Cellular Final Flashcards
1
Q
Nicotinic Acetylcholine receptors are
A
Ion Channels
2
Q
An individual nicotinic receptor requires the binding of ____ number of acetylcholine molecules to open
A
two
3
Q
Acetylcholine esterase
A
breaks down acetylcholine in the synaptic cleft
4
Q
As opposed to AMPA glutamate receptors, NMDA receptors are always
A
permeable to calcium
5
Q
Under normal physiological conditions, AMPA receptors open prior to NMDA receptors because
A
NMDA receptors need to be relieved of their Magnesium block by membrane depolarization
6
Q
mGluR5 receptors belong to group __________ of the mGluR groups
A
I
7
Q
Glutamate is packaged in vesicles by
A
VGluT
8
Q
GABAA receptor channels are composed of ________ subunits to form a pore-forming channel
A
5
9
Q
Shunting inhibition with GABAA receptor activation works primarily by:
A
reducing resistance of the membrane requiring a larger current to cause a change in voltage
10
Q
Ionotropic GABA receptors are GABAA channels while metabotropic GABA receptors are
A
GABAB receptors
11
Q
The amino acid precursor for dopamine is
A
Tyrosine
12
Q
L-DOPA is converted into Dopamine via
A
A decarboxylation reaction
13
Q
The second molecule shown above is
A
Norepinephrine
14
Q
The first molecule shown above acts in the brain via the activation of:
A
GPCRs
15
Q
Dopaminergic neurons are found primarily in the substantia nigra and the ventral tegmental area. These two areas project primarily to _____________ and ______________, respectively
A
striatum, nucleus accumbens
16
Q
Drugs of abuse are known to increase dopamine release in the nucleus accumbens. This dopamine release acts on ___________ receptors.
A
D2
17
Q
Catecholamines, once released, can be removed from the synaptic cleft
A
through specific reuptake transporters found on the presynaptic membrane, via enzymatic breakdown by COMT enzymes, via enzymatic breakdown by monoamine oxidase enzymes
D) All of the above
18
Q
The amino acid precursor for serotonin is:
A
Tryptophan
19
Q
As a general principle, GABA and glutamate are taken up after release by ________ whereas monoamines are taken up by ______________
A
glia, presynaptic nerve terminal
20
Q
Stimulation of the medial forebrain bundle can be reinforcing when matched to a task because it causes:
A
dopamine release in the nucleus accumbens
21
Q
Peptide neurotransmitters, as opposed to single amino acid precursor neurotransmitters
A
are encoded in the genome, are first synthesized as pre-pro transmitters, are released from dense core vesicles
D) all of the above
22
Q
Pre-pro-peptides are cleaved by proteases to remove their
A
signal sequence
23
Q
Which of the following is a correct pairing of opioid peptide to opioid receptor?
A
endorphin – mu receptor
24
Q
Opioid peptide release in the periaqueductal grey leads to:
A
analgesia
25
The primary enzyme responsible for the breakdown of 2-arachidonyl glycerol is:
mono-acyl glycerol lipase
26
The most abundant GPCR in the human brain is the:
CB1 cannabinoid receptor
27
Anandamide is synthesized by ____________ and metabolized by _____________________ .
Phospholipase D, Fatty acid amide hydrolase
28
2 arachidonyl glycerol acts primarily as a _________ neurotransmitter in the brain.
retrograde
29
The receptor responsible for sensation of noxious heat and that is selectively responsive to capsaicin is
TRPV1
30
G-protein coupled receptors transduce an extracellular signal to an intracellular signal through their action on
Heterotrimeric G proteins
31
After a ligand binds to a GPCR this can induce a change in the conformation of the receptor. That conformational change can then:
cause the Ga subunit to exchange GDP for GTP to initiate signaling
32
Gas proteins:
stimulate adenylyl cyclase
33
\_\_\_\_\_\_\_\_ molecules are required to activate PKA
4 cAMP
34
G protein signaling after ligand binding to a GPCR is terminated by
the intrinsic GTPase activity of Ga subunits
35
PKA is regulated by ________ and PKG is regulated by \_\_\_\_\_\_\_\_\_\_
cAMP, cGMP
36
Intracellular Calcium stores are operated by receptors that are activated by ________ .
