NSCI 175 Quizzes

Quizzes are due:

1 hour before class time

Which of the following statements about EPSPs in the central nervous system is false?

EPSPs are often caused by the influx of Cl- into the neuron

The relative ability of an electrical charge to migrate from one point to another is the ___

Electrical conductance

What is the meaning of an ion's equilibrium potential?

Electrical potential difference that exactly balances an ionic concentration gradient

What is a gap junction?

Electrical synapse

The Institutional Animal Care and Use Committee is formed by the animal rights representatives.

False

A scientist looks through a microscope at the structure of a neuron. The scientist notices a layer of molecules separating the neuron's intracellular space from the extracellular space. What is this part of the neuron known as?

Neuronal membrane

What are vesicular transporters? What is their role?

Special proteins embedded in the vesicle membrane; responsible for concentrating neurotransmitters inside the vesicle

What type of channel is affected by tetrodotoxin (TTX)?

TTX blocks the Na+ channel by binding tightly to a specific sight on the outside of the channel.

GABA and glycine receptors gate a Cl- channel.

True

I will refrain from distracting others in the class with my digital device and will use my digital device in class for completing/accessing course content.

True

Make up work after a university approved absence (missed polls, in class assignments, etc.) is due 1 week after you return to class

True

Midterm Make-up exams are only permitted for students with university approved absences.

True

ACh binds to the __ subunits on a nicotinic ACh receptor.

alpha

Which cells are involved in neurogenesis and also serve as scaffolds for the migration of newly generated neurons?

radial glia cells

The primary function of oligodendroglia is:

myelinate neuron in the brain and spinal cord

The major function of Schwann cells is the

myelination of peripheral nerve fibers.

Most IPSPs are attributable to the

opening of chloride channels.

The mode of action potential propagation along myelinated axons is called

saltatory.

Modulation of synaptic transmission

works through activation of g-protein-coupled receptors

An argument against using computer models rather than animal models is:

you must understand what you are modeling before you can make a good model

A simple reflex requires the nervous system to perform three functions. Two of these functions are to collect and distribute information. What is the third function?

Integrate information

How does myelin help increase conduction velocity?

It provides electrical insulation.

At rest, which of the following is true about ion concentrations?

K+ is more concentrated on the inside; Na+ and Cl- are more concentrated on the outside.

Under what conditions will late assignments be accepted for grading?

Late assignments will not be accepted with out a university approved absence

What is microionophoresis?

Method of applying small amounts of neurotransmitter candidates to the surface of neurons

What are second messengers?

Molecules that activate additional enzymes in the cytosol

Out of 11 writing assignments, you must submit how many?

3

The equilibrium potential for sodium is about _______ mV.

+62

What is synaptic integration?

A process by which multiple synaptic potentials combine within one postsynaptic neuron

Convergence of effects can take place at the level of the A. G-protein B. second messenger cascade C. type of ion channel D. None of these

A,B,C

Why are neuromuscular junctions such reliable synapses?

A. Because the presynaptic terminal contains a large number of active zones B. Because the motor end-plate contains a series of shallow folds *C. All of these are reasons!* D. Because the axon terminal is so large

The following are characterized by progressive degeneration of specific neurons in the brain (Select all that apply):

Alzheimer's disease, Parkinson's disease

These cells are the most numerous cells in the brain.

Astrocytes

What is meant by the action potential threshold?

Critical level of depolarization required to trigger an action potential

If the extracellular concentration of K+ increased, what would happen to the neuron's membrane potential?

Depolarization

What property of the voltage-gated potassium channels allows K+ ions to pass?

Depolarization causes the four polypeptide subunits specific to the voltage-gated K+ channel to twist into a shape that allows the K+ ions to pass.

What is the function of a neurotransmitter receptor in the dendritic membrane?

Detect neurotransmitters

What is resting membrane potential? Choose the correct option.

Difference in electrical charge across the membrane at rest

A neurotransmitter only has one effect.

False

Where should written assignments be submitted?

On Sakai

How does the sodium potassium pump help maintain the resting membrane potential?

Pumps potassium in and sodium out

What is a primary function of MAPs?

Regulate the function and assembly of microtubules

What indicates an equilibrium state has been reached?

The net flow of K+ ions across the membrane ceases.

An afterpotential is

a brief hyperpolarization that follows an action potential (undershoot).

"Spiny" and "aspinous" refers to a property of

dendrites

Neurons can be classified based on (select all that apply):

dendritic trees, axon length, number of neurites

Inhibitory postsynaptic potentials differ from excitatory postsynaptic potentials most significantly in their

direction of membrane polarization.

The NMDA receptor is a type of receptor for the neurotransmitter

glutamate.

In a metabotropic receptor, the g-protein receptor is on the ___ side of the membrane, and the transmitting binding site is on the ___ side of the membrane.

intracellular; extracellular

In many sensory neurons, the spike-initiation zone

is near the sensory nerve endings.

An example of an observation in the scientific process would be (select all that apply):

lesioning the hippocampus to see what happens to memory, cutting nerve fibers to see what happens to movement

An agonist

mimics the effects of a neurotransmitter

One advantage of G-protein coupled receptors is

signal amplification

A neuron without myelin would propagate nerve impulses:

slowly

Dendrites do not generate action potential because

they have few voltage-gated sodium channels.

Which of the following factors determines the ion selectivity of specific ion channels?

