Question 1

Explain how G protein-coupled receptors become activated after binding neurotransmitter ligand?

Accepted Answer

Activation of a G protein-coupled metabo

Question 2

What would happen to metabotropic signaling in a cell if you added GDP-β-s to the cell cytoplasm?

Accepted Answer

A)  This would irreversibly activate all G protein-coupled metabotropic signaling. 
B)  This would irreversibly inhibit all G protein-coupled metabotropic signaling. 
C)  This would have no effect on G protein-coupled metabotropic signaling. 
D)  This would irreversibly activate G protein-coupled metabotropic signaling mediated by only Gi and Go. 
E)  This would irreversibly inhibit G protein-coupled metabotropic signaling mediated by only Gi and Go. 
A)  This would irreversibly activate all G protein-coupled metabotropic signaling. 
B)  This would irreversibly inhibit all G protein-coupled metabotropic signaling. 
C)  This would have no effect on G protein-coupled metabotropic signaling. 
D)  This would irreversibly activate G protein-coupled metabotropic signaling mediated by only Gi and Go. 
E)  This would irreversibly inhibit G protein-coupled metabotropic signaling mediated by only Gi and Go.

Question 3

List four factors that determine how a cell responds to transmitters.

Accepted Answer

(1) the receptors present in a particula

Question 4

Feedback inhibition, or auto-inhibition, is defined as

Accepted Answer

A)  diffusion around sites of release to affect neighboring cells. 
B)  the use of a chemical signal that communicates from the presynaptic cell to the postsynaptic cell. 
C)  the use of a second messenger signal within the postsynaptic cell. 
D)  the use of a chemical signal that communicates from the postsynaptic cell to the presynaptic cell. 
E)  the use of a chemical signal that communicates from the presynaptic cell back onto the same presynaptic cell. 
A)  diffusion around sites of release to affect neighboring cells. 
B)  the use of a chemical signal that communicates from the presynaptic cell to the postsynaptic cell. 
C)  the use of a second messenger signal within the postsynaptic cell. 
D)  the use of a chemical signal that communicates from the postsynaptic cell to the presynaptic cell. 
E)  the use of a chemical signal that communicates from the presynaptic cell back onto the same presynaptic cell.

Question 5

Non-hydrolysable GTP analog is an analog of GTP that

Accepted Answer

A)  cannot bind to G proteins associated with metabotropic receptors. 
B)  is rapidly cleaved by GTPases to GDP. 
C)  cannot be cleaved by GTPases to GDP. 
D)  cannot be used in G protein-mediated signaling. 
E)  remains persistently bound in a heterotrimer. 
A)  cannot bind to G proteins associated with metabotropic receptors. 
B)  is rapidly cleaved by GTPases to GDP. 
C)  cannot be cleaved by GTPases to GDP. 
D)  cannot be used in G protein-mediated signaling. 
E)  remains persistently bound in a heterotrimer.

Question 6

When using the cell-attached patch clamp recording technique to record single potassium channel currents from cardiac muscle cells, explain why muscarinic receptor agonists applied to the bath outside of the patch are unable to activate these potassium channels?

Accepted Answer

Muscarinic receptor-activated βγ-subunit

Question 7

For G protein-coupled metabotropic receptors, GTP binds to the

Accepted Answer

A)  cytoplasmic surface of the metabotropic receptor. 
B)  transmembrane domains of the metabotropic receptor. 
C)  β-subunitof the heterotrimer. 
D)  α-subunit of the heterotrimer. 
E)  the γ-subunit of the heterotrimer. 
A)  cytoplasmic surface of the metabotropic receptor. 
B)  transmembrane domains of the metabotropic receptor. 
C)  β-subunitof the heterotrimer. 
D)  α-subunit of the heterotrimer. 
E)  the γ-subunit of the heterotrimer.

Question 8

What is the concentration of calcium in cell cytoplasm?

