Term
| What is the synapse between a neuron and an effector cell called? |
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Definition
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Term
| What are the terms for the first neuron and the second neuron which receives the signal? |
|
Definition
| Presynaptic neuron; postsynaptic neuron |
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Term
| What is the space between the presynaptic and postsynaptic neuron called? |
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Definition
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Term
| What is the term for a synapse between an axon terminal and a dendrite? |
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Definition
|
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Term
| What is the term for a synapse between an axon terminal and a cell body? |
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Definition
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Term
| What is the term for a synapse between two axon terminals on different cells? |
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Definition
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Term
| What is the function of an axoaxonic synapse? |
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Definition
| Modulating communication at axodendritic and axosomatic synapses |
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Term
| What stores neurotransmitters in the presynaptic neuron? |
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Definition
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Term
| What triggers release of a synaptic vesicle? |
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Definition
| Opening of a calcium channel after a depolarization |
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Term
| What are three ways to get rid of neurotransmitters in the synapse? |
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Definition
| Degragation by enzymes, reuptake, or diffusion away from the synaptic cleft |
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Term
| What is another name for a channel-linked receptor? |
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Definition
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Term
| What is the term for a G-protein linked receptor a neurotransmitter binds to? |
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Definition
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Term
| What are two differences between a channel-linked receptor and a G protein-linked receptor? |
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Definition
| G protein-linked receptors are slower and can cause a channel to open or close |
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Term
| What two ways can a G protein-linked channel respond to a neurotransmitter? |
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Definition
| By activating an ion channel, or activating a 2nd messenger system |
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Term
| Are neurotransmitter effects always excitatory? |
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Definition
| No, they can be inhibitory (hyperpolarizing) as well |
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Term
| What is the term for an excitatory response due to a neurotransmitter? |
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Definition
| An excitatory post synaptic potential (EPSP) |
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Term
| Are EPSPs and IPSPs graded? |
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Definition
| Yes, they are strongest at the site of origin (usually a dendrite or cell body) |
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Term
| Explain how a EPSP would work |
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Definition
| By binding a neurotransmitter to an ion channel (sodium would move much faster in than potassium would move out) |
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Term
| What usually causes an IPSP? |
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Definition
| The opening of a chloride channel |
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Term
| Which direction is the force for chloride in a neuron? |
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Definition
| Into the cell, hyperpolarizing it |
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Term
| What two results can an inhibitory synapse cause in the posynaptic cell? |
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Definition
| It can hyperpolarize it or stabalize the neuron at resting value |
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Term
| Why is the movement of chloride into a cell an IPSP? |
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Definition
| Because chloride is negative |
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Term
| If chloride channels are open in a cell, what is the effect on an EPSP? |
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Definition
| It can diminish or erase it because the EPSP will make the inside of the cell more positive and pull chloride in |
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Term
| What is a "divergence" arrangement? |
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Definition
| The axon of one neuron has several collaterals that bind to several other neurons |
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Term
| What is a "convergence" arrangement? |
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Definition
| A neuron recieves communication from 100s-1000s of ther neurons |
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Term
| Define neural integration |
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Definition
| The summation proccess from the 100s-1000s of signals arriving from all active synapses |
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Term
| Describe frequency coding |
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Definition
| If action potentials occur at higher frequency, then more neurotransmitter is released, causing stronger communication in the next neuron |
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Term
| In axoaxonic synapses, what is another name for the presynaptic neuron? |
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Definition
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Term
| How does a modulating neuron generally work? |
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Definition
| By changing the amount of calcium in the cytosol of the 2nd axon, inhibiting or facilitating neurotransmitter release |
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Term
| What effect does increasing the amount of calcium in the cytosol of an axon terminal (presynaptic facilitation)? |
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Definition
| It increases the amount of neurotransmitter released |
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Term
| What is the most abundant neurotransmitter in the PNS? |
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Definition
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Term
| From what is acetylcholine synthesized? |
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Definition
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Term
| What enzyme catalyzes the synthesis of acetylcholine? |
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Definition
| Choline acetyl transferase |
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Term
| Why is acetylcholine found in almost all cells of the body? |
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Definition
| It is a 2-carbon molecule produced during energy catabolism and is the initial substrate for the Kreb cycle |
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Term
| What is the term for neurons that synthesize and release acetylcholine? |
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Definition
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Term
| What is the term for postsynaptic neurons that recieve acetylcholine? |
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Definition
|
|
Term
| What enzyme degrades acetylcholine? |
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Definition
|
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Term
| What does acetylcholine break down into? |
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Definition
|
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Term
| What are the two types of acetylcholine receptors? |
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Definition
| Nicotinic cholinergic receptots (named because nicotine can bind to it) and muscarine cholinergic receptors (named because muscarine can bind to it) |
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Term
| What are the three catecholamines? |
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Definition
| Dopamine (DA), norepinephrine (NE), epinephrine (EPI) |
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Term
| Where are muscarine cholinergic receptors found? |
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Definition
| On visceral organs and in the central nervous system |
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Term
| What do the biogenic amines include? |
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Definition
| The catacholamines, serotonin, and histamine |
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Term
| What catechoamine(s) is/are released primarily in the CNS? |
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Definition
| Dopamine and norpeinephrine |
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Term
| What catechoamine(s) is/are released primarily in the PNS? |
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Definition
|
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Term
| What are the receptors for epinephrine and norepinephrine called? |
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Definition
|
|
Term
| What are receptors that bind to dopamine called? |
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Definition
|
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Term
| What kind of response do biogenic amines usally create in a cell |
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Definition
| Activate G proteins and 2nd messenger systems, or act as autocrines |
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Term
| What are the two enzymes that degrade catecholamine neurotransmitters? |
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Definition
| monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) |
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Term
| Where is catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO) located? |
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Definition
|
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Term
| What are the functions of serotonin? |
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Definition
| Regulate sleep and emotions |
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Term
| What amino acid neurotransmitters are excitatory? |
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Definition
|
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Term
| What amino acid neurotransmitters are inhibatory? |
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Definition
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Term
| What is the most commonly released amino acid neurotransmitter at excitatory synapses? |
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Definition
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Term
| How are neuropeptides synthesized? |
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Definition
| Like other proteins, in the soma |
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Term
| What neuropeptides are classically known as hormones? |
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Definition
| TRH, vasopressin, and oxytocin |
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Term
| What is the function of the neuropeptide "endogenous opoids"? |
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Definition
| Similar effects as morphine |
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Term
| What neurotransmitters do the endogenous opoids include? |
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Definition
| Enkephalins and endorphins |
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Term
| How does nitric oxide defy the general pattern for neurotransmitters? |
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Definition
| It is a gas, has a very simple structure, is synthesized and diffuses on demand, and can travel to a far away synapse and diffuse inside it |
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Term
| What enzyme controls the rate of nitric oxide releae? |
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Definition
Nitric-oxide synthetase
(Note: nitric oxide degrades on its own in a few seconds without enzymes) |
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Term
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Definition
| A motor neuron plus all the muscle fibers it innervates |
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Term
| What is the neurotransmitter for the neuromuscular junction? |
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Definition
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Term
| What kind of receptors are on the motor end plate? |
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Definition
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Term
| What type of potential is an end plate potential? |
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Definition
| Graded, but is almost always of sufficient magnitude to depolarize a muscle fiber to threshold |
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Term
| What degrades acetylcholine, and where is it found on the motor end plate? |
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Definition
| Acetylcholinesterase, between the invaginations |
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Term
| In the breakdown of Ach, what is recycled, and what diffuses away? |
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Definition
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Term
| What is the effect of crotoxin? |
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Definition
| Inhibits release of Ach, flaccid paralysis |
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Term
| What is the effect of curae? |
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Definition
| Nicotonic receptor agonist |
|
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Term
| What are the effects of organophosphates? |
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Definition
Block acetylcholinesterase
