Quiz Canvas: Chapter 23-25 of Purves Flashcards
Which of the following does not play an important role in the establishment of axon tracts and in growth cone navigation?
Cytoskeletal proteins
Cell adhesion molecules
The establishment of cell polarity
All of the options do play an important role.
Second messenger systems
All of the options do play an important role.
The first step in developing the adult morphology of a neuron is
establishment of an apical–basal cytoskeletal polarity.
the appearance of an axon as the first protrusion from the cell body.
insertion of voltage-gated ion channels into the cell membrane.
none of the options stated are observed during morphological development.
the appearance of an apical dendrite as the first protrusion from the cell body.
establishment of an apical–basal cytoskeletal polarity.
Axon guidance cues can affect
actin and tubulin dynamics.
the complement of receptors and channels at the surface of the plasma membrane.
None of the options.
the expression of different neural genes.
All of the options.
All of the options.
Extracellular matrix molecules serve as ligands for
cadherin.
L1.
integrin receptors.
unc5 and robo.
plexin.
integrin receptors.
The chemoattractant signaling molecule netrin
can signal by binding to the DCC (“deleted in colorectal cancer”) receptor.
is present in very high quantities and thus attracts many axons.
is present only in birds and mammals.
is an integral, or fixed, component of the extracellular matrix.
is named for nectar, because it has been equated to a nectar of the gods for its trophic effects.
can signal by binding to the DCC (“deleted in colorectal cancer”) receptor.
The two molecules that aid the molecular construction of most CNS synapses by recruiting pre- and post-synaptic machinery are ___and ___.
SynCAM; cadherin
neurexin; neuroligin
ephrin; the Eph receptor
cadherin; protocadherin
netrin; ephrin
neurexin; neuroligin
Neurotrophic factors
play a role in adjusting the size of neuronal populations to an appropriate number.
deliver glucose to sustain cells.
deliver ATP to sustain cells.
allow the CNS to produce and maintain a large number of excess neurons.
provide hundreds of directional cues to guide axons to correct target locations.
play a role in adjusting the size of neuronal populations to an appropriate number.
Which of the following statements about the p75 receptor is false?
It can be activated by the same neurotrophins that activate Trk receptors.
It can act through Rho GTPases to regulate neurite outgrowth.
It is identical to the Trk receptors in terms of molecular structure and signaling pathways.
It is best activated by “unprocessed” neurotrophins.
It can initiate the c-jun transcriptional activation pathway
It is identical to the Trk receptors in terms of molecular structure and signaling pathways.
Which of the following correctly describes a critical period?
Cortical neural networks are connected and activated for the first time.
Latent, adaptive neural plasticity requires sensory input for its utilization.
Dendritic branching and synaptogenesis accelerate on a massive scale throughout the CNS.
Failure to respond typically results in the immediate death of the animal.
Sensory inputs are first connected to regions controlling motor outputs.
Latent, adaptive neural plasticity requires sensory input for its utilization.
Critical periods are present for all of the following except
All of the options are associated with critical periods.
song learning by some species of birds.
various forms of imprinting.
language learning in humans.
certain kinds of visual information processing.
All of the options are associated with critical periods.
Which of the following is not a form of imprinting?
Rats’ preference for nipple odors
All of the options are examples of imprinting.
A ewe subjected to its own lamb’s scent
Maternal milk let-down in response to a baby’s crying
Geese following a moving object
Maternal milk let-down in response to a baby’s crying
Hubel and Wiesel’s discovery of a critical period in visual system development was based on their observations of _______ during this period.
changes in ocular dominance
the number of cortical layers formed
changes in orientation selectivity
change in the total number of cortical neurons
the diversity of neuronal cell types formed
changes in ocular dominance
In response to the suturing of an eyelid, it was found that
the consequences of suturing were similar in kittens and adult cats.
neural cell death occurred specifically in the areas of the animal’s cortex innervated by the sutured eye.
suturing resulted in a cortical lamination inversion, whereby layer 4 was moved above layers 2 and 3.
neural cell death occurred throughout the sutured animal’s visual cortex.
suturing had dramatic effects on kittens but very little effect on cats.
suturing had dramatic effects on kittens but very little effect on cats.
Which of the following is not a feature of critical periods that support the proper development of visual systems?
They persist over a limited window of time (relative to the animal’s lifespan).
They result in essentially permanent changes in the affected neural circuitry.
Large circuitry effects can occur on a time scale of days.
Sensory input is required for the adaptive process to occur.
All of the options
All of the options
A major implication of Hubel and Wiesel’s findings of an ocular dominance critical period is that children with an eye that is visually impaired or obstructed throughout the critical period will
be unable to perceive motion or color in either eye.
become blind in just the impaired eye.
have permanently impaired depth perception and binocular fusion.
have a visual deficit that initially is serious but can largely be ameliorated with subsequent visual training.
suffer serious vision loss in both eyes.
have permanently impaired depth perception and binocular fusion.
