Quiz 3: Neural Conduction/ Neurotransmission

Question 1

Curare is a compound that functions as a muscle relaxant by reducing signal transmission at neuromuscular junctions. This drug is most likely a(n):

a) Epinephrine receptor agonist
b) Glutamate receptor antagonist
c) Acetylcholine receptor antagonist
d) Acetylcholine receptor agonist

Answer 1

c) Acetylcholine receptor antagonist

Question 2

The effect of tetrodotoxin on neuron activity demonstrates the necessity of __________ activity for __________

a) Voltage gated potassium channel; repolarization
b) Voltage gated sodium channel; membrane depolarization
c) Voltage gated potassium channel; hyperpolarization
d) Sodium-potassium pump; maintaining the resting membrane potential

Answer 2

b) Voltage gated sodium channel; membrane depolarization

Question 3

Which of the following scientists are best known for discovering the chemical nature of communication between neurons?

a) Henry Dale and Otto Loewi
b) Andrew Hodgkin and Alen Huxley
c) Donald Hebb and Henry Dale
d) Santiago Ramon Y Cajal and Camillo Golgi

Answer 3

a) Henry Dale and Otto Loewi

Question 4

Given the tendency of sodium ions to flow into the cell, which of the following is true about the concentration gradient for sodium at rest?

a) The intracellular sodium concentration is greater than the extracellular concentration
b) The extracellular sodium concentration is greater than the intracellular concentration
c) The intracellular and extracellular sodium concentrations are equal
d) Both a and c may be true

Answer 4

b) The extracellular sodium concentration is greater than the intracellular concentration

Question 5

In a famous experiment that led to the discovery of chemical neurotransmission, what was done to a frog’s heart?

a) It was isolated (detached) from its vagus nerve
b) It was placed in a bath of dilute palytoxin
c) It was detached from the excitatory branch of its vagus nerve
d) It was detached from the excitatory branch of its vagus nerve

Answer 5

a) It was isolated (detached) from its vagus nerve

Question 6

A drug that binds to and activates a receptor is called a(n) ____________ for that receptor

a) agonist
b) competitive antagonist
c) antagonist
d) partial agonist

Answer 6

a) agonist

Question 7

The sodium-potassium pump moves

a) 2 sodium ions out of the cell and 3 potassium ions out of the cell
b) 3 sodium ions out of the cell and 2 potassium ions into the cell
c) 3 sodium ions into the cell and 2 potassium ions out of the cell
d) 2 sodium ions into the cell and 3 potassium ions out of the cell

Answer 7

b) 3 sodium ions out of the cell and 2 potassium ions into the cell

Question 8

Which of the following statements is true regarding graded potentials?

a) Graded potentials are non-decremental and “all-or-none”
b) Graded potentials move faster along myelinated axons than unmyelinated axons
c) Graded potentials are hyperpolarizing and counteract action potentials
d) The magnitude of a graded potential is determined by the magnitude of the stimulus

Answer 8

d) The magnitude of a graded potential is determined by the magnitude of the stimulus

Question 9

Which of the following points about neurotransmitters is false?

a) They are released into the synaptic cleft upon presynaptic neuron activation
b) They are synthesized within the postsynaptic site (spine)
c) They are stored within vesicles prior to release
d) They act on receptors to excite or inhibit nearby postsynaptic neurons

Answer 9

b) They are synthesized within the postsynaptic site (spine)

Question 10

Which of the following is true of gap junctions (electrical synapses)?

a) Large molecule neurotransmitters can pass through gap junctions
b) Gap junctions are larger than synapses
c) Gap junctions allow for electrical transmission within neurons
d) Gap junctions allow for electrical transmission between neurons

Answer 10

d) Gap junctions allow for electrical transmission between neurons

Question 11

Which of the following techniques can be used to study the membrane currents that underlie action potentials?

a) Electroencephalography
b) Positron emission tomography
c) Functional magnetic resonance imaging
d) Single unit recording

Answer 11

d) Single unit recording

Question 12

Aricept is a drug commonly used to treat the symptoms of Alzheimer’s disease. Aricept improves memory by preventing the enzymatic breakdown of a neurotransmitter that is less abundant in the brains of patients with Alzheimer’s disease. Which neurotransmitter system does Aricept primarily alter?

