5. Neurotransmitter Systems Flashcards
Monoamine serotonin is derived from tryptophan and is located where, has what functions?
located at raphe nuclei
functions in mood and wakefulness
Acetylcholine Location: Function: Ionotropic Receptors: Muscarinic Receptors: Other
Location: Pons/midbrain
Function: Wakefulness/motor control (REM sleep)
Ionotropic Receptors: Nicotinic
Muscarinic Receptors: Muscarinic (M1-M5)
Other: Changing subunits changes properties of channel
Acetylcholine is synthesized via choline and acetate and moved into clear vesicles via ?
vesicular Ach transporter protein (VAChT)
How is acetylcholine removed from the synapse?
acetylcholinesterase bound to post synaptic cell membrane
What are the two major inhibitory amino acids?
GABA (gamma-amino-butyric acid)
glycine
GABA Location: Function: Ionotropic Receptors: Muscarinic Receptors: Other
Location: Higher CNS (cortex/cerebellum) Function: motor control / consciousness Ionotropic Receptors: GABAa Muscarinic Receptors: GABAb Other: extrasynaptic receptors - anesthetics
GABA is synthesize from glutamate via glutamate decarboxylase (GAD). How is GABA transported into vesicles and removed from synapse?
Transported via Vesicular GABA transporter protein (VGAT)
Removed via GAT1 and GAT2
If GAT1 (which is on the presynaptic terminal) takes up GABA, then what happens?
GABA is repackaged into vesicles as is
If GAT2 (which is on the astrocyte) takes up GABA at the synpatic cleft, GABA is converted to glutamine and then what?
released to ECF where it is taken into the presynaptic terminal and made back into glutamate to make GABA
(***KNOWN as glutamate shunt)
What would happen regarding GABA if the astrocytes were not working?
an excess of glutamate is toxic and could kill the neuron
What is the difference between IPSP and EPSP?
inhibitory post-synaptic potential
excitatiry postsynaptic potential
GABAa receptor is ionotropic and produces an IPSP. What are some of the binding sites? 3
Benzodiazepine
ehtanol
some steriods
What receptors have many extra synaptic receptors which are believed to be the site of action for general anesthetics such as propofol?
GABA a receptors
GABAb receptors are metabotropic and have Gi and Go. Located presynaptically to regulate NT release and postsynaptically to inhibit cell. What does Gi and Go do?
activate K+ channel GIRK close down (inhibit) Ca+ channel
Glycine Location: Function: Ionotropic Receptors: Muscarinic Receptors: Other
Location: Spinal Cord and Lower CNS (medulla) Function: Spinal inhibitions Ionotropic Receptors: GlyR Muscarinic Receptors: None Other