NTS Flashcards
this hypothesis states that all axon terminals of a single neuron use one and only one NT though co release of multiple transmitters has been documented?
Dales Hypothesis
the first transmitters of the PNS to be discovered?
Ach and Norepi
what is the general approach of NT release? T/F can be manipulated pharmacologically
synthesis storage release presynaptic receptor high affinity reuptake postsynaptic receptor transmitter metabolism postsynaptic response
ACh is synthesized by what enzyme? via what substrates
choline acetyltransferase (ChAT)
AcCoA + Choline
where does the AcCoA come from? choline?
mitochondrial metabolism of pyruvate
diet and 50% of ACh production uses recycled choline following high affinity reuptake
what terminates cholinergic transmission by degrading ACh to choline and acetate? where are these localized
choline esterase like acetylcholine esterase and made in the liver.
ACh synapses
name the agent based on this effect:
ACh depletion
-Napthylvinyl pyridine
name the agent based on this effect:
release vesicles, depleting number for future use
+B-Bungarotoxin
+Black widow spider venom (BWSV)
name the agent based on this effect:
few vesicles released
-Botulinum toxin
name the agent based on this effect:
deplete ACh because choline is scarce
-Hemicholinium
name the agent based on this effect:
prolongs ACh transmission, over stimulation
2 agents that are reversible and irreversible
-reversibly
Neostigmine
physostigmine
(medically useful)
-irreversibly Malathion Nerve gas (deadly but also useful) myasthenia gravis
what are is the purpose of nicotinic and muscurinic receptors and their subtypes?
they are found in different tissues and this allows fro more specific drugs with fewer side affects
dopamine-DA, norepinephrine-NE, epinphrine-EPi
catecholamines
what are the stages for the synthesis of catecholamines?
L-tyrosine L-Dopa Dopamine Norepinephrine Epinephrine
what converts L-Tyrosine to L-Dopa?
tyrosine hydroxylase (cytosolic)
what converts L-Dopa to dopamine?
dopa decarboxylase (in many tissues)
what converts dopamine to norepinephrine?
dopamine-B-hydroxylase (inside many vesicles of cells that release NE)
what converts norepinephrine to epinephrine?
phenylethanolamine-N-methyl-transferase (PNMT) (cytosolic)
what it tyrosine hydroxylase inhibited by?
alpha methyl tyrosine
what is Dopa decarboxylase inhibited by?
alpha methyl dopa
what is dopamine-B-hydroxylase inhibited by?
diethyldithiocarbamate
what is phenylethanolamine-N-methyl-transferase stimulated by?
corticosteroids
where is epinephrine mainly found?
adrenal medulla and brainstem
what causes the release of NTs?
elevated intracellular Ca++