EAA and Monoamines Flashcards
What are the excitatory amino acids?
Glutamate and Aspartate
Main function of excitatory amino acids?
Excitatory actions all over the brain
What is an ionotropic receptor?
A channel that once activated will allow ions through
What is a metabotropic receptor (serpentine)?
A G protein coupled receptor
What are the ionotropic receptors for EAA?
NMDA, AMPA, Kainate
Which ionotropic receptor for EAA is voltage and ligand gated?
NMDA
What is allowed into the post-synaptic cell from NMDA?
Calcium
What is allowed into the post-synaptic cell from AMPA?
Sodium
What is allowed into the post-synaptic cell from Kainate?
Sodium and small amounts of calcium
What molecules are needed to either bind or leave the NMDA receptor in order to open it?
EAA (NMDA, glutamate, aspartate), GLYCINE, and then MAGNESIUM is required to leave and unblock!
What does magnesium need in order to leave and unblock the NMDA receptor?
Cell depolarization
How does a post-synaptic cell with an NMDA receptor get depolarized?
It will have either an AMPA or Kainate receptor activated allowing sodium to enter the cell and depolarize it
What are the metabotropic receptors for EAA?
Group 1 = Gq = increases IP3 and DAG
Groups 2 and 3 = Gi = decreased CAMP
How do you limit the amount of EAA that is available?
Nearby glial cell will uptake it along with ATP and convert it back to glutamine
Describe how nitric oxide is created from an NMDA receptor opening?
Calcium enters and binds to calcineurin
Calcineurin activates nitric oxide synthase (NOS)
NOS takes arginine to NO and citruline
Cons of nitric oxide?
Produces free radicals that kills neurons!
What are the monoamines?
Epinephrine, Norepinephrine, dopamine, serotonin, histamine
What are the metabotropic receptors for epinephrine and norepinephrine?
alpha and beta adrenergic
What is the process of making dopamine, norepinephrine and epinephrine?
Tyrosine (using tyrosine hydroxylase) L Dopa Dopamine Norepinephrine Epinephrine
How do you limit actions for epinephrine, norepinephrine, serotonin, and dopamine?
Reuptake and degradation by MAO or COMT
How do you limit actions for histamine?
Reuptake and degradation by DAO or COMT
What puts dopamine/epinephrine into vesicles?
VMAT 1 and VMAT 2
What stops VMAT1 and VMAT2 from putting dopamine/epinephrine into vesicles?
Reserpine
Where will you find norepinephrine?
Locus ceruleus
Where will you find epinephrine?
Medulla
Where are some places that dopamine is located?
Basal ganglia, limbic system, hypothalamus, cortex
What are the metabotropic receptors for dopamine?
D1 and D5 = increase CAMP
D2, D3, D4 = decrease CAMP
Where is serotonin located?
Brainstem raphe nuclei, hypothalamus and cerebellum
What is serotonin made from?
Tryptophan
What are the receptors for serotonin?
ionotropic = 5HT3 metabotropic = 5HT1, 2, 4, 5, 6,
Where will you find the ionotropic serotonin receptor (5HT3)?
Area postrema
What does the 5HT6 serotonin receptor do?
Anti-depressent effect
Where is histamine located?
Tuberomammillary nucleus of hypothalamus
What monoamines contribute to wakefulness?
Norepinephrine and histamine
What is histamine derived from?
Histadine
What are the metabotropic receptors for histadine?
H1, H2, H3