IP3
37
Under normal conditions, intraneuronal Ca2+ is very low because:
Ca2+ acts as a signaling molecule
38
The N terminus of a GPCR is always found:
on the extracellular side of the cell
39
GPCRs that couple through Gaq G proteins act via phospholipases to stimulate which type of kinase:
PKC
40
b(gamma) subunits
can bind to and inhibit voltage gated Ca2+ channels, are always found in a protein-protein complex with each another, are released from Ga subunits when Ga subunits exchange GDP for GTP
D) all of the above
41
There are two major forms of protein kinases:
serine/threonine and tyrosine kinases
42
Most protein kinases contain autoinhibitory domains. When the autoinhibitory domain moves away from the catalytic domain the kinase
becomes active
43
Calcium/calmodulin dependent protein kinase type II is stimulated when:
calcium binds to calmodulin and interacts with the kinase to change it conformation
44
Kinases are often regulated by phosphorylation. When kinases are phosphorylated this generally
changes the conformation of the kinase such that the catalytic site is now exposed effectively turning on the kinase
45
Tyrosine kinase receptors (or Trks) tranduce an extracellular signal to an intracellular signal when the ligand for the receptor binds on the extracellular side causing:
the intracellular kinase domain of the receptor to turn on
46
It is difficult to target individual kinases with highly specific drugs because
kinases are embedded deep inside the cell and drugs cannot reach them
47
There are approximately __________ kinases in the human genome
500
48
Tyrosine kinase receptors can signal via multiple signaling pathways once they are activated but the best-studied downstream pathway is the ___________ pathway
MAPK
49
CREB is a ________________ activated by multiple upstream pathways including the _______________ pathway.
transcription factor, MAPK
50
Dendritic spines contain post-synaptic densities that are enriched in:
signaling molecules involved in plasticity
51
Which of the following statements about neural and glial cells is false
The endoplasmic reticulum is concentrated in axons, and Glial cells rapidly transmit long-range electrical signals
## Footnote
e. Both b and d
52
Which of the following is not an established role for glial cells
Integrating information to assist neural computation
53
Which of the following type of glial cell myelinates peripheral axons?
Schwann cells
54
The technique that first revealed the tremendous diversity of neuronal cell types (numbering in the hundreds or thousands in vertebrate animals) is called
the Golgi stain
55
The type of nerve cell that synapses upon muscles is called a(n)
motor neuron (or motoneuron)
56
Antibody staining is used to
## Footnote
identify neurons expressing specific genes, and visualize the distribution of specific proteins in the nervous system
57
Which of the following is not a usual kind of potential exhibited by nerve cells?
Reaction
58
The synaptic potential
makes communication between nerve cells possible.
59
Typically, neurons firing action potentials encode a signal’s intensity by
changing the frequency of their action potentials
60
Which of the following statements about action potentials is false?
They are elicited by hyperpolarization
61
The different electrical signals occurring in nerve cells are caused by _______ the cell membrane.
fluxes of ions across
62
Which of the following is not necessary for neurons to communicate electrically
Separation of large amounts of electrical charge, with excess positive charges stored inside the cell
63
Which of the following statements about electrochemical equilibrium is false?
. For a given ion concentration gradient, the resulting potential is independent of the number of charges on the ion.
64
The equation used to calculate membrane potential when there are multiple permeant ions is called the _______ equation.
Goldman
65
Which of the following factors is important in determining the membrane potential when there are multiple permeant ions?
The concentration gradient of the individual ionic species, The permeability of the membrane to the individual ionic species
d. Both a and b
66
Which of the following statements about the ionic permeability of cell membranes is false?
In resting nerve cells, the membrane is quite permeable to sodium.
67
Which of the following statements about ionic distributions in nerve cells is false?
The total concentration of all ionic species is approximately the same for all nerve cells in all animals
68
In their studies of the resting membrane potential of the squid giant axon, Hodgkin and Katz found that:
increasing potassium outside the axon depolarized the axon’s potential.
69
The resting membrane potential is not exactly equal to the Nernst potential for potassium because
the membrane has some resting permeability to species other than potassium
70
Studies of the ionic basis of the action potential in squid giant axon found that
decreasing sodium outside the cell decreases the size of the action potential.
71
Hodgkin and Katz proposed that sodium was the predominant ion associated with the firing of an action potential because
the membrane potential approaches the Na+ Nernst potential during the rising phase.
72
Which of the following is not integral to the action potential waveform?
An initial decrease in the potassium current
73
Action potentials are generated
only when the cell reaches threshold
74
For which of the following reasons was the development of the voltage clamp critical to investigations of the ionic basis of the action potential?
Voltage clamping allows simultaneous control of membrane potential and measurement of permeability changes.
75
Which of the following was not seen in the voltage-clamp study of squid action potentials?
Capacitive currents in response to hyperpolarizing voltage steps, Capacitive currents in response to depolarizing voltage steps, A transient inward current as a result of depolarization, A sustained outward current as a result of hyperpolarization
e. All of the above were seen in squid giant axons.