Accepted Answer

A)  100 nM 
B)  100 µM 
C)  1 µM 
D)  100 mM 
E)  1 mM 
A)  100 nM 
B)  100 µM 
C)  1 µM 
D)  100 mM 
E)  1 mM

Question 9

Each particular metabotropic receptor (e.g., a metabotropic glutamate receptor)

Accepted Answer

A)  exists one-to-one with a particular G protein complex in the cell. 
B)  couples to only one type of second messenger signaling system in the cytoplasm. 
C)  can only couple to one subtype of G protein (i.e., Gi). 
D)  can couple to a variety of G proteins that are more plentiful than receptors. 
E)  competes with other metabotropic receptors for the same G protein. 
A)  exists one-to-one with a particular G protein complex in the cell. 
B)  couples to only one type of second messenger signaling system in the cytoplasm. 
C)  can only couple to one subtype of G protein (i.e., Gi). 
D)  can couple to a variety of G proteins that are more plentiful than receptors. 
E)  competes with other metabotropic receptors for the same G protein.

Question 10

Explain why synaptic interactions mediated by indirect mechanisms typically develop more slowly and last much longer than those mediated by direct mechanisms

Accepted Answer

Direct mechanisms involved ligand-gated

Question 11

Nitric oxide is a(n)

Accepted Answer

A)  peptide transmitter. 
B)  amino acid transmitter. 
C)  gas transmitter. 
D)  small molecule transmitter. 
E)  enzyme. 
A)  peptide transmitter. 
B)  amino acid transmitter. 
C)  gas transmitter. 
D)  small molecule transmitter. 
E)  enzyme.

Question 12

Ionotropic nicotinic acetylcholine receptors are known to excite cells based on the flux of sodium ions into the cell cytoplasm when these channels are activated near resting membrane potential. However, how can the calcium flux through these receptors lead to an inhibitory influence?

Accepted Answer

A)  Calcium flux through nicotinic receptors can act back on the nicotinic receptor to inhibit it. 
B)  Calcium flux through nicotinic receptors directly depolarizes the cell. 
C)  Calcium flux through nicotinic receptors directly hyperpolarizes the cell. 
D)  Calcium flux through nicotinic receptors can activate a calcium-activated potassium channel whose potassium flux hyperpolarizes the cell. 
E)  Calcium flux through nicotinic receptors can activate a calcium-activated potassium channel whose potassium flux depolarizes the cell. 
A)  Calcium flux through nicotinic receptors can act back on the nicotinic receptor to inhibit it. 
B)  Calcium flux through nicotinic receptors directly depolarizes the cell. 
C)  Calcium flux through nicotinic receptors directly hyperpolarizes the cell. 
D)  Calcium flux through nicotinic receptors can activate a calcium-activated potassium channel whose potassium flux hyperpolarizes the cell. 
E)  Calcium flux through nicotinic receptors can activate a calcium-activated potassium channel whose potassium flux depolarizes the cell.

Question 13

When different transmitters or hormones act through different G protein-coupled metabotropic receptors,

Accepted Answer

A)  each receptor is always coupled to a different type of G protein. 
B)  multiple receptors can be coupled to the same type of G protein. 
C)  the G protein that is coupled to the receptor is determined by the transmitter or hormone that is the ligand for that receptor. 
D)  the second messenger cascade that is coupled to the receptor is determined by the transmitter or hormone that is the ligand for that receptor. 
E)  the second messenger cascade that is coupled to the receptor is always determined by the specific G protein type that is coupled to that receptor. 
A)  each receptor is always coupled to a different type of G protein. 
B)  multiple receptors can be coupled to the same type of G protein. 
C)  the G protein that is coupled to the receptor is determined by the transmitter or hormone that is the ligand for that receptor. 
D)  the second messenger cascade that is coupled to the receptor is determined by the transmitter or hormone that is the ligand for that receptor. 
E)  the second messenger cascade that is coupled to the receptor is always determined by the specific G protein type that is coupled to that receptor.

Question 14

How does the transmitter nitric oxide mediate its actions in cells?

