Question 1

Explain the sequence of events in which agrin leads to the phosphorylation of ACh receptors.

Accepted Answer

Agrin binds to Lrp4, leading to the phos...

Question 2

What is a plausible reason that, as a treatment, regularly ablating the glial scar will still not result in full recovery of function in a spinal cord injury?

Accepted Answer

A)   Such surgery would deplete neurotrophic and neuroprotective factors.
B)   Reactive glial cells will increase scars and gliosis in response to such an intervention.
C)   Reactive glial cells will increase their proliferation and therefore, the scars and gliosis in response to such an intervention.
D)   The correct timing of when to ablate the scar is unknown.
E)   The correct amount to ablate is unknown.

Question 3

Why would inhibition of Nogo likely not result in full recovery of locomotor function following spinal cord injury?

Accepted Answer

A)   The complexity of even a simple axotomy is too high that recovery is dependent on a plethora of factors, as well as on the timing of when these factors are active.
B)   How Nogo is inhibited, whether by a drug or an antibody, is critical whether full recovery occurs.
C)   Nogo is not expressed in amounts high enough that would impact full recovery.
D)   Nogo receptors are not expressed in high enough amounts that would impact full recovery.
E)   Nogo binds to its receptor with relatively low affinity.

Question 4

If you had a transgenic mouse in which the rabsyn gene was knocked out, which of the following would your mouse not be able to do?

Accepted Answer

A)   Form neuromuscular synapses
B)   Survive past birth
C)   Coordinate movements, such as walking
D)   Cluster acetylcholine receptors
E)   Myelinate axons

Question 5

In a microarray mRNA screening experiment, which showed that growth-promoting molecules and their receptors were over-expressed, while growth-inhibiting molecules and their receptors were under-expressed in 9-day-old animal, but the reverse occurred in 12-day-old animals, explain what more conclusive experiment should be done.

Accepted Answer

Because timing and amount of t...

Question 6

Because axons in the immature mammalian CNS are not yet myelinated, these neurons are more amenable to regeneration. Which of the following properties of myelin, therefore, would be responsible in preventing such regeneration from occurring?

Accepted Answer

A)   Insulating properties against action potential propagation
B)   Physical barrier to axons that are elongating
C)   Myelin's basic protein
D)   The propagation of inhibitory potentials
E)   Lowered neuronal resting membrane potential

Question 7

Although the Neuronal Relay Strategy can be applied to injury or disease, would it be possible to implement it in a healthy brain to enhance certain functions, such as learning and memory, central blindness or deafness?

Accepted Answer

Probably not to enhance learning or memo...

Question 8

Denervation super sensitivity is highly dependent on

Accepted Answer

A)   ACh receptor number.
B)   ACh receptor density.
C)   sensitivity to ACh.
D)   distance between the site of innervation and that of denervation.
E)   strength of the current.

Question 9

Briefly explain how epigenetic mechanisms can influence peripheral nerve regeneration.

Accepted Answer

In younger animals, the influence of epi...

Question 10

Although the growth factors, BDNF and NGF, and the ApoE and LIF secreted by Schwann cells and macrophages promote neuronal survival, many other such cytokines can also collect at the site of injury. Such a gathering of these molecules is a normal physiological response to injury but can also inhibit axon re-innervation. This response is called

Accepted Answer

A)   blood clotting.
B)   recruitment.
C)   inflammation.
D)   apoptosis.
E)   sprouting.

Question 11

In a complete spinal cord injury, one of the major impediments to functional recovery is

Accepted Answer

A)   destruction of permissive environments.
B)   compromised blood brain barrier.
C)   increased expression of inhibitory factors.
D)   enhanced gliosis and glial scarring.
E)   decreased expression of growth and survival factors.

Question 12

Following spinal cord injury, one of the best ways to help ensure that recovery of function occurs is a(n)

Accepted Answer

A)   aggressive battery of anti-inflammatory drugs.
B)   aggressive battery of anti-depressant drugs.
C)   reliable and challenging physical therapy regimen.
D)   combination of anti-inflammatory drug regimen and physical therapy.
E)   combination of anti-inflammatory and antidepressant drug regimen plus physical therapy.

Question 13

When an axon is severed, what likely causes the presynaptic cell to withdraw axons?

Accepted Answer

A)   The postsynaptic neuron dying, initiating apoptotic cascades
B)   The postsynaptic neuron condensing, and widening the synapse to pull axons away
C)   Invading macrophages crowding into the synapse, effectively pushing the presynaptic neuron away
D)   The de-differentiation of Schwann cells pulling the postsynaptic neuron away
E)   Both the pre- and postsynaptic neurons expressing repulsive cues, such as Slit and its Robo receptor

Question 14

Propose an explanation for why if a cut motor nerve is placed on an intact or innervated muscle, no new endplates will form, whereas if the muscle has been denervated or its endplate blocked by F1F1F1S1F1F1F10-bungarotoxin, new endplate synapses will form.

Accepted Answer

It is possible that the denervated or bl...

