pharm Flashcards
excitatory AA transmitters
glutamate
aspartate
inhibitory AA transmitters
GABA
glycine
small molecule transmitters
actylcholine
monoamine
histamine
monoamines
catecholamines (dopamine and NE)
serotonin (5-HT)
peptides
opioids
tachykinins
opioids
enkephalins
endorphins
dynorphins
tachykinins
substance P
what is the most common effect of retrograde transmission
modification of NT release
NTs that activate inotropic Rs
glutamate GABA Acetylcholine glycine 5-HT
NTs that activate metabotropic Rs
glutamate GABA Acetylcholine dopamine NE 5-HT H2 neuropeptides endocannabinoids
glutamate
excitatory
non-essential aa that does not cross BBB
glutamate synthesis
occurs in brain form glucose
glutamate storage
taken up into synaptic vesicles by an ATP-dependent transporter
inactivation of glutamate
initially taken up by glial cells and converted into glutamine -> transported out of glial cells into glutamatergic nn cells and converted back to glutamate
glutamate ionotropic Rs
AMPA
NMDA
AMPA
mediate vast majority of excitatory transmission in brain
ligand gated Na/K Ch
GluR1-4
NMDA
ligand gated Na/K Ch which is also highly permeable to Ca
are also voltage dependent b/c they are blocked by Mg until depolarized and then allow Ca flux
-overstimulation of these during hypoxia -> apoptosis
PCP (angle dust) and ketamine
non-competitive antagonists at NMDA R
NMDA R subtypes
NR1 NR2A NR2B NR2C NR2D
glutamate metabotrophic Rs
postsynaptic- decreases K -> increases IP3 and DAG
presynaptic -> decreased Ca conductance -> decreases cAMP
GABA
inhibitory
GABA synthesis
locally from glucose, pyruvate, or other AA precursors
GABA storage
loaded into synpatic vesicles by vesicular transporter
GABA inactivation
terminated by rapid reuptake by several types of plasma membrane transporters
also taken up by glial cells
inotropic GABA Rs
ligand gated ClChs
GABAa R activation hyperpolarizes cell d/t influx of Cl
over 15 subtypes
metabotropic GABA Rs
postsynaptic- increases K conductance
presynaptic- decreases Ca conductance
what drugs will bind GABA Rs
Benzodiazepines
barbiturates
glycine
ligand-gated ClChs
tetanus toxin inhibits glycine release
anatgonists is strychnine
can act as co-agonist w/glutamate at NMDA Rs
Ach synthesis
in presynaptic terminal from choline and acetly-CoA via choline acetyltransferase
Ach Storage
Ach loaded into vesicles by VAT
Ach inactivation
enzymatic degradation via AchE
Ach ionotropic/nicotinic Rs
increases cation conductance
located at NM jxn, postganglionic nn, CNS
agonist- nicotine
antagonist- curare-like drugs
metabotropic/muscarinic Ach Rs
M1- excitatory -> decreases K conductance -> increased IP3 and DAG
M2- inhibitory -> increases K conductance -> decreases cAMP
agonists- muscarine, pilocarpine
antagonists- atropine, glycopyyrolate
DA synthesis
presynaptic terminal from tyrosine by enzymes tyrosine hydroxylase and dopa decarboxylase
DA storage
loaded into vesicles by VMAT
DA inactivation
reuptake mediated by high affinity DAT and low affinity PMAT
DA Rs
D1-5
D1- stimulatory increases cAMP
D2- inhibitory:
- postsynaptic -> increases K -> decreased cAMP
- presynaptic -> decreases Ca conductance
cocaine
produces DA uptake block
amphetamine
increases DA release
NE synthesis
inside NE granules from DA via dopamine beta-hydroxylase
NE storage
in granules which it was produced
NE inactivation
reuptake into presynaptic cell mediated by NET
NE Rs
all metabotropic
alpha 1, 2
Beta 1,2,3
alpha 1
excitatory
decreased K conductance -> increased IP3 and DAG
agonists- phenylephrine
antagonists- phentolamine, prasozin
alpha 2
inhibitory postsynaptic- increases K conducatance -> decreases cAMP presynaptic -> decreases Ca conductance agonist- clonidine antagonist- yohimbine
Beta 1
excitatory
decreased K conductance -> increased cAMP
agonist- isoproternol
antagonist- propanolol
beta 2
inhibitory
increases cAMP
agonist- albuterol
antagonist- butoamine
5-HT synthesis
in presynaptic terminal from tryptophan via tryptophan hydroxylase
5-HT storage
loaded into vesicles
5-HT inactivation
SERT (inhibited by many anti-depressants)
pumps 5-HT back into nn terminal
5-HT ionotropic Rs
5-HT3
nonselective cation Ch
5-HT metabotropic Rs
5HT1,2,4-7
5HT1
inhibitory
5-HT2a and 4
excitatory
what drugs interact with 5-HT Rs
ecstacy (MDMA)
LSD
ondansetron (antiemetic
atypical antipychotics
H Rs
all are metabotropic
H1-4
1 and 2 excitatory
peptide NT synthesisis
in cell body
peptide NT storage
packed into large dense core vesicles for transport down axon
peptide NT inactivation
unknown
peptide NT Rs
each peptide has its own R, usually metabotropic
endocannabinoids synthesis
endogenous lipophilic cannabinoids (anandamide and 2-arachidonylglycerol) occurs locally and rapidly in response to depolarization and Ca influx
endocannabinoids storage
non-classical NT not stored in vesicles
endocannabinoids release
non-classical
retrograde messengers
endocannabinoids Rs
all metabotropic
CB1-brain
inhibitory