2.10: Multiple Choice

2.1 Neural Communication

1.

All of the following are involved with synaptic transmission at chemical synapses except:

1. postsynaptic neurons.
2. presynaptic neurons.
3. gap junctions.
4. neurotransmitters.

2 .

Chemical messages released at synapses lead to different types of responses in postsynaptic neurons. Which type of response changes the patterns of growth, connectivity, or signaling for the post-synaptic neuron?

1. Excitatory postsynaptic potentials
2. Inhibitory postsynaptic potentials
3. Neuromodulation
4. None of the above

3.

Which is a brief electrical change in the postsynaptic neuron that excites the neuron and pushes it towards threshold?

1. EPSP
2. IPSP
3. Action potential
4. Resting potential

4 .

Which event occurs last in the process of chemical synaptic transmission?

1. Released neurotransmitter is broken down or removed from the cleft
2. The presynaptic neuron stores transmitter in vesicles
3. The released neurotransmitter binds to postsynaptic receptors
4. An action potential arrives at the presynaptic terminal leading to release of neurotransmitter

5.

All of the following are involved with synaptic transmission at electrical synapses except:

1. gap junctions.
2. synaptic vesicles.
3. presynaptic neurons.
4. postsynaptic neurons.

2.2 Neural Circuits

6 .

Imagine a sensory neuron that does not fire unless stimulated. With light touch the neuron generates an action potential. What would happen with strong touch?

1. Action potentials would occur more frequently
2. Action potentials would not occur
3. There would be no change in the frequency of action potentials, but the magnitude of each spike would increase
4. Action potential frequency and magnitude would increase

7.

If neural networks use parallel processing it means that:

1. they display rhythmic or cyclical activity.
2. information spreads along multiple pathways at the same time.
3. they are highly efficient.
4. a neuron influences the activity it will later receive.

8 .

Which subfield of neuroscience is involved with developing mathematical models of neurons and neural networks?

1. Cognitive neuroscience
2. Systems neuroscience
3. Computational neuroscience
4. Cellular and molecular neuroscience

9.

Researchers have developed devices that have the potential to replace or repair a part of the nervous system using a computer model that can simulate the processing in that brain region. This is an example of:

1. neurofeedback.
2. optogenetics.
3. deep brain stimulation.
4. a neural prosthetic.

2.3 Principles of Bioelectricity

10 .

What determines the movement of ions?

1. Forces from both diffusion and electrical charge
2. Forces from both the sun and the wind
3. Forces from both ATP and GTP
4. Forces from both dynein and kinesin

11.

In diffusion, molecules move:

1. down a concentration gradient.
2. up a concentration gradient.
3. down a voltage gradient.
4. up a voltage gradient.

12 .

Which is the best definition for electrical potential?

1. The flow of charge
2. The ease with which charge flows
3. The pressure for charge to flow
4. All of the above

13.

Which is the best description for conductance?

1. The flow of charge
2. The ease with which charge flows
3. The pressure for charge to flow
4. None of the above

2.4 Mechanisms of Neural Signaling

14 .

What is a resting potential?

1. A wave of positive electrical potential that sweeps through a neuron
2. An overall positive electrical potential neurons maintain while at rest
3. An overall negative electrical potential neurons maintain while at rest
4. A small, local change in potential caused when transmitter is received from a partner neuron

15.

Why do neurons have a resting potential?

1. Because they have leak K+ channels that allow K+ to pull the neuron towards a negative potential
2. Because they have leak K+ channels that allow K+ to pull the neuron towards a positive potential
3. Because they have leak Na+ channels that allow K+ to pull the neuron towards a negative potential
4. Because they have leak Na+ channels that allow K+ to pull the neuron towards a positive potential

16 .

An action potential is due to:

1. a departure of organic ions.
2. an entrance of Cl-.
3. a departure of Na+ followed by the influx of K+.
4. an influx of Na+ followed by the departure of K+.

17.

During an action potential, what happens when K+ channels open?

1. K+ rushes out making the neuron more negative
2. K+ rushes in making the neuron more negative
3. K+ rushes out making the neuron more positive
4. K+ rushes in making the neuron more positive

18 .

When a neuron is at rest, which of these could be Vm?

1. 0 mV
2. +60 mV
3. -60 mV
4. None of the above

19.

At the peak of the rising phase, which of these could be Vm?

1. -60 V
2. +60 V
3. +60 mV
4. -60 mV

20 .

Compared to an actional potential, which is true about graded potentials?

1. Larger
2. Faster
3. Local
4. Release more neurotransmitter

21.

An EPSP is generated when:

1. a neurotransmitter binds to a ligand-gated Na+ channel.
2. a neurotransmitter binds to a ligand-gated Ka+ channel.
3. K+ binds to a ligand-gated Na+ channel.
4. Ca2+ binds to a ligand-gated Cl- channel.

22 .

Why are graded potentials so short-lived?

1. Transmitter is broken down or reabsorbed
2. K+ leak channels
3. Ion pumps
4. All of the above

23.

Ion channels and ion pumps are similar in that:

1. both are proteins.
2. both use energy.
3. both move ions against their gradient.
4. both move ions down their gradient.

24 .

Which is not a property of voltage-gated K+ channels?

1. Slow to open and close
2. Transition between open, closed, and inactivated states
3. Open at depolarizing voltages
4. Permeable to a single ion