synaptic responses: Degradative enzymes |
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Definition
For some neurotransmitters, synaptic responses are terminated by specific enzymes e.g:
ACh - acetylcholinesterase
ATP - nucleotideases
Peptides - peptidases |
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Term
| Inactivation of synaptic responses: Reuptake transporters |
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Definition
For synapses using GABA, glutamate, glycine, histamine and catcholamines: no inactivating enzymes exist.
Instead transmitter is removed by reuptake pump which pumps transmitter back into cell
Pump inhibitors are e.g. SSRI's (Prozac) |
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Term
| ionotropic receptor families |
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Definition
1. Cys loop
2. iGluR
3. P2X |
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Term
| nicotinic ACh receptor (cys loop) |
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Definition
| - 5 subunits 4 TM domains - M2 = major area of each sub-unit - ACh binds to extracellular cys-loop - NEED 2 molecules of ACh to bind to activate channel |
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Term
| GABAa and Glycine receptors (cys loop family) |
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Definition
GABAa are main inhibitory recptors in brain
Glycine are major inhibitory receptors of spinal cord
5 subunits with 4 TM domains
Channels only allow CL- flow
GABA generates outward current (inward CL- flow) hyperpolarizing cell
Valium, barbituatres, alcohol keep GABAa open longer, causing inhibition
strychnine blocks glycine channel |
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Term
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Definition
poor loop on INSIDE of cell
binding domain is extracellular
4 subunits |
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Term
| Glutamate receptors (iGluR) |
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Definition
have completely diff structure than nAChRs
- 4 subunits with 3 TM domains each
- pore loop between TM1 and TM2
- glutamate binds within single subunit
AMPA and kainate (KA) subtypes have 4 glutamate binding sites
NMDA subtype have has 2 glutamate sites and 2 glycine sites |
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Term
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Definition
Present in all vertebrates
seven genes in humans
3 subunits with 2 TM domains each
site of ATP binding is between subunits (need 2 molecules) large extracellular loop |
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