a) glutamate
b) dopamine
c) GABA
d) acetylcholine

Answer 12

d) acetylcholine

Question 13

Vasovagal syncope occurs when one faints due to overstimulation of the vagus nerve. Overstimulation of the vagus nerve can cause fainting by rapidly:

a) decreasing balance
b) increasing blood pressure
c) decreasing heart rate
d) increasing heart rate

Answer 13

c) decreasing heart rate

Question 14

Depression is commonly treated with selective serotonin reuptake inhibitors (SSRIs). Which of the following drugs would likely exacerbate the symptoms of depression?

a) A norepinephrine reuptake inhibitor
b) A serotonin receptor agonist
c) A serotonin receptor antagonist
d) A drug that increases serotonin release from presynaptic neurons

Answer 14

c) A serotonin receptor antagonist

Question 15

Schizophrenia is associated with excessive levels of dopamine in the brain. Schizophrenia is often treated with medications that selectively antagonize dopamine receptors. Which of the following would be the most likely side effect of such medications?

a) mania
b) depression
c) pseudodementia
d) pseudoparkinsonism

Answer 15

d) pseudoparkinsonism

Question 16

Hodgkin and Huxley discovered that voltage-gated potassium channels open and potassium flows out of the neuron during an action potential. Potassium efflux is associated with which phase of the action potential?

a) depolarization
b) repolarization
c) hyperpolarization
d) both b and c

Answer 16

d) both b and c

Question 17

While recording from a hippocampal neuron, you see that an electrical event has occurred that changed the membrane potential from -65 mV to -70 mV. This event was an __________ and the membrane became ____________

a) IPSP; depolarized
b) IPSP; hyperpolarized
c) EPSP; depolarized
d) EPSP; hyperpolarized

Answer 17

b) IPSP; hyperpolarized

Question 18

You have just identified a novel membrane receptor in rat neocortical neurons. The receptor has a heptahelical transmembrane domain and responds to serotonin. Activation of the receptor hyperpolarizes the postsynaptic neuron and this effect is mediated by G protein activation. This receptor is most likely a(n):

a) voltage-gated ion channel
b) ionotropic receptor
c) metabotropic receptor
d) ligand-gated ion channel

Answer 18

c) metabotropic receptor

Question 19

The neuromodulator estradiol is synthesized in a number of brain regions. Dr. Soutar presented evidence for aromatase (estrogen synthase) expression in the adult rat brain. In what brain region did she detect aromatase expression?

a) neocortex
b) amygdala
c) hippocampus
d) auditory thalamus

Answer 19

a) neocortex

Question 20

The transmission of EPSPs and IPSPs is:

a) decremental
b) excitatory
c) all-or-none
d) saltatory

Answer 20

a) decremental

Question 21

which of the following analogies best exemplifies the speed at which postsynaptic potential travel from their site of origin?

a) postsynaptic potentials travel like electrical signals along a cable
b) postsynaptic potential travel like sound waves in an open environment
c) postsynaptic potentials travel like the ripples seen when who drop a stone in calm water
d) EPSPs and IPSPs travel like a rabbit and a tortoise, respectively

Answer 21

a) postsynaptic potentials travel like electrical signals along a cable

Question 22

postsynaptic hyperpolarization’s are called IPSPs because they

a) decrease the chance that an ion channel will open
b) increase the chance that an ion channel will open
c) decrease the chance that a neuron will fire
d) increase the chance that a neuron will fire

Answer 22

c) decrease the chance that a neuron will fire

Question 23

when postsynaptic potentials produced in rapid succession at the same synapse sum, it is known as:

a) temporal summation
b) spatial summation
c) the refractory period
d) an all-or-none response

Answer 23

a) temporal summation

Question 24

in which of the following ways is the firing of a neuron like the firing of a gun?

a) both are the result of temporal summation
b) both are triggered by ungraded responses
c) both are triggered by graded responses
d) both are the result of spatial inhibition

