Week 5

Question 1

What are the three major classes of neurotransmitters?

Answer 1

amino acids, monoamines, and peptides

Question 2

Cholinergic Definition

Answer 2

compounds and receptors that use acetylcholine to send signals in the nervous system

Question 3

Noradrenergic Definition

Answer 3

the system of neurons that release and respond to the neurotransmitter norepinephrine

Question 4

Glutamatergic Definition

Answer 4

relating to glutamate, the most common excitatory neurotransmitter in the brain

Question 5

GABAergic Definition

Answer 5

brain and nervous system’s network of neurons that use the neurotransmitter GABA

Question 6

Peptidergic Definition

Answer 6

relating to, or involving, short peptide chains that act as neurotransmitters

Question 7

What criteria must be met for a molecule to be considered a neurotransmitter?

Answer 7

• Enzymes for synthesis and vesicles for storage in presynaptic neuron
• Have a vesicle that stores the neurotransmitters
• Released from the pre-synaptic terminal in response to the arrival of action potentials
• When action potential invades and depolarizes it leads to synaptic release
• Experimental application of molecule mimics its effect on postsynaptic neuron

Question 8

What are the principles of immunocytochemistry hybridization? What do the methods measure?

Answer 8

laboratory technique that uses antibodies to identify & visualize specific proteins in cells

Question 9

Microiontophoresis is used for the assessment of what?

Answer 9

deliver the drug by using an electric current and ejecting molecules from a micropipette

Question 10

What is meant by receptor subtype?

Answer 10

multiple receptors to bind to: ionotropic or Metabotropic - typically both

Question 11

What are examples of acetylcholine?

Answer 11

not derived from amino acid but from choline: muscles, memory, learning

Question 12

What are examples of glutamate

Answer 12

the principal excitatory neurotransmitter, ex: GABA, learning and memory

Question 13

What agonists bind to acetylcholine?

Answer 13

nicotine and muscarine

Question 14

What agonists bind to glutamate?

Answer 14

NMDA (N-methyl-D-aspartate), AMPA and kainate

Question 15

What is Dale’s principle?

Answer 15

mature neuron constraints, release one neurotransmitter at synapse one neuron that makes connections throughout the brain

Question 16

Co - transmitter definition

Answer 16

more than one neuron is released at a time, peptide containing neuron

Question 17

What’s the function of ChAT?

Answer 17

Choline acetyltransferase the enzyme responsible for synthesizing ACh within the presynaptic terminal

Question 18

Where is ChAT synthesized to get to the presynaptic terminal?

Answer 18

produced in the soma and transported down the axon to reach the presynaptic terminal where it is most concentrated, allowing for the local production of acetylcholine at the synapse

Question 19

What are neuronal membrane transporters?

Answer 19

found on the neuron plasma membrane and moves neurotransmitters across the membrane from the synaptic cleft back into the neuron

Question 20

What are vesicular transporters?

Answer 20

found on the membrane of synaptic vesicles, actively pumps neurotransmitters from the neuronal cytoplasm into the vesicle lumen, allowing for storage and release of the neurotransmitter at the synapse

Question 21

What’s the rate-limiting step of ACh synthesis?

Answer 21

uptake of choline into the presynaptic neuron by the choline transporter determines how much choline is available for conversion into ACh

Question 22

What is the function of ACh synthesis?

Answer 22

Once inside the neuron, ChAT catalyzes the synthesis of ACh from choline

Question 23

What is an ionotropic receptor?

Answer 23

fast process: neurotransmitter binding opens an ion channel

Question 24

What are ligand-gated ion channels?

Answer 24

physically linked for IPSP and EPSP. Has specific spot on binding receptor: ion channel opening determined by ligand binding

Question 25

What are metabotropic receptors?

Answer 25

slow process: neurotransmitter binding activates g-proteins that initiate cascade of events, second messenger production, widespread effect

Question 26

What is Cyclic AMP?

Answer 26

seconds to min of downstream effects depends on the system - seconds to implement outcome on the post-synaptic cell

Question 27

What type of neurotransmitter is sodium going to depolarize a patch or membrane to create EPSPs

Answer 27

Ionotropic Receptor

Question 28

How are Ionotropic Receptors opened and closed?

Answer 28

3 - 5 protein subunits to form a physical pore that can be opened or closed

Question 29

What are ionotropic receptors permeable for?

Answer 29

Permeable to sodium or calcium - also can be chloride (anion) with neg net charge. They drive membrane potential away and more negative

Question 30

What neurotransmitters binding activates G-proteins

Answer 30

Metabotropic receptor

Question 31

What are the 3 G - protein subunits in metabotropic receptors?

Answer 31

Alpha: associated with and bound GDP Gamma and Beta: stay together - bind to downstream effector molecules

Question 32

What happens when a metabotropic receptor is inactivated?

Answer 32

bound to GDP: when binding to the receptor it allows G-protein to be associated with the intracellular side of the protein

Question 33

what happens in the presence of a transmitter-bound metabolic receptor

Answer 33

G - protein binds to the receptor and exchanges GDP for GTP

Question 34

What happens when a metabotropic receptor is activated?

Answer 34

kicks off GDP - has binding site for GTP which was floating in the cytosol until it becomes bound to alpha subunit

Question 35

What happens to the subunits when G-protein is activated?

Answer 35

splits into G-alpha and G-beta/gamma subunits Each subunit is active and can affect effector proteins Can go off to faraway targets

Question 36

What is the shortcut Pathway in G-Protein coupled receptors?

Answer 36

Direct G-protein to ion channel binding Very localized - only affects nearby channels

Question 37

Explain G- protein activated enzymes

Answer 37

An initiate complex intracellular signaling cascades Doesn’t need to stay local: can diffuse around neurons to active other enzymes, open channels, activate transcription factors, and travel away

Question 38

What are Norepinephrine(NE) beta receptor steps:

Answer 38

- NE binds the o beta receptor and activates the G protein - The G - protein activates the nearby enzyme adenylyl cyclase(effector protein) - Adenylyl cyclase converts ATP into cAMP(second messenger) - Protein kinase closes the potassium channel - Net result: depolarization - excitability

Question 39

What are the classic criteria for a neurotransmitter?

Answer 39

- Once committed to making certain kinds of neurotransmitters, doesn’t ever change throughout the life of a neuron - Enzymes for synthesis and vesicles for storage in presynaptic neuron - Released from the pre-synaptic terminal in response to the arrival of action potentials - When action potential invades and depolarizes it leads to synaptic release - Experimental application of molecule mimics its effect on postsynaptic neuron