76
Which of the following is not an observation that helped to identify sodium as the early current of the action potential?
When the late current was blocked, the reversal potential of the inward current shifted to a negative membrane potential.
77
Which of the following was shown to eliminate the early inward current in squid giant axons?
Removal of external sodium
78
Voltage clamp data, in which investigators analyzed membrane conductances during action potentials, showed all of the following except
depolarization leads to a time-dependent inactivation of the potassium current.
79
Which of the following was not one of the features of Hodgkin and Huxley’s mathematical model?
The undershoot can be accounted for by the time course of sodium current reactivation.
80
Neurons exhibit a threshold above which an action potential is triggered because of
a positive feedback loop between depolarization and sodium current activation.
81
Which of the following explains the unidirectional propagation of action potentials?
The presence of a refractory period at a location where an action potential has just passed
82
The _______ most directly affects the rate of information processing within the central nervous system
propagation speed of action potentials
83
The mode of action potential propagation along myelinated axons is called
saltatory.
84
Transcription is isolated to the cell nucleus whereas translation occurs ______ .
at essentially any location in the neuron
85
Without mitochondrial function ______ .
The Na+/K+ ATPase would not function
86
Anterograde transport is mediated by ____ while retrograde transport is mediated by _____ .
kinesin / dynein
87
Phospholipids impede the movement of ____ across the cell membrane.
charged molecules
88
Long, thin dendritic spines are associated with what type of synapses:
immature synapses
89
The neuron doctrine, which is the foundation for modern neuroscience, was proposed by:
Santiago Ramon y Cajal
90
When microglia become chronically activated, they are thought to contribute to disease through:
release of cytokines and chemokines
91
Oligodendrocyte myelinate _______ axons while schwann cells myelinate ______ axons.
multiple / single, and CNS / PNS
d. a and b
92
Mice are frequently used in neuroscience research because:
their genomes are easily manipulated to create transgenic mice, their protein coding genome shares high homology with the human protein coding genome, many mouse models of human neurological disorders have been created
d. all of the above
93
Units of current are ______ .
Amps
94
Conductance (g) is the _____ of resistance
inverse
95
\_\_\_\_\_ potassium channels play a strong role in setting the resting membrane potential (Vm)
leak
96
In the Nernst equation, z = ______ .
the charge of the ion
97
In a mammalian neuron, if you raise the extracellular K+ concentration this will cause a ________ of the resting membrane potential.
depolarization
98
In the Goldman equation P is the key term for determination of which ion contributes most to the resting membrane potential. This is due to ________ .
permeability of the membrane to that ion at rest
99
In a mammalian adult neuron the intracellular concentration of Na and K at rest are usually constant but intracellular Cl concentration can vary from approximately __________ mM.
7 – 50
100
Inactivation of voltage gated Na+ channels occurs because of _________ .
the intrinsic biophysical properties of these channels, the inactivation gate flipping into the channel pore, depolarization causing the channel to open which is always followed by inactivation
d. all of the above
101
Which of the following is not true for ion channels?
They signal via small GTPases
102
At a membrane potential of -50mV most voltage gated Na channels are
A. closed
103
The IV plot for a voltage gated K channel shown here only displays an outward current because
the reversal potential for K is more negative than threshold for channel opening
104
Tertiary protein structure is defined as
the complex structure of a protein made up of interactions between different structural domains
105
Voltage gated Na channels are composed of
a single protein with 24 membrane spanning domains
106
The protein shown above could be
a subunit of a voltage gated K channel
107
Beta (b) subunits of voltage gated channels
help traffic the channels to the cell membrane, can have a single membrane spanning domain, can be intracellular proteins that associate with intracellular domains of the channel, have multiple isoforms for each voltage gated channel family
E. all of the above
108
The voltage sensor of voltage gated Na and Ca channels is found
within the 4th transmembrane domain of each of 4 pore forming domains
109
The selectivity filter of voltage gated K+ channels relies on _______ for selectivity
carbonyl oxygens in the pore
110
Lidocaine blocks voltage gated Na channels
by blocking the intracellular side of the pore
111
The functional consequence of a drug that prolongs Nav inactivation is
decreased cell excitability
112
The most diverse ion channel family is
the voltage gated K channel family
113
The voltage gated Na channel that is primarily found at nodes of Ranvier and the axon hillock is
Nav1.6
114
A specific inhibitor of Nav1.4 would likely to lead to which of the following physiological effects
muscle weakness
115
The neuronal voltage gated Ca2+ channels (Cav2 family) are mostly found
at presynaptic terminals
116
The Na/K ATPase is absolutely required to
maintain the resting membrane potential of neurons
117
Chloride extrusion in adult CNS neurons is primarily achieved by
KCC2
118
Chloride extrusion plays a key role in adult CNS neurons because
it allows for fast GABAA receptor-mediated hyperpolarizing currents, it sets the Cl- reversal potential at a point that is usually more negative than Vrest, it clears intracellular Cl- loads during intense GABAergic neurotransmission
D. all of the above
119
KCC2 function can be altered by
calpain-mediated cleavage, phosphorylation, membrane trafficking
D. all of the above
120
T-type Ca2+ channels require
small changes in voltage to open (low voltage activation)
121
In Otti Loewi’s famous experiment demonstrating neurotransmission substances stimulating the vagus nerve and then placing the fluid sample on a donor heart caused
a decrease in heart rate
122
Which of the following criteria are not used to define a substance as a neurotransmitter
the substance must be packaged in dense-core vesicles
123
Small molecule neurotransmitters differ from peptides in their
synthesis pathways
124
Generally speaking, peptide neurotransmitter release is engaged
after small molecules have been released by low frequency stimulation, when the neuron fires at a higher frequency, by fusion of large, dense-core vesicles
D. all of the above
125
Receptors at the neuromuscular junction respond to endogenously released
acetylcholine
126
Key variables that characterize quantal release do not include
the probability of action potential summation
127
The major class of voltage gated Ca2+ channels contributing to neurotransmitter release at central synapses are
P/Q type channels
128
The active zone is determined by
an accumulation of neurotransmitter receptors on the postsynaptic membrane, an accumulation of vesicles at the presynaptic side, the presence of a postsynaptic density, an accumulation of voltage gated Ca2+ channels
E. all of the above
129
The major Ca2+ sensor at the presynaptic membrane is
synaptotagmin
130
The probability of neurotransmitter release is tied primarily to
Ca2+ influx
131
Which of the following is not a role of proteins involved in synaptic release?
Target vesicles to active zones, Recycle vesicles by retrieving the fused membrane, Dock vesicles to active zones, Restrain vesicles
E. All of the above are roles of proteins involved in synaptic release.
132
The reversal potential of an _______ is _______ the resting membrane potential.
IPSP / more negative than
133
Synapsins are regulated by
cAMP-dependent kinase, Ca2+-/Calmodulin-dependent kinase
D. A & B
134
In endycytosis, _______ forms coated pits while _______ pinches coated vesicles closed.
clathrin / dynamin
135
Which of the following is not a SNAp receptor (SNARE)?
Synaptotagmin
136
What is the primary function of SNAPs?
priming SNARE proteins for fusion to membrane
137
Which of the following is/are true regarding shunting inhibition?
Increase in the resistance and decrease in the conductance of the resting membrane potential
ECl- \< RMP
Simultaneous EPSPs will be amplified
E. None of the above
138
Receptors of which of the following neurotransmitters do not open chloride channels?
Glutamate
139
In what case(s) can a depolarizing synaptic potential also be inhibitory?
ECl- is more negative than the action potential threshold
140
Which of the following is not a model for synaptic recycling following exocytosis?
Metabotropic recycling
141
Astrocytes display a form of cellular excitability. Which of the statements below best describes excitability in astrocytes?
Release of intracellular stores of calcium ions
142
The tripartite synapse is composed of a presynaptic neuron, postsynaptic neuron, and a glial cell that surrounds the synapse. Which glial cell is the most common member of the tripartite synapse?
Astrocyte
143
An astrocyte responding to glutamate release from a Schaffer collateral but not responding to glutamate release from a projection from the Alveus, is an example of what criteria for an astrocyte having a modulatory role in synaptic transmission?
Selective responses to specific inputs
144
Which of the below diseases result from glial dysfunction
Amyloid Lateral Sclerosis, Epilepsy, Certain forms of pathological pain
D. All of the above
145
Which of the gliotransmitters below is only found in astrocytes?
D-Serine
146
Glutamate is able to initiate the release of intracellular stores of calcium in astrocytes by binding to which class of membrane bound receptor?
G-protein coupled receptors
147
Intracellular stores of calcium are released into the intracellular space through opening of the Ryanodine receptor from which cell organelle?
Endoplasmic Reticulum
148
Which of the mechanisms below are ways in which astrocytes are able to prevent excitotoxicity?
Removal of glutamate from the synaptic cleft through excitatory amino acid transporters
149
Which of the below is not an amino acid transporter?
P2X
150
The figure below is an electromicrograph of a tripartite synapse. Which labeled cell is the astrocyte?
2