Answer 24

c) both are triggered by graded responses

Question 25

Mechanisms in the membrane of a cell that actively transport ions or molecules across the membrane are known as:

a) membrane holes
b) ligand junctions
c) transporters
d) gap junctions

Answer 25

c) transporters

Question 26

The three phases of an action potential are, in order:

a) rising phase, hyperpolarization phase, repolarization phase
b) repolarization phase, rising phase, hyperpolarization phase
c) hyperpolarization phase, repolarization phase, rising phase
d) rising phase, repolarization phase, hyperpolarization phase

Answer 26

d) rising phase, repolarization phase, hyperpolarization phase

Question 27

The ____ refractory period is followed by the ____ refractory period:

a) absolute, relative
b) hyperpolarizing, repolarizing
c) relative, absolute
d) rising, dropping

Answer 27

a) absolute, relative

Question 28

Axonal conduction from the cell body to terminal buttons is called:

a) orthodromic conduction
b) antidromic conduction
c) absolute conduction
d) saltatory conduction

Answer 28

a) orthodromic conduction

Question 29

The advantage of presynaptic facilitation and inhibition (compared to EPSPs and IPSPs) is that they can:

a) inhibit an EPSP
b) depolarization
c) selectively influence one particular synapse rather than the entire presynaptic neuron
d) block action potentials

Answer 29

c) selectively influence one particular synapse rather than the entire presynaptic neuron

Question 30

Small-molecule neurotransmitters are typically synthesized in the cytoplasm of the terminal button and packaged in ______ by the button’s ________:

a) synaptic vesicles; Golgi complex
b) synaptic vesicles; endoplasmic reticulum
c) synaptic receptors; Golgi complex
d) metabotropic; endoplasmic reticulum

Answer 30

a) synaptic vesicles; Golgi complex

Question 31

______ are associated with ligand-activated ion channels, whereas _______ are associated with signal proteins and G proteins:

a) ionotropic receptors, endoplasmic receptors
b) ionotropic receptors; metabotropic receptors
c) metabotropic receptors; golgi receptors
d) ionotropic receptors, signal receptors

Answer 31

b) ionotropic receptors; metabotropic receptors

Question 32

__________, which is the main active ingredient of belladonna, is a receptor blocker that exerts its antagonist effect by binding to muscarinic receptors, thereby blocking the effects of acetylcholine on them

a) botox
b) atropine
c) nicotine
d) muscarine

Answer 32

b) atropine

Question 33

_______ are neurotransmitters that are similar to the delta-9 tetrahydrocannabinol (THC), the main psychoactive constituent of marijuana:

a) sativoids
b) endocannabinoids
c) deltoids
d) marijuanoids

Answer 33

b) endocannabinoids

Question 34

The hypothesis that synaptic transmission depends on communication among three cells (presynaptic neuron, postsynaptic neuron, and astrocyte) is referred to as the:

a) astrosynaptic hypothesis
b) tricellular hypothesis
c) tripartite synapse
d) three’s company hypothesis

Answer 34

c) tripartite synapse

Question 35

when Cl- channels open in a neuron at rest, which of the following will occur?

a) Cl- will flow out of the cell and the cell will be hyperpolarized
b) Cl- will flow out of the cell and the cell will be depolarized
c) Cl- will flow into the cell and the cell will be hyperpolarized
d) Cl- will flow into the cell and the cell will be depolarized

Answer 35

c) Cl- will flow into the cell and the cell will be hyperpolarized

Question 36

if a neuron at rest become highly permeable to sodium (i.e. Na+ channels open) , the membrane potential will become:

a) polarized
b) depolarized
c) hyperpolarized
d) repolarized

Answer 36

b) depolarized

Question 37

Researchers often record the activity of neurons in fresh, living brain slices. Preparing brain slices without killing all of the neurons on the slice is extremely difficult. One strategy for maintaining neuron health when preparing a slice is to prevent them from firing action potentials. How might this be accomplished?

a) bathing the slices in a solution lacking K+
b) bathing the slices in a solution lacking Cl-
c) bathing the slices in a solution that contains high levels of Na+
d) bathing the slices in a solution lacking Na+

Answer 37

d) bathing the slices in a solution lacking Na+

Question 38

while recording from a neuron in a slice of brain tissue, you identify a novel membrane protein that facilitates the movement of Na+ using energy derived from glucose. What type of membrane protein have you likely identified?

a) Na ion channel
b) co-transporter
c) exchanger
d) pump

Answer 38

d) pump

Question 39

which of the following drugs would reduce the ability of neuron to generate an action potential?

a) tetrodotoxin, which prevents the opening of Na+ channels
b) DDT, an insecticide that opens Na+ channels
c) batrachotoxin, which results in persistent activation of Na+ channels
d) lorazepam, a drug that opens ligand-gated Cl- channels

Answer 39

a) tetrodotoxin, which prevents the opening of Na+ channels

Question 40

here is a list of four (hypothetical) drugs and their respective LD50 values. Which of these drugs is the safest for you to consume

a) drug A: LD50=3kg/kg body weight
b) drug B: LD50 = 4 g/kg body weight
c) drug c: LD50= 5 mg/kg body weight
d) drug D: LD50 = 6ug/kg body weight

Answer 40

drug A: LD50 = 3kg/kg body weight

Question 41

You are a biopsychologist investigating a newly discovered brain area (area X). Your experience involves (a) exciting a (b) inhibiting neurons in area X and observing effects on the behavior in mice. To cause neuronal excitation and inhibition, you use drugs with the following effects on ion channels:

a) excitation: open K+ channels; inhibition: open Na+ channels
b) excitation: open Na+ channels; inhibition: open K+ channels
c) excitation: open Na+ channels; inhibition: open Cl- channels
d) excitation: open Cl- channels; inhibition: open K+ channels
e) both (b) and (c) are correct

Answer 41

e) both b and c are correct

Question 42

which of the following pain drugs are used clinically to alleviate chronic (neuropathic) pain by modifying the activity of Na+ channels?

a) selective serotonin reuptake inhibitors
b) tricyclic antidepressants
c) local anesthetics
d) tetrodotoxin
e) both (b) and (c) are correct

Answer 42

e) both (b) and (c) are correct

Question 43

given that action potentials are all-or-none, what measure might a researcher use to determine whether a drug is excitatory or inhibitory while recording from a single neuron?

a) the amplitude of action potentials
b) the frequency of action potentials
c) the shape of action potentials
d) none of the above measures are informative in this case

Answer 43

b) the frequency of action potentials

Question 44

how might a researcher induce the generation of action potentials when recording from a neuron?

a) injecting positive (depolarizing) current into the neuron
b) injecting negative (hyperpolarizing) current into the neuron
c) applying an excitatory drug to the neuron
d) both A and C

Answer 44

d) both A and C

Question 45

The EEG can be recorded with varying numbers of electrodes attached to the skull, ranging from as few as two electrodes to hundreds. The more electrodes are used, the more time-consuming the procedure will be. Assume that you are a very buys neurologist who sees 20-30 patients a day. today, one of your patients is suspected of having a tumor, which interferes with their auditory processing. what would you suggest to do for the EEG assessment

a) use a smaller number of electrodes, since it will save valuable time
b) use many electrodes, spaced out over the entire brain (i.e all four lobes of the cortex)
c) use an intermediate number of electrodes, all spaced out over the occipital cortex
d) use an intermediate number of electrodes, all spaced out over the temporal cortex

Answer 45

d) use an intermediate number of electrodes, all spaced out over the temporal cortex

Question 46

the following is NOT an example of neuroprosthetic?

a) deep brain simulation
b) a retinal implant that bypasses retinal neurons to transmit visual signals to the brain
c) a device that electrically stimulates the spinal cord to restoring movement
d) an EEG cap that records brain activity to detect seizures

Answer 46

d) an EEG cap that records brain activity to detect seizures

Question 47

which of the following is NOT involved in deep-brain stimulation?

a) stereotactic surgery to implant leads and electrodes into the brain
b) surgical implantation of a pulse generator to control brain stimulation
c) programming of electrical pulse parameters to optimize brain stimulation
d) anticonvulsant medications to enhance the effects of brain stimulation

Answer 47

d) anticonvulsant medications to enhance the effects of brain stimulation

Question 48

a neurologist and neurosurgeon implant deep-brain stimulation electrodes into a patient diagnosed with short-term memory deficits to enhance brain signals in a relevant brain areas. which brain area should they target?

a) hippocampus
b) neocortex
c) prefrontal cortex
d) basal ganglia

Answer 48

c) prefrontal cortex

Question 49

given what yoy have learned about excitatory and inhibitory neurotransmitters, which of the following neurotransmitters was the excitatory substance released by sympathetic nerve stimulation in Otto Loewi’s experiments

a) acetylcholine
b) epinephrine / adrenaline
c) glycine
d) GABA

Answer 49

b) epinephrine / adrenaline

Question 50

the substances responsible for increases and decreasing heart rate in Otto Loewi’s experiments belong to which of the following classes of neurotransmitters, respectively?

a) catecholamines; unconventional neurotransmitters
b) catecholamines; amino acids
c) catecholamines; acetylcholine
d) indolamines; acetylcholine

Answer 50

c) catecholamines; acetylcholine

Question 51

which of the following processes is primarily responsible for breaking down the neurotransmitter released by stimulation of the vagus nerve innervating the heart?

a) enzymatic degradation
b) reuptake by transposers
c) diffusion
d) none of the above

Answer 51

a) enzymatic degradation

Question 52

acetylcholine has an inhibitory effect on cardiac tissue, but it has an excitatory effect in other tissues (e.g., at the neuromuscular junctions). Which of the following factors explains the dual effects of this transmitter?

a) the quantity of transmitter released at axon terminals
b) the way the transmitter is removed from the synaptic cleft
c) the receptor subtypes to which the transmitters binds
d) the number of receptors available for transmitter binding

Answer 52

c) the receptor subtypes to which the transmitter binds

Question 53

which of the following best describes an endorphin?

a) neurotransmitter
b) neuromodulator
c) neurohormone
d) neurosteroid

Answer 53

b) neuromodulator

Question 54

where can you find receptors for estradiol within neurons?

a) the plasma membrane
b) the cytoplasm
c) the nucleus
d) all of the above

Answer 54

d) all of the above

Question 55

which of the following is NOT a test for learning and memory in rodents?

a) the Morris water maze
b) the radial arm maze
c) the elevated plus-maze
d) the social recognition test

Answer 55

c) the elevated plus-maze

Question 56

which of the following is NOT a component of a metabotropic receptor

a) a signal protein that traverses the plasma membrane 5 times
b) a signal protein that transverses the plasma membrane 7 times
c) a ligand binding site
d) a G protein with a, b, and y subunits

Answer 56

a) a signal protein that transverses the plasma membrane 5 times

Question 57

the motor symptoms of Parkinson’s disease are attributed to degeneration of neurons producing which of the following neurotransmitters?

a) acetylcholine
b) serotonin
c) dopamine
d) GABA

Answer 57

c) dopamine

Question 58

which neurotransmitter is primarily involved in alertness and arousal

a) norepinephrine
b) serotonin
c) dopamine
d) GABA

Answer 58

a) norepinephrine

Question 59

which of the following is the primary neurotransmitter at neuromuscular junctions?

a) dopamine
b) acetylcholine
c) glutamate
d) GABA

Answer 59

b) acetylcholine

Question 60

The drug DNQX is a selective antagonist for a particular subtype of the glutamate receptor. What will be the result of applying DNQX to a neuron prior to applying glutamate to the same neuron

a) the effect of glutamate will be amplified
b) the effect of glutamate will be diminished or blocked
c) the effect of glutamate will be unchanged
d) the neuron will be depolarized

Answer 60

b) the effect of glutamate will be diminished or blocked

Question 61

the acetylcholinesterase inhibitor donepezil is used to treat:

a) depression
b) Parkinson’s disease
c) Alzheimer’s disease
d) Epilepsy

Answer 61

c) Alzheimer’s disease

Question 62

As we discussed, excessive levels of dopamine (DA) are involved in schizophrenia. Thus, this disorder is typically treated with DA antagonists. Which of the following may be an unintended consequence (i.e., side effect) of these drugs?

a) muscle tremors
b) pain
c) mania
d) hyperactivity

Answer 62

a) muscle tremors

Question 63

which of the following drug classes are typically used to treat depression?

a) selective serotonin reuptake inhibitors (SSRIs)
b) norepinephrine reuptake inhibitors (NRIs)
c) serotonin-norepinephrine reuptake inhibitors (SNRIs)
d) all of the above

Answer 63

d) all of the above