Question 15

In an incomplete spinal cord injury (as opposed to a complete spinal cord injury) , one of the most obvious effects is

Accepted Answer

A)   recovery of motor function.
B)   recovery of sensory function.
C)   spontaneous recovery of motor function.
D)   spontaneous recovery of sensory function.
E)   rapid spontaneous recovery of motor function.

Exam 29: Regeneration and Repair of Synaptic Connections After Injury

Correct Answer
verified

Why would inhibition of Nogo likely not result in full recovery of locomotor function following spinal cord injury?

Correct Answer
verified

Briefly explain how epigenetic mechanisms can influence peripheral nerve regeneration.

Correct Answer
verified
In younger animals, the influence of epi...
View Answer

Although the Neuronal Relay Strategy can be applied to injury or disease, would it be possible to implement it in a healthy brain to enhance certain functions, such as learning and memory, central blindness or deafness?

Correct Answer
verified
Probably not to enhance learning or memo...
View Answer

Propose an explanation for why if a cut motor nerve is placed on an intact or innervated muscle, no new endplates will form, whereas if the muscle has been denervated or its endplate blocked by -bungarotoxin, new endplate synapses will form.

Correct Answer
verified
It is possible that the denervated or bl...
View Answer

Because axons in the immature mammalian CNS are not yet myelinated, these neurons are more amenable to regeneration. Which of the following properties of myelin, therefore, would be responsible in preventing such regeneration from occurring?

Correct Answer
verified

When an axon is severed, what likely causes the presynaptic cell to withdraw axons?

Correct Answer
verified

Denervation super sensitivity is highly dependent on

Correct Answer
verified

If you had a transgenic mouse in which the rabsyn gene was knocked out, which of the following would your mouse not be able to do?

Correct Answer
verified

In a complete spinal cord injury, one of the major impediments to functional recovery is

Correct Answer
verified

Correct Answer
verified
Because timing and amount of t...
View Answer

Explain the sequence of events in which agrin leads to the phosphorylation of ACh receptors.

Correct Answer
verified
Agrin binds to Lrp4, leading to the phos...
View Answer

What is a plausible reason that, as a treatment, regularly ablating the glial scar will still not result in full recovery of function in a spinal cord injury?

Correct Answer
verified

Following spinal cord injury, one of the best ways to help ensure that recovery of function occurs is a(n)

Correct Answer
verified

In an incomplete spinal cord injury (as opposed to a complete spinal cord injury) , one of the most obvious effects is

Correct Answer
verified

Exam 29: Regeneration and Repair of Synaptic Connections After Injury

Correct AnswerverifiedShow Answer

Why would inhibition of Nogo likely not result in full recovery of locomotor function following spinal cord injury?

Correct AnswerverifiedShow Answer

Briefly explain how epigenetic mechanisms can influence peripheral nerve regeneration.

Correct AnswerverifiedIn younger animals, the influence of epi...View AnswerShow Answer

Although the Neuronal Relay Strategy can be applied to injury or disease, would it be possible to implement it in a healthy brain to enhance certain functions, such as learning and memory, central blindness or deafness?

Correct AnswerverifiedProbably not to enhance learning or memo...View AnswerShow Answer

Propose an explanation for why if a cut motor nerve is placed on an intact or innervated muscle, no new endplates will form, whereas if the muscle has been denervated or its endplate blocked by -bungarotoxin, new endplate synapses will form.

Correct AnswerverifiedIt is possible that the denervated or bl...View AnswerShow Answer

Because axons in the immature mammalian CNS are not yet myelinated, these neurons are more amenable to regeneration. Which of the following properties of myelin, therefore, would be responsible in preventing such regeneration from occurring?

Correct AnswerverifiedShow Answer

When an axon is severed, what likely causes the presynaptic cell to withdraw axons?

Correct AnswerverifiedShow Answer

Denervation super sensitivity is highly dependent on

Correct AnswerverifiedShow Answer

If you had a transgenic mouse in which the rabsyn gene was knocked out, which of the following would your mouse not be able to do?

Correct AnswerverifiedShow Answer

In a complete spinal cord injury, one of the major impediments to functional recovery is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedBecause timing and amount of t...View AnswerShow Answer

Explain the sequence of events in which agrin leads to the phosphorylation of ACh receptors.

Correct AnswerverifiedAgrin binds to Lrp4, leading to the phos...View AnswerShow Answer

What is a plausible reason that, as a treatment, regularly ablating the glial scar will still not result in full recovery of function in a spinal cord injury?

Correct AnswerverifiedShow Answer

Following spinal cord injury, one of the best ways to help ensure that recovery of function occurs is a(n)

Correct AnswerverifiedShow Answer

In an incomplete spinal cord injury (as opposed to a complete spinal cord injury) , one of the most obvious effects is

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
In younger animals, the influence of epi...
View Answer

Correct Answer
verified
Probably not to enhance learning or memo...
View Answer

Correct Answer
verified
It is possible that the denervated or bl...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Because timing and amount of t...
View Answer

Correct Answer
verified
Agrin binds to Lrp4, leading to the phos...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified