Cellular Final Flashcards
Nicotinic Acetylcholine receptors are
Ion Channels
An individual nicotinic receptor requires the binding of ____ number of acetylcholine molecules to open
two
Acetylcholine esterase
breaks down acetylcholine in the synaptic cleft
As opposed to AMPA glutamate receptors, NMDA receptors are always
permeable to calcium
Under normal physiological conditions, AMPA receptors open prior to NMDA receptors because
NMDA receptors need to be relieved of their Magnesium block by membrane depolarization
mGluR5 receptors belong to group __________ of the mGluR groups
I
Glutamate is packaged in vesicles by
VGluT
GABAA receptor channels are composed of ________ subunits to form a pore-forming channel
5
Shunting inhibition with GABAA receptor activation works primarily by:
reducing resistance of the membrane requiring a larger current to cause a change in voltage
Ionotropic GABA receptors are GABAA channels while metabotropic GABA receptors are
GABAB receptors
The amino acid precursor for dopamine is
Tyrosine
L-DOPA is converted into Dopamine via
A decarboxylation reaction
The second molecule shown above is
Norepinephrine
The first molecule shown above acts in the brain via the activation of:
GPCRs
Dopaminergic neurons are found primarily in the substantia nigra and the ventral tegmental area. These two areas project primarily to _____________ and ______________, respectively
striatum, nucleus accumbens
Drugs of abuse are known to increase dopamine release in the nucleus accumbens. This dopamine release acts on ___________ receptors.
D2
Catecholamines, once released, can be removed from the synaptic cleft
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
The amino acid precursor for serotonin is:
Tryptophan
As a general principle, GABA and glutamate are taken up after release by ________ whereas monoamines are taken up by ______________
glia, presynaptic nerve terminal
Stimulation of the medial forebrain bundle can be reinforcing when matched to a task because it causes:
dopamine release in the nucleus accumbens
Peptide neurotransmitters, as opposed to single amino acid precursor neurotransmitters
are encoded in the genome, are first synthesized as pre-pro transmitters, are released from dense core vesicles
D) all of the above
Pre-pro-peptides are cleaved by proteases to remove their
signal sequence
Which of the following is a correct pairing of opioid peptide to opioid receptor?
endorphin – mu receptor
Opioid peptide release in the periaqueductal grey leads to:
analgesia
The primary enzyme responsible for the breakdown of 2-arachidonyl glycerol is:
mono-acyl glycerol lipase
The most abundant GPCR in the human brain is the:
CB1 cannabinoid receptor
Anandamide is synthesized by ____________ and metabolized by _____________________ .
Phospholipase D, Fatty acid amide hydrolase
2 arachidonyl glycerol acts primarily as a _________ neurotransmitter in the brain.
retrograde
The receptor responsible for sensation of noxious heat and that is selectively responsive to capsaicin is
TRPV1
G-protein coupled receptors transduce an extracellular signal to an intracellular signal through their action on
Heterotrimeric G proteins
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
Gas proteins:
stimulate adenylyl cyclase
________ molecules are required to activate PKA
4 cAMP
G protein signaling after ligand binding to a GPCR is terminated by
the intrinsic GTPase activity of Ga subunits
PKA is regulated by ________ and PKG is regulated by __________
cAMP, cGMP
Intracellular Calcium stores are operated by receptors that are activated by ________ .
IP3
Under normal conditions, intraneuronal Ca2+ is very low because:
Ca2+ acts as a signaling molecule
The N terminus of a GPCR is always found:
on the extracellular side of the cell
GPCRs that couple through Gaq G proteins act via phospholipases to stimulate which type of kinase:
PKC
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
There are two major forms of protein kinases:
serine/threonine and tyrosine kinases
Most protein kinases contain autoinhibitory domains. When the autoinhibitory domain moves away from the catalytic domain the kinase
becomes active
Calcium/calmodulin dependent protein kinase type II is stimulated when:
calcium binds to calmodulin and interacts with the kinase to change it conformation
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
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
It is difficult to target individual kinases with highly specific drugs because
kinases are embedded deep inside the cell and drugs cannot reach them
There are approximately __________ kinases in the human genome
500
Tyrosine kinase receptors can signal via multiple signaling pathways once they are activated but the best-studied downstream pathway is the ___________ pathway
MAPK
CREB is a ________________ activated by multiple upstream pathways including the _______________ pathway.
transcription factor, MAPK
Dendritic spines contain post-synaptic densities that are enriched in:
signaling molecules involved in plasticity
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
e. Both b and d
Which of the following is not an established role for glial cells
Integrating information to assist neural computation
Which of the following type of glial cell myelinates peripheral axons?
Schwann cells
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
The type of nerve cell that synapses upon muscles is called a(n)
motor neuron (or motoneuron)
Antibody staining is used to
identify neurons expressing specific genes, and visualize the distribution of specific proteins in the nervous system
Which of the following is not a usual kind of potential exhibited by nerve cells?
Reaction
The synaptic potential
makes communication between nerve cells possible.
Typically, neurons firing action potentials encode a signal’s intensity by
changing the frequency of their action potentials
Which of the following statements about action potentials is false?
They are elicited by hyperpolarization