Exam 2: Synaptic Transmission Questions

Peptide neurotransmitters are released faster than amine or amino acid neurotransmitters True False

False

Proteins can move between cells through gap junctions. True False

False

Which of the following statements is FALSE? Two different neurotransmitters don't bind to the same receptor Each neurotransmitter can bind to different subtypes Nicotinic acetylcholine receptors are G protein linked Agonists and antagonists can be used to classify receptor subtypes

Nicotinic acetylcholine receptors are G protein linked

EPSPs are produced when ion channels allowing anion entry are opened. True False

False

Which of the following is FALSE? All neurotransmitters are released quickly at the synapse Synaptic vesicle membranes are recycled by endocytosis Some synaptic vesicles are docked before an action potential arrives v-SNARES and t-SNARES are both involved in docking and synaptic vesicle release

All neurotransmitters are released quickly at the synapse

Which of the following is correct regarding the synapse? Active zones are present on the presynaptic neuron The cleft is not empty, but contains multiple proteins The cleft is approximately 20-50 nm in width Two of the above All of the above

All of the above

Neurotransmitters are removed form the synaptic cleft by: Reuptake Diffusion Degradation Two of the responses All of the responses

All of the responses

Which of the following is FALSE? Astrocytes can modulate neuronal signaling over a wide area An action potential at a CNS synapse can lead to the release of one or a few synaptic vesicles The number of channels that open depends on quantity of neurotransmitter released All of the responses are true

All of the responses are true

Which of the following statements is FALSE? An axon can form multiple active zones when synapsing on a target neuron Astrocytes are often found in close proximity to synapses Synapses can be formed between dendrites All of these statements are TRUE

All of these statements are TRUE

Acetylcholine is a(n): Amino acid transmitter Peptide transmitter Amine transmitter Lipid transmitter

Amine transmitter

Gray's type II synapses: Are usually inhibitory Are usually excitatory Are asymmetrical More than one of the above

Are usually inhibitory

Some neurons make multiple neurotransmitters that: Are released from the same vesicle Are contained in different vesicles which are released upon different levels of stimulation Both responses None of the responses

Both responses

Removing calcium from the synapse would eliminate neurotransmitter release because: Calcium is required to bind to vSNAREs and initiate vesicle fusion Calcium is required to bind to tSNAREs and initiate vesicle fusion It would block action potentials in presynaptic neuron It would have no effect on vesicle release

Calcium is required to bind to vSNAREs and initiate vesicle fusion

Which of the following statements is FALSE? Symmetrical synapses are usually inhibitory Synapses exist in various sizes Astrocytes are close to many synapses Chemical synapses are bidirectional

Chemical synapses are bidirectional

Which of the following is FALSE? Many toxins used to study signaling come from nature Antagonists block the actions of neurotransmitters Black widow venom increases acetylcholine release Curare is an agonist

Curare is an agonist

Which of the following is FALSE about length constants? Depends on internal resistance and membrane resistance Does not depend on number of ion channels open Quantifies how currents dissipate as they move down a dendrite Not the same value for all dendrites

Does not depend on number of ion channels open

Which of the flowing is FALSE regarding neurotransmitter release? Every action potential always releases a large number of synaptic vesicles Some synaptic vesicles are docked Vesicle membranes are recycled by endocytosis Exocytosis occurs rapidly

Every action potential always releases a large number of synaptic vesicles

Which of the following is FALSE regarding transmitter-gated channels? Channels open rapidly upon binding of the neurotransmitter They are not as selective as voltage-gated channels Excitatory channels allow Cl- entry Channel is usually closed until the neurotransmitter is bound

Excitatory channels allow Cl- entry

Autoreceptors are often transmitter gated channels: True False

False

A dendrite with what properties would have the highest length constant? High membrane resistance and low internal resistance Low membrane resistance and high internal resistance High membrane resistance and high internal resistance Low membrane resistance and low internal resistance

High membrane resistance and low internal resistance

A dendrite with these properties would have the lowest length constant: High membrane resistance and low internal resistance Low membrane resistance and high internal resistance High membrane resistance and high internal resistance Low membrane resistance and low internal resistance

Low membrane resistance and high internal resistance

Endorphins are: Amino acid transmitters Peptide transmitters Amine transmitters Lipid transmitters

Peptide transmitters

Lack of removal of neurotransmitters from the synaptic cleft can lead to: Receptor desensitization Receptor degradation Increased neurotransmitter release None of the responses

Receptor densitization

Which of the following is FALSE regarding the NMJ? Signaling is slow, but are reliable synapses Easier to study than CNS synapses Large number of acetylcholine receptors are present on the muscle Are between motor neurons and muscle cells

Signaling is slow, but are reliable synapses

Which of the following is FALSE regarding neuromuscular junction synapses? Small and thus easy to manipulate experimentally Fast, reliable synapses Similar to CNS synapses All are TRUE

Small and thus easy to manipulate experimentally

When EPSPs add up due to rapid firing of an input axon this is called: Spatial summation Quantal summation Temporal summation Shunting inhibition

Temporal Summation

Which of the following is FALSE regarding electrical synapses? They consist of unique connections called gap junctions They are common in glial cells They are considered evolutionarily old (present in many primitive species) They are unidirectional

They are unidirectional

Dense core vesicles contain peptide neurotransmitters. True False

True

The amplitude of a cell's EPSP is a sum of the miniamplitudes produced by each individual channel. True False

True

Voltage-gated calcium channels are often concentrated at synaptic terminals: True False

True