Neurotransmitter Flashcards
Where is acetylcholine located in the brain? (2) What are the functions of acetylcholine in these locations?
- ) Brainstem -> arousal
2. ) Basal ganglia (striatum) -> motor control
What is acetylcholine synthesized from?
Choline and acetate
How is acetylcholine transported into vesicles?
VAchT
How is acetylcholine removed from the synapse?
Acetylcholinesterase
What binds to ionotropic receptors?
Nicotine and acetylcholine
What binds to Muscarinic receptors?
Muscarine and acetylcholine
Ionotropic receptors are what kind of channel?
ion channel
What is the ion that passes through a nicotinic channel?
Na+
How many subunits do inotropic channels contain?
5
What Muscarinic receptors are Gq coupled? What is the second messenger?
M1, M3, M5. IP3/DAG which leads to Ca release
What muscarinic receptors are Gi coupled? What is the second messenger?
M2, M4. Decreased AC via inhibition
What is the major inhibitory neurotransmitter of the CNS?
GABA
What area of the CNS has the least amount of GABA?
The spinal cord
What is GABA critical in? (3)
- ) Consciousness
- ) Motor control
- ) Vision (retina)
What is GABA synthesized from? Via what enzyme?
Glutamate. GAD.
How is GABA transported into vesicles?
Via VGAT.
How is GABA removed from the synapse?
Via GAT (GABA transporter)
What are the two forms of GAT?
GAT 1 and GAT 2
What is the function of GAT 1?
It is on the presynaptic terminal and takes GABA up to repackage it into vesicles.
What is the function of GAT 2?
It is located on astrocytes. It takes GABA up and the GABA is converted to glutamine and released into the ECF. Glutamine is then taken up by the presynaptic terminal and recycled into GABA.
GABAa is what kind of receptor? What does it allow into the cell?
Ionotropic. Cl-
Activation of GABA causes what in adult neurons?
IPSP
What three chemicals potentiate GABA?
- ) Ethanol
- ) Benzodiazepines
- ) Some steroids
GABAb is what kind of receptor?
Metabotropic
What is the second messenger of GABAb and what are their functions?
Gi/Go protein coupled.
Activate a K+ channel
Close down and inhibit a Ca channel.
What does a presynaptic GABAb do?
Regulates NT release
What does a postsynaptic GABAb do?
Inhibits post synaptic cells
Where is glycine found?
Spinal cord > medulla > least in the higher areas of brain
What is the function of glycine?
Inhibitor
What removes glycine from the synapse?
GAT, same as GABA.
Glycine binds to what kind of channel?
Ionotropic (which releases Cl which leads to ipsp)
What two chemicals bind to and potentiate glycine?
Ethanol & general anesthetics
What is the name of the glycine receptor?
GlyR
What are the three purine neurotransmitters?
ATP, ADP, and adenosine
What are the 2 purine receptors?
P1 and P2
What is the ligand for the P1 receptor?
Adenosine only
When the P1 receptor is bound to post-synaptically, what are the two effects?
- ) sleep induction
2. ) general inhibition of neural function
What are the two types of P2 receptors?
P2X and P2Y
P2X is what kind of receptor? What is the ligand?
Ionotropic. ATP
P2Y is what kind of receptor? What is the ligand(s)?
Metabotropic. ATP, ADP, UTP, and UDP.
What are the functions of P2X and P2Y receptors?
Learning and memory. Modification of the locomotor pathways.
Where are opioids made?
Basal ganglia and hypothalamus
What are the 2 general functions of opioids?
- ) modification of nociceptive inputs
2. ) mood/affect
What are the 4 precursor molecules for opioids?
- ) POMC
- ) Pro-enkephalin
- ) Pro-dynorphin
- ) Orphanin FQ
How are opioids removed from the synaptic cleft?
Probably by re-uptake. Maybe by enzymatic destruction by enkephalinase and aminopeptidase
The Mu opioid receptors are what kind of receptor?
metabotropic (serpentine)
Activation of the Mu receptors causes what?
Analgesia, respiratory distress, euphoria, constipation, and sedation
What kind of receptors are Kappa opioid receptors?
Serpentine (metabotropic)
What kind of effects do Kappa opioid receptors produce?
Analgesia and dysphoria
What kind of receptors are Delta opioid receptors?
Serpentine (metabotropic)
What kind of effects do Delta opioid receptors produce?
Analgesia
Mu receptors lead to what?
An increase in potassium efflux and hyper polarization via Gi
Delta and Kappa receptors lead to what?
Decreased calcium influx via Go
Endocannabinoids are derived from what?
Arachadonic acid
What is the central location of endocannabinoids?
Basal ganglia, cortex, spinal cord.
What are the functions of endocannabinoids?
Mood, neuroprotective, nociception
What is the metabotropic receptor for endocannabinoids?
CB-1
The CB-2 receptor has what function?
anti-inflammatory
What are the two excitatory amino acids?
Glutamate and aspartate
What is glutamate derived from?
a-ketoglutarate
What does EAA stand for?
Excitatory amino acid neurotransmitter system.
NMDA receptors are what kind of receptors? What activates them?
Ionotropic which allow calcium in. Glutamate, aspartate and they REQUIRE glycine as a co-agonist.
Where is the magnesium binding site within NMDA receptors? What is the function?
Within the channel itself. Blocks the channel at RMP.
