Quiz Canvas: Chapter 6-8 and 22 of Purves Flashcards
Acetylcholine is used as a neurotransmitter at
postganglionic synapses of the sympathetic nervous system.
preganglionic synapses of the autonomic (visceral motor) nervous system.
widely distributed synapses in the central nervous system.
the neuromuscular junction
All of the options
All of the options
Glutamate is
neurotoxic at high concentrations.
All of the options
often synthesized from glial-synthesized glutamine.
the most commonly used neurotransmitter in the brain.
a nonessential amino acid.
all of the options
Which of the following receptor types can be modulated by both barbiturates and benzodiazepines?
GABA-C
Glycine
Muscarinc ACh receptor
GABA-B
GABA-A
GABA-A
The two main families of neurotransmitter receptors are _ and _.
cationic; anionic
excitatory; inhibitory
voltage-gated; voltage-modulated
ionotropic; metabotropic
ligand-gated; ion-gated
ionotropic; metabotropic
In a signal transduction cascade using G-proteins and cAMP, which of the following is not a signal amplification step?
Activation of adenylyl cyclase molecules by G-proteins
Creation of cAMP molecules by adenylyl cyclase
Phosphorylation of target proteins by protein kinase A
Amplification occurs in all the steps described.
Activation of G-proteins by an activated receptor
Activation of adenylyl cyclase molecules by G-proteins
Which of the following is an “effector” of G-protein-initiated signaling mechanisms?
Phospholipase C
Adenylyl cyclase
Guanylyl cyclase
All of the options
None of the options
All of the options
Which of the following signaling pathways does not directly involve calcium?
Ryanodine receptor
Phospholipase C
cGMP
Calmodulin
IP-3 receptor
cGMP
Dendritic spines
are the sites of all excitatory and inhibitory synaptic transmission in the mammalian CNS.
serve as “electrical compartments” to ensure localized depolarization.
serve as “chemical compartments” to concentrate biochemical mechanisms
collectively form a set of hard-wired permanent neural connections.
were discovered with the invention of electron microscopy in the 1950s.
serve as “chemical compartments” to concentrate biochemical mechanisms
Which of the following statements about the plasticity of synapses in the mammalian CNS is false?
Changes in synaptic efficacy can occur over time scales ranging from milliseconds to years.
The efficacy of synapses can be adjusted by modulating the amount of neurotransmitter that is released.
Calcium ions play a central role in at least some forms of synaptic plasticity.
The hallmark of both short-term and long-term synaptic plasticity is that they always increase the strength of synaptic connections.
A variety of molecular mechanisms are involved in the different forms of synaptic plasticity.
The hallmark of both short-term and long-term synaptic plasticity is that they always increase the strength of synaptic connections.
Firing an action potential in an axon initially causes a 10 mV depolarization (EPSP) in a postsynaptic neuron, but after giving a certain stimulus to the axon, firing it causes an 8 mV depolarization, after each action potential. This phenomenon is called
depression.
enhancement.
facilitation.
potentiation.
augmentation.
depression.
After firing a short burst of action potentials in an axon, researchers observe a larger EPSP in the postsynaptic cell, and this effect seems to last a few tens of milliseconds. This is most likely due to the presynaptic terminal having
extra sodium.
extra magnesium.
reduced sodium.
lowered calcium.
extra calcium.
extra calcium.
The three main layers in the early embryonic stage of brain development are the
gastrula, blastula, and notochord.
ectoplasm, endoplasm, and mesoplasm.
ectoderm, ectoplasm, and notochord.
inner, outer, and middle.
ectoderm, endoderm, and mesoderm.
ectoderm, endoderm, and mesoderm.
Once the neural tube has formed, the next step in the formation of the nervous system is
neuronal migration.
neurogenesis.
synaptogenesis.
process outgrowth.
synaptic pruning.
neurogenesis
Hox genes
are activated whenever there are perturbations of homeostasis.
All of the options
enable the progressive regionalization of the developing neural tube.
allow differentiating neurons to “home in” on their eventual specialized phenotype by small random changes in gene expression.
are found on all chromosomes in all vertebrate animals.
enable the progressive regionalization of the developing neural tube.
The peptide hormone that induces motor neuron development via the cooperative binding of patched and smoothened is called
TGF.
Wnt.
Sonic hedgehog.
brain morphogenetic protein.
retinoic acid.
Sonic hedgehog.