Accepted Answer

A)  Nitric oxide diffuses across cell membranes and binds to an ionotropic receptor. 
B)  Nitric oxide diffuses across cell membranes and only stimulates guanylate cyclase to synthesize cGMP. 
C)  Nitric oxide diffuses across cell membranes and stimulates guanylate cyclase to synthesize cGMP or can s-nitrosylate proteins. 
D)  Nitric oxide diffuses across cell membranes and only s-nitrosylates proteins. 
E)  Nitric oxide diffuses across cell membranes and binds to a metabotropic receptor. 
A)  Nitric oxide diffuses across cell membranes and binds to an ionotropic receptor. 
B)  Nitric oxide diffuses across cell membranes and only stimulates guanylate cyclase to synthesize cGMP. 
C)  Nitric oxide diffuses across cell membranes and stimulates guanylate cyclase to synthesize cGMP or can s-nitrosylate proteins. 
D)  Nitric oxide diffuses across cell membranes and only s-nitrosylates proteins. 
E)  Nitric oxide diffuses across cell membranes and binds to a metabotropic receptor.

Question 15

By what G protein-coupled signaling mechanism does stimulation of the vagus nerve slow the heartbeat?

Accepted Answer

The vagus nerve releases acetylcholine,

Question 16

How is nitric oxide (NO) terminated after release?

Accepted Answer

A)  NO is taken back up into cells by a transporter. 
B)  NO is degraded by a specific enzyme in the synaptic cleft. 
C)  NO is a reactive gas that is inactivated when it reacts with proteins or superoxides. 
D)  NO remains active until it diffuses away from the synapse. 
E)  NO action is not terminated. 
A)  NO is taken back up into cells by a transporter. 
B)  NO is degraded by a specific enzyme in the synaptic cleft. 
C)  NO is a reactive gas that is inactivated when it reacts with proteins or superoxides. 
D)  NO remains active until it diffuses away from the synapse. 
E)  NO action is not terminated.

Exam 12: Indirect Mechanisms of Synaptic Transmission

Explain how G protein-coupled receptors become activated after binding neurotransmitter ligand?

What would happen to metabotropic signaling in a cell if you added GDP-β-s to the cell cytoplasm?

List four factors that determine how a cell responds to transmitters.

Feedback inhibition, or auto-inhibition, is defined as

Non-hydrolysable GTP analog is an analog of GTP that

When using the cell-attached patch clamp recording technique to record single potassium channel currents from cardiac muscle cells, explain why muscarinic receptor agonists applied to the bath outside of the patch are unable to activate these potassium channels?

For G protein-coupled metabotropic receptors, GTP binds to the

What is the concentration of calcium in cell cytoplasm?

Each particular metabotropic receptor (e.g., a metabotropic glutamate receptor)

Explain why synaptic interactions mediated by indirect mechanisms typically develop more slowly and last much longer than those mediated by direct mechanisms

Nitric oxide is a(n)

Ionotropic nicotinic acetylcholine receptors are known to excite cells based on the flux of sodium ions into the cell cytoplasm when these channels are activated near resting membrane potential. However, how can the calcium flux through these receptors lead to an inhibitory influence?

When different transmitters or hormones act through different G protein-coupled metabotropic receptors,

How does the transmitter nitric oxide mediate its actions in cells?

By what G protein-coupled signaling mechanism does stimulation of the vagus nerve slow the heartbeat?

How is nitric oxide (NO) terminated after release?

Principles of Signaling and Organization

Signaling in the Visual System

Functional Architecture of the Visual Cortex

Ion Channels and Signaling

Structure of Ion Channels

Ionic Basis of the Resting Potential

Ionic Basis of the Action Potential

Electrical Signaling in Neurons

Ion Transport Across Cell Membranes

Properties and Functions of Neuroglial Cells

Mechanisms of Direct Synaptic Transmission

Release of Neurotransmitters

Neurotransmitters in the Central Nervous System

Transmitter Synthesis, Storage, Transport, and Inactivation

Synaptic Plasticity

The Molecular and Cellular Biology of Synaptic Plasticity

Mechanisms of Extrasynaptic Communication

Autonomic Nervous System

Walking, Flying, and Swimming: Cellular Mechanisms of Sensorimotor Behavior in Invertebrates

Sensory Transduction

Transduction and Transmission in the Retina

Touch, Pain, and Texture Sensation

Auditory and Vestibular Sensation

Constructing Perception

Initiation and Control of Coordinated Muscular Movements

Development of the Nervous System

Critical Periods in Sensory Systems

Regeneration and Repair of Synaptic Connections After Injury

Appendix

Filters