Nature of the groups lining the ion channel

We now understand that most differences between neurons ultimately can be explained by differences in gene expression

True

Which of the following statements are true? Select all that apply.

Procedures involving animals should be designed and performed with due consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society, Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative, Animals selected for procedures should be of an appropriate species, quality, and the minimum number required to obtain valid results., Living conditions of animals should be appropriate for their species and contribute to their health and comfort.

What is the other name for dense-core vesicles? Choose the correct option.

Secretory granules

What is the most important function of the rough endoplasmic reticulum?

Site of protein synthesis

Why do action potentials travel in only one direction?

The membrane just behind the action potential is refractory due to inactivated sodium channels.

What is the rationale behind the use of animal models to understand the human brain?

The nervous systems of different species of animals and humans share many common mechanisms.

Distinguish between the head and tail of phospholipids.

The phospholipids head contains hydrophilic phosphate and tail contains a hydrophobic hydrocarbon.

The neuron doctrine stipulates that neurons

are not continuous with one another.

Acetylcholine (Ach) is the main transmitter used at mammalian

neuromuscular junctions.

The gaps between segments of myelin are known as

nodes of Ranvier.

Myelin increases the speed of conduction because it

offers considerable resistance to the flow of current across the membrane.

Membrane resistance _____

represents the resistance to current flowing across the membrane

The process that couples a neurotransmitter to activation of a downstream enzyme is referred to as ___

second messenger cascade

Primary sensory neurons:

have neurites in the sensory surfaces of the body

How long does an action potential last from the beginning of the rising phase to the end of the falling phase?

2 milliseconds

Whether or not an EPSP contributes to the action potential depends on:

A. the number of coactive excitatory synapses B. the distance the synapse is from the axon hillock C. the properties of the dendritic membrane D. inhibitory synapses *All of them*

How do action potentials differ from passively conducted electrical signals?

Action potentials are signals of fixed size and duration; passively conducted signals are not signals of fixed size and duration

What types of cells can a neuron communicate with at a synapse?

Another neuron; Muscle cell; Glandular cell

Which of the following statements are true about transporters? Select all that apply. A. They only transport glutamate B. They pack transmitter into synaptic vesicles C. They are large proteins that span cell membranes D. They shuttle transmitter from extracellular fluid to the presynaptic terminal E. They are the molecular site at which many psychoactive drugs work

B,C,D,E

Select the differences between AMPA and NMDA receptors. A. Glutamate binds to AMPA but not to NMDA. B. NMDA receptors are permeable to calcium, but AMPA receptors are not C. AMPA receptors are permeable to calcium, but NMDA receptors are not D. NMDA receptors are both voltage and ion gated, whereas AMPA receptors are only ion gated.

B,D

Deadlines for writing assignments and quizzes can be found where? Chose all that apply.

B. Sakai Site C. The syllabus

How do the lipids of the neuronal membrane contribute to the neuronal membrane potential?

Forms a barrier to water-soluble ions and water

In the mammalian brain, the major inhibitory neurotransmitter is

GABA.

Some neurons have long axon that stretches from one part of the CNS to another. What are these called?

Golgi type I neurons

Some neurons have short axons that do not extend beyond the vicinity of the cell body. What are these called? Choose the correct option.

Golgi type II neurons

The movement of what ion is reflected in the rising phase of the action potential?

Inward Na+

Which of the following is the major charge carriers involved in the conduction of electricity in neurons?

Ions

Which of the following statements about multiple sclerosis (MS) is false?

MS is characterized by increases in conduction velocity of the optic nerve.

Which equation can be used to calculate the equilibrium potential for an ion?

Nernst Equation

Under what conditions are peptide neurotransmitters released from the synaptic terminal?

Only with high-frequency trains of action potentials

What is the best way to communicate with your course instructor? Select all that apply

Piazza, Sign up for office hours using the Sakai "sign-up" tool

Which of the following are a function of microglia?

Remodeling synaptic connections

What is the difference between replication and verification?

Replication is repeating the experiment in other subjects to rule out the possibility of chance. In verification, the experiment is repeated and the same observations are obtained by any scientist following the same protocol as the original observer.

Which of the following is not a catecholamine neurotransmitter?

Serotonin

What property of amino-acid gated channels determines the duration of a neurotransmitter's effect?

The kinetics of the binding process

Which of the following statements about length constant are false?

The length constant is an index of how far hyperpolarization spread down a dendrite or axon.

Where is the spike-initiation zone in a typical neuron?

The part of the neuron where the axon originates from the soma

When an equilibrium state is reached, which of the following is true?

The the diffusional and electrical forces are equal.

What is the absolute refractory period?

The time period of 1 msec after one action potential is initiated and before the next one is initiated.

A membrane at rest is sensitive to changes in extracellular potassium.

True

All work that you do for this class must be completed according to the UNC Honor Code.

True

Which of the following channels in the active zones of the synaptic terminal open when the membrane depolarizes and causes the release of synaptic vesicles?

Voltage-gated calcium channels

How long does it take for a voltage-gated potassium channel to open?

Voltage-gated potassium channels do not open immediately upon depolarization; they take about 1 msec to open after the membrane is depolarized.

What role do voltage-gated potassium channels play in the action potential?

Voltage-gated potassium channels restore negative membrane potential after the spike.

he cholinergic drug atropine _______ receptors.

blocks muscarinic

Miniature postsynaptic potentials are produced

by spontaneous release of neurotransmitter.