It is used as insecticides and nerve gas |
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Term
| What is one cause of epilepsy? |
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Definition
| A lack of inhibitory neurotransmittors |
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Term
|
Definition
receptors on nerve terminal that are activated by neurotransmitter
released by the nerve terminal. Activation of autoreceptors decreases neurotransmitter
release (negative feedback). |
|
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Term
| Where are nicotinic (NAChR) receptors found? |
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Definition
| Both on muscle and in the peripheral and central nervous system |
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|
Term
| What is acetylcholine associated with in the brain? |
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Definition
|
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Term
| Describe the synthesis of catecholamines in order |
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Definition
1. Tyrosine
2. L-Dopa
3. Dopamine
4. Norepinephrine
5. Epinephrine |
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Term
| What are two treatment of Parkinson's disease involving neurotransmitters? |
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Definition
1. L-dopa is given to people with Parkinson's to make more dopamine
2. COMT inhibitors are used to discourage catecholamine elimination |
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Term
| What is the primary mechanism of elimination of the catecholamines (and indolamines? |
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Definition
| Reuptake into the nerve terminal |
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|
Term
| Describe Monoamine oxidase |
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Definition
| (MAO)- localized in mitochondria in the nerve terminal. MAO metabolizes both catecholamines and indolamines |
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|
Term
| Describe Catechol-O-methyl transferase (COMT) |
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Definition
| Primarily localized in the synaptic cleft, COMT degrades catecholamines. |
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|
Term
| What are the catecholamine receptors? |
|
Definition
1. dopamine – D1-D5
2. adrenergic receptors (norepinephrine and epinephrine)
α1, α 2, β1, β 2, β 3 |
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|
Term
|
Definition
| An Indolamine, also known as 5-hydroxytryptamine (5-HT), derived from tryptophan |
|
|
Term
| What are the serotonin receptors? |
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Definition
5-HT1 – 5-HT7
14 different subtypes of 5-HT receptors |
|
|
Term
| What are the inhibitory amino acid receptors? |
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Definition
GABA receptors: GABAA& GABAB
Glycine receptors abbreviated GlyR |
|
|
Term
| What are the excitatory amino acid receptors? |
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Definition
| Ionotropic (ligand-gated channels) – AMPA, kainate, N-methyl-D-aspartic acid (NMDA) |
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Term
| How are the amino acid neurotransmitters eliminated? |
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Definition
| Though reuptake into the presynaptic nerve terminal and glia |
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|
Term
|
Definition
| Many neuropeptides are also hormones, synthesized in cell body and transported down axon to nerve terminal |
|
|
Term
| What are the endogenous opiates? |
|
Definition
| Endorphins, dynorphins and enkephalins |
|
|
Term
|
Definition
| Opiate (neuropeptide) receptor for morphine and endorphin |
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Term
|
Definition
| Opiate (neuropeptide) receptor for enkephalins |
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|
Term
|
Definition
| Opiate (neuropeptide) receptor for dynorphin |
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|
Term
| Describe the receptors for Substance P, a neuropeptide |
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Definition
| tachykinin receptors NK1 – NK3 |
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|
Term
| What is Aprepitant (EMEND) used for? |
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Definition
| An NK1 antagonist, is used to prevent nausea due to chemotherapy by preventing Substance P from binding |
|
|
Term
| Define Nitric Oxide and what it does |
|
Definition
(endothelial derived relaxing factor, EDRF)
Found in nerves and other tissues such as endothelial cells lining blood vessels
Stimulates guanylate cyclase to produce cGMP |
|
|
Term
| How is Nitric Oxide synthesized? |
|
Definition
| NO is synthesized from arginine by nitric oxide synthase, which is Ca++ dependent. |
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Term
| What are four ways for a modulator to inhibit neurotransmission? |
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Definition
1. Blockade of action potential
2. Inhibition of neurotransmitter synthesis
3. Inhibition of neurotransmitter release
4. Receptor antagonism |
|
|
Term
| How do local anesthetics such as lidocane basically work? |
|
Definition
| They block action potentials in the presynaptic neuron |
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|
Term
| How does Clostridium botulinus (botox) work? |
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Definition
By inhibiting neurotransmitter release
Botulinium toxin gets rid of all the
snare proteins used for synaptic
fusion and release |
|
|
Term
| List three examples of receptor antagonism causing neurotransmitter inhibition |
|
Definition
curare (nicotinic receptor antagonist),
atropine (muscarinic receptor antagonist),
propranolol (β-adrenergic receptor antagonist) |
|
|
Term
| What are five ways for a modulator to potentiate neurotransmission? |
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Definition
1. Inhibition of neurotransmitter metabolism
2. Blockade of neurotransmitter reuptake
3. Allosteric modulation of receptor
4. Agonists
5. Precursors |
|
|
Term
| What effects can MAO inhibitors have on the body? |
|
Definition
The potentiation increases Norepinephrine and 5-HT levels.
Used as antidepressants and for Parkinson’s disease. |
|
|
Term
| Give two examples of Blockade of neurotransmitter reuptake |
|
Definition
Cocaine blocks dopamine reuptake
fluoxetine (Prozac) blocks serotonin uptake. |
|
|
Term
| Define Allosteric modulation of receptor |
|
Definition
| drugs bind to sites on receptor independent of the neurotransmitter biding site and modulate (increase or decrease) the activity of the neurotransmitter |
|
|
Term
| Give an example of Allosteric modulation of receptor |
|
Definition
| diazepam (Valium) binds to GABA receptors and potentiates the GABA-stimulated chloride conductance. |
|
|
Term
| Give an example of an agonist used for neurotransmitter potentiation |
|
Definition
| Administration of exogenous agonists phenylepherine, an α-adrenergic agonist |
|
|
Term
| How does neurotransmission in sensory neurons work? |
|
Definition
| If a sensory nerve's graded potential is stimulated to threshold, an action potential is propagated to the spinal cord. Neurotransmitter then released from the nerve terminals and activates the post-synaptic neuron in the CNS |
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