Neurotransmitters Flashcards
where are neurotransmitters synthesized
cell bodies (nuclei, grey matter)
where are neurons that make ACh found?
midbrain
pons
striatum of basal ganglia
what is the function of ACh from the striatum of basal ganglia?
control of voluntary motion
what is the function of ACh from the midbrain and pons?
REM sleep
awakening
what two molecules contribule to the synthesis of ACh
choline and acetate
what does VAChT do
vesicular ACh transporter protein -
moves ACh into vesicles
where is AChE found?
the post-synaptic cell membrane
what are the metabotropic cholinergic receptors called?
MUSCARINIC
which muscarinic receptor is active at neurons?
M1
what is the MOA of M1 receptor
Gq - increase IP3/DAG
increase Ca2+
where are M4 cholinergic receptors found and what is the MOA
striatum of basal ganglia
Gi - decrease cAMP
which muscarinic receptor is active at cerebrovasculature
M5
which muscarinic receptor is active at the dopaminergic neurons of basal ganglia?
M5
what is the MOA of M5 cholinergic receptor
Gq - increase IP3/DAG
increase Ca
are nicotinic receptors ionotropic or metabotropic
ionotropic
what are the two major inhibitory amino acids?
GABA
glycine
what is the major inhibitory amino acid of the CNS?
GABA
how is GABA distributed throughout the CNS?
higher at the more superior levels (ie cortex)
lowest in the spinal cord
what are the three functions we were given for GABA?
conciousness
motor control
vision (retina)
what amino acid is GABA synthesized from
glutamate
what is the important enzyme in GABA synthesis?
GAD - glutamate decarboxylase
how is GABA transported to vesicles
VGAT - vesicular GABA transporter protein
what protein removes GABA from synapses?
GAT - GABA transporter
where is GAT1 found?
on the presynaptic terminal
where is GAT2 found?
on the glial cells surrounding the synapse
what is the difference between the actions of GAT 1 and 2?
GABA removed by GAT1 is repackaged into vesicles
GABA removed by GAT2 is converted to glutamine and release to ECF
what receptors are the target of general anesthetics
extra-synaptic GABA A receptors
Are GABA A receptors metabotropic or ionotropic?
ionotropic
what is the MOA of GABA B receptors
Gi/Go coupled - activate K+ channel
inhibit Ca2+ channel
Are GABA B receptors metabotropic or ionotropic?
metabotropic
where are GABA B receptors found
both presynaptic (to regulate NT release AND postsynaptic (to inhibit post-synaptic cell)
how is glycine distributed throughout the CNS
LOWER in more superior areas
highest in SC and brainstem
how is glycine removed from a synapse?
GAT
what is the MOA of glycine receptors?
ionotropic - causes influx of chloride => IPSP
what protein packages purines in vesicles (ATP)
VNUT
where does dephosphorylation of ATP occur?
in the synaptic cleft
what is the function of post-synaptic P1
inhibits neural function, induces sleep
what is the function of pre-synaptic P1
inhibits NT release
what ligand activates P1
adenosine
are P2 receptors ionotropic or metabotropic?
P2X is ionotropic
P2Y is metabotropic
what is the function of P2 receptors
learning and memory
modification of locomotor pathways
how are opiod transporters transported from the cell body to the axon?
fast axonal transport
what do endorphins, enkephalins, dynorphins and nociceptin have in common
they are all opioid peptides
where are opioid peptides synthesized?
basal ganglia
pons
medulla
hypothalamus
what is the function of opiods?
modification of cutaneous sensation
mood
what is the precursor molecule for nociceptin?
orphanin FQ
what is PCOM (proopiomelanocortinin) a precursor for?
endorphins
what two enzymes remove opioids from synaptic clefts?
enkephalinase
aminopeptidase
what are the receptors for opioid peptides?
Mu
Kappa
Delta
what is the function of MuR activation?
analgesia respiratory depression euphoria constipation sedation
what is the function of kappaR activation?
analgesia
dysphoria
what is the function of deltaR activation?
analgesia
what opioid receptor leads to in increase in K efflux => hyperpolarization?
MuR
what is the MOA of opioid receptors?
all are metabotropic
use Gi/Go
what is the function of endocannabinoids in the basal ganglia
mood
motor performance
what is the function of endocannabinoids in the SC
modulation of nociception
what is the function of endocannabinoids in the cortex
neuroprotection
from what molecule are endocannabinoids synthesized?
presynaptic membrane lipids (arachidonic acid)
what is the MOA of CB1?
Gi coupled protein inhibits EAA and GABA release
where is CB1 found
pre-synaptic terminals
what is CB2 associated with
immune system - anti-inflammatory
what is the MOA of P1?
Gs/Gq
