Corso - Ionotropic Receptors

the sodium potassium ATPase pumps out _____ ions of sodium and pumps in ____ ions of potassium

3 ions of sodium OUT

2 ions of potassium IN

when a cell becomes polarized, the inside of the cell has a net ______ charge compared to the outside of the cell

a. positive

b. negative

b.

what commonly creates second messengers inside of a post-synaptic cell?

a. metabotropic receptors

b. ionotropic receptors

a.

what causes the initial depolarization in the post-synaptic cell?

a. metabotropic receptors

b. ionotropic receptors

b.

what propagates the action potential down the length of an axon?

a. voltage gated sodium channels

b. voltage gated potassium channels

c. voltage gated calcium channels

a.

what repolarizes the axon in a delayed fashion?

a. voltage gated sodium channels

b. voltage gated potassium channels

c. voltage gated calcium channels

b.

what is found at the terminal of an axon and is needed to cause a synapse?

a. voltage gated sodium channels

b. voltage gated potassium channels

c. voltage gated calcium channels

c.

__________ contain NTs to be released from the axon terminal in a voltage and calcium-dependent manner

synaptic vesicles

how many subunits are found in a ligand gated sodium ion channel? ex: N1 receptor

5

in typical myasthenia gravis, what subunit is attacked by antibodies?

a. gamma

b. epsilon

c. alpha-1

d. delta

e. beta-1

c.

in acquired slow channel syndrome (MG), what subunit is affected?

a. gamma

b. epsilon

c. alpha-1

d. delta

e. beta-1

b.

in neonatal MG and recurrent arthrogryposis, what subunit is affected?

a. gamma

b. epsilon

c. alpha-1

d. delta

e. beta-1

a.

what drug class is used for the most common treatment of myasthenia gravis?

a. statins

b. COMTIs

c. SSRIs

d. acetylcholinesterase inhibitors

e. MAOIs

d.

in Lambert-Eaton myasthenic syndrome (LEMS), which protein is the target of the autoimmune reaction?

a. voltage gated calcium channels

b. sodium/potassium ATPase antiporters

c. voltage gated potassium channels

d. voltage gated sodium channels

a.

MG vs LEMS

MG: antibodies attack acetylcholine receptors

LEMS: antibodies target the voltage gated calcium channels

both have a decrease in the amount of acetylcholine in neuromuscular junction

tx for both: acetylcholinesterase inhibitors

which serotonin receptor is a ligand gated sodium channel?

a. 5HT-1

b. 5HT-2

c. 5HT-3

d. 5HT-4

e. 5HT-5

c.

inhibitors of the serotonin ligand gated sodium channel are commonly used to treat which disorder?

a. myasthenia gravis

b. Parkinson’s

c. nausea caused by chemo

d. LEMS

c.

ex: ondansetron

5HT-3 inhibitors

Which Glutamate Ligand-gated sodium channel is most associated with learning and memory?

a. NMDA

b. kainate

c. mGluR5

d. AMP

a.

what neurotransmitter activates the AMPA and Kainate receptors?

a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid

e. glycine

a.

what neurotransmitter activates the N1 and N2 receptors?

a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid

e. glycine

b.

what neurotransmitter activates the 5HT-3 receptor?
a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid

e. glycine

c.

what neurotransmitter activates the GABA-A, GABA-B, and GABA-C receptors?

a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid (GABA)

e. glycine

d.

BRAIN

what neurotransmitter activates the Gly receptor?

a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid

e. glycine

e.

what neurotransmitters activates the NMDA receptor? (SATA)

a. glutamate

b. acetylcholine

c. serotonin

d. gamma-aminobutyric acid

e. glycine

a.

e.

BRAIN

what are the classical fast acting glutamate transmission channels?

AMPA and Kainate receptors

glutamate binds

sodium enters —> depolarization of postsynaptic neuron

what are the slow acting glutamate transmission channels?

NMDA receptors

glutamate and glycine bind

sodium enters, calcium enters

require partial depolarization of the membrane

what receptor is most associated with learning and memory?

NMDA

____ receptors are activated by ATP

P2X

remember: ATP considered a co-transmitter since it is released aloongside other classical NTs

what do GABA-B receptors do after activation?

open outward potassium channels

what receptors are linked to inward chloride channels?

(INHIBITORY —> decreases likelihood of postsynaptic neuron firing an action potential)

GABA-A

GABA-C

glycine (spinal cord)

how do benzodiazepines alleviate anxiety?

bind to GABA-A receptor

amplify the effects of GABA —> increased flow of chloride ions into the neuron

reduces neuronal excitability

what do Gly receptors do after activation?

open inward chloride ion channels

what receptors are linked to outward potassium channels?

(INHIBITORY —> decreases likelihood of postsynaptic neuron firing an action potential)

GABA-B

mu

delta

what do AMPA receptors do after activation?

open inward sodium channels

what causes the action potential in the post-synaptic cell?

1. NT binds to ligand gated channels —> ligand gated channels open

2. entering ions depolarize immediate region (sodium, calcium)

3. adjacent voltage gated channels open (sodium) —> action potential

4. voltage gated potassium channels open to repolarize axon —> back to resting

what causes the release of neurotransmitter? (presynaptic neuron)

1. action potential reaches terminal

2. voltage gated calcium channels open

3. calcium binds to proteins on vesicles permitting fusion with terminal membrane

4. release of neurotransmitter

what receptors are linked to inward sodium channels?

(EXCITATORY —> increases likelihood of postsynaptic neuron firing an action potential)

N1

N2

5HT3

AMPA

Kainate

NMDA

P2X

what neurotransmitters activate mu and delta receptors?

leu-enkephalin

met-enkephalin

mu only: endorphins

list examples of GABA-B agonists

what do they do?

baclofen —> muscle relaxant

propofol —> anesthetic

makes sense since it is INHIBITORY and we are agonizing that action, so we are decreasing the likelihood of an action potential firing