E3 Cholinergic Synapse & Biogenic Amines Flashcards
what are the two types of receptors in a cholinergic synapse
-nAChR or nicotinic
-mAChR or muscarinic
what are the two subcategories of nicotinic receptors
Nm
Nn
what are the subcategories of muscarinic receptors
M1-5
what are the major differences btwn muscarinic and nicotinic receptors
Muscarinic: G protein
Nicotinic: ion channel
where is acetylcholinesterase found
presynaptic and postsynaptic membranes
which muscarine receptors are used for inhibition
Even: M2 and M4
which muscarine receptors are used for stimulation
Odd: M1, M3, and M5
where are cholinergic synapses found
-neuromuscular junctions in somatic
-all neuromuscular/neuroglandular junctions in Parasympathetic
-many synapses in CNS
-all neuron-neuron synapses in ANS
what are some examples of preganglionic neurons
-Adrenal medulla
-Sympathetic
-parasympathetic
what does the the adrenal medulla pathway look like
-uses ACh receptors
-epinephrin released/used
-effector is an adrenergic receptor
what does the adrenal medulla do
-modified types of glandular cells that release epinephrine
-responsible for fight or flight
what are the two divisions of the sympathetic system
uses norepinephrine and ACh
what is effected from the release of norepinephrine from the sympathetic pathway
Adrenergic receptors
-Cardiac/Smooth muscle
-gland cells
-nerve terminals
what is effected by ACh released from the sympathetic nervous system
muscarinic receptors
-sweat glands
what happens during the parasympathetic pathway
Muscarinic receptors for ACh
-Cardiac/Smooth muscle
-gland cells
-nerve terminals
what is different about the somatic pathway
-no ganglia
-use Nicotinic receptors(ACh used)
-effects skeletal muscles
what does prednisone limit
syntheses from prostaglandin
what are leukotrienes
inflammatory mediators produced during hypersensitivity
what does Cytochrome P450 do
helps with liver and metabolism
T/F: Prostaglandins have an effect that is seen globally
F, only affects locally
What does thromboxane A2 do?
-Vasoconstriction
-stimulates platelet aggregation
what does EP2 do(Prostaglandin E2)
targets smooth muscle by:
-vasodilation
-increases blood flow
What does IP do?
-helps w clotting
-vasodilation
what happens after ACh is released from the receptor
Acetylcholinesterase breaks it down into:
Acetate
Choline
where do the parts of ACh go after acetylcholinesterase breaks it down
Choline: goes back into the cell
Acetate: released
where are most muscarinic inhibitor receptors found in the synapse
presynaptic membrane
where are most muscarinic stimulator receptors found in the synapse
postsynaptic membrane
what inhibitor muscarinic receptor found on the postsynaptic membrane
M4
where are orthosteric binding sites found
in the middle of the alpha transmembrane segments of the muscarinic receptor
where are the putative allosteric binding sites
end of the alpha transmembrane segments of the muscarinic receptor
what are biogenic amines and what do they montane
catecholamines
-catechol ring
what are examples of catecholamines
-dopamine
-norepinephrine(noradrenaline)
-epinephrine(adrenaline)
what are the neuronal fibers types for catecholamines
-dopaminergic
-noradrenergic
-adrenergic
how are catecholamines removed from the synapse
glial transporters which cause reuptake
what does reuptake of catecholamines do
prevents further release
what catabolizes catecholamines
Monoamine oxidases (MAO and MAO-B)
Catechol-methyltransferase (COMT)
where are the enzymes that catabolize catecholamines located
intracellular in neurons and glial cells(astrocytes)
what does tyrosine make in the synthesis of catecholamines and what enzyme does it use
L-Dopa
-by Tyrosine hydroxylase
what does L-Dopa make in the synthesis of catecholamines and what enzyme does it use
Dopamine
-by Dopa decarboxyalse
what does Dopamine make in the synthesis of catecholamines and what enzyme does it use
Norepinephrine
-by dopamine B-hydroxylase
what does norepinephrine make in the synthesis of catecholamines and what enzyme does it use
Epinephrin
-phenylethanolamine N-methyltransferase
what does the relative expression of neuron depend on
the enzymes present
where does catecholamine synthesis take place?
ER
what type of effect does norepinephrine have
-excitatory/depolarizing effect
where is norepinephrine distributed
brain
Sympathetic part of ANS
what does norepinephrine help
fight or flight response
What are all adrenergic receptors
metabotropic (deal w second messengers)
what are the 2 types of adrenergic receptors
alpha and beta
what are the 2 types of alpha adrenergic receptors
alpha1 and alpha2
where are Alpha2 adrenergic receptors
-presynaptic autoreceptor
-postsynaptic
What do Alpha1 adrenergic receptors do?
stimulate or inhibit diff types of potassium channels
what do beta adrenergic receptors do
increase cAMP
what are the 3 types of beta adrenergic receptors
beta 1, beta 2, and beta 3
where are beta 2 adrenergic receptors found
-smooth and cardia muscle
-glands
where are beta 3 adrenergic receptors found
metabolic pathways
-adipose
where is dopamine brought to be converted to norepinephrine
adrenergic terminals by vesicles
what is the most prominent class of neurons that make norepinephrine and why
Peripheral sympathetic ganglion neuronal cells
-norepinephrine is major transport here
what also uses norepinephrine
locus coeruleus
What is the locus coeruleus and what does it do
Brainstem nucleus
-projects to most of forebrain
what does the coeruleus influence
-sleep
-wakefulness
-attention
-feeding behavior
what are the two types of g-proteins linked to beta adrenergic receptors
-Gs=stimulatory
-Gi= inhibitory
