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35 Cards in this Set
- Front
- Back
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How does cocaine addiction affect the makeup of the nervous system? |
Increase in dendritic spinal density Sensitisation of neurons through the upregulation of the gene MEF2. |
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What do optogenetics in mice show? |
Shows that newly acquired motor skill depends on the formation of task specific dense synaptic ensembles |
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What effect does the alkaloid "Muscarine" have on the body? What species is it from? |
Slows heart rate. Amanita muscarina |
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What effect does the alkaloid "Atropine" have on the body? What species is it from? |
Alkaloid which blocks the actions of muscarine and shows vagal stimulation. Deadly Nighthase - Atropa belladonna |
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What effect does nicotine have on the body? |
Stimulates contraction of skeletal muscles. |
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What effect does 'Curare' have on the body? In the past whats was this used for? |
Blocks action of nicotine and the neuromuscular junction. Used as the poison on the tip of poison arrows of SA indians. |
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What processes can be targeted in the pre synaptic knob for inhibition? Give an example of a molecule or group of molecules which block each. |
1. Acetlycholine (ACh) carrier inhibition - so ACh vesicles are not shuttled to the membrane - Vesamicol 2. Acetylcholine exocytosis inhibition - Presynaptic toxins 3. Choline carrier inhibition to prevent reuptake of choline into the presynaptic knob - hemicholinium 4. Inhibition of the pre-synaptic nicotinic ACh receptor - Non depolarising blocking agents |
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What are the effects of tetanus in the nervous system and thus on the wider body? |
Prevents fusion of vesicles wit h the presynaptic membrane. Functions on inhibitory neurons so increases muscular contraction. |
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What processes can be targeted in the post synaptic knob & synaptic cleft for inhibition? Give an example of a molecule or group of molecules which block each. |
1. Acetylcholinesterase inhibition - prevents breakdown of acetylcholine - Neostigmine, Sarin 2. Non Depolarising Blocking Agents - prevent fusion of acetylcholine to the post synaptic ligand bound receptors. 3. Depolarising blocking agents which mimic acetylcholine but are not broken down by acetylcholinesterase - succinylcholine. |
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What are the effects of sarin in the nervous system and thus on the wider body? |
Sarin is a nerve gas which inhibits acetylcholinesterase. This results in uncontrolled muscle contraction. |
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What are the effects of tetrodotoxin in the nervous system and thus on the wider body? |
Binds to voltage gated sodium channels and prevents action potentials from forming. Results in paralysis. |
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What type of receptor are muscarinic receptors? |
G - Protein coupled |
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Where are muscarinic receptors found? |
Post-ganglionic parasympathetic nerve terminals. |
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How many types of Muscarinic receptors are there? What is the nomenclature? |
5 types - M1, M2, M3, M4, M5 |
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What is another name for M1 receptors? |
Neural |
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What G protein types make up M1 receptors? |
Gi, Gs & Gq |
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Where are M1 receptors found? How are they signalled? |
1. Mainly found in the CNS 2. Signalled via IP3 / Ca2+ pathway and inhibition of K+ channels |
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What is another name for M2 receptors? |
Cardiac |
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What G protein types are M2 receptors? |
Gi |
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Where are M2 receptors found? How are they signalled? What is their effect? |
1. Mainly in the heart and some in the CNS 2. Signal via cAMP inhibition and activation of K+ channels 3. Effect: slows the speed of depolarisation |
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What is another name for M3 receptors? |
Glandular / Smooth muscle receptors |
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What G protein type are M3 receptors? |
Gq |
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Where are M3 receptors found? What physiological responses do they promote? |
1. Mainly glands and smooth muscle 2. Promotes glandular secretion, vasoconstriction of the lung and vasodilation of the blood vessles. |
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Where are M4 and M5 receptors found? What G protein types are they? |
1. Mainly in the CNS 2. M4 - Gi M5 - Gq |
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What is the drug type which stimulate muscarinic receptors termed? And inhibits? |
1. Parasympathomimetics - effects resemble PS system stimulation 2. Parasympatholytics - effects reverse of PS system |
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What drug can be used to target M3 receptors? What effect does this have? |
1. Bethanechol
2. Clinically used to relieve bladder + GI hypotonia |
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What drug can be used to treat glaucoma? |
Pilocarpine |
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How specific are most muscarinic receptor agonists? |
Most are non selective for the M1 - M5 subtypes |
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What are the cardiovascular effects of muscarinic agonists. |
1. Bradycardia (BPM <60) 2. Low Cardiac output 3. Vasodilation - lowers blood pressure |
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What are the effects of muscarinic agonists on smooth muscle? What physiological effects does this have? |
1. Contraction of smooth muscle except vascular smooth muscle 2. - increase in peristaltic activity, bladder contraction, constriction of bronchioles |
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What are the effects of muscarinic agonists on the eye? What is the key physiological effect this has? |
1. Pupil constriction 2. Constriction of the ciliary muscle - decrease in intraocular pressure (perfect for treating glaucoma) |
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What are the effects of muscarinic agonists on glands and the central nervous system? |
Increase in glandular secretion. 'Central' effects: 1. Tremor 2. Hypothermia 3. Increased locomotive activity 4. Improved cognition |
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What are the clinical uses of muscarinic agonists? |
Main: For treating glaucoma Secondary: Dry eye & mouth Rare: Urinary retention - bethanechol |
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How would you treat urinary retention or weak muscles in the GI tract? What are its side effects? |
Bethanechol Side effects: 1. Sweating 2. Blurred vision 3. Bradycardia |
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What is the drug used by opticians to make pupils dilate? What is the effect on muscarinic receptors? |
1. Atropine 2. Is a muscarinic antagonist. |
