ionotropic receptors form a pore
Post on 16-Jan-2016
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Ionotropic receptors form a pore
unbound, closed bound, open
Metabotropic receptors are activated
unboundunactivated
boundactivated
AMPA receptor activation alone
Mg++ block intactrapid, brief, and small EPSP (Na +)
NMDA receptor activation alone
Mg++ block intactno electrical effect
Mg++ block relievedlarge EPSP (Na +, Ca ++); Ca++ release from internal stores
Coincident AMPA & NMDA receptor activation
Neuromuscular junction
Stained acetylcholine receptors
The GABAA receptor
Metabotropic receptor amplification
Dark current
Light turns off the dark current
Glaucoma
• Loss of peripheral vision typically associated with elevated ocular pressure due to insufficient drainage
• Treatment is aimed at either increasing drainage or decreasing aqueous humour production (even though excess aqueous humour production is rarely the pathological problem)
• Note that there is low (or normal) pressure glaucoma, poorly understood.
Ciliary body
Drugs used to treat glaucoma
Drug Receptor Drug action
Pilocarpine M3 agonist Contracts ciliary muscle, which allows more aqueous humour drainage, thereby decreasing intraocular pressure
Apraclonidine, brimonidine
α2 agonist Inhibits secretion of aqueous humour from the ciliary body and facilitates drainage of same, thereby decreasing pressure in the eye
Betaxolol 1 antagonist
Inhibits secretion of aqueous humour from the ciliary body
Timolol, levobunolol
1-2
antagonistInhibits secretion of aqueous humour from the ciliary body
Note this subset of the drugs used to treat glaucoma are ones that act on the ANS.
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