Synaptic transmission Flashcards
(81 cards)
The final physiologic action of a neurotransmitter is determined by the ____________
a) mechanism of termination of the physiologic effects of the neurotransmitter.
b) intrinsic properties of the receptor that binds with the transmitter.
c) intracellular 2nd messenger cascade system
d) chemical properties of the neurotransmitter.
B
What is the most important physiologic advantage of a chemical synapse have over an electrical synapse?
a) Chemical synapse can amplify signal and ensure efficient signal transmission.
b) It ensures unidirectional transmission of the action potential.
c) It has a longer lasting effect in the nervous system
d) It can mediate both excitatory and inhibitory responses.
A
Which item below does not belong to the group?
a) cAMP
b) DAG
c) G-protein
d) IP3
C
Which of the following statement(s) is/are TRUE about the role of calcium in synaptic transmission?
a) Without calcium, our nervous system would not have no outputs.
b) Neurons translate their electrical signals into action by fluxes of calcium through ligand-gated calcium channels.
c) Calcium ions serve as the generator of action potential in the presynaptic neuron
d) AOTA are true.
A
In which step of neurotransmission do calcium ions NOT play a role?
a) Mobilization of the vesicle into the active zone.
b) Docking and fusion of the vesicle with the presynaptic membrane
c) Exocytosis of the neurotransmitter
d) Reuptake of the transmitter through the transporter system
D
In another experimental set-up consisting of several interconnecting neurons, one neuronal circuit was found to be hyperexcitable. Electrical stimulation of the neuron that belonged to this circuit showed short latency and produced
prolonged depolarization. If you want to diminish or inhibit the excitability of this neuronal circuit, what type of chemical substance or drug will you apply to the system?
a) one that inhibits the voltage-gated calcium channels
b) one that blocks sodium channels
c) one that increases the potassium conductance
d) Any of the above
D
Which of the following statements is/are true of nicotinic receptors?
a) They directly gate an ion channel.
b) They produce the fast excitatory postsynaptic potentials
c) They are found in the muscle and autonomic ganglia
d) AOTA statements are true
D
Which of the following statements characterize NMDA receptors EXCEPT
a) They are ligand operated
b) They are voltage sensitive
c) Glycine removes the Mg+2 block
d) They allow sodium, potassium and calciumions to pass through.
C
Which of the following receptors are ionotropic?
a) Adrenergic receptors
b) Glycine receptors
c) Dopamine receptors
d) Opioid receptors
B
Which vitamin is a co-enzyme in the synthesis of GABA
a) Vitamin B1
b) Vitamin B6
c) Vitamin B12
d) Folic Acid
B
Which statement/s is/are ture about the fate of noradrenaline and serotonin at the synaptic cleft?
a) Both neurotransmitters utilize high affinity transporter-mediated reuptake into the presynaptic terminal
b) Both transmitters are degraded by intracellular monoamine oxidase (MAO)
c) Both neurotransmitters are degraded by catechol-O-methyltransferase (COMT)
d) AOTA statements are true
AB
In which nervous system in acetylcholine a neurotransmitter?
a) Control of movement
b) Cognition
c) Autonomic nervous system
d) AOTA
D
Which of the following neurotransmitters is/ are involved in pain modulation?
a) Serotonin
b) Glutamate
c) Opioids
d) AOTA
D
The components of the synapse include
a) Pre-synaptic membrane
b) Synaptic cleft
c) Post-synaptic membraned
d) Release of NT in the synaptic left
e) AOTA
E
Two types of synapses
Electrical and chemical synapses
Cell junction correlated with electrical synapses
Gap junction
Channels at the presynaptic neuron that let Ca into the cell
Voltage-gated calcium channels
Ions that trigger the release of neurotransmitters
Ca
At the peak of action potential, relatively little calcium enters the terminal. T/F
T
The membrane potential is positive, and the voltage gradient opposes the entry of calcium because of its positive charge
Nonpeptide neurotransmitters can fuse with the presynaptic membrane only at which specific sites?
Active zones
Proteins on the plasma membrane and vesicle membrane that bring the membranes together before fusion in the presynaptic terminal
SNARE
synaptobrevin (v-SNARE)
syntaxin and SNAP-25 (t-SNAREs)
The calcium sensors in the presynaptic terminal
Synaptotagmin
Two mechanisms of recycling vesicle membranes
Endocytotic pathway and “kiss and run”
Endocytotic pathway: coated pits form in the plasma membrane and then pinch off to form coated vesicles.
Kiss and run: the vesicle does not fuse completely with the plasma membrane, and instead detaches itself once the neurotransmitters are released
The NMDA channel is both ligand and voltage-gated. T